UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13D
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                              (AMENDMENT NO. ___)*

                          SangStat Medical Corporation.
- -------------------------------------------------------------------------------
                                (Name of Issuer)

                    Common Stock, par value $0.001 per share
- -------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    801003104
- -------------------------------------------------------------------------------
                                 (CUSIP Number)

                      Jose M. de Lasa, 100 Abbott Park Road
              Abbott Park, Illinois 60064-3500; Phone 847 937 8905
- -------------------------------------------------------------------------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                 August 6, 1999
- -------------------------------------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(b)(3) or (4), check the following box [ _ ].

NOTE: Six copies of this statement, including all exhibits, should be filed with
the Commission. See Rule 13d-1(a) for other parties to whom copies should be
sent.

* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).





CUSIP No. 801003014
- -------------------------------------------------------------------------------
1)       NAME OF REPORTING PERSON
         I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

                  Abbott Laboratories
                  IRS Identification No. 36-0698440
- -------------------------------------------------------------------------------
2)       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP     (a)      [   ]
                                                              (b)      [   ]
- -------------------------------------------------------------------------------
3)       SEC USE ONLY

- -------------------------------------------------------------------------------
4)       SOURCE OF FUNDS

         OO (see Item 3 below)
- -------------------------------------------------------------------------------
5)       CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
         TO ITEMS 2(d) OR 2(e)                                         [   ]
- -------------------------------------------------------------------------------
6)       CITIZENSHIP OR PLACE OF ORGANIZATION
         Illinois
- -------------------------------------------------------------------------------
NUMBER OF                           (7)   SOLE VOTING POWER
SHARES                                    893,996
BENEFICIALLY                              ------------------------------------
OWNED BY                            (8)   SHARED VOTING POWER
EACH                                      0
REPORTING                                 ------------------------------------
PERSON WITH                         (9)   SOLE DISPOSITIVE POWER
                                          893,996
                                          ------------------------------------
                                    (10)  SHARED DISPOSITIVE POWER
                                          0
                                          ------------------------------------
- -------------------------------------------------------------------------------
11)      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         893,996
- -------------------------------------------------------------------------------
12)      CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
         SHARES (SEE INSTRUCTIONS)                                     [   ]
- -------------------------------------------------------------------------------
13)      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         5.4% (see Item 5 below)
- -------------------------------------------------------------------------------
14)      TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
         CO
- -------------------------------------------------------------------------------
                                Page 2 of 8 pages





ITEM 1.  SECURITY AND ISSUER

                  This statement relates to shares of the common stock, par
value $0.001 per share (the "Common Stock"), of SangStat Medical Corporation, a
Delaware corporation (the "Issuer"), whose principal executive offices are
located at 6300 Dumbarton Circle, Fremont, California 94555.

ITEM 2.  IDENTITY AND BACKGROUND

                  (a) - (c), and (f) The person filing this statement is Abbott
Laboratories ("Abbott"), an Illinois corporation. Abbott's principal business is
the discovery, development, manufacture, and sale of a broad and diversified
line of health care products and services. Abbott's principal office is located
at 100 Abbott Park Road, Abbott Park, Illinois 60064-3500.

                  The names, citizenship, business addresses, present principal
occupation or employment and the name, and the principal business and address of
any corporation or other organization in which such employment is conducted of
the directors and executive officers of Abbott are as set forth in Exhibit 1
hereto and incorporated herein by this reference.

                  (d) and (e) Neither Abbott, nor to the best of its knowledge,
any person listed on Exhibit 1 has during the last five years (i) been convicted
in a criminal proceeding (excluding traffic violations or similar misdemeanors)
or (ii) been a party to a civil proceeding of a judicial or administrative body
of competent jurisdiction and as a result of such proceeding was or is subject
to a judgment, decree or final order enjoining future violations of, or
prohibiting or mandating activities subject to, federal or state securities laws
or finding any violation with respect to such laws.

ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION

                  Abbott has acquired an aggregate of 893,996 shares of Common
Stock (the "Shares"), of which 534,157 (the "Initial Shares") were acquired on
May 10, 1999; and 359,839 (the "Additional Shares") were acquired on August 6,
1999. The aggregate $14,000,000 purchase price of the Shares consists of a
purchase price of $7,000,000 each for the Initial Shares and the Additional
Shares. The source of funds for the Shares is Abbott's general assets.

ITEM 4.  PURPOSE OF THE ACQUISITION

                  Abbott acquired the Shares as an investment and in connection
with its co-promotion alliance with the Issuer.

                                Page 3 of 8 pages



                  Abbott intends to monitor its interests in the Issuer on an
ongoing basis and to take such measures as it deems appropriate from time to
time in furtherance of such interests. Abbott may from time to time acquire
additional shares of Common Stock, dispose of some or all of the shares of
Common Stock then beneficially owned by it, and take such other actions as
Abbott may deem appropriate. Notwithstanding the foregoing, except as
described in this Item 4 and in Item 6, Abbott has no present plan or
proposal which relate to or would result in any of the matters referred to in
Items (a) through (j) of Item 4 of Schedule 13D of the Securities and
Exchange Commission. Abbott does, however, reserve the right to adopt such
plans or proposals subject to compliance with applicable regulatory
requirements and its contractual obligations.

ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER

                  (a) Abbott is the beneficial owner of the Shares, representing
approximately 5.4% of the outstanding shares of the Common Stock. The
calculation of the foregoing percentage is based on the number of shares of
Common Stock shown as being outstanding on the Form 10-Q Quarterly Report filed
by the Issuer with the Securities and Exchange Commission for the quarter ended
March 31, 1999.

                  (b) Abbott has sole power to vote or to direct the vote and
the sole power to dispose or to direct the disposition of the Shares.

                  (c) Except as described herein, there have been no
transactions by Abbott or the persons whose names are listed on Exhibit 1 in
securities of the Issuer during the past sixty days.

                  (d) No one other than Abbott has the right to receive or
the power to direct the receipt of dividends from, or the proceeds from a
sale of, the Shares.

                  (e) Not applicable.

ITEM 6.  CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH
RESPECT TO SECURITIES OF THE ISSUER

                  The summaries of certain terms of the following agreements do
not purport to be complete and are subject to, and are qualified in their
entirety by reference to, all provisions of the agreements and reference is made
to the full text of such agreements which are filed as exhibits to this
Statement and are incorporated herein by reference.

A.       STOCK PURCHASE AGREEMENT

                                Page 4 of 8 pages





                  Abbott purchased the Initial Shares pursuant to a Stock
Purchase Agreement, dated May 7, 1999 (the "Stock Purchase Agreement"), by and
between Abbott and the Issuer. The Stock Purchase Agreement provides that, on or
before the ninetieth day following the signing of the agreement, the Issuer may
at its sole discretion sell to Abbott additional shares of Common Stock at a
price equal to the lesser of: (i) $19.99; or (ii) the average of the closing
prices, as quoted on the Nasdaq National Market, on each of the 20 trading days
immediately preceding the day which is 90 days after the signing of the Stock
Purchase Agreement. The Issuer exercised this right on August 4, 1999. Under the
terms of the Stock Purchase Agreement, Abbott may not, among other things, sell
the Shares before December 31, 2001 without the Issuer's prior consent.

B.       REGISTRATION RIGHTS AGREEMENT

                  The Registration Rights Agreement, dated May 7, 1999 (the
"Registration Rights Agreement"), is by and between Abbott and the Issuer.
The Registration Rights Agreement covers the Issuer's Common Stock issued to
Abbott under the Stock Purchase Agreement and any Common Stock of the Issuer
issued as a dividend or other distribution with respect to such Common Stock
(the "Registrable Securities"). After November 15, 2001, if the issuer
receives a written request from Abbott or a transferee of Abbott with
registration rights assigned under the Registration Rights Agreement (the
"Holder"), the Issuer shall use commercially reasonable efforts to file a
registration statement on Form S-3 or such other registration statement as is
the available. The Issuer is responsible for registration expenses except
underwriting discounts, commissions, legal and accounting fees incurred by
the Holder. Abbott may transfer its registration rights subject to certain
specified conditions contained in Section 1.6 of the Registration Rights
Agreement. Under certain circumstances, the Registration Rights Agreement
terminates if all Registrable Securities may be sold under Rule 144
promulgated under the Securities Exchange Act of 1934, as amended.

C.       CALL OPTION AGREEMENT

                  The Call Option Agreement by and between Abbott and the Issuer
is dated May 7, 1999 (the "Call Option Agreement"). Under the Call Option
Agreement, Abbott grants the Issuer the right to repurchase the Shares at any
time until December 31, 2001 (the "Call Option"). The Issuer may exercise the
Call Option for the Initial Shares or the Additional Shares or both, in whole or
in part. The exercise price of the Call Option for the Initial Shares is two
times the price per Initial Share paid by Abbott under the Stock Purchase
Agreement. The exercise price of the Call Option for the Additional Shares is
two times the price per Additional Share paid by Abbott under the Stock Purchase
Agreement.

D.       RIGHT OF FIRST REFUSAL AGREEMENT

                  The Right of First Refusal Agreement, dated May 7, 1999 (the
"First Refusal Agreement"), is by and between Abbott and the Issuer. Under its
terms, Abbott must give the

                                Page 5 of 8 pages



Issuer notice if, after December 31, 2001, Abbott proposes to transfer any of
the Shares (the "Offered Shares") to one or more third parties or in an open
market transaction. For a period of 30 days after receipt of such notice, the
Issuer has the option to purchase the Offered Shares at the same price and on
the same material terms and conditions as proposed to be transferred or sold
by Abbott. The Issuer may purchase all of the Offered Shares if the Abbott
notice proposes a transfer to one or more third parties in a transaction not
in the open market, or purchase all or a portion of the Offered Shares if the
Abbott notice proposes an open market transaction. If such transfer or sale
is on the open market, the purchase price for the Issuer shall be the average
of the closing prices of the Issuer's Common Stock, as quoted on the Nasdaq
National Market, on each of the 20 trading days immediately preceding the
date of Abbott's notice of transfer. The Issuer's right terminates if the
Issuer does not exercise its right within the stated time period.

                  Notwithstanding the restrictions above, Abbott may sell or
assign Shares to any affiliate or successor in interest if such transferee or
successor executes documents assuming Abbott's obligations under the First
Refusal Agreement.

                  If the purchase price is payable in property other than cash
or evidences of indebtedness, the Issuer may pay such purchase price in the form
of cash equal in amount to the value of such property. If Abbott and the Issuer
cannot agree on the cash value within 10 days after the Issuer receives notice
of transfer from Abbott, the valuation shall be made by an appraiser selected by
Abbott and the Issuer. If they cannot agree on an appraiser within 20 days of
the receipt of the notice, each shall select an appraiser and the two appraisers
shall select a third appraiser, whose appraisal shall determine the pertinent
value. Any selected appraiser must be of recognized standing.

                  The First Refusal Agreement terminates on the earlier of: (i)
December 31, 2004; and (ii) the closing of the Issuer's sale of all or
substantially all of its assets or the acquisition of the Issuer by another
entity through a merger, consolidation or other transaction or series of related
transactions resulting in the exchange of the outstanding shares of the Issuer's
capital stock such that the stockholders of the Issuer prior to such transaction
own less than 50% of the voting power of the surviving entity.

ITEM 7.  MATERIAL TO BE FILED AS EXHIBITS

  Exhibit 1 -       Information Concerning Executive Officers and
                    Directors of Abbott Laboratories.

  Exhibit 2 -       Stock Purchase Agreement, dated as of May 7, 1999.

  Exhibit 3 -       Registration Rights Agreement, dated as of May 7, 1999.

  Exhibit 4 -       Call Option Agreement, dated as of May 7, 1999.

                                Page 6 of 8 pages




  Exhibit 5 -       Right of First Refusal Agreement, dated as of May 7, 1999.

