SOMATOGEN INC
8-K, 1998-03-10
BIOLOGICAL PRODUCTS, (NO DIAGNOSTIC SUBSTANCES)
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                      SECURITIES AND EXCHANGE COMMISSION

                           Washington, D.C. 20549

                                 Form 8-K

                               CURRENT REPORT

                    Pursuant to Section 13 or 15(d) of the
                       Securities Exchange Act of 1934


              Date of Report (Date of earliest event reported):
                              February 23, 1998

                             SOMATOGEN, INC.
         (Exact name of registrant as specified in its charter)


                                Delaware
                       (State of Incorporation)

       0-19423                                      84-0991858
 Commission File Number                  IRS Employer Identification No.)


            2545 Central Avenue,  Suite FD1, Boulder,  CO 80301-2857 
             (Address of principal executive offices and Zip Code)


                                (303) 440-9988
               Registrant's telephone number, including area code:






Somatogen and the Somatogen logo are tradenames of Somatogen,  Inc. Optro(TM) is
a trademark of Somatogen,  Inc. All other brand names or trademarks appearing in
this 8-K are the property of their respective holders.





<PAGE> 2


Item 5.  Other Events.

     On February 24, 1998, Somatogen, Inc. (the "Company") announced that it had
entered into an Agreement and Plan of Merger (the "Merger  Agreement"),  by and
among the Company, Baxter International Inc. ("Baxter") and  RHB1 Acquisition
Corp., a wholly owned subsidiary of Baxter ("RHB1") on February 23, 1998. A copy
of the joint press release announcing the execution of the Merger Agreement,  
Merger Agreement and form of Contingent Payment Rights Agreement are filed
as Exhibits 99.7, 99.8 and 99.9, respectively, to this Form 8-K.

Item 7.  Exhibits.

     99.7  Press Release, dated as of February 24, 1998 entitled "Baxter to 
Acquire Somatogen."

     99.8  Agreement and Plan of Merger, dated February 23, 1998, between
Baxter, RHB1 and Somatogen, Inc.

     99.9  Form of Contingent Payment Rights Agreement, between Baxter and
First Truct National Association.


                                    SIGNATURE

    Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the  
undersigned, thereunto duly authorized.

Dated March 9, 1998


                                            SOMATOGEN, INC.
    
                                            By:   Andre de Bruin
                                            Its:  Chairman, President and CEO





FOR IMMEDIATE RELEASE

                         BAXTER TO ACQUIRE SOMATOGEN

             ACQUISITION OF SOMATOGEN WILL ENHANCE BAXTER'S LONG-TERM
                     POSITION IN HEMOGLOBIN THERAPEUTICS


       DEERFIELD, IL, and BOULDER, CO, Feb. 24, 1998 -- Baxter International
Inc. (NYSE: BAX) and Somatogen (Nasdaq:  SMTG) jointly announced today that they
have  entered into an agreement  under which  Baxter will acquire  Somatogen,  a
biopharmaceutical  company developing recombinant  hemoglobin  technology,  in a
stock-merger  transaction.  The acquisition  will enhance  Baxter's  position in
oxygen-carrying  therapeutics,  or "blood  substitutes," a new class of products
designed to carry oxygen to the vital organs of patients  suffering  acute blood
loss,  potentially  saving lives and reducing  complications for trauma victims,
surgical patients and other critically ill patients.

     Baxter  will pay $9.00 per share in Baxter  common  stock at the closing of
the stock  merger,  plus a contingent  deferred  cash payment of up to $2.00 per
share  based on five  percent  of sales of  certain  future-generation  products
through Dec. 31, 2007.

     "The  acquisition  of Somatogen will  strengthen our long-term  position in
hemoglobin therapeutics, and demonstrates our commitment to being on the leading
edge of technology and innovation in this field," said Harry M. Jansen  Kraemer,
Baxter  president.  "This acquisition will enable us to develop a new technology
platform for the future by allowing us to capitalize on Somatogen's  recombinant
hemoglobin technology to develop next-generation products"

     Thomas  Schmitz,   general  manager  of  Baxter's  Hemoglobin  Therapeutics
Division,  says that Somatogen's  scientific and  technological  expertise is an
excellent complement to Baxter's long-term strategy for hemoglobin therapeutics.

     "We  believe  that  oxygen-carrying   therapeutics  have  a  wide-range  of
potential   clinical    applications,    requiring   products   with   different
characteristics,"   Schmitz  said.  "By  integrating  Baxter's  and  Somatogen's
scientific expertise and technology, we will more quickly and effectively expand
our  capabilities  to develop  future  generations  of  hemoglobin  therapeutics
designed to meet multiple clinical needs in the marketplace."

     The  acquisition  will  be  accounted  for as a  purchase,  which  requires
allocation of the purchase price based on the fair value of  Somatogen's  assets
and liabilities. It is expected that a substantial portion of the purchase price
will be allocated to  Somatogen's  in-process  research and  development  which,
under generally accepted accounting principles,  will be expensed by Baxter upon
closing the transaction. Baxter expects to complete the transaction,  subject to
approval by governmental  authorities and Somatogen shareholders,  in the second
quarter of 1998.

<PAGE> 2

     Complementary Research Strategies

     Baxter's and  Somatogen's  research  programs are both based on hemoglobin,
the  iron-containing  protein in red blood cells that enables blood to transport
oxygen  to  tissues   throughout  the  body.   Baxter's  product,   HemAssist(R)
(Hemoglobin  Crosfumaril)  is derived from human  hemoglobin,  which the company
chemically modifies and subjects to rigorous purification procedures.  Somatogen
uses recombinant technology to develop the human form of hemoglobin. Recombinant
means that the genetic  information for making a therapeutic protein is inserted
into the DNA of a cell.  The DNA then  instructs the cell to produce the desired
protein, in this case a new form of hemoglobin.

     "The  combination  of Baxter's  experience  and extensive  learning in this
field,  with the power of  Somatogen's  recombinant  technology  is an excellent
match for  accelerating  product  development and realizing the potential of our
technology,"  said  Andre de Bruin,  Somatogen  president  and  chief  executive
officer. "Baxter meets  all of the  criteria  for a  strong  corporate  partner,
particularly  the  most  important  condition  --  a  strategic   commitment  to
hemoglobin-based  oxygen  therapeutics.  Our  team of  scientific  and  clinical
researchers is excited about the opportunity to join Baxter's team."

     Clinical Status

     Baxter's  product  currently  is being  tested in  final-stage  (Phase III)
clinical  trials in the  United  States and Europe in  patients  suffering  from
severe  trauma,  and in a Phase III trial in  elective  surgery  patients in the
United  States.  Baxter has  enrolled  more than 1,000  patients in its clinical
program to date. The company  expects to receive market  clearance for HemAssist
in late 1999 or early 2000.

     Hemoglobin  therapeutics have several potential advantages over whole blood
in  critical  medical  situations.  They do not  require  blood  typing or cross
matching,  and therefore can be  administered  immediately to the critically ill
and injured.  They also can be stored for much longer periods of time than whole
blood. Additionally,  hemoglobin therapeutics' ability to redistribute oxygen to
organs most in need is being assessed.