                           *********************************


After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

                                       Abbott Laboratories



DATED: August 13, 1999              By: /s/ Gary P. Coughlan
                                       ---------------------------------------
                                       Gary P. Coughlan, Senior Vice President,
                                       Finance and Chief Financial Officer

                                Page 7 of 8 pages




                                  EXHIBIT INDEX


Exhibit Number       Description
- --------------       -----------

    1                Information Concerning Executive Officers and Directors of
                     Abbott Laboratories.

    2                Stock Purchase Agreement, dated as of May 7, 1999.

    3                Registration Rights Agreement, dated as of May 7, 1999.

    4                Call Option Agreement, dated as of May 7, 1999.

    5                Right of First Refusal Agreement, dated as of May 7, 1999.

                                Page 8 of 8 pages








                                    Exhibit 1

                  Information Concerning Executive Officers and
                        Directors of Abbott Laboratories

                       -----------------------------------

         The current corporate officers and directors of Abbott Laboratories are
listed below. The address of Abbott Laboratories is: Abbott Laboratories, 100
Abbott Park Road, Abbott Park, Illinois 60064-3500. Abbott Laboratories does not
consider all of its corporate officers to be executive officers as defined by
the Securities Exchange Act of 1934 or Releases thereunder. Unless otherwise
indicated, all positions set forth below opposite an individual's name refer to
positions within Abbott Laboratories, and the business address listed for each
individual not principally employed by Abbott Laboratories is also the address
of the corporation or other organization which principally employs that
individual.

POSITION/PRESENT PRINCIPAL OCCUPATION OR EMPLOYMENT NAME AND BUSINESS ADDRESS CITIZENSHIP CORPORATE OFFICERS Miles D. White(1) Chairman of the Board and Chief Executive Officer U.S.A. Robert L. Parkinson, Jr.(1) President, Chief Operating Officer and Director U.S.A. Joy A. Amundson(1) Senior Vice President, Ross Products U.S.A. Christopher B. Begley (1) Senior Vice President, Chemical and Agricultural U.S.A. Products Thomas D. Brown(1) Senior Vice President, Diagnostic Operations U.S.A. Gary P. Coughlan(1) Senior Vice President, Finance and Chief Financial U.S.A. Officer Jose M. de Lasa(1) Senior Vice President, Secretary and General U.S.A. Counsel William G. Dempsey(1) Senior Vice President, International Operations U.S.A. Richard A. Gonzalez(1) Senior Vice President, Hospital Products U.S.A. Arthur J. Higgins(1) Senior Vice President, Pharmaceutical Operations United Kingdom CORPORATE OFFICERS CONTINUED Thomas M. Wascoe(1) Senior Vice President, Human Resources U.S.A. Josef Wendler Senior Vice President Germany Catherine V. Babington Vice President, Investor Relations and Public U.S.A. Affairs Patrick J. Balthrop Vice President, Diagnostic Commercial U.S.A. Operations Mark E. Barmak Vice President, Litigation and Government U.S.A. Affairs Christopher A. Bleck Vice President, Pediatrics, Ross Products U.S.A. Douglas C. Bryant Vice President, Diagnostic Operations, Asia U.S.A. and Pacific Gary R. Byers Vice President, Internal Audit U.S.A. Thomas F. Chen Vice President, Pacific, Asia, and Africa U.S.A. Operations Kenneth W. Farmer Vice President, Management Information U.S.A. Services and Administration Edward J. Fiorentino Vice President, Pharmaceutical Products, U.S.A. Marketing, and Sales Gary L. Flynn(1) Vice President and Controller U.S.A. Thomas C. Freyman Vice President and Controller, Hospital Products U.S.A. Stephen R. Fussell Vice President, Compensation and Development U.S.A. David B. Goffredo Vice President, European Operations U.S.A. Robert B. Hance Vice President, Diagnostic Operations, Europe, Africa U.S.A. and Middle East Guillermo A. Herrera Vice President, Latin America and Canada Colombia Operations James J. Koziarz, Ph.D. Vice President, Diagnostic Products Research U.S.A. and Development Elaine R. Leavenworth Vice President, Abbott Health Systems U.S.A. CORPORATE OFFICERS CONTINUED John M. Leonard Vice President, Pharmaceutical Development U.S.A. Greg Linder Vice President and Treasurer U.S.A. John F. Lussen Vice President, Taxes U.S.A. Edward L. Michael Vice President, Diagnostic Assays and Systems U.S.A. Daniel W. Norbeck Vice President, Pharmaceutical Discovery U.S.A. Edward A. Ogunro Vice President, Hospital Products Research and U.S.A. Development William H. Stadtlander Vice President, Ross Medical Nutritional Products U.S.A. Marcia A. Thomas Vice President, Quality Assurance and Regulatory U.S.A. Affairs Steven J. Weger Vice President, Corporate Planning and U.S.A. Development Susan M. Widner Vice President, Diagnostic Operations, U.S. and Canada U.S.A. Lance B. Wyatt Vice President, Corporate Engineering U.S.A.
(1) Pursuant to Item 401 (b) of Regulation S-K Abbott has identified these persons as "executive officers" within the meaning of Item 401 (b).
NAME POSITION/PRESENT PRINCIPAL OCCUPATION OR EMPLOYMENT AND BUSINESS ADDRESS CITIZENSHIP DIRECTORS H. Laurance Fuller Co-Chairman, U.S.A. BP Amoco, p.l.c. 200 East Randolph Drive Mail Code 3000 Chicago, Illinois 60601 David A. Jones Chairman of the Board U.S.A. Humana Inc. 500 W. Main Street Humana Building Louisville, Kentucky 40202 Jeffrey M. Leiden, M.D., Ph.D. Elkan R. Blout Professor of Biological Sciences U.S.A. Harvard School of Public Health Professor of Medicine Harvard Medical School Laboratory of Cardiovascular Biology 677 Huntington Ave.-Bldg. II, Rm. 117 Boston, Massachusetts 02115 The Rt. Hon. the Lord Physician, Politician, and Businessman United Kingdom Owen CH House of Lords Westminster, London SW1A 0PW, England Robert L. Parkinson, Jr. Officer of Abbott U.S.A. Boone Powell, Jr. President and Chief Executive Officer U.S.A. Baylor Health Care System and Baylor University Medical Center, Vice President, Baylor University 3500 Gaston Avenue Dallas, Texas 75246 DIRECTORS - CONTINUED Addison Barry Rand Former Executive Vice President U.S.A. Xerox Corporation 800 Long Ridge Road Stamford, Connecticut 06904-1600 W. Ann Reynolds, Ph.D. President U.S.A. The University of Alabama at Birmingham 701 S. 20th Street Birmingham, Alabama 35294-0110 Roy S. Roberts Vice President and Group Executive U.S.A. North American Vehicle Sales, Service and Marketing General Motors Corporation 100 Renaissance Center Mail Code 482-A30-D10 Detroit, Michigan 48243 William D. Smithburg Retired Chairman, President and Chief Executive Officer U.S.A. The Quaker Oats Company 676 N. Michigan Avenue Suite 3860 Chicago, Illinois 60611 John R. Walter Chairman U.S.A. Ashlin Management Corp. 100 South Wacker Drive Suite 2100 Chicago, Illinois 60606 William L. Weiss Chairman Emeritus, Ameritech Corporation U.S.A. One First National Plaza Suite 2530C Chicago, Illinois 60603-2006 Miles D. White Officer of Abbott U.S.A.


                                  Exhibit 2

                            STOCK PURCHASE AGREEMENT

                  THIS STOCK PURCHASE AGREEMENT (the "Agreement") is made as of
the 7th day of May, 1999, by and between SangStat Medical Corporation, a
Delaware corporation ("SangStat") and Abbott Laboratories, an Illinois
corporation ("Abbott").

                  WHEREAS, SangStat and Abbott have agreed to enter into a Right
of First Refusal Agreement, a Call Option Agreement, a Registration Rights
Agreement, and a Co-Promotion Agreement, all of even date herewith (collectively
the "Alliance Agreements"); and

                  WHEREAS, subject to the terms and conditions of this Agreement
and on the basis of the representations and warranties set forth herein,
SangStat and Abbott have agreed to the purchase and sale of shares of SangStat's
common stock $.001 par value (the "Common Stock").

                  THE PARTIES HEREBY AGREE AS FOLLOWS:

                  1. PURCHASE AND SALE OF INITIAL SHARES. Subject to the terms
and conditions of this Agreement and on the basis of the representations and
warranties set forth herein, SangStat shall issue and sell to Abbott and Abbott
shall purchase from SangStat, at the Initial Share Closing provided for in
SECTION 1.3, shares of SangStat's Common Stock (the "Initial Shares") having an
aggregate value of Seven Million Dollars ($7,000,000).

                     1.1 PRICE PER INITIAL SHARE. The price per share to be
paid by Abbott for each of the Initial Shares (the "Price per Initial Share")
shall be equal to the average of the closing prices, as quoted on the Nasdaq
National Market, on each of the twenty (20) trading days preceding the day on
which this Agreement is signed.

                     1.2 NUMBER OF INITIAL SHARES. On the day before the
Initial Share Closing, SangStat shall determine the number of Initial Shares
to be issued, purchased, and sold pursuant to this Agreement by dividing:

                         (a) Seven Million Dollars ($7,000,000) by

                         (b)  the Price per Initial Share

and then rounding down to the nearest whole number the number obtained by that
division.

                     1.3 INITIAL SHARE CLOSING. The closing of the purchase
and sale of the Initial Shares (the "Initial Share Closing") shall be held at
the offices of Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP,
155 Constitution Drive, Menlo Park, California 94025, on May 10, 1999, at
10:00 a.m., or at such other time and place upon which SangStat and Abbott
shall agree.



                     1.4 DELIVERY. At the Initial Share Closing, SangStat
will issue a certificate to Abbott registered in Abbott's name representing
the number of Initial Shares being purchased by Abbott against payment to
SangStat of Seven Million Dollars ($7,000,000). The purchase price shall be
paid to SangStat by wire transfer to the bank account of SangStat:

                     Name of Bank:      State Street Bank
                     Name of Account:   SangStat Medical Corporation
                     Account No.        17039843
                     ABA#               011000028

                  2. PURCHASE AND SALE OF OPTION SHARES. At the sole discretion
of SangStat, but subject to the terms and conditions of this Agreement and on
the basis of the representations and warranties set forth herein, SangStat shall
issue and sell to Abbott and Abbott shall purchase from SangStat, at the Option
Share Closing provided for in SECTION 2.4, shares of SangStat's Common Stock
(the "Option Shares") having the aggregate value described in SECTION 2.3.

                     2.1 NOTICE OF PURCHASE AND SALE OF OPTION SHARES. On or
before the ninetieth (90th) day following the signing of this Agreement,
SangStat shall notify Abbott in writing as to whether or not the issuance,
sale, and purchase of the Option Shares shall take place.

                     2.2 PRICE PER OPTION SHARE. The price per share to be
paid by Abbott for each of the Option Shares (the "Price per Option Share")
shall be equal to the lesser of:

                         (a) $19.99 or

                         (b) the average of the closing prices, as quoted on
the Nasdaq National Market, on each of the twenty (20) trading days
immediately preceding the day which is ninety (90) days after the signing of
this Agreement.

For example, if this Agreement is signed on April 30, 1999, then the day
which is 90 days after the day on which it is signed will be July 29,1999 and
the Price per Option Share will be the lesser of (a) $19.99 or (b) the
average of the closing prices, as quoted on the Nasdaq National Market, on
each of the twenty (20) trading days immediately preceding July 29, 1999.

                     2.3 NUMBER OF OPTION SHARES. On the day before the
Option Share Closing, SangStat shall determine the number of Option Shares to
be issued, purchased, and sold pursuant to this Agreement by dividing:

                         (a) Seven Million Dollars ($7,000,000) by

                         (b)  the Price per Option Share





and then rounding down to the nearest whole number the number obtained by that
division. In no event, however, shall the number of Option Shares to be issued,
purchased, and sold pursuant to this SECTION 2.3, together with the Initial
Shares, cause Abbott, or any of its affiliates, to be deemed to be an Acquiring
Person, as such term is defined in the Stockholders Rights Plan, dated as of
August 14, 1995, between SangStat and The First National Bank of Boston, as
Rights Agent (the "Rights Plan"). Accordingly, in the event that the quotient
that is obtained by implementing the foregoing formula results in the issuance
of a number of Option Shares that, together with the Initial Shares, would cause
Abbott, or any of its affiliates, to be deemed to be an Acquiring Person, then
the numerator shall be reduced to the largest number that is less than Seven
Million Dollars ($7,000,000) that when divided by the Price per Option Share and
rounded down to the nearest whole number would result in a number of Option
Shares that, together with the Initial Shares, represents a number that is less
than fifteen percent (15%) of the total number of shares of the Common Stock
outstanding immediately after the Option Share Closing.

                     2.4 OPTION SHARE CLOSING. The closing of the purchase
and sale of the Option Shares (the "Option Share Closing") shall be held at
the offices of Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP,
155 Constitution Drive, Menlo Park, California 94025, on August 6, 1999, at
10:00 a.m., or at such other time and place upon which SangStat and Abbott
shall agree.

                     2.5 DELIVERY. At the Option Share Closing, SangStat will
issue a certificate to Abbott registered in Abbott's name representing the
number of Option Shares being purchased by Abbott against payment to SangStat
of Seven Million Dollars ($7,000,000). The purchase price shall be paid to
SangStat by wire transfer to the bank account of SangStat:

                     Name of Bank:      State Street Bank
                     Name of Account:   SangStat Medical Corporation
                     Account No.        17039843
                     ABA#               011000028

                  3. REPRESENTATIONS AND WARRANTIES OF SANGSTAT. Except as set
forth in the Schedule of Exceptions attached hereto as EXHIBIT - SECTION 3
(SCHEDULE OF EXCEPTIONS) specifically identifying the relevant subsection of
this Agreement, SangStat hereby represents, warrants, and covenants to Abbott
that:

                     3.1 AUTHORITY.

                         (a) SangStat has full legal right power and
authority to execute and deliver this Agreement and each of the Alliance
Agreements and to consummate the transactions contemplated hereby and thereby.

                         (b) All corporate action on the part of SangStat,
its officers, directors and stockholders necessary for the execution and
delivery of, and the consummation of the transactions contemplated by this
Agreement and the Alliance Agreements and the performance of all obligations
of SangStat hereunder and thereunder have been taken.

                         (c) This Agreement and each of the Alliance
Agreements, upon





execution and delivery by SangStat and, assuming the due and proper execution
and delivery by Abbott, constitute legal, valid and binding obligations of
SangStat, enforceable in accordance with their respective terms, except as
may be limited by: (i) applicable bankruptcy, insolvency, reorganization or
other laws of general application relating to or affecting the enforcement of
creditors rights generally, (ii) the effect of rules of law governing the
availability of equitable remedies, and (iii) the enforceability of the
indemnity obligations of SECTION 1.7 of the Registration Rights Agreement.

                         (d) The making and performance of the Agreement and
the Alliance Agreements by SangStat and the consummation of the transactions
contemplated by the Agreement and the Alliance Agreements will not violate
any provision of the organizational documents of SangStat or any of its
subsidiaries and will not result in the creation of any lien, charge,
security interest or encumbrance upon any assets of SangStat pursuant to the
terms or provisions of, and will not conflict with, result in the breach or
violation of, or constitute, either by itself or upon notice or the passage
of time or both, a default under any agreement, mortgage, deed of trust,
lease, franchise, licence, indenture, permit or other instrument to which
SangStat or any of its subsidiaries is a partner or by which SangStat or any
of its subsidiaries or any of their respective properties may be bound or
affected and in each case which have a material adverse affect on the
condition (financial or otherwise), properties, business, prospects, or
results of operations of SangStat and its subsidiaries taken as a whole (a
"Material Adverse Effect") or, to SangStat's knowledge, any statute or any
authorization, judgment, decree, order, rule or regulation of any court or
any regulatory body, administrative agency or other governmental body
applicable to SangStat or any of its subsidiaries or any of their respective
properties.

                     3.2 ORGANIZATION, GOOD STANDING AND QUALIFICATION.

                         (a) SangStat and each of its subsidiaries, has been
duly incorporated and is validly existing as a corporation in good standing
under the laws of its jurisdiction of incorporation, with full power and
authority (corporate and other) to own and lease its properties and conduct
its businesses as presently conducted and as proposed to be conducted.
SangStat and each of its subsidiaries, is duly qualified to do business and
in good standing as a foreign corporation in each jurisdiction in which the
ownership or leasing of properties or the conduct of its business requires
such qualification, except for jurisdictions in which the failure to so
qualify would not have a Material Adverse Effect; and no proceeding has been
instituted in any such jurisdiction, revoking, limiting or curtailing, or
seeking to revoke, limit or curtail such power and authority or qualification.

                         (b) Except as set forth on EXHIBIT - SECTION 3
(SCHEDULE OF EXCEPTIONS), SangStat has no direct or indirect loans to any
partnership, corporation, joint venture, business association, or other
entity.





                         (c) SangStat has delivered to Abbott complete and
correct copies of the Certificate of Incorporation and Bylaws, or similar
charter documents, of SangStat and of each of its Significant Subsidiaries
[as such term is defined in Rule 405 of the Securities Act of 1933, as
amended (the "Securities Act")] that is incorporated in a jurisdiction in the
United States, in each case as amended to the date hereof, and will furnish to
Abbott true and correct copies of any amendments thereto throughout the term of
this Agreement.

                         (d) Except as set forth on EXHIBIT - SECTION 3
(SCHEDULE OF EXCEPTIONS), SangStat has no Significant Subsidiaries or
affiliated companies and does not otherwise own or control, directly or
indirectly, any equity interest in any partnership, corporation, joint
venture, association, or entity. The term "subsidiary" means any corporation
more than fifty percent (50%) of whose total equity interest is, directly or
indirectly, owned by that person. The term "affiliate" when used to indicate
a relationship with a specified person, shall mean a person that directly, or
indirectly through one or more intermediaries, control, or is controlled by,
or is under common control with, such specified person.

                     3.3 CAPITALIZATION.

                         (a) The authorized capital stock of SangStat
consists of 25,000,000 shares of Common Stock $0.001 par value and 5,000,000
shares of Preferred Stock, $$0.001 par value.

                         (b) As of May 3, 1999, there were 16,393,110 shares
of Common Stock issued and outstanding and no shares of Preferred Stock
issued and outstanding. All such issued an outstanding shares have been duly
authorized and validly issued and are fully paid and non-assessable and no
issued and outstanding shares are subject to preemptive rights created by
statute, the Certificate of Incorporation or Bylaws, or any agreement to
which SangStat is a party or by which SangStat may be bound.

                         (c) All outstanding shares of SangStat's capital
stock have been issued in compliance with applicable federal and state
securities laws.

                         (d) SangStat has reserved for issuance 3,392,200
shares of Common Stock (and has requested the approval of its shareholders to
increase the number of such reserved shares to 3,892,200) pursuant to
SangStat's 1993 Stock Option Plan, of which, at April 1, 1999, options to
purchase 2,427,844 shares were outstanding and 565,017 shares (not including
the 500,000 additional shares referred to above) remain available for
issuance pursuant to options that may be granted under that plan.

                         (e) SangStat has reserved for issuance 500,000
shares of Preferred Stock pursuant to the Shareholder Rights Plan, dated as
of August 14, 1995, between SangStat and First National Bank of Boston.

                         (f) Except as set forth on EXHIBIT - SECTION 3
(SCHEDULE OF EXCEPTIONS), there are no other options, warrants, conversion
privileges or other contractual rights presently outstanding or in existence
to purchase or otherwise acquire any authorized but unissued shares of
SangStat's capital stock or other





securities or the capital stock or other securities of any subsidiary of
SangStat.

                     3.4 VALID ISSUANCE OF COMMON STOCK. Both the Initial
Shares and the Option Shares have been duly authorized and, when issued,
delivered, and paid for in the manner set forth in this Agreement, will be
duly authorized, validly issued, fully paid and nonassessable, and (assuming
that Abbott is a BONA FIDE purchaser for value within the meaning of Section
8-302 of the Uniform Commercial Code) Abbott shall have good and marketable
title to both the Initial Shares and the Option Shares free of any liens or
restrictions (unless created by Abbott), other than the restrictions
expressly set forth in this Agreement or the Alliance Agreements or under
applicable state and federal securities laws. No preemptive rights or other
rights to subscribe for or purchase exist with respect to the issuance and
sale of either the Initial Shares and the Option Shares by SangStat pursuant
to this Agreement.

                     3.5 GOVERNMENTAL CONSENTS.  Other  than  compliance
with the  Securities  Act and such filings as may be required to be made with
the National Association of Securities Dealers, no consent, approval order or
authorization of, or registration, qualification, designation, declaration or
filing with, any federal state or local governmental authority on the part of
SangStat is required in connection with the consummation of the transactions
contemplated by this Agreement.

                     3.6 OFFERING.  Subject in part to the truth and accuracy
of Abbott's representations set forth in SECTION 4 of this Agreement, the
offer, sale and issuance of the Common Stock as contemplated by this
Agreement are exempt from the registration requirements of the Securities
Act, and neither SangStat nor any authorized agent acting on its behalf will
take any action hereafter that would cause the loss of such exemption.

                     3.7 LITIGATION. Other than as disclosed in Item 3 -
Legal Proceedings  of SangStat's Annual Report on Securities and Exchange
Commission Form 10-K for the year ended December 31, 1998 (the "Form 10-K")
or EXHIBIT - SECTION 3 (SCHEDULE OF EXCEPTIONS), there are no legal or
governmental actions, suits or proceedings pending or, to SangStat's
knowledge, threatened to which SangStat or any of its subsidiaries is or may
be a party or of which property owned or leased by SangStat or any of its
subsidiaries is or may be the subject, which actions, suits or proceedings
might, individually or in the aggregate, prevent or adversely affect the
transactions contemplated by this Agreement or result in a Material Adverse
Effect. SangStat is not a party or subject to the provisions of any material
injunction, judgment, decree or order of any court, regulatory body,
administrative agency or other governmental body. There are no material legal
or governmental actions, suits or proceedings pending or, to SangStat's
knowledge, threatened against any executive officers or directors of SangStat.





                     3.8 DISCLOSURE. SangStat has provided Abbott with all
the information that Abbott has requested for deciding whether to purchase
the Common Stock. Neither this Agreement, nor any other statements or
certificates made or delivered in connection herewith or therewith contains
any untrue statement of a material fact or omits to state a material fact
necessary to make the statements herein or therein not misleading.

                     3.9 CHANGES.  Since December 31, 1998, except as
otherwise disclosed in the Form 10-K:

                         (a) SangStat has not incurred any material
liabilities or obligations, indirect, direct or contingent, or entered into
any material verbal or written agreement or other transaction which is not in
the ordinary course of business;

                         (b) SangStat has not sustained any material loss or
interference with its business or properties from fire, flood, windstorm,
accident or other calamity, whether or not covered by insurance;

                         (c) SangStat  has not  paid or  declared  any
dividends  or other distributions with respect to its capital stock and
SangStat is not in default in the payment of principal or interest on any
outstanding debt obligations;

                         (d) there has not been any change in the capital
stock or, other than in the ordinary course of business, indebtedness
material to SangStat; and

                         (e) there has not been any event, change or
development resulting in or which may reasonably be expected to result in a
Material Adverse Event.

                     3.10 SEC DOCUMENTS.

                          (a) SangStat has filed in a timely manner each
statement,  annual, quarterly and other report, registration statement and
definitive proxy statement required to be filed (other than preliminary
material) by SangStat with the United States Securities and Exchange
Commission since its initial public offering, (the "SEC Documents"). As of
their respective filing dates, the SEC Documents complied in all material
respects with the requirements of the Securities Act or the Securities
Exchange Act of 1934, as amended (the "Securities Exchange Act) as the case
may be, and, as of their respective filing dates, none of the SEC Documents
contained any untrue statement of a material fact or omitted to state a
material fact required to be stated therein or necessary to make the
statements made therein, in light of the circumstances in which they were
made, not misleading.

                          (b) As of their respective  filing dates, the
audited  consolidated financial statements and unaudited consolidated interim
financial statements of SangStat included in SangStat's SEC Documents fairly
present in all material respects in conformity with United States generally
accepted accounting principles applied on a consistent basis (except as may
be indicated in the notes thereto), the consolidated financial position of
SangStat as of the dates thereof and SangStat's consolidated results of
operations and cash flows for the periods then ended. Except as reflected or
reserved against in the consolidated balance sheet of SangStat at December
31, 1998, SangStat has no liabilities of any nature (whether accrued,
absolute,




contingent or otherwise), except for liabilities incurred in the ordinary
course of business since December 31, 1998 and liabilities which would not,
individually or in the aggregate, have a Material Adverse Effect.

                          (c) Since December 31, 1998, there have been no
events or transactions that would require adjustment to, or disclosure in,
the audited financial statements of SangStat for the period then ended in
order to keep them from being misleading.

                     3.11 RIGHTS PLAN.  The execution of this Agreement and
the Alliance Agreements and the consummation of the transactions contemplated
hereby and thereby, will not cause any adverse consequence to Abbott or its
affiliates or SangStat as a consequence of the Rights Plan, including,
without limitation, the occurrence of the Distribution Date (as defined in
the Rights Plan), the occurrence of any adjustment to the Purchase Price (as
defined in the Rights Plan) or Abbott or any of its affiliates being deemed
to be an Acquiring Person (as defined in the Rights Plan).