     Baxter International,  through its subsidiaries,  is a global leader in the
development of products and  technologies  related to the blood and  circulatory
system. The company has market-leading positions in four areas: blood therapies,
cardiovascular medicine, kidney-disease therapy and medication delivery. Through
a  combination  of  technological  innovation  and global  expansion,  Baxter is
advancing medical care and improving the lives of millions of people worldwide.

     Somatogen is a biopharmaceutical company engaged in the research, clinical
development and commercialization of genetically engineered hemoglobin-based
products.

     This news release  contains  forward-looking  statements that involve risks
and uncertainties, including those related to the possible inability to complete
Baxter's  acquisition of Somatogen as scheduled,  or at all. Assuming completion
of the  acquisition,  such risks and  uncertainties  include  risks set forth in
Baxter's and  Somatogen's  respective  forms 10-K,  including  risks  concerning
whether any future products will be successfully developed, and thus whether any
amounts will actually be paid under the  contingent  payment rights to be issued
to Somatogen's stockholders as part of the merger consideration.                

                              ------------
     CS First Boston acted as  financial  advisor to Baxter and Lehman  Brothers
acted as financial advisor to Somatogen.











                          AGREEMENT AND PLAN OF MERGER

                                  by and among

                           BAXTER INTERNATIONAL INC.,

                             RHB1 ACQUISITION CORP.

                                       and

                                 SOMATOGEN, INC.

                          Dated as of February 23, 1998










===============================================================================

<PAGE> 2



<TABLE>
<CAPTION>

                                TABLE OF CONTENTS


                                                                                                            Page(s)
<S>       <C>            <C>                                                                                    <C>

ARTICLE I    THE MERGER.........................................................................................6

          Section 1.1    The Merger.............................................................................6
          Section 1.2    Effective Time of the Merger...........................................................6
          Section 1.3    Closing................................................................................6
          Section 1.4    Effects of the Merger..................................................................6
          Section 1.5    Certificate of Incorporation and Bylaws................................................6
          Section 1.6    Directors..............................................................................7
          Section 1.7    Officers...............................................................................7

ARTICLE II    CONVERSION OF SHARES..............................................................................7
          Section 2.1    Merger Consideration...................................................................7
          Section 2.2    Exchange Ratio for Company Stock Options...............................................8
          Section 2.3    Dissenter's Rights.....................................................................9
          Section 2.4    Exchange of Certificates Representing Shares...........................................9
          Section 2.5    Dividends.............................................................................10
          Section 2.6    No Fractional Shares..................................................................10
          Section 2.7    Closing of Company Transfer Books.....................................................10
          Section 2.8    Unclaimed Amounts.....................................................................10
          Section 2.9    Lost Certificates.....................................................................10

ARTICLE III    REPRESENTATIONS AND WARRANTIES
                          OF THE COMPANY.......................................................................11
          Section 3.1    Organization and Qualification; Subsidiaries..........................................11
          Section 3.2    Capitalization........................................................................12
          Section 3.3    Authority.............................................................................13
          Section 3.4    Consents and Approvals; No Violation..................................................13
          Section 3.5    Company SEC Reports...................................................................14
          Section 3.6    Financial Statements..................................................................15
          Section 3.7    Absence of Undisclosed Liabilities....................................................15
          Section 3.8    Absence of Certain Changes............................................................15
          Section 3.9    Taxes.................................................................................16
          Section 3.10   Litigation............................................................................16
          Section 3.11   Employee Benefit Plans; ERISA.........................................................17
          Section 3.12   Environmental Matters.................................................................19
          Section 3.13   Compliance with Applicable Laws.......................................................20
          Section 3.14   Material Contracts....................................................................20
          Section 3.15   Intellectual Property Rights..........................................................20
          Section 3.16   Insurance.............................................................................22
          Section 3.17   Opinion of Financial Advisor..........................................................22
          Section 3.18   Rights Agreement; Takeover Laws.......................................................22
          Section 3.19   Company Disclosure....................................................................22
          Section 3.20   Labor Matters.........................................................................23
          Section 3.21   WARN Act..............................................................................23
          Section 3.22   Transactions with Related Parties.....................................................23
          Section 3.23   Absence of Certain Payments...........................................................24
          Section 3.24   Title to Properties; Absence of Liens and
                                  Encumbrances; Condition of Equipment.........................................24
          Section 3.25   FDA Matters...........................................................................25
          Section 3.26   Registration Statement and Proxy Statement/Prospectus.................................25
          Section 3.27   Brokers...............................................................................25

<PAGE> 3

ARTICLE IV    REPRESENTATIONS AND WARRANTIES
                          OF BAXTER AND MERGER SUB.............................................................26
          Section 4.1    Organization..........................................................................26
          Section 4.2    No Ownership of Company Common Stock..................................................26
          Section 4.3    Capitalization........................................................................26
          Section 4.4    Authority.............................................................................26
          Section 4.5    Baxter Stockholder Approval...........................................................27
          Section 4.6    Consent and Approvals; No Violation...................................................27
          Section 4.7    Merger Sub's Operations...............................................................28
          Section 4.8    Baxter SEC Reports....................................................................28
          Section 4.9    Baxter Disclosure.....................................................................28
          Section 4.10   Baxter Financial Statements...........................................................28
          Section 4.11   Registration Statement and Proxy Statement/Prospectus.................................29
          Section 4.12   Brokers...............................................................................29
          Section 4.13   Shares................................................................................29

ARTICLE V    COVENANTS OF THE COMPANY..........................................................................29
          Section 5.1    Ordinary Course.......................................................................29
          Section 5.2    Rule 145 Affiliates...................................................................31
          Section 5.3    No Solicitation.......................................................................31
          Section 5.4    No WARN Act Activities................................................................32
          Section 5.5    Stockholders' Meeting.................................................................33
          Section 5.6    Rights Plan...........................................................................33
          Section 5.7    Company Stock Option Plans............................................................33

ARTICLE VI      COVENANTS OF BAXTER AND MERGER SUB.............................................................33
          Section 6.1    Directors' and Officers' Indemnification and Insurance................................33
          Section 6.2    Blue Sky..............................................................................34
          Section 6.3    CPR Agreement.........................................................................34
          Section 6.4    NYSE Listing..........................................................................35
          Section 6.5    Employment Matters....................................................................35

<PAGE> 4

ARTICLE VII    MUTUAL COVENANTS................................................................................35
          Section 7.1    Access to Information; Confidentiality................................................35
          Section 7.2    HSR Act...............................................................................36
          Section 7.3    Consents and Approvals................................................................36
          Section 7.4    Publicity.............................................................................36
          Section 7.5    Filings with the Commission...........................................................36
          Section 7.6    Advice of Changes.....................................................................37
          Section 7.7    Additional Agreements.................................................................37
          Section 7.8    Tax Matters...........................................................................37

ARTICLE VIII    CONDITIONS TO CONSUMMATION OF
                             THE MERGER........................................................................37
          Section 8.1    Conditions to Each Party's Obligation to
                                Effect the Merger..............................................................37
          Section 8.2    Conditions of Obligations of Baxter and Merger Sub....................................38
          Section 8.3    Conditions of Obligations of the Company..............................................39

ARTICLE IX    TERMINATION, AMENDMENT AND WAIVER................................................................40
          Section 9.1    Termination...........................................................................40
          Section 9.2    Effect of Termination and Abandonment.................................................41