                     3.12 USE OF PROCEEDS. SangStat will use the proceeds
from the sale of the Initial Shares and the Option Shares for research and
development and for working capital.

                  4. REPRESENTATIONS, WARRANTIES AND COVENANTS OF ABBOTT.
Abbott hereby represents, warrants and covenants to SangStat that:

                     4.1 AUTHORIZATION. Abbott has full power and authority
to execute and deliver, and to consummate the transactions contemplated by
the Initial Share Closing, the Option Shares Closing, and this Agreement. All
corporate action on the part of Abbott necessary for (i) the execution and
delivery of, and the consummation of the transactions contemplated by, this
Agreement, and (ii) as of the Initial Share Closing and the Option Shares
Closing, the performance of all obligations of Abbott under this Agreement,
has been taken. This Agreement and each of the Alliance Agreements, upon
execution and delivery by Abbott and assuming the due and proper execution
and delivery by SangStat, constitutes a legal, valid and binding obligation
of Abbott, enforceable in accordance with its terms, except as may be limited
by (i) applicable bankruptcy, insolvency, reorganization or other laws of
general application relating to or affecting the enforcement of creditors
rights generally, and (ii) the effect of rules of law governing the
availability of equitable remedies.

                     4.2 PURCHASE ENTIRELY FOR OWN ACCOUNT. This Agreement is
made with Abbott in reliance upon Abbott's representation to SangStat, which
by Abbott's execution of this Agreement Abbott hereby confirms, that the
shares to be received by Abbott will be acquired for investment for Abbott's
own account, not as a nominee or agent, and not with a view to the resale or
distribution of any part thereof, and that Abbott has no present intention of
selling, granting any participation in, or otherwise distributing the same.
By executing this Agreement, Abbott further represents that, other than the
Call Option Agreement, Abbott does not have any contract, undertaking,
agreement or arrangement with any person to sell, transfer or grant
participations to such person or to any third person, with respect to any of
the shares.

                     4.3 GOVERNMENTAL CONSENTS. Other than compliance with
the Securities Act, the Securities Exchange Act, and such filings as may be
required to be made with the Securities and Exchange Commission or the
National Association of Securities Dealers, no consent, approval, order or
authorization of, or registration, qualification, designation,





declaration or filing with, any federal, state or local governmental
authority on the part of Abbott is required in connection with the
consummation of the transactions contemplated by this Agreement.

                     4.4 NO CONSENT. No consent, approval, waiver or other
action by any entity under any material contract, agreement, indenture,
lease, instrument or other document to which Abbott is a party or by which it
is bound is required or necessary for the execution, delivery and performance
of, or the consummation of the transactions contemplated by, this Agreement
by Abbott.

                     4.5 DISCLOSURE OF INFORMATION. Abbott believes it has
received all the information it considers necessary or appropriate for
deciding whether to purchase the Initial Shares and the Option Shares. Abbott
further represents that it has had an opportunity to ask questions and
receive answers from SangStat regarding the terms and conditions of the
offering of the Initial Shares and the Option Shares and the business,
properties, prospects and financial condition of SangStat. The foregoing,
however, does not limit or modify the representations and warranties of
SangStat in SECTION 3 of this Agreement or the right of Abbott to rely
thereon.

                     4.6 INVESTMENT EXPERIENCE. Abbott is an investor in
securities of companies in the development stage and acknowledges that it is
able to fend for itself, can bear the economic risk of its investment, and
has such knowledge and experience in financial or business matters that it is
capable of evaluating the merits and risks of the investment in the Initial
Shares and the Option Shares. Abbott has not been organized for the purpose
of acquiring either the Initial Shares or the Option Shares.

                     4.7 RESTRICTED SECURITIES.  Abbott understands that the
Common Stock it is purchasing are characterized as "restricted securities"
under the federal securities laws inasmuch as they are being acquired from
SangStat in a transaction not involving a public offering and that under such
laws and applicable regulations such securities may be resold without
registration under the Securities Act, only in certain limited circumstances.
In this connection, Abbott represents that it is familiar with Securities and
Exchange Commission Rule 144, as presently in effect, and understands the
resale limitations imposed thereby and by the Securities Act.

                     4.8 LEGENDS. Each certificate or instrument representing
Initial Shares or Option Shares shall bear legends in substantially the
following forms:

                         (a)     "THE SECURITIES REPRESENTED BY THIS
         CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
         1933 (THE "SECURITIES ACT") AND ARE "RESTRICTED SECURITIES" AS
         DEFINED IN RULE 144 PROMULGATED UNDER THE SECURITIES ACT. THE
         SECURITIES MAY NOT BE SOLD OR OFFERED FOR SALE OR OTHERWISE
         DISTRIBUTED EXCEPT (I) IN CONJUNCTION WITH AN EFFECTIVE REGISTRATION
         STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT, OR (II) IN
         COMPLIANCE WITH RULE 144, OR (III) PURSUANT TO AN OPINION OF COUNSEL
         REASONABLY SATISFACTORY TO THE ISSUER OF THESE SECURITIES THAT SUCH
         REGISTRATION OR COMPLIANCE IS NOT REQUIRED AS TO SUCH SALE, OFFER OR
         DISTRIBUTION".



                         (b) Any other legends  required by California law or
         other applicable blue sky or state securities laws.

Except as provided in the Registration Rights Agreement, SangStat need not
register a transfer of any Initial Shares or Option Shares, and may also
instruct its transfer agent not to register a transfer of any such shares,
unless the conditions specified in the foregoing legends are satisfied to the
extent applicable.

                     4.9 ACCREDITED INVESTOR. Abbott is an "accredited
investor" within the meaning of Securities and Exchange Commission Rule 501
of Regulation D, as presently in effect.

                     4.10 MARKET STAND-OFF. Abbott agrees that from the date
hereof through December 31, 2001, it shall not directly or indirectly sell,
make any short sale of, loan, hypothecate, pledge, offer, grant or sell any
option or other contract for the purchase of, purchase any option or other
contract for the sale of, or otherwise dispose of or transfer, or agree to
engage in any of the foregoing transactions with respect to, any of the
Initial Shares or any of the Option Shares (the "Market Stand-Off") without
the prior written consent of SangStat. In the event of the declaration of a
stock dividend, a spin-off, a stock split, an adjustment in conversion ratio,
a recapitalization or a similar transaction affecting SangStat's outstanding
securities without receipt of consideration, any new, substituted or
additional securities which are by reason of such transaction distributed
with respect to any Initial Shares or Option Shares subject to the Market
Stand-Off, or into which such shares thereby become convertible, shall
immediately be subject to the Market Stand-Off. In order to enforce the
Market Stand-Off, SangStat may impose stop-transfer instructions with respect
to the Initial Shares and the Option Shares until the end of the Market
Stand-Off. This SECTION 4.10 shall not, however, prevent Abbott from
acquiring additional shares of, or securities convertible into or exercisable
for any shares of, any class of capital stock of SangStat.

                  5. CONDITIONS OF ABBOTT'S OBLIGATIONS AT CLOSING. Abbott's
obligation to purchase the Initial Shares at the Initial Share Closing and its
obligation to purchase the Option Shares at the Option Share Closing are subject
to fulfillment, on or prior to the Initial Share Closing with respect to the
Initial Shares and the Option Share Closing with respect to the Option Shares,
of each of the following conditions unless waived by Abbott.

                     5.1 REPRESENTATIONS AND WARRANTIES. The representations
and warranties of SangStat contained in SECTION 3 and in each of the Alliance
Agreements shall be true and correct when made and at the closing with the
same effect as though such representations and warranties had been made on
and as of the date of the closing.



                     5.2 PERFORMANCE. SangStat shall have performed and
complied with all agreements, obligations and conditions contained in this
Agreement that are required to be performed or complied with by it on or
before the closing.

                     5.3 QUALIFICATIONS. All authorizations, approvals, or
permits, if any, of any governmental authority or regulatory body of the
United States or of any state that are required in connection with the lawful
issuance and sale of the shares pursuant to this Agreement shall be duly
obtained and effective as of the closing.

                     5.4 PROCEEDINGS AND DOCUMENTS. All corporate and other
proceedings in connection with the transactions contemplated at the closing
and all documents incident thereto shall be reasonably satisfactory in form
and substance to Abbott, and it shall have received all such counterpart
original and certified or other copies of such documents as it may reasonably
request.

                     5.5 ALLIANCE AGREEMENTS. The parties shall have entered
into each of the Alliance Agreements and the Alliance Agreements remain in
full force and effect.

                     5.6 OPINION OF COUNSEL TO SANGSTAT. Purchaser shall have
received from Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP,
counsel to SangStat, an opinion addressed to it, dated as of the date of the
closing and in substantially the form of EXHIBIT 5.6.

                     5.7 NO ORDER PENDING. There shall not then be in effect
any order enjoining or restraining the transactions contemplated by this
Agreement or the Alliance Agreements.

                     5.8 COMPLIANCE CERTIFICATE. SangStat shall have
delivered to Abbott a certificate, in substantially the form of EXHIBIT 5.8,
executed on behalf of SangStat by the President of SangStat, dated as of the
date of the closing and certifying to the fulfillment of the conditions
specified in SECTION 5.1.

                  6. CONDITIONS OF SANGSTAT'S OBLIGATIONS AT CLOSING.
SangStat's obligation to issue and sell the Initial Shares at the Initial
Share Closing and its obligation to issue and sell the Option Shares at the
Option Share Closing are subject to fulfillment, on or prior to the Initial
Share Closing with respect to the Initial Shares and the Option Share Closing
with respect to the Option Shares, of each of the following conditions unless
waived by SangStat.

                     6.1 REPRESENTATIONS AND WARRANTIES. The representations
and warranties of Abbott contained in SECTION 4 and in each of the Alliance
Agreements shall be true and correct when made and at the closing with the
same effect as though such representations and warranties had been made on
and as of the date of the closing.

                     6.2 PAYMENT OF PURCHASE PRICE. Abbott shall have
delivered the purchase price.



                     6.3 QUALIFICATIONS. All authorizations, approvals, or
permits, if any, of any governmental authority or regulatory body of the
United States or of any state that are required in connection with the lawful
issuance and sale of the Initial Shares and the Option Shares pursuant to
this Agreement shall be duly obtained and effective as of the closing for
those shares.

                     6.4 ALLIANCE AGREEMENTS. The parties shall have entered
into each of the Alliance Agreements and the Alliance Agreements remain in
full force and effect.

                     6.5 OPINION OF COUNSEL TO ABBOTT. SangStat shall have
received from John A. Berry, counsel to Abbott, an opinion addressed to it,
dated as of the date of the closing and certifying, in substantially the form
of EXHIBIT 6.5.

                     6.6 NO ORDER PENDING. There shall not then be in effect
any order enjoining or restraining the transactions contemplated by this
Agreement or the Alliance Agreements.

                     6.7 COMPLIANCE CERTIFICATE. The Purchaser shall have
delivered to SangStat a certificate, in substantially the form of EXHIBIT
6.7, executed on behalf of the Purchaser by an officer of the Purchaser,
dated as of the date of the closing and certifying to the fulfillment of the
conditions specified in SECTION 6.1.

                  7. MISCELLANEOUS.

                     7.1 SURVIVAL OF WARRANTIES. The warranties,
representations and covenants of SangStat and Abbott contained in or made
pursuant to this Agreement shall survive the execution and delivery of this
Agreement and the closings and shall in no way be affected by any
investigation of the subject matter thereof made by or on behalf of Abbott or
SangStat.

                     7.2 ASSIGNMENT: SUCCESSORS AND ASSIGNS. No provision of
this Agreement may be assigned without the prior written consent of the other
party hereto. Except as otherwise provided herein, the terms and conditions
of this Agreement shall inure to the benefit of and be binding upon the
respective successors and assigns of the parties (including transferees of
any of the Initial Shares or Option Shares). Nothing in this Agreement,
express or implied, is intended to confer upon any party other than the
parties hereto or their respective successors and assigns any rights,
remedies, obligations, or liabilities under or by reason of this Agreement,
except as expressly provided in this Agreement.

                     7.3 GOVERNING LAW. This Agreement shall be governed by
and construed under the laws of the State of Delaware without regard to
conflicts of law principles.

                     7.4 COUNTERPARTS. This Agreement may be executed in two
or more counterparts, each of which shall be deemed an original, but all of
which together shall constitute one and the same instrument.



                     7.5 TITLES AND SUBTITLES. The titles and subtitles used
in this Agreement are used for convenience only and are not to be considered
in construing or interpreting this Agreement.

                     7.6 NOTICES, ETC. All notices and other communications
required or permitted hereunder shall be in writing and shall be sent by
personal delivery, facsimile, overnight courier or mailed by certified or
registered mail, postage prepaid, return receipt requested, to the facsimile
number or address as follows:

           SangStat:         SangStat Medical Corporation
                             1505 Adams Drive
                             Menlo Park, California 94025
                             Telephone:       (650) 328-0300
                             Facsimile:       (650) 853-1601
                             Attention:       Chief Executive Officer and
                                              General Counsel

           with a copy (which will not constitute notice) to:

                             Gunderson Dettmer Stough Villeneuve
                             Franklin & Hachigian, LLP,
                             155 Constitution Drive
                             Menlo Park, CA 94025
                             Telephone: (650) 321-2400
                             Facsimile: (650) 321-2800
                             Attention: Jeffrey P. Higgins, Esq.

           Abbott:           Arthur J. Higgins, D-309 AP30
                             Senior Vice President, Pharmaceutical Operations
                             Abbott Laboratories
                             200 Abbott Park Road
                             Abbott Park, Illinois 60064-6184
                             Telephone:       (847) 938-6863
                             Facsimile:       (847) 938-5383

           with a copy (which will not constitute notice) to:

                             Brian J. Smith, D-32L AP6D
                             Divisional Vice President,
                             Domestic Legal Operations
                             Abbott Laboratories
                             100 Abbott Park Road
                             Abbott Park, Illinois 60064-6049
                             Telephone:       (847) 937-6472
                             Facsimile:       (847) 938-1206

or to such other facsimile number or address provided to the parties to this
Agreement in accordance with this SECTION 7.6. Such notices or other
communications shall be deemed delivered upon receipt, in the case of overnight
delivery, personal delivery or facsimile transmission (as evidenced by the
confirmation thereof), or 2 days after deposit in the mails (as





determined by reference to the postmark).

                     7.7 FINDER'S FEE.

                         (a) Each party represents that it neither is nor
will be obligated for any finders' fee or commission in connection with this
transaction. Abbott agrees to indemnify and hold harmless SangStat from any
liability for any commission or compensation in the nature of a finders' fee
(and the costs and expenses of defending against such liability or asserted
liability) for which such Abbott or any of its officers, partners, employees
or representatives is responsible.

                         (b) SangStat agrees to indemnify and hold harmless
Abbott from any liability for any commission or compensation in the nature of
a finders' fee (and the costs and expenses of defending against such
liability or asserted liability) for which SangStat or any of its officers,
employees or representatives is responsible.

                     7.8 EXPENSES. Irrespective of whether either of the
closings is effected, each party shall pay all costs and expenses that it
incurs with respect to the negotiation, execution, delivery and performance
of this Agreement.

                     7.9 ALTERNATIVE DISPUTE RESOLUTION. The parties agree to
effectuate all reasonable efforts to resolve in an amicable manner any and
all disputes between them in connection with this Agreement. The parties
agree that any dispute that arises in connection with this Agreement, which
cannot be amicably resolved informally shall be finally settled as set forth
in the Alternative Dispute Resolution provisions of EXHIBIT E to the
Co-Promotion Agreement between Abbott and Sangstat dated as of May 7, 1999.

                     7.10 AMENDMENTS AND WAIVERS. Any term of this Agreement
may be amended and the observance of any term of this Agreement may be waived
(either generally or in a particular instance and either retroactively or
prospectively) only with the written consent of SangStat and Abbott. Any
amendment or waiver effected in accordance with this paragraph shall be
binding upon each holder of any securities purchased under this Agreement at
the time outstanding (including securities into which such securities are
convertible), each future holder of all such securities and SangStat.

                     7.11 SEVERABILITY. If one or more provisions of this
Agreement are held to be unenforceable under applicable law, such provision
shall be excluded from this Agreement and the balance of the Agreement shall
be interpreted as if such provision were so excluded and shall be enforceable
in accordance with its terms.

                     7.12 ENTIRE AGREEMENT. This Agreement, the Alliance
Agreements, and the documents referred to herein and therein constitute the
entire agreement among the parties and no party shall be liable or bound to
any other party in any manner by any warranties, representations, or
covenants except as specifically set forth herein or therein.

                     7.13 FURTHER ASSURANCES. SangStat and Abbott shall do
and perform or cause to be performed all such further acts and things and
shall execute and deliver all such other agreements, certificates,
instruments or documents as the other party may reasonably request from time
to time in order to carry out the intent and purposes of this Agreement and
the consummation of the transactions contemplated by the Agreement. Neither
SangStat nor Abbott





shall voluntarily undertake any course of action inconsistent with the
satisfaction of the requirements applicable to them as set forth in this
Agreement, and each shall promptly do all such acts and take all such
measures as may be appropriate to enable them to perform as early as
practicable their obligations under this Agreement.

                     7.14 NO THIRD PARTY RIGHTS. Nothing in this Agreement
shall create or be deemed to create any rights in any person or entity not a
party to his Agreement.

                     7.15 MUTUAL DRAFTING. This Agreement is the joint
product of SangStat and Abbott and each provision of the Agreement has been
subject to consultation, negotiation and agreement of SangStat and Abbott and
their respective legal counsel and advisers and any rule of construction that
a document shall be interpreted or construed against the drafting party shall
not apply.



                  IN WITNESS WHEREOF, the parties have executed this Agreement
as of the date first above written.

                                SangStat Medical Corporation



                                By:

                                Title:


                                Abbott Laboratories



                                By:
                                         --------------------------------


                                Title:
                                         --------------------------------




                                  Exhibit 3

                          REGISTRATION RIGHTS AGREEMENT



     THIS REGISTRATION RIGHTS AGREEMENT (this "Agreement") is made as of the 7th
day of May, 1999, by and between SangStat Medical Corporation, a Delaware
corporation ("SangStat"), and Abbott Laboratories, an Illinois corporation
("Abbott").

                                    RECITALS

     WHEREAS, SangStat and Abbott are parties to the Stock Purchase Agreement,
dated the Closing Date (together with all exhibits, schedules, supplements and
any amendments thereto, the "Stock Purchase Agreement");

     WHEREAS, the execution and delivery of this Agreement is a condition to the
Closing of the Stock Purchase Agreement; and

     WHEREAS, all terms not otherwise defined herein shall have the same
meanings ascribed to them in the Stock Purchase Agreement;

     NOW, THEREFORE, THE PARTIES HEREBY AGREE AS FOLLOWS:

     1.       REGISTRATION RIGHTS.  SangStat covenants and agrees as follows:

              1.1      DEFINITIONS.  For purposes of this Agreement:

                       (a)      The term "Act" means the Securities Act of
1933, as amended.

                       (b) The term "1934 Act" shall mean the Securities
Exchange Act of 1934, as amended.

                       (c) The term "Holder" means both Abbott and any
transferee of Abbott to whom registration rights granted under this Agreement
are assigned pursuant to Section 1.6 of this Agreement.

                       (d) The terms "register," "registered," and
"registration" refer to a registration effected by preparing and filing a
registration statement or similar document in compliance with the Act, and
the declaration or ordering of effectiveness of such registration statement
or document.

                       (e) The term "Registrable Securities" means the Common
Stock of SangStat issued to Abbott pursuant to the Stock Purchase Agreement,
and any Common Stock of SangStat issued as a dividend or other distribution
with respect to such Common Stock.

                       (f) The term "Rule 144" shall mean Rule 144
promulgated under the Act, as amended, or any similar successor rule thereto
that may be promulgated by the SEC.

                       (g) The term "SEC" shall mean the Securities and
Exchange Commission.





              1.2      REGISTRATION.

                       (a) If SangStat shall receive at any time after
November 15, 2001, a written request from a Holder that SangStat file a
registration statement under the Act covering the registration of all of the
Registrable Securities, then SangStat shall use all commercially reasonable
efforts to file within 45 days of such written request, at its own expense
(excluding any brokers fees or commissions) a registration statement on Form
S-3 (or such other registration statement as is then available) and any
related qualification or compliance with respect to all of the Registrable
Securities so as to permit or facilitate the sale and distribution of all of
the Registrable Securities. SangStat agrees to use reasonable commercial
efforts to accelerate the effectiveness of the registration statement as soon
as practicable after filing but no less than within three (3) business days
of any notification by the SEC of its decision not to review the registration
statement or its determination that it has completed its review of the
registration statement and has no further comments for SangStat.

                       (b) SangStat agrees it will not include any additional
securities of SangStat other than the Registrable Securities and will not
permit any other person or entity to include any additional securities in the
registration statement to be filed pursuant to this Section 1.

              1.3 OBLIGATIONS OF SANGSTAT. Whenever required under this
Section 1 to effect the registration of any Registrable Securities, SangStat
shall:

                       (a) Prepare and file with the SEC a registration
statement under the Act to register the resale of the Registrable Securities
by the Holder and use its best efforts to cause such registration statement
to become effective, and, subject to the provisions below, use its best
efforts to keep such registration statement effective until the distribution
contemplated in the registration statement has been completed or until the
provisions of Section 1.8 hereof are applicable. If at any time after a
registration statement becomes effective, SangStat advises Abbott in writing
that the registration statement shall contain any untrue statement of a
material fact or omit to state any material fact required to be stated
therein or necessary to make the statements therein not misleading, or any
prospectus comprising a part of such registration statement shall contain any
untrue statement of a material fact or omit to state any material fact
required to be stated therein or necessary to make the statements therein, in
light of the circumstances under which they were made, not misleading or the
occurrence or existence of any pending corporate development that, in the
reasonable discretion of SangStat, makes it appropriate to suspend the
availability of the registration statement and the related prospectus,
SangStat shall give notice to Abbott that the availability of the
registration statement is suspended and Abbott shall suspend any further sale
of Registrable Securities pursuant to the registration statement until Abbott
has been informed in writing that the registration statement is available.
With respect to pending corporate developments, SangStat shall be entitled to
exercise its right to suspend the availability of the registration statement
for a period exceeding not more than sixty (60) days in any six (6) month
period, not to exceed in the aggregate one hundred twenty (120) days in any
twelve (12) month period. With respect to material misstatements or
omissions, SangStat shall use reasonable commercial efforts to amend the
registration statement to correct such misstatements or omissions as soon as
reasonably practicable.





                       (b) Subject to subsection 1.3(a), prepare and file
with the SEC such amendments and supplements to such registration statement
and the prospectus used in connection with such registration statement as may
be necessary to comply with the provisions of the Act with respect to the
disposition of all securities covered by such registration statement.

                       (c) Furnish to the Holder such numbers of copies of a
prospectus, including a preliminary prospectus, in conformity with the
requirements of the Act, and such other documents as the Holder may
reasonably request in order to facilitate the disposition of Registrable
Securities owned by the Holder.

                       (d) Use its best efforts to register and qualify the
securities covered by such registration statement under such other securities
or Blue Sky laws of such jurisdictions as shall be reasonably requested by
the Holder; provided that SangStat shall not be required in connection
therewith or as a condition thereto to qualify to do business or to file a
general consent to service of process in any such states or jurisdictions,
unless SangStat is already subject to service in such jurisdiction and except
as may be required by the Act.

                       (e) Amend its listing application with the Nasdaq
Stock Market and any other securities exchange on which similar securities of
SangStat are or become listed or quoted to include the Registrable Securities
as soon as practicable after the Closing Date.

                       (f) Notify the Holder, promptly after SangStat shall
have received notice thereof, of the date and time the registration statement
and each post-effective amendment thereto has become effective or a
supplement to any prospectus forming a part of such registration statement
has been filed.

              1.4 INFORMATION FROM THE HOLDER. It shall be a condition
precedent to the obligations of SangStat to take any action pursuant to this
Section 1 with respect to the Registrable Securities that the Holder shall
furnish to SangStat the information requested on Appendix 1.4 hereto, which
shall include such information regarding the Holder, the Registrable
Securities held by it, and the intended method of disposition of such
securities, and such other information as shall be reasonably requested by
SangStat and required to effect the registration of the Registrable
Securities.

              1.5 EXPENSES OF REGISTRATION. All expenses of the Holder,
except underwriting discounts (if any) or commissions, including (without
limitation) all registration, filing and qualification fees, printers' and
accounting fees, fees and disbursements of counsel for SangStat shall be
borne by SangStat; provided, however, that SangStat shall not be required to
pay any legal and accounting fees incurred by the Holder.