ARTICLE X    GENERAL PROVISIONS................................................................................41
          Section 10.1   Fees and Expenses.....................................................................41
          Section 10.2   Amendment and Modification............................................................42
          Section 10.3   Nonsurvival of Representations and Warranties.........................................42
          Section 10.4   Notices...............................................................................42
          Section 10.5   Definitions; Interpretation...........................................................43
          Section 10.6   Specific Performance..................................................................43
          Section 10.7   Counterparts..........................................................................43
          Section 10.8   Entire Agreement; No Third-Party Beneficiaries........................................43
          Section 10.9   Severability..........................................................................43
          Section 10.10  Governing Law.........................................................................43
          Section 10.11  Assignment............................................................................43


ANNEX A..Form of CPR Certificate
ANNEX B..Form of Affiliate Letter
ANNEX C..Form of Opinion of Cooley Godward LLP
ANNEX D..Form of Opinion of Thomas J. Sabatino, Jr., General Counsel of Baxter

</TABLE>

<PAGE> 5




                          AGREEMENT AND PLAN OF MERGER



                  AGREEMENT  AND PLAN OF MERGER,  dated as of February  23, 1998
(this  "Agreement"),   by  and  among  Baxter  International  Inc.,  a  Delaware
corporation  ("Baxter"),  RHB1 Acquisition  Corp., a Delaware  corporation and a
wholly  owned  subsidiary  of Baxter  ("Merger  Sub"),  and  Somatogen,  Inc., a
Delaware corporation (the "Company").

                  WHEREAS,  it is the  intention of the parties that the Company
merge with and into Merger Sub (the  "Merger"),  with Merger Sub  surviving as a
wholly owned subsidiary of Baxter;

                  WHEREAS, the Board of Directors of each of Baxter,  Merger Sub
and the  Company  has  determined  that the  transactions  contemplated  by this
Agreement,  including,  without limitation, the Merger, are advisable and in the
best  interest  of  their  respective  corporations  and  stockholders  and have
approved this Agreement;

                  WHEREAS,  as a  condition  to the  willingness  of Baxter  and
Merger  Sub to enter  into this  Agreement,  Eli Lilly and  Company,  an Indiana
corporation and a stockholder of the Company,  and Merger Sub shall have entered
into a Voting Agreement,  dated the date hereof, providing,  among other things,
that such  stockholder  will  vote all of the  shares  of  capital  stock of the
Company owned by it in favor of the Merger; and

                  WHEREAS,  each of  Baxter  and the  Company  desires  that the
merger  qualify as a  reorganization  under Section 368 of the Internal  Revenue
Code of 1986, as amended (the "Code").

                  NOW,  THEREFORE,  in  consideration  of the  foregoing and the
respective  representations,  warranties,  covenants  and  agreements  set forth
herein, the parties hereto, intending to be legally bound, agree as follows:



<PAGE> 6


                                    ARTICLE I

                                   THE MERGER

                  Section  1.1 The  Merger.  Upon the terms and  subject  to the
conditions of this Agreement, at the Effective Time (as defined in Section 1.2),
in  accordance  with the General  Corporation  Law of the State of Delaware (the
"DGCL"), the Company shall be merged with and into Merger Sub in accordance with
this Agreement and the separate existence of the Company shall cease. Merger Sub
shall be the surviving corporation in the Merger (hereinafter sometimes referred
to as the "Surviving Corporation").

                  Section 1.1 Effective  Time of the Merger.  Upon the terms and
subject to the conditions  hereof, a certificate of merger (the  "Certificate of
Merger")  shall be duly  prepared,  executed and  acknowledged  by the Surviving
Corporation  and thereafter  delivered to the Secretary of State of the State of
Delaware,  for filing,  on the Closing  Date (as  defined in Section  1.3).  The
Merger shall become effective as of the date and at such time as the Certificate
of  Merger,  pursuant  to  Section  251 of the  DGCL,  and any  other  documents
necessary to effect the Merger in  accordance  with the DGCL are duly filed with
the  Secretary of State of the State of Delaware or at such  subsequent  date or
time as shall be agreed by the  Company  and  Merger  Sub and  specified  in the
Certificate  of Merger (the time the Merger  becomes  effective  pursuant to the
DGCL being referred to herein as the "Effective Time").

                  Section 1.2 Section  Closing.  Subject to the  satisfaction or
waiver of all of the conditions to closing contained in Article VIII hereof, the
closing  of the Merger  (the  "Closing")  will take place at 8:00 a.m.,  Chicago
time, on a date to be specified by the parties, which shall be no later than the
second  Business Day (as defined below) after the  satisfaction or waiver of the
conditions  to Closing  contained  in Article  VIII,  at the offices of Skadden,
Arps, Slate, Meagher & Flom (Illinois), 333 West Wacker Drive, Chicago, Illinois
60606-1285,  unless another date or place is agreed to in writing by the parties
hereto.  The date and time at which the Closing  occurs is referred to herein as
the "Closing Date."  "Business Day" shall mean any day other than a Saturday,  a
Sunday  or a day on  which  banking  institutions  in New  York  City,  Chicago,
Illinois or Denver, Colorado are not required to be open.

                  Section 1.4 Effects of the Merger.  The Merger  shall have the
effects set forth in the DGCL. Without limiting the generality of the foregoing,
and  subject  thereto,  at the  Effective  Time,  all  the  properties,  rights,
privileges,  powers and  franchises  of the Company and Merger Sub shall vest in
the Surviving Corporation,  and all debts, liabilities and duties of the Company
and Merger Sub shall become the debts,  liabilities  and duties of the Surviving
Corporation.

                  Section 1.5  Certificate  of  Incorporation  and  Bylaws.  (a)
Subject to Section 6.1, the  certificate  of  incorporation  of Merger Sub as in
effect  immediately  prior to the  Effective  Time shall be the  certificate  of
incorporation of the Surviving  Corporation until amended in accordance with the
terms thereof and with applicable law.

                           (b)      Subject to  Section  6.1,  the bylaws of 
Merger Sub in effect at the Effective  Time shall be the bylaws of the Surviving
Corporation  until  amended  in  accordance  with  the  terms  thereof  and with
applicable law.


<PAGE> 7

                  Section  1.6  Directors.  The  directors  of Merger Sub at the
Effective Time shall be the initial directors of the Surviving Corporation, each
to hold office from the Effective  Time in accordance  with the  certificate  of
incorporation  and  bylaws  of the  Surviving  Corporation  and until his or her
successor is duly elected and qualified.

                  Section  1.7  Officers.  The  officers  of the  Company at the
Effective Time shall be the initial officers of the Surviving Corporation,  each
to hold office from the Effective  Time in accordance  with the  certificate  of
incorporation  and  bylaws  of the  Surviving  Corporation  and until his or her
successor is duly appointed and qualified.

                                   ARTICLE II

                              CONVERSION OF SHARES

                  Section 2.1       Merger  Consideration.  As of the  Effective
Time,  by virtue of the Merger and without any action on the part of Merger Sub,
the Company or the holder thereof:

                           (a)      Each share of Common  Stock,  par value 
$.001 per share, of the Company (the "Company Common Stock"),  held by Baxter or
any  subsidiary  of Baxter shall be cancelled and retired and cease to exist and
no consideration shall be delivered in exchange therefor.