              1.6 ASSIGNMENT OF REGISTRATION RIGHTS. The rights to cause
SangStat to register Registrable Securities pursuant to this Agreement may be
assigned by Abbott to a transferee of Registrable Securities only if: (a)
SangStat is, prior to such transfer, furnished with written notice of the
name and address of such transferee and the Registrable Securities with
respect to which such registration rights are being assigned and a copy of a
duly executed written instrument in form reasonably satisfactory to SangStat
by which such transferee assumes all of





the obligations and liabilities of its transferor hereunder and agrees itself
to be bound hereby; (b) immediately following such transfer the disposition
of such Registrable Securities by the transferee is restricted under the Act;
(c) such assignment includes all of the Registrable Securities then held by
Abbott; PROVIDED, HOWEVER, that such share limitation shall not apply to
transfers by Abbott to its subsidiaries if all such transferees or assignees
agree in writing to appoint a single representative as their attorney-in-fact
for the purpose of receiving any notices and exercising their rights under
this Agreement, and (d) Abbott guarantees the performance of the Holder of
its obligations under this Agreement.

              1.7      INDEMNIFICATION.

                       (a) The Holder will indemnify and hold harmless
SangStat, as well as each of its directors, each of its officers who has
signed the registration statement, affiliates, each person, if any, who
controls SangStat within the meaning of the Act, against any losses, claims,
damages, or liabilities (joint or several) to which any of the foregoing
persons may become subject (under the Act, the 1934 Act or otherwise),
insofar as such losses, claims, damages or liabilities (or actions or
proceedings in respect thereto) arise out of or are based upon omissions or
violations (collectively, a "Violation"): (i) any untrue statement or alleged
untrue statement of a material fact contained in such registration statement,
including any preliminary prospectus or final prospectus contained therein or
any amendments or supplements thereto, (ii) any omission or alleged omission
to state therein a material fact required to be stated therein, or necessary
to make the statements therein not misleading, or (iii) any violation or
alleged violation by SangStat of the Act, the 1934 Act, any rule or
regulation promulgated under the Act or the 1934 Act or other federal or
state law, in each case to the extent that such Violation is contained in any
written information furnished by the Holder for inclusion in such
registration; and the Holder will pay, as incurred, any legal or other
expenses reasonably incurred by any person intended to be indemnified
pursuant to this subsection 1.7(a), in connection with investigating or
defending any such loss, claim, damage, liability, or action; provided,
however, that the indemnity agreement contained in this subsection 1.7(a)
shall not apply to amounts paid in settlement of any such loss, claim,
damage, liability, action or proceeding if such settlement is effected
without the consent of the Holder, which consent shall not be unreasonably
withheld; PROVIDED, THAT, in no event shall any indemnity under this
subsection 1.7(a) exceed the net proceeds from the offering received by such
Holder.

                       (b) SangStat will indemnify and hold harmless a
Holder, as well as each of such Holders's officers, directors, partners,
legal counsel, affiliates and persons controlling Holder, against any losses,
claims, damages, or liabilities (joint or several) to which any of the
foregoing persons may be subject (under the Act, the 1934 Act or otherwise),
insofar as such losses, claims, damages or liabilities (or actions or
proceedings in respect thereto) arise out of or are based upon any of the
following statements, omissions or violations (collectively, a "Violation"):
(i) any untrue statement or alleged untrue statement of a material fact
contained in a registration statement, including any preliminary prospectus
or final prospectus contained therein or any amendments or supplements
thereto, (ii) any omission or alleged omission to state therein a material
fact required to be stated therein, or necessary to make the statements
therein not misleading, or (iii) any violation or alleged violation by the
Holder of the Act, the 1934 Act or




any rule or regulation promulgated under the Act or the 1934 Act or other
federal or state law, in each case to the extent that such Violation is based
on any untrue statement or omission or alleged untrue statement or omission
made in reliance upon and in conformity with any written information
furnished by SangStat in an instrument duly executed by the Holder; and
SangStat will pay, as incurred, any legal or other expenses reasonably
incurred by any person intended to be indemnified pursuant to this subsection
1.7(b) in connection with investigating or defending any such loss, claim,
damage, liability or action; provided, however, that the indemnity agreement
contained in this subsection 1.7(b) shall not apply to amounts paid in
settlement of any such loss, claim, damage, liability, action, or proceeding
if settlement is effected without the consent of SangStat, which consent
shall not be unreasonably withheld.

                       (c) Promptly after receipt by an indemnified party
under this Section 1.7 of notice of the commencement of any action (including
any governmental action), such indemnified party will, if a claim in respect
thereof is to be made against any indemnifying party under this Section 1.7,
deliver to the indemnifying party a written notice of the commencement
thereof and the indemnifying party shall have the right to participate in at
the indemnifying party's expense, and, to the extent the indemnifying party
so desires, jointly with any other indemnifying party similarly noticed, to
assume the defense thereof with counsel mutually satisfactory to the parties
at the indemnifying party's expense; provided, however, that an indemnified
party (together with all other indemnified parties which may be represented
without conflict by one counsel) shall have the right to retain one separate
counsel, with the fees and expenses to be paid by the indemnifying party, if
representation of such indemnified party by the counsel retained by the
indemnifying party would be inappropriate due to actual or potential
conflicts of interests between such indemnified party and any other party
represented by such counsel in such proceeding. No indemnifying party, in
defense of any such claim or litigation, shall, except with the consent of
each indemnified party, consent to entry of any judgement or enter into any
settlement which does not include as an unconditional term thereof the giving
by the claimant or plaintiff to the indemnified party of a release from all
liability in respect to such claim or litigation.

                       (d) If the indemnification provided for in this
Section 1.7 is unavailable or insufficient to hold harmless to an indemnified
party with respect to any loss, liability, claim, damage, or expense referred
to therein, then the indemnifying party, in lieu of indemnifying such
indemnified party hereunder, shall contribute to the amount paid or payable
by such indemnified party as a result of such loss, liability, claim, damage,
or expense in such proportion as is appropriate to reflect the relative fault
of the indemnifying party on the one hand and of the indemnified party on the
other in connection with the statements or omissions that resulted in such
loss, liability, claim, damage, or expense as well as any other relevant
equitable considerations. The relative fault of the indemnifying party and of
the indemnified party shall be determined by reference to, among other
things, whether the untrue or alleged untrue statement of a material fact or
the omission to state a material fact relates to information supplied by the
indemnifying party or by the indemnified party and the parties' relative
intent, knowledge, access to information, and opportunity to correct or
prevent such statement or omission. Notwithstanding the provisions of this
paragraph (d), Holder shall not be required to contribute any amount in
excess of the amount of net proceeds received by such Holder from the sale of





such Holder's Registrable Securities. Moreover, no person or entity guilty of
fraudulent misrepresentation within the meaning of Section 11(f) of the Act
shall be entitled to contribution from any person or entity who was not
guilty of such fraudulent misrepresentation.

                       (e) The obligations of a Holder under this Section 1.7
shall survive the completion of any offering of Registrable Securities in a
registration statement under this Agreement and shall be in addition to any
other liability which SangStat and the Holder may have.

                       (f) Notwithstanding the foregoing, to the extent that
the provisions on indemnification and contribution contained in an
underwriting agreement (if any) entered into in connection with the
underwritten public offering are in conflict with the foregoing provisions,
the provisions in the underwriting agreement shall control.

              1.8 TERMINATION OF REGISTRATION RIGHTS. The registration rights
provided in this Section 1 shall terminate if all shares of Registrable
Securities may be sold pursuant to Rule 144 in any three (3) month period.
Upon the termination of registration rights pursuant to this Section 1.8,
SangStat shall have the right to withdraw the registration statement, or any
portion thereof, covering the Registrable Securities.

              1.9 LEGENDS. Each certificate representing the Common Stock
purchased pursuant to the terms of the Stock Purchase Agreement, shall be
stamped or otherwise imprinted with a legend substantially in the following
form:

                  "THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933 OR ANY STATE SECURITIES LAWS AND MAY NOT BE TRANSFERRED OR OTHERWISE
DISPOSED OF UNLESS IT HAS BEEN REGISTERED UNDER SUCH ACT AND ALL SUCH APPLICABLE
LAWS OR AN EXEMPTION FROM REGISTRATION IS AVAILABLE."

A certificate shall not bear such legend if in the opinion of counsel reasonably
satisfactory to SangStat the securities being sold thereby may be publicly sold
without registration under the Securities Act and any applicable state
securities laws.

              1.10 REPORTS UNDER SECURITIES EXCHANGE ACT OF 1934. With a view
to making available to a Holder the benefits of Rule 144 promulgated under
the Act and any other rule or regulation of the SEC that may at any time
permit a Holder to sell securities of SangStat to the public without
registration or pursuant to a registration on Form S-3, SangStat agrees to:

                       (a) make and keep public information  available,  as
those terms are understood and defined in SEC Rule 144, at all times;

                       (b) file with the SEC in a timely manner all reports
and other documents required of SangStat under the Act and the 1934 Act; and

                       (c) furnish to the Holder, so long as the Holder owns
any Registrable



Securities, forthwith upon request (i) a written statement by SangStat that
it has complied with the reporting requirements of SEC Rule 144, the Act and
the 1934 Act, or that it qualifies as a registrant whose securities may be
resold pursuant to Form S-3, (ii) a copy of the most recent annual or
quarterly report of SangStat and such other reports and documents so filed by
SangStat, and (iii) such other information as may be reasonably requested in
availing the Holder of any rule or regulation of the SEC that permits the
selling of any such securities without registration or pursuant to such form.

2.       MISCELLANEOUS.

              2.1 AMENDMENT. This Agreement may only be amended by a writing
signed by the Holder and SangStat.

              2.2 ENTIRE AGREEMENT; CONTROLLING DOCUMENT. This Agreement
constitutes the entire agreement of the parties with respect to the subject
matter hereof and supersedes any and all prior negotiations, correspondence
and understandings between the parties with respect to the subject matter
hereof, whether oral or in writing.

              2.3 COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

              2.4 HEADINGS. The section headings used in this Agreement are
intended principally for convenience and shall not by themselves determine
the rights and obligations of the parties to this Agreement.

              2.5 DELAY AND WAIVER. No delay on the part of either party in
exercising any right under this Agreement shall operate as a waiver of such
right. The waiver by either party of any other term or condition of this
Agreement shall not be construed as a waiver of a subsequent breach or
failure of the same term or condition or a waiver of any other term or
condition contained in this Agreement.

              2.6 GOVERNING LAW. This Agreement shall be governed by and
construed under the laws of the State of Delaware without regard to conflicts
of law principles.

              2.7 TITLES AND SUBTITLES. The titles and subtitles used in this
Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

              2.8 EXPENSES. Each party shall pay all costs and expenses that
it incurs with respect to the negotiation, execution, and delivery of this
Agreement.

              2.9 ALTERNATIVE DISPUTE RESOLUTION. The parties agree to
effectuate all reasonable efforts to resolve in an amicable manner any and
all disputes between them in connection with this Agreement. The parties
agree that any dispute that arises in connection with this Agreement, which
cannot be amicably resolved informally shall be finally settled as set forth
in the Alternative Dispute Resolution provisions of Exhibit E to the
Co-Promotion Agreement between




Abbott and SangStat dated as of May 7, 1999.

              2.10 AMENDMENTS AND WAIVERS. Any term of this Agreement may be
amended and the observance of any term of this Agreement may be waived
(either generally or in a particular instance and either retroactively or
prospectively) only with the written consent of SangStat and the Holder.

              2.11 SEVERABILITY. If one or more provisions of this Agreement
are held to be unenforceable under applicable law, such provision shall be
excluded from this Agreement and the balance of the Agreement shall be
interpreted as if such provision were so excluded and shall be enforceable in
accordance with its terms.

              2.12 FURTHER ASSURANCES. SangStat and Abbott shall do and
perform or cause to be performed all such further acts and things and shall
execute and deliver all such other agreements, certificates, instruments or
documents as the other party may reasonably request from time to time in
order to carry out the intent and purposes of this Agreement and the
consummation of the transactions contemplated by the Agreement. Neither
SangStat nor Abbott shall voluntarily undertake any course of action
inconsistent with the satisfaction of the requirements applicable to them as
set forth in this Agreement, and each shall promptly do all such acts and
take all such measures as may be appropriate to enable them to perform as
early as practicable their obligations under this Agreement.