                           (b) Each share of  Company  Common  Stock  issued and
outstanding  immediately  prior to the Effective Time,  other than (x) shares of
Company  Common Stock to be cancelled in accordance  with Section 2.1(a) and (y)
Dissenting Shares (as defined in Section 2.3), shall be converted into the right
to receive, without withholding or deduction on account of any tax, levy, impost
or other governmental charge:

                                    (i) the  fraction  of a  share  (calculated 
and rounded to the nearest  ten-thousandth  of one share) of Common  Stock,  par
value $1 per share, of Baxter  ("Baxter  Common Stock"),  the numerator of which
fraction  shall be (A)  $9.00,  and the  denominator  of which  shall be (B) the
Baxter   Stock  Price  (as  defined  in  Section   2.1(c)   below)  (the  "Share
Consideration").

                                    (ii) a  Contingent  Payment  Right (a "CPR")
(as defined in the certificate representing the CPR substantially in the form of
Annex A attached hereto (the "CPR  Certificate")).  The CPR Certificates will be
issued by Baxter  pursuant to a Contingent  Payment  Rights  Agreement (the "CPR
Agreement")  to  be  entered  into  between  Baxter  and  First  Trust  National
Association,  a national association (the "Trustee"). The consideration referred
to in (subparagraphs (i) and (ii) of this Section 2.1(b) is hereinafter referred
to as the "Merger Consideration").

                  All  such  shares  of  Company  Common  Stock  converted,   in
accordance with Section 2.1, into the right to receive Merger Consideration (the
"Shares"),  when  so  converted,  shall  no  longer  be  outstanding  and  shall
automatically be cancelled and retired and shall cease to exist, and each holder
of a certificate  formerly  representing any such Shares (each, a "Certificate")
shall  cease to have any rights  with  respect  thereto,  except to receive  the
Merger   Consideration,   without  interest  thereon,  upon  surrender  of  such
Certificates.

<PAGE> 8

                           (c)  For purposes of calculating the Share Considera-
tion,  the "Baxter Stock Price" shall be an amount equal to the average  closing
sale price of a share of a Baxter Common Stock on United States stock  exchanges
as reported in The Wall Street Journal under the caption New York Stock Exchange
("NYSE") Composite  Transactions or, if not available,  such other authoritative
publication  as may be reasonably  selected by Baxter,  for the ten  consecutive
trading days ending on and  including the fifth trading day prior to the Closing
Date.  In the event Baxter  changes (or  establishes a record date for changing)
the number or kind of shares of Baxter Common Stock issued and outstanding prior
to  the  Effective  Time  as  a  result  of  a  stock  split,   stock  dividend,
distribution,  recapitalization,  reclassification,  reorganization  or  similar
transaction  with respect to the outstanding  Baxter Common Stock and the record
date therefor  shall be prior to the  Effective  Time,  the Share  Consideration
shall be proportionately  adjusted in such manner as Baxter,  Merger Sub and the
Company shall agree, which adjustment may include, as appropriate,  the issuance
of securities,  property or cash on the same basis as any of the foregoing shall
have been issued,  distributed or paid to the holders of shares of Baxter Common
Stock generally.

                           (d) Each  share of Common  Stock,  par value $.01 per
share, of Merger Sub issued and outstanding  immediately  prior to the Effective
Time shall be converted into and become one fully paid and  nonassessable  share
of Common Stock, par value $.01 per share, of the Surviving Corporation.

                  Section 2.2 Exchange  Ratio for Company  Stock  Options.  Each
employee,  consultant  and  director or other option  (individually,  a "Company
Stock Option") not previously  exercised,  outstanding  immediately prior to the
Effective  Time and granted under the  Company's (i) Amended and Restated  Stock
Option Plan, (ii) Amended and Restated  Nonemployee  Director Stock Option Plan,
(iii)  Amended and  Restated  Consultants  Stock  Option Plan and (iv) any other
stock option plan or arrangement of the Company  (collectively,  (other than the
Company's  Employee  Stock Purchase Plan (the "ESPP")) the "Company Stock Option
Plans"),  whether vested or unvested, will be exchanged or cancelled as provided
in this Section 2.2. Each Company  Stock Option having an exercise  price of $11
or more that is  outstanding  immediately  prior to the Effective  Time shall be
cancelled  immediately  prior to the Effective Time for no  consideration.  Each
Company  Stock  Option (in the case of persons who are  employed by or providing
services to the Company as of the Effective Time, whether vested or unvested and
in the case of persons who are no longer  employed by or  providing  services to
the Company,  as of the  Effective  Time,  only to the extent such Company Stock
Option  was vested on the date such  person's  employment  or  service  with the
Company  ceased)  having an exercise  price of less than $9 that is  outstanding
immediately prior to the Effective Time shall be exchanged  immediately prior to
the Effective  Time for (x) payment by the Company to the holder of such Company
Stock Option, of an amount in cash equal to (1) the product of $9 and the number
of shares of Company Common Stock subject to such Common Stock Option,  less (2)
the  aggregate  exercise  price of such Common Stock Option and (y) the right to
receive one CPR per share of Company  Common Stock covered by such Company Stock
Option. Each Company Stock Option (in the case of persons who are employed by or
providing  services to the Company as of the Effective  Time,  whether vested or
unvested  and in the case of persons who are no longer  employed by or providing
services  to the  Company,  as of the  Effective  Time,  only to the extent such
Company Stock Option was vested on the date such person's  employment or service
with the Company  ceased) having an exercise price that is greater than or equal
to $9 and less than $11 that is outstanding  immediately  prior to the Effective
Time, shall be exchanged  immediately  prior to the Effective Time for the right
to receive one CPR per share of Company  Common  Stock  covered by such  Company
Stock  Option.  The  purchase  period (as  defined  in the ESPP) (the  "Purchase
Period") in effect under ESPP shall terminate immediately prior to the Effective
Time, and the payroll  deductions  accumulated during such Purchase Period shall
then be applied to the purchase of shares of Company  Common Stock in accordance
with the ESPP (subject to participants'  right to withdraw from such plan at any
time).  Any shares of  Company  Common  Stock so issued  under the ESPP shall be
converted  into the right to receive  Merger  Consideration  in accordance  with
Section  2.1(b).  The  Company  and Baxter  shall  take such  action as shall be
required or necessary  under the terms of the ESPP, and the Company Stock Option
Plans and any other  agreements  pursuant  to which a Company  Stock  Option was
subject  immediately prior to the Effective Time to effectuate the provisions of
this Section 2.2, including,  but not limited to, the amendment of such plans or
agreements.


<PAGE> 9

                  Section 2.3 Dissenter's  Rights.  Notwithstanding  anything in
this  Agreement to the  contrary,  shares of Company  Common  Stock  outstanding
immediately  prior to the Effective  Time and held by a holder who has not voted
in favor of the Merger or consented  thereto in writing and who has  delivered a
written  demand for appraisal of such shares in  accordance  with Section 262 of
the DGCL, if such Section 262 provides for  appraisal  rights for such shares in
the  Merger  ("Dissenting  Shares"),  shall not be  converted  into the right to
receive the Merger  Consideration,  as provided in Section 2.1(b) hereof, unless
and until such holder  fails to perfect or  effectively  withdraws  or otherwise
loses his right to  appraisal  and payment  under  Section 262 of the DGCL.  If,
after the  Effective  Time,  any such  holder  fails to perfect  or  effectively
withdraws  or loses  his  right  to  appraisal,  such  Dissenting  Shares  shall
thereupon be treated as if they had been converted as of the Effective Time into
the right to receive the Merger  Consolidation to which such holder is entitled,
without  interest or dividends  thereon.  The Company  shall give Baxter  prompt
notice of any demands received by the Company for appraisal of shares of Company
Common Stock, and Baxter shall have the right to participate in all negotiations
and proceedings  with respect to such demands.  Prior to the Effective Time, the
Company  shall not,  except with the prior written  consent of Baxter,  make any
payment with respect to or offer to settle, any such demands.

                  Section 2.4 Exchange of Certificates  Representing Shares. (a)
Baxter shall  deposit,  or shall cause to be deposited,  with an exchange  agent
selected by Baxter and  reasonably  satisfactory  to the Company (the  "Exchange
Agent"),  for the benefit of the holders of Shares,  for exchange in  accordance
with  this  Article  II,  (i) on the date of the  Effective  Time,  certificates
representing   the  number  of  shares  of  Baxter  Common  Stock  and  the  CPR
Certificates issuable as part of the Merger Consideration, and (ii) from time to
time, cash to be paid in lieu of the issuance of fractional  shares, as provided
in Section 2.6 and as requested by the Exchange  Agent,  and dividends and other
distributions  payable  in  respect  of the  shares  of Baxter  Common  Stock as
provided in Section 2.5 (such cash, CPR Certificates and certificates for shares
of Baxter Common Stock, if any,  together with dividends or  distributions  with
respect  thereto being  hereinafter  referred to  collectively  as the "Exchange
Fund").

                           (b)      Promptly  after the Effective  Time,  Baxter
shall cause the Exchange  Agent to mail (or deliver at its principal  office) to
each  holder  of record of  Shares  and to each  holder of record of  Dissenting
Shares (i) a letter of  transmittal  which shall (A) specify that delivery shall
be effected,  and risk of loss and title to the  Certificates  shall pass,  only
upon delivery of the  Certificates to the Exchange Agent and (B) be in customary
form  and  (ii)   instructions  for  use  in  effecting  the  surrender  of  the
Certificates.  Upon surrender of a Certificate for  cancellation to the Exchange
Agent,  together  with a letter of  transmittal,  duly executed and completed in
accordance with the instructions  thereto,  the holder thereof shall be entitled
to receive in exchange  therefor  that portion of the  Exchange  Fund which such
holder has the right to receive  pursuant to the  provisions of this Article II,
after giving  effect to any required  withholding  tax, and the  Certificate  so
surrendered shall forthwith be cancelled. No interest will be paid or accrued on
the cash or other consideration to be paid as part of the Merger  Consideration.
In the  event  of any  transfer  of  ownership  of  Shares  which  has not  been
registered in the transfer records of the Company (an "Unregistered  Transfer"),
a CPR Certificate and  certificates  representing the proper number of shares of
Baxter  Common  Stock,  if any,  together with a check in an amount equal to the
cash  component,  if any, of the Exchange Fund, will be issued to the transferee
of the  Unregistered  Transfer when the Certificate is presented to the Exchange
Agent,  accompanied  by all  documents  required  to  evidence  and  effect  the
Unregistered  Transfer and to evidence that any applicable  stock transfer taxes
associated with such Unregistered Transfer were paid.


<PAGE> 10

                 Section 2.5  Dividends.  No dividends  or other  distributions
with respect to shares of Baxter  Common Stock  constituting  part of the Merger
Consideration  shall be paid to the  holder  of any  unsurrendered  Certificates
until such  Certificates  are  surrendered as provided in Section 2.4. Upon such
surrender,  all  dividends  and other  distributions  payable  in respect of the
shares of Baxter  Common  Stock to be issued  in  exchange  therefor,  on a date
subsequent to, and in respect of a record date after the Effective  Time,  shall
be  paid,  without  interest,  to the  person  in whose  name  the  certificates
representing  the shares of Baxter  Common  Stock into  which such  Shares  were
converted are  registered or as otherwise  directed by that person.  In no event
shall the person entitled to receive such dividends or distributions be entitled
to receive interest on any such dividends or distributions.

                 Section 2.6 No Fractional  Shares.  No  certificates  or scrip
representing  fractional  shares of Baxter Common Stock shall be issued upon the
surrender of  Certificates  pursuant to this  Article II and no dividend,  stock
split or other  change in the capital  structure  of Baxter  shall relate to any
fractional  interest,  and such fractional interests shall not entitle the owner
thereof  to vote or to any  rights  of a  security  holder.  In lieu of any such
fractional interest,  each holder of a Certificate who would otherwise have been
entitled  to a fraction  of a share of Baxter  Common  Stock upon  surrender  of
Certificates  pursuant to this Article II shall be paid cash upon such surrender
in an amount  equal to the  product of such  fraction  multiplied  by the Baxter
Stock Price.

                  Section  2.7  Closing  of  Company   Transfer  Books.  At  the
Effective  Time,  the stock transfer books of the Company shall be closed and no
transfer of Shares  shall  thereafter  be made.  If, after the  Effective  Time,
Certificates are presented to the Surviving Corporation, they shall be cancelled
and exchanged as provided in this Article II.

                  Section 2.8  Unclaimed  Amounts.  Any portion of the  Exchange
Fund which  remains  unclaimed  by the former  stockholders  of the  Company six
months after the  Effective  Time shall be  delivered  by the Exchange  Agent to
Baxter. Any former stockholders of the Company who have not theretofore complied
with this  Article II shall  thereafter  look only to Baxter for  payment of the
Merger  Consideration,  cash in lieu of fractional  shares, and unpaid dividends
and  distributions  in respect of shares of Baxter Common Stock  deliverable  as
part of the Merger Consideration, each as determined pursuant to this Agreement,
in all cases  without  any  interest  thereon.  None of  Baxter,  the  Surviving
Corporation, the Exchange Agent or any other Person will be liable to any former
holder of Shares for any amount properly delivered to a public official pursuant
to applicable abandoned property, escheat or similar laws.

                  Section 2.9 Lost  Certificates.  In the event any  Certificate
shall have been lost,  stolen or  destroyed,  upon the making and delivery of an
affidavit  of that fact by the person  claiming  such  Certificate  to have been
lost, stolen or destroyed and, if required by Baxter, the posting by such person
of a bond in such  reasonable  amount as Baxter may direct as indemnity  against
any claim that would be made against the Company,  the Surviving  Corporation or
Baxter  with  respect to such  Certificate,  the  Exchange  Agent shall issue in
exchange  for such lost,  stolen or  destroyed  Certificate  the  portion of the
Exchange Fund deliverable in respect thereof pursuant to this Article II.


<PAGE> 11

                                   ARTICLE III

                  REPRESENTATIONS AND WARRANTIES OF THE COMPANY

                  Except as  otherwise  disclosed  to Baxter and Merger Sub in a
letter  delivered  to them prior to the  execution  hereof  (which  letter shall
contain appropriate  references to identify the specific section herein to which
the information in such letter relates) (the "Company  Disclosure Letter") or as
disclosed in the Company SEC Reports (as defined herein), the Company represents
and warrants to Baxter and Merger Sub as follows:

                  Section 3.1 Organization and Qualification;  Subsidiaries. (a)
The  Company is a  corporation  duly  organized,  validly  existing  and in good
standing  under  the laws of the  State of  Delaware,  is duly  qualified  to do
business as a foreign  corporation and is in good standing in the  jurisdictions
listed on Section 3.1(a) of the Company Disclosure  Letter,  which includes each
jurisdiction in which the character of the Company's properties or the nature of
its business makes such  qualification  necessary,  except in jurisdictions,  if
any, where the failure to be so qualified would not result in a Material Adverse
Effect (as defined  below).  The Company has all  requisite  corporate  or other
power and  authority  to own,  use or lease its  properties  and to carry on its
business as it is now being  conducted.  The Company has  delivered  to Baxter a
complete  and  correct  copy  of  its  Amended  and  Restated   Certificate   of
Incorporation  (the  "Certificate  of   Incorporation")   and  its  Bylaws  (the
"Bylaws"),  each as  currently  in effect.  The Company is not in default in any
material respect in the performance, observation or fulfillment of any provision
of the Certificate of Incorporation or the Bylaws.

                           (b)      No Person (as defined below) is a Subsidiary
(as defined below).

                           (c) For purposes of this  Agreement,  (i) a "Material
Adverse Effect" shall mean any event,  circumstance,  condition,  development or
occurrence,   individually  or  in  the  aggregate,  causing,  resulting  in  or
reasonably  likely to have a material  adverse  effect on the  business  (as now
conducted  or as now  proposed  by the  Company  to be  conducted),  results  of
operations  or  financial  condition  of  the  Company  other  than  any  event,
circumstance,  development or occurrence (A) arising from or relating to general
business or economic conditions,  (B) relating to or affecting the biotechnology
industry  generally,  (C) relating to or affecting the  hemoglobin-based  oxygen
therapeutics   industry   generally,   (D)  arising  from  or  relating  to  any
pre-clinical trials or studies conducted by the Company, and (E) arising from or
relating to the development,  discovery or  commercialization  of any present or
proposed  technology,  processes or product that is (or that may  reasonably  be
expected to be) competitive with or superior to any of the technology, processes
or products of the Company,  (ii)  "Subsidiary"  shall mean, with respect to any
party,  any  corporation  or  other   organization,   whether   incorporated  or
unincorporated,  of which (x) at least 50 percent or more of the  securities  or
other  interests  having  voting  power  to  elect a  majority  of the  board of
directors  or  others   performing   similar  functions  with  respect  to  such
corporation or other  organization is directly or indirectly owned or controlled
by such  party or by any one or more of its  subsidiaries,  or by such party and
one or more of its  subsidiaries,  or (y) such party or any other  subsidiary of
such party is a general partner (excluding such partnerships where such party or
any  subsidiary  of such party do not have a majority of the voting  interest in
such  partnership),  and (iii) "Person" shall mean any corporation,  individual,
limited  liability  company,  joint stock company,  joint venture,  partnership,
unincorporated  association,  governmental  regulatory entity, country, state or
political subdivision thereof, trust, municipality or other entity.

<PAGE> 12

                  Section 3.2  Capitalization.  (a) The authorized capital stock
of the Company consists of 10,000,000 shares of Preferred Stock, par value $.001
per share ("Company  Preferred Stock"),  and 35,000,000 shares of Company Common
Stock, of which (i) 4,525,960  shares are reserved for issuance upon exercise of
outstanding Company Stock Options under the Company's Amended and Restated Stock
Option Plan; (ii) 300,000 shares are reserved for issuance under the ESPP; (iii)
180,000  shares are  reserved  for  issuance  under the  Company's  Amended  and
Restated  Consultants  Stock Option Plan;  (iv) 470,000  shares are reserved for
issuance  under the Company's  Amended and Restated  Nonemployee  Director Stock
Option  Plan and (v)  35,000  shares  are  reserved  for  issuance  under  other
non-employee  stock option  agreements.  As of December 31, 1997, (A) 20,921,839
shares of Company Common Stock were issued and  outstanding,  of which no shares
of  Company  Common  Stock  were held in  treasury,  (B) no  shares  of  Company
Preferred Stock were issued or outstanding,  (C) 2,593,433 Company Stock Options
were issued and  outstanding  under the  Company's  Amended and  Restated  Stock
Option Plan; (D) 61,000 Company Stock Options were issued and outstanding  under
the Company's  Amended and Restated  Consultants  Stock Option Plan; (E) 201,250
Company Stock Options were issued and  outstanding  under the Company's  Amended
and Restated Nonemployee Director Stock Option Plan and (F) 35,000 Company Stock
Options  were issued and  outstanding  under  other  non-employee  stock  option
agreements.  Other than rights  issued under the Rights  Agreement,  dated as of
June 5, 1997 (the  "Rights  Agreement"),  by and  between  the Company and Chase
Mellon  Shareholder  Services,  L.L.C., no agreement or other document grants or
imposes  on any  shares  of the  Company  Common  Stock any  right,  preference,
privilege or restriction  with respect to the  transaction  contemplated  hereby
(including,  without  limitation,  any rights of first  refusal)  other than the
right to vote on the  Merger.  All of the issued and  outstanding  shares of the
Company  Common  Stock are,  and all shares of Company  Common Stock that may be
issued pursuant the ESPP or to the exercise of outstanding Company Stock Options
will be, when issued in  accordance  with the terms  thereof,  duly  authorized,
validly issued,  fully paid,  nonassessable and free of preemptive rights. There
are no bonds,  debentures,  notes or other  indebtedness  having  general voting
rights (or convertible  into securities  having such rights)  ("Voting Debt") of
the Company issued and outstanding.  There are no stock appreciation rights with
respect to the Company  Common Stock  (each,  a "SAR")  issued and  outstanding.
Except as otherwise  permitted  or  contemplated  by this  Agreement or upon the
exercise or  termination  of an  outstanding  Company Stock Option in accordance
with its terms as set  forth  above,  (x)  there  are no  shares of the  Company
authorized,  issued  or  outstanding  and (y)  there  are no  existing  options,
warrants, calls, preemptive rights,  subscriptions or other rights,  agreements,
arrangements  or  commitments  of any character  (including  without  limitation
"earn-out"  arrangements)  obligating the Company to issue,  transfer or sell or
cause to be  issued,  transferred  or sold any  shares of or Voting  Debt of, or
other  equity  interests  in,  or any  interest  relating  to or whose  value is
dependent  on the value of the equity  interests  in, the Company or  securities
convertible  into or  exchangeable  for  such  shares  or  equity  interests  or
obligations  of the  Company  to grant,  extend or enter  into any such  option,
warrant,  call,   subscription  or  other  right,   agreement,   arrangement  or
commitment.  There are no outstanding  contractual obligations of the Company to
repurchase,  redeem or otherwise  acquire any shares of the Company or affiliate
of the  Company or to  provide  funds to make any  investment  (in the form of a
loan, capital contribution or otherwise) in any other entity.

                           (b)    There are no voting trusts or other agreements
or  understandings to which the Company is a party with respect to the voting of
the shares of the Company.  Except as expressly  contemplated by this Agreement,
the Company  will not be required to redeem,  repurchase  or  otherwise  acquire
shares  of  capital  stock  of the  Company,  as a  result  of the  transactions
contemplated by this Agreement.

<PAGE> 13

                  Section 3.3 Authority.  The Company has full  corporate  power
and authority to execute and deliver this Agreement and,  subject to approval of
this  Agreement  by the  holders of a majority  of the shares of Company  Common
Stock  outstanding on the record date to be established  for the special meeting
of the  stockholders  of the  Company to vote on the Merger as  contemplated  by
Section 5.6 hereof (the "Special  Meeting").  The execution and delivery of this
Agreement and the  consummation of the transactions  contemplated  hereby on the
part of the Company have been duly and validly authorized by the Company's Board
of Directors,  and no other corporate proceedings on the part of the Company are
necessary,  as a  matter  of law  or  otherwise,  for  the  consummation  of the
transactions  contemplated  hereby, other than the adoption of this Agreement by
the Company's  stockholders at the Special Meeting. This Agreement has been duly
and  validly  executed  and  delivered  by the  Company  and,  assuming  the due
authorization,  execution  and delivery of this  Agreement by each of Baxter and
Merger Sub, is a valid and binding agreement of the Company, enforceable against
it in  accordance  with its  terms,  except to the extent  that the  enforcement
thereof  may  be  limited  by  (i)   bankruptcy,   insolvency,   reorganization,
moratorium,  fraudulent  conveyance  or other  similar  laws now or hereafter in
effect  relating to  creditor's  rights  generally,  (ii) general  principles of
equity  (regardless of whether such enforcement is considered in a proceeding at
law or in equity and (iii) the remedy of specific performance and injunctive and
other forms of equitable  relief may be subject to the  discretion  of the court
before which any enforcement proceeding therefor may be brought.

                  Section  3.4  Consents  and  Approvals;   No  Violation.   The
execution and delivery of this Agreement by the Company, the consummation by the
Company  of the  transactions  contemplated  hereby and the  performance  by the
Company of its obligations hereunder will not:

                           (a)      conflict  with or result in any breach of
any provision of the  Certificate  of Incorporation or the Bylaws;

                           (b)      require  any  consent,   approval,  order,  
authorization or permit of, or registration, filing with or notification to, any
court,  governmental or regulatory authority or agency (a "Governmental Entity")
or  any  private  third  party,  except  for  (i)  the  filing  of a  pre-merger
notification  and  report  form  by  the  Company  under  the  Hart-Scott-Rodino
Antitrust  Improvements Act of 1976, as amended (the "HSR Act"), (ii) the filing
with the Securities and Exchange  Commission (the  "Commission")  of (A) a proxy
statement  relating to the  Special  Meeting to be held in  connection  with the
transactions  contemplated  by this  Agreement  (together  with  any  amendments
thereof  or  supplements  thereto,  the "Proxy  Statement/Prospectus"),  if such
approval is  required by law and (B) such  reports  under  Section  13(a) of the
Securities and Exchange Act of 1934, as amended (the "Exchange  Act"), as may be
required in connection  with this  Agreement and the  transactions  contemplated
hereby and (iii) the filing of the  Certificate  of Merger with the Secretary of
State of the State of Delaware,  (iv) the delivery of a prospectus supplement to
holders of Company Stock Options pursuant to the applicable  securities laws and
(v) such  other  consents,  approvals,  orders,  authorizations,  registrations,
declarations  and  filings  which if not  obtained or made would have a Material
Adverse  Effect  or a  material  adverse  effect  on the  Company's  ability  to
consummate the transactions contemplated by this Agreement;


<PAGE> 14

                           (c)      result in any  violation  of or the  breach
of or constitute a default (with notice or lapse of time or both) under (or give
rise to any right of  termination,  cancellation  or  acceleration or guaranteed
payments under or to, a loss of a material  benefit or result in the creation or
imposition  of a lien under) any of the terms,  conditions  or provisions of any
note,  lease,  mortgage,  indenture,  license,  agreement or other instrument or
obligation to which the Company is a party or by which the Company or any of its
properties  or  assets  may be  bound,  except  for such  violations,  breaches,
defaults, or rights of termination,  cancellation or acceleration, losses or the
imposition of liens as to which requisite waivers or consents have been obtained
or will be obtained prior to the Effective Time or which, individually or in the
aggregate,  would not (i) result in a Material  Adverse Effect,  (ii) materially
impair  the  ability  of the  Company  to  perform  its  obligations  under this
Agreement  or  (iii)  prevent  the  consummation  of  any  of  the  transactions
contemplated by this Agreement;

                           (d)      violate  the provisions  of any order, writ,
injunction,  judgment,  decree,  statute,  rule or regulation  applicable to the
Company,  in such a manner as to (i) result in a Material  Adverse Effect,  (ii)
materially  impair the ability of the Company to perform its  obligations  under
this  Agreement or (iii)  prevent the  consummation  of any of the  transactions
contemplated by this Agreement; or

                           (e)      result in the creation of any lien,  charge 
or  encumbrance  upon any shares of capital  stock,  properties or assets of the
Company  under any agreement or instrument to which the Company is a party or by
which the  Company  is bound,  in such a manner as to (i)  result in a  Material
Adverse Effect, (ii) materially impair the ability of the Company to perform its
obligations under this Agreement or (iii) prevent the consummation of any of the
transactions contemplated by this Agreement.

                  Section 3.5 Company  SEC  Reports.  The Company has filed with
the  Commission,  and has heretofore  made available to Baxter true and complete
copies  of,  each  form,  registration  statement,  report,  schedule,  proxy or
information  statement  and  other  document,  as  amended  (including  exhibits
thereto),  including,  without  limitation,  its Annual Reports to  Stockholders
incorporated  by  reference  in  certain  of such  reports,  but  excluding  any
preliminary  proxy  materials  and  pre-effective   amendments  to  registration
statements,  required to be filed with the Commission  since June 30, 1995 under
the Securities Act of 1933, as amended (the  "Securities  Act"), or the Exchange
Act (collectively,  the "Company SEC Reports").  As of the respective dates such
Company SEC Reports were filed or, if any such Company SEC Reports were amended,
as of the date such  amendment  was  filed,  each of the  Company  SEC  Reports,
including,  without limitation,  any financial  statements or schedules included
therein,   (a)  complied,   in  all  material  respects,   with  all  applicable
requirements of the Securities Act and the Exchange Act, as the case may be, and
the applicable  rules and regulations  promulgated  thereunder,  and (b) did not
contain any untrue statement of a material fact or omit to state a material fact
required  to be stated  therein  or  necessary  in order to make the  statements
therein,  in  light  of the  circumstances  under  which  they  were  made,  not
misleading.


<PAGE> 15

                 Section  3.6  Financial   Statements.   Each  of  the  audited
financial statements and unaudited  consolidated interim financial statements of
the  Company   (including  any  related  notes  and   schedules)   included  (or
incorporated  by reference)  in its Annual  Reports on Form 10-K for each of the
three fiscal years ended June 30, 1995, 1996 and 1997 and its Quarterly  Reports
on Form  10-Q for all  interim  periods  during  each  such  annual  period  and
subsequent thereto (collectively, the "Financial Statements") have been prepared
from,  and are in  accordance  with,  the  books  and  records  of the  Company,
complied, as of their date, in all material respects, with applicable accounting
requirements and with the published rules and regulations of the Commission with
respect  thereto,  have been prepared in accordance with United States generally
accepted accounting principles ("GAAP") applied on a consistent basis (except as
may be  indicated  in the notes  thereto and  subject,  in the case of quarterly
financial  statements,  to normal and recurring year-end adjustments) and fairly
present,  in all  material  respects,  in  conformity  with  GAAP  applied  on a
consistent  basis  (except  as  may be  indicated  in the  notes  thereto),  the
financial  position  of the  Company as of the dates  thereof and the results of
operations  and cash flows (and  changes in financial  position,  if any) of the
Company  for  the  periods   presented   therein  (subject  to  normal  year-end
adjustments and the absence of financial  footnotes in the case of any unaudited
interim financial statements).

                  Section 3.7  Absence of  Undisclosed  Liabilities.  Except for
liabilities and obligations  incurred in the ordinary course of business,  since
June 30, 1997 the Company has not incurred any liabilities or obligations of any
nature (contingent or otherwise) which, individually or in the aggregate,  would
be reasonably likely to have a Material Adverse Effect.

                  Section 3.8 Absence of Certain  Changes.  Except as  expressly
contemplated  by this  Agreement,  since June 30, 1997 the Company has conducted
its  business  in all  material  respects  only in,  and has not  engaged in any
material transaction other than according to, the ordinary and usual course, and
there has not been, nor has the Company agreed, whether in writing or otherwise,
to take any action that would result in, (a) any Material  Adverse  Effect;  (b)
any declaration,  setting aside or payment of any dividend or other distribution
(whether in cash,  stock or property)  with respect to the capital  stock of the
Company or any  redemption,  repurchase  or other  acquisition  of any shares of
capital stock of the Company;  (c) any change by the Company in tax or financial
accounting  principles,  practices or methods;  (d) any material  asset damaged,
sold,  disposed of (except  inventory sold in the ordinary  course of business),
mortgaged,  pledged or subjected to any lien, charge or other  encumbrance;  (e)
any increase in the  compensation  payable or which could become  payable by the
Company to its directors,  officers,  employees, agents or consultants;  (f) any
adoption  or  amendment  of any  Plan (as  defined  herein));  (g) any  material
indebtedness  incurred by the Company,  except such as may have been incurred in
the ordinary course of business; (h) any material loan made or agreed to be made
by the Company,  nor has the Company become liable or agreed to become liable as
a guarantor  with  respect to any material  indebtedness;  (i) any waiver by the
Company  of any right or  rights of  material  value or any  payment,  direct or
indirect,  of any  material  debt,  liability  or other  obligation,  except  in
accordance with its terms;  (j) any change in or amendment to the Certificate of
Incorporation or the Bylaws;  (k) any payment,  loan or advance of any amount to
or in respect  of, or the sale,  transfer or lease of any  properties  or assets
(whether real,  personal or mixed,  tangible or intangible) to, or entering into
of any agreement arrangement or transaction with, any officer or director of the
Company or any affiliate thereof, or any business or entity in which the Company
or any  affiliate  thereof,  or relative of any such  person,  has any  material
direct or indirect interest  (collectively,  "Related Parties"),  except for (1)
directors'  fees, (2)  compensation to the officers and employees of the Company
in the  ordinary  course of business and (3)  advancement  or  reimbursement  of
expenses in the ordinary  course of business;  (l) any material  modification or
change  that would  result in a  diminishment  of coverage  under any  insurance
policies;  (m)  any  write-offs  as  uncollectible  of  any  notes  or  accounts
receivable of the Company or write-downs of the value of any assets or inventory
by the Company  other than in  immaterial  amounts or in the ordinary  course of
business;  or (n) any material adverse change to a Material Contract (as defined
herein).


<PAGE> 16

                  Section 3.9 Taxes.  (a) The  Company has timely  filed (or has
had timely  filed on its behalf) or will file or cause to be timely  filed,  all
material Tax Returns (as defined  below)  required by applicable law to be filed
by it prior to, or as of, the Closing Date.  All such Tax Returns are or will be
true, complete and correct in all material respects.

                           (b)      The Company has paid (or has had paid on its
behalf) or has  established  (or has had  established  on its behalf and for its
sole benefit and  recourse),  or will establish or cause to be established on or
before the Closing  Date,  an  adequate  accrual on the books and records of the
Company  for the  payment  of all  material  Taxes (as  defined  below) due with
respect to any fiscal quarter ending prior to or as of the Closing Date.

                           (c)      Since January 1, 1995, the Company has not
received  notification  of any Audit (as defined  below) by a Tax Authority with
respect to any Tax Returns  filed by, or Taxes due from,  the Company.  No issue
has been raised by any Tax  Authority in any Audit of the Company that if raised
with respect to any other period not so audited could be expected to result in a
material  proposed  deficiency  for  any  period  not so  audited.  No  material
deficiency or adjustment for any Taxes has been threatened,  proposed,  asserted
or assessed against the Company. There are no liens for Taxes upon the assets of
the  Company,  except  liens for  current  Taxes not yet due for which  adequate
reserves have been established in accordance with GAAP.

                           (d) Since January 1, 1995,  the Company has not given
or been requested to give any waiver of statutes of limitations  relating to the
payment of any  material  Taxes and has not  executed  powers of  attorney  with
respect to any material Tax matters, which will be outstanding as of the Closing
Date.

                           (e)      Prior to the date hereof,  the Company has  
disclosed  all material Tax sharing,  Tax  indemnity,  or similar  agreements to
which the Company is a party to, is bound by, or has any obligation or liability
for Taxes,  and any changes in  accounting  methods or any rulings  from any Tax
Authority.

                           (f) As used in this Agreement, (i) "Audit" shall mean
any  audit,  assessment  of  Taxes,  other  examination  by any  Tax  Authority,
proceeding or appeal of such  proceeding  relating to Taxes;  (ii) "Taxes" shall
mean all federal, state, local and foreign taxes, including, without limitation,
sales and use taxes, value added taxes,  property taxes,  payroll and employment
taxes and other  assessments of a similar nature  (whether  imposed  directly or
through  withholding),  including any  interest,  additions to tax, or penalties
applicable  thereto;  (iii)  "Tax  Authority"  shall mean the  Internal  Revenue
Service (the "Service") and any other domestic or foreign governmental authority
responsible for the  administration  of any Taxes;  and (iv) "Tax Returns" shall
mean  all  federal,   state,  local  and  foreign  tax  returns,   declarations,
statements,  reports,  schedules,  forms and information returns and any amended
Tax Return relating to Taxes.

                  Section  3.10  Litigation.  There is no suit,  claim,  action,
proceeding  or, to the  Company's  knowledge,  investigation  pending or, to the
Company's  knowledge,  threatened in writing against or affecting the Company or
any of the directors or officers of the Company in their  capacity as such which
would be  reasonably  likely to have a  Material  Adverse  Effect.  Neither  the
Company  nor