              2.13 NO THIRD PARTY RIGHTS. Nothing in this Agreement shall
create or be deemed to create any rights in any person or entity not a party
to his Agreement.

              2.14 MUTUAL DRAFTING. This Agreement is the joint product of
SangStat and Abbott and each provision of the Agreement has been subject to
consultation, negotiation and agreement of SangStat and Abbott and their
respective legal counsel and advisers and any rule of construction that a
document shall be interpreted or construed against the drafting party shall
not apply.



                  IN WITNESS WHEREOF, the parties have executed this
Registration Rights Agreement as of the date first above written.


                      SANGSTAT MEDICAL CORPORATION



                      By:



        Address:      1505 Adams Drive
                      Menlo Park, CA 94025



                      ABBOTT LABORATORIES:



                      By:
                      Name:
                      Title:



        Address:





                                  APPENDIX 1.4

                               ABBOTT INFORMATION:

All information furnished below by the undersigned for use in the Registration
Statement on Form S-3 is, and on the date such shares registered thereunder,
will be true, correct, and complete in all material respects, and does not, and
on the date on which the undersigned sells such shares, will not, contain any
untrue statement of a material fact or omit to state any material fact necessary
to make such information not misleading. By completing and returning this
information statement, the undersigned hereby consents to the use of its,
address, and share ownership information in the Form S-3 of SangStat Medical
Corporation.


A. DATE.

   Fill in Date:                                ______________________________


B. NAME.                                                    Print:

   Print and sign name or names                 ______________________________
   exactly as name or names appear on
   share certificate.  If certificate is held   ______________________________
   in more than one name, all must sign.

                                                            Sign:

                                                ______________________________

                                                ______________________________

C. ADDRESS.

   Fill in your address:                        ______________________________

                                                ______________________________

                                                ______________________________







D. STOCK OWNED.

   Fill in number of shares of              Of Record           Beneficially
   Common Stock owned of record
   and beneficially.
                                        --------------------   ----------------



E. AGGREGATE NUMBER OF SHARES OF COMMON STOCK TO BE SOLD:

                  _____________ Shares


F. STATUS.

   The undersigned is an individual ( ), partnership ( ), corporation ( ), or
other, as more fully described below ( ). The undersigned is not acting in a
fiduciary capacity or as a nominee in selling shares in the public offering,
except as indicated below.

- ------------------------------------------------------------------------------

- ------------------------------------------------------------------------------

- ------------------------------------------------------------------------------




                                    Exhibit 4

     THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,
     AS AMENDED. THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED
     IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THE SECURITIES
     UNDER SAID ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO ABBOTT
     LABORATORIES, AN ILLINOIS CORPORATION, THAT SUCH REGISTRATION IS NOT
     REQUIRED.

                               CALL OPTION AGREEMENT

       THIS CALL OPTION AGREEMENT (the "Agreement") is made as of May 7,
1999, between SangStat Medical Corporation, a Delaware corporation,
("SangStat") and Abbott Laboratories, an Illinois corporation ("Abbott").

       WHEREAS, SangStat and Abbott have entered a Stock Purchase Agreement
even date herewith (the "Stock Purchase Agreement"); and

       WHEREAS, subject to the terms and conditions of this Call Option
Agreement (the "Agreement") and on the basis of the representations and
warranties set forth in this Agreement and in the Stock Purchase Agreement,
Abbott has agreed to grant SangStat the right to repurchase from Abbott the
Initial Shares and Option Shares purchased by Abbott from SangStat pursuant
to the Stock Purchase Agreement.

       NOW THEREFORE, THE PARTIES HEREBY AGREE AS FOLLOWS:

       1.     CERTAIN DEFINITIONS.

              1.1    TERMS DEFINED IN THE STOCK PURCHASE AGREEMENT. To the
extent a term is not otherwise defined in this Agreement, it shall have the
same meaning as the meaning given to it in the Stock Purchase Agreement.

              1.2    CALL OPTION. The term "Call Option" shall mean either a
Call Option for the Initial Shares or a Call Option for the Option Shares, as
the context requires.

              1.3    CALL OPTION FOR THE INITIAL SHARES. The term "Call
Option for the Initial Shares" shall mean the right of SangStat to purchase
SangStat stock from Abbott described in SECTION 2.1 (a) below.

              1.4    CALL OPTION FOR THE OPTION SHARES. The term "Call Option
for the Option Shares" shall mean the right of SangStat to purchase SangStat
stock from Abbott described in Section 2.1(b) below.





       2.     CALL OPTIONS.

              2.1    GRANT OF CALL OPTIONS, EXERCISE PRICE. Subject to the
terms and conditions herein set forth, Abbott hereby grants to SangStat:

                     (a)    the right (the "Call Option for the Initial Shares")
                            to purchase from Abbott any or all of the Initial
                            Shares at an exercise price per share equal to two
                            times the Price per Initial Share paid by Abbott to
                            SangStat pursuant to SECTION 1.1 of the Stock
                            Purchase Agreement); and

                     (b)    the right (the "Call Option for the Option Shares")
                            to purchase from Abbott any or all of the Option
                            Shares at an exercise price per share equal to two
                            times the Price per Option Share paid by Abbott to
                            SangStat pursuant to SECTION 2.2 of the Stock
                            Purchase Agreement.

              2.2    TERM OF THE CALL OPTIONS. SangStat may exercise either
or both of the Call Options, in whole or in part, at any time after the date
hereof until December 31, 2001.

              2.3    MANNER OF EXERCISING CALL OPTION. SangStat may exercise
a Call Option only by surrendering a completed and fully-executed Call Option
Subscription Form (in the form attached hereto as EXHIBIT A) to Abbott. On
the fifth day following proper exercise of the Call Option (the "Closing
Date"), SangStat shall pay the exercise price for the Call Option to Abbott.
The Call Option shall be deemed to have been exercised immediately prior to
the close of business on the Closing Date, and any person(s), entity or
entities entitled to receive the shares of Common Stock issuable upon
exercise shall be treated for all purposes as the holder of record of such
shares as of the close of business on such date. The exercise price for a
Call Option shall be paid to Abbott by wire transfer to the bank account of
Abbott.

       3.     CHANGES IN CAPITAL STRUCTURE. If SangStat shall at any time
change the number of its issued common shares without receiving new
consideration (such as by stock dividends or stock splits), then the number
of shares of SangStat common stock covered by each of the Call Options and
the exercise price of each of the Call Options shall be adjusted so that the
aggregate consideration payable to Abbott and the value of the Call Options,
in the aggregate, shall not be changed.

       4.     CALIFORNIA COMMISSIONER OF CORPORATIONS.

     THE SALE OF THE SECURITIES WHICH ARE THE SUBJECT OF THIS AGREEMENT HAS NOT
     BEEN QUALIFIED WITH THE COMMISSIONER OF CORPORATIONS OF, THE STATE OF
     CALIFORNIA AND THE ISSUANCE OF SUCH SECURITIES OR THE PAYMENT OR RECEIPT OF
     ANY PART OF THE CONSIDERATION FOR SUCH SECURITIES PRIOR TO





     SUCH QUALIFICATION IS UNLAWFUL, UNLESS THE SALE OF SECURITIES IS EXEMPT
     FROM ALL QUALIFICATION BY SECTION 25100, 25102 OR 25105 OF THE
     CALIFORNIA CORPORATIONS CODE. THE RIGHTS OF ALL PARTIES TO THIS
     AGREEMENT ARE EXPRESSLY CONDITIONED UPON SUCH QUALIFICATION BEING
     OBTAINED, UNLESS THE SALE IS SO EXEMPT.

       5.     REPRESENTATIONS, WARRANTIES AND COVENANTS OF ABBOTT.

              Abbott represents and warrants as of this date, and covenants for
the period beginning on this date and ending the termination of this Agreement,
that:

              (a)    Abbott has the right to enter into this Agreement and to
                     transfer to SangStat all or any part of the Initial Shares
                     and the Option Shares, free and clear of any lien, claim,
                     encumbrance or restriction of any type or nature whatsoever
                     (other than those created by SangStat or restrictions on
                     resale that may arise under applicable federal and state
                     securities laws); and

              (b)    Abbott is not a party to any agreement and will not enter
                     into an agreement, by which Abbott is or would be bound (or
                     to which Abbott is or would become subject) that conflicts
                     or would conflict with this Agreement or the performance of
                     Abbott's obligations under this Agreement.

       6.     MISCELLANEOUS.

              6.1    ENTIRE AGREEMENT, CONTROLLING DOCUMENT. This Agreement
constitutes the entire agreement of the parties with respect to the subject
matter hereof and supersedes any and all prior negotiations, correspondence
and understandings between the parties with respect to the subject matter
hereof, whether oral or in writing.

              6.2    COUNTERPARTS. This Agreement may be executed in two or
more counterparts, each of which shall be deemed an original, but all of
which together shall constitute one and the same instrument.

              6.3    DELAY AND WAIVER. No delay on the part of either party in
exercising any right under this Agreement shall operate as a waiver of such
right. The waiver by either party of any other term or condition of this
Agreement shall not be construed as a waiver of a subsequent breach or failure
of the same term or condition or a waiver of any other term or condition
contained in this Agreement.





              6.4    ASSIGNMENT: SUCCESSORS AND ASSIGNS. No provision of this
Agreement may be assigned without the prior written consent of the other
party hereto. Except as otherwise provided herein, the terms and conditions
of this Agreement shall inure to the benefit of and be binding upon the
respective successors and assigns of the parties (including transferees of
any of the Initial Shares or Option Shares). Nothing in this Agreement,
express or implied, is intended to confer upon any party other than the
parties hereto or their respective successors and assigns any rights,
remedies, obligations, or liabilities under or by reason of this Agreement,
except as expressly provided in this Agreement.

              6.5    GOVERNING LAW. This Agreement shall be governed by and
construed under the laws of the State of Delaware without regard to conflicts
of law principles.

              6.6    TITLES AND SUBTITLES. The titles and subtitles used in
this Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

              6.7    EXPENSES. Irrespective of whether either of the Call
Options is exercised, each party shall pay all costs and expenses that it
incurs with respect to the negotiation, execution, delivery and performance
of this Agreement.

              6.8    ALTERNATIVE DISPUTE RESOLUTION. The parties agree to
effectuate all reasonable efforts to resolve in an amicable manner any and
all disputes between them in connection with this Agreement. The parties
agree that any dispute that arises in connection with this Agreement, which
cannot be amicably resolved informally, shall be finally settled as set forth
in the Alternative Dispute Resolution provisions of Exhibit E to the
Co-Promotion Agreement between Abbott and SangStat dated as of May 7, 1999.

              6.9    AMENDMENTS AND WAIVERS. Any term of this Agreement may
be amended and the observance of any term of this Agreement may be waived
(either generally or in a particular instance and either retroactively or
prospectively) only with the written consent of SangStat and Abbott. Any
amendment or waiver effected in accordance with this paragraph shall be
binding upon each holder of any securities purchased under this Agreement at
the time outstanding (including securities into which such securities are
convertible), each future holder of all such securities and SangStat.

              6.10   SEVERABILITY. If one or more provisions of this
Agreement are held to be unenforceable under applicable law, such provision
shall be excluded from this Agreement and the balance of the Agreement shall
be interpreted as if such provision were so excluded and shall be enforceable
in accordance with its terms.





              6.11   FURTHER ASSURANCES.  SangStat and Abbott shall do and
perform or cause to be performed all such further acts and things and shall
execute and deliver all such other agreements, certificates, instruments or
documents as the other party may reasonably request from time to time in
order to carry out the intent and purposes of this Agreement and the
consummation of the transactions contemplated by the Agreement. Neither
SangStat nor Abbott shall voluntarily undertake any course of action
inconsistent with the satisfaction of the requirements applicable to them as
set forth in this Agreement, and each shall promptly do all such acts and
take all such measures as may be appropriate to enable them to perform as
early as practicable their obligations under this Agreement.

              6.12   NO THIRD PARTY RIGHTS. Nothing in this Agreement shall
create or be deemed to create any rights in any person or entity not a party
to his Agreement.

              6.13   MUTUAL DRAFTING. This Agreement is the joint product of
SangStat and Abbott and each provision of the Agreement has been subject to
consultation, negotiation and agreement of SangStat and Abbott and their
respective legal counsel and advisers and any rule of construction that a
document shall be interpreted or construed against the drafting party shall
not apply.

       IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first above written.

                                   SangStat Medical Corporation

                                   By: ______________________________

                                   Title: ___________________________


                                   Abbott Laboratories

                                   By:  ______________________________

                                   Title: ____________________________



                SIGNATURE PAGE TO COMMON STOCK PURCHASE AGREEMENT







       EXHIBIT A
       ---------

       CALL OPTION SUBSCRIPTION FORM

       (To be signed only upon exercise of Call Option)

       To:

       The undersigned, the holder of the attached Call Option, hereby
irrevocably elects to exercise the purchase right represented by that Call
Option for, and to purchase under that Call Option, ________ shares of Common
Stock of _______________ and herewith makes payment of an aggregate price of
$ ___________  for those shares and requests that the certificates for the
shares be issued in the name of, and delivered to, __________________ address
is ____________________________________ and that all other actions be taken
as are necessary to transfer title to such other property subject to the Call
Option.

       Dated: ___________________________________

              ___________________________________

              By: _______________________________

              Title: ____________________________

              Address: __________________________

              ___________________________________






       EXHIBIT B
       ---------

       ASSIGNMENT SEPARATE FROM CERTIFICATE

       FOR VALUE RECEIVED, _______________ hereby sell, assign and transfer
unto _________________, ______________ Shares of the Common Stock of SangStat
Medical Corporation, a Delaware corporation ("SangStat"), standing in its
name on the books of SangStat represented by Certificate No. ________
herewith and do hereby irrevocably constitute and appoint EquiServ LLP to
transfer said stock on the books of SangStat with full power of substitution
in the premises.

       Dated: ______________________________________

                        Signature

                        _____________________________________

                        _____________________________________


       This Assignment Separate from Certificate was executed in conjunction
with the terms of a Call Option Agreement dated ___________________, 1999,
and shall not be used in any manner except as provided in such Agreement.



                                    Exhibit 5

                        RIGHT OF FIRST REFUSAL AGREEMENT



     This RIGHT OF FIRST REFUSAL AGREEMENT is entered into as of the 7th day of
May, 1999 by and among SangStat Medical Corporation, a Delaware corporation
("SangStat"), and Abbott Laboratories, an Illinois corporation ("Abbott").


                              W I T N E S S E T H :

     WHEREAS, SangStat and Abbott are parties to the Stock Purchase Agreement of
even date herewith (the "Stock Purchase Agreement"), pursuant to which Abbott is
purchasing those shares of SangStat's common stock $0.001 par value (the "Common
Stock") that are defined in the Stock Purchase Agreement as being the "Initial
Shares" and may purchase those shares of the Common Stock that are defined in
the Stock Purchase Agreement as being the "Option Shares" (the Initial Shares
and the Option Shares are referred to collectively herein as the "Shares"); and

     WHEREAS, SangStat and Abbott wish to provide further inducements to each
other to consummate the proposed transaction;

     WHEREAS, all terms not otherwise defined herein shall have the same
meanings ascribed to them in the Stock Purchase Agreement;

     NOW, THEREFORE, in consideration of the premises and the mutual promises
set forth in this Agreement;

     THE PARTIES AGREE AS FOLLOWS:

     1.       RIGHT OF REFUSAL.

              (A) TRANSFER NOTICE. If at any time after the expiration of the
Market Stand-Off set forth in the Stock Purchase Agreement, Abbott proposes
to transfer any of the Shares to one or more third parties or in an open
market transaction (a "Transfer"), then Abbott shall give SangStat written
notice of Abbott's intention to make the Transfer (the "Transfer Notice"),
which Transfer Notice shall include (i) a description of the Shares to be
transferred ("Offered Shares"), (ii) the identity of the prospective
transferee(s) if it is not an open market transaction and (iii) the
consideration and the material terms and conditions upon which the proposed
Transfer is to be made. The Transfer Notice shall also include a copy of any
written proposal, term sheet or letter of intent, or other agreement relating
to the proposed Transfer.

              (B) SANGSTAT'S OPTION. SangStat shall have an option for a
period of thirty (30) days from receipt of the Transfer Notice to elect to
purchase the Offered Shares at the same price and subject to the same
material terms and conditions as described in the Transfer Notice or if the
Transfer Notice proposes an open market transaction, then the purchase price
for SangStat shall be the average of the closing prices for SangStat's Common
Stock, as quoted on the Nasdaq




National Market, on each of the twenty (20) trading days immediately
preceding the date of the Transfer Notice. SangStat may exercise such
purchase option and, thereby, purchase all of the Offered Shares if the
Transfer Notice proposes a transfer to one or more third parties not in an
open market transaction, or purchase all (or a portion of) the Offered Shares
if the Transfer Notice proposes an open market transaction by notifying
Abbott in writing before expiration of the such thirty (30) day period as to
the number of such shares which it wishes to purchase. If SangStat gives
Abbott notice that it desires to purchase such shares, then payment for the
Offered Shares shall be by check or wire transfer, against delivery of the
Offered Shares to be purchased at a place agreed upon between the parties and
at the time of the scheduled closing therefor, which shall be no later than
forty-five (45) days after SangStat's receipt of the Transfer Notice, unless
the Transfer Notice contemplated a later closing with the prospective third
party transferee(s) or unless the value of the purchase price has not yet
been established pursuant to Section 1.1(c).

              (C) VALUATION OF PROPERTY. Should the purchase price specified
in the Transfer Notice be payable in property other than cash or evidences of
indebtedness, SangStat shall have the right to pay the purchase price in the
form of cash equal in amount to the value of such property. If Abbott and
SangStat cannot agree on such cash value within ten (10) days after
SangStat's receipt of the Transfer Notice, the valuation shall be made by an
appraiser of recognized standing selected by Abbott and SangStat or, if they
cannot agree on an appraiser within twenty (20) days after SangStat's receipt
of the Transfer Notice, each shall select an appraiser of recognized standing
and the two appraisers shall designate a third appraiser of recognized
standing, whose appraisal shall be determinative of such value. The cost of
such appraisal shall be shared equally by Abbott and SangStat. If the time
for the closing of SangStat's purchase but for the determination of the value
of the purchase price offered by the prospective transferee(s), then such
closing shall held on or prior to the fifth business day after such valuation
shall have been made pursuant to this subsection.

     1.2 NON-EXERCISE OF RIGHTS. To the extent that SangStat has not
exercised its right to purchase the Offered Shares within the time period
specified in Section 1.1, the rights set forth herein shall terminate.

     1.3 LIMITATIONS TO RIGHT OF REFUSAL. Notwithstanding the provisions of
Section 1.1 and 1.2 of this Agreement, Abbott may sell or otherwise assign,
with or without consideration, Shares to any affiliate or successor in
interest of Abbott provided that each such transferee or assignee, prior to
the completion of the sale, transfer, or assignment shall have executed
documents assuming the obligations of Abbott under this Agreement with
respect to the transferred securities.

     2. ASSIGNMENTS AND TRANSFERS; NO THIRD PARTY BENEFICIARIES. This
Agreement and the rights and obligations of the parties hereunder shall inure
to the benefit of, and be binding upon, their respective successors, assigns
and legal representatives, but shall not otherwise be for the benefit of any
third party.

     3. LEGEND. Each existing or replacement certificate for shares now owned
by Abbott





shall bear the following legend upon its face:

       "THE SALE, PLEDGE, HYPOTHECATION, ASSIGNMENT OR TRANSFER OF
       THE SECURITIES REPRESENTED BY THIS CERTIFICATE IS SUBJECT TO
       THE TERMS AND CONDITIONS OF A CERTAIN RIGHT OF FIRST REFUSAL
       AGREEMENT BY AND BETWEEN THE STOCKHOLDER AND THE CORPORATION.
       COPIES OF SUCH AGREEMENT MAY BE OBTAINED UPON WRITTEN REQUEST
       TO THE SECRETARY OF THE CORPORATION."

     4. TERM. This Agreement shall terminate upon the earlier of (i) December
31, 2004 and (ii) the closing of SangStat's sale of all or substantially all
of its assets or the acquisition of SangStat by another entity by means of
merger, consolidation or other transaction or series of related transactions
resulting in the exchange of the outstanding shares of SangStat's capital
stock such that the stockholders of SangStat prior to such transaction own,
directly or indirectly, less than 50% of the voting power of the surviving
entity.

     5.       MISCELLANEOUS.

     5.1 ENTIRE AGREEMENT; CONTROLLING DOCUMENT. This Agreement constitutes
the entire agreement of the parties with respect to the subject matter hereof
and supersedes any and all prior negotiations, correspondence and
understandings between the parties with respect to the subject matter hereof,
whether oral or in writing.

     5.2 COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

     5.3 DELAY AND WAIVER. No delay on the part of either party in exercising
any right under this Agreement shall operate as a waiver of such right. The
waiver by either party of any other term or condition of this Agreement shall
not be construed as a waiver of a subsequent breach or failure of the same
term or condition or a waiver of any other term or condition contained in
this Agreement.

     5.4 ASSIGNMENT: SUCCESSORS AND ASSIGNS. No provision of this Agreement
may be assigned without the prior written consent of the other party hereto.
Except as otherwise provided herein, the terms and conditions of this
Agreement shall inure to the benefit of and be binding upon the respective
successors and assigns of the parties (including transferees of any of the
Initial Shares or Option Shares). Nothing in this Agreement, express or
implied, is intended to confer upon any party other than the parties hereto
or their respective successors and assigns any rights, remedies, obligations,
or liabilities under or by reason of this Agreement, except as expressly
provided in this Agreement.

     5.5 GOVERNING LAW. This Agreement shall be governed by and construed
under the laws of the State of Delaware without regard to conflicts of law
principles.




     5.6 TITLES AND SUBTITLES. The titles and subtitles used in this
Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

     5.7 EXPENSES. Irrespective of whether the Right of First Refusal is
exercised, each party shall pay all costs and expenses that it incurs with
respect to the negotiation, execution, delivery and performance of this
Agreement.

     5.8 ALTERNATIVE DISPUTE RESOLUTION. The parties agree to effectuate all
reasonable efforts to resolve in an amicable manner any and all disputes
between them in connection with this Agreement. The parties agree that any
dispute that arises in connection with this Agreement, which cannot be
amicably resolved informally shall be finally settled as set forth in the
Alternative Dispute Resolution provisions of Exhibit E to the Co-Promotion
Agreement between Abbott and SangStat dated as of May 7, 1999.

     5.9 AMENDMENTS AND WAIVERS. Any term of this Agreement may be amended
and the observance of any term of this Agreement may be waived (either
generally or in a particular instance and either retroactively or
prospectively) only with the written consent of SangStat and Abbott. Any
amendment or waiver effected in accordance with this paragraph shall be
binding upon each holder of any securities purchased under this Agreement at
the time outstanding (including securities into which such securities are
convertible), each future holder of all such securities and SangStat.

     5.10 SEVERABILITY. If one or more provisions of this Agreement are held
to be unenforceable under applicable law, such provision shall be excluded
from this Agreement and the balance of the Agreement shall be interpreted as
if such provision were so excluded and shall be enforceable in accordance
with its terms.

     5.11 FURTHER ASSURANCES. SangStat and Abbott shall do and perform or
cause to be performed all such further acts and things and shall execute and
deliver all such other agreements, certificates, instruments or documents as
the other party may reasonably request from time to time in order to carry
out the intent and purposes of this Agreement and the consummation of the
transactions contemplated by the Agreement. Neither SangStat nor Abbott shall
voluntarily undertake any course of action inconsistent with the satisfaction
of the requirements applicable to them as set forth in this Agreement, and
each shall promptly do all such acts and take all such measures as may be
appropriate to enable them to perform as early as practicable their
obligations under this Agreement.

     5.12 NO THIRD PARTY RIGHTS. Nothing in this Agreement shall create or be
deemed to create any rights in any person or entity not a party to his
Agreement.

     5.13 MUTUAL DRAFTING. This Agreement is the joint product of SangStat
and Abbott and each provision of the Agreement has been subject to
consultation, negotiation and agreement of SangStat and Abbott and their
respective legal counsel and advisers and any rule of construction that a
document shall be interpreted or construed against the drafting party shall
not apply.



                  IN WITNESS WHEREOF, the parties hereto have executed this
Agreement as of the date first written above.




                                SANGSTAT MEDICAL CORPORATION


                                By: _______________________________________
                                    President and Chief Executive Officer

                  Address:      1505 Adams Drive
                                Menlo Park, CA 94025


                                ABBOTT LABORATORIES


                                By:
                                Name:
                                Title:



                  Address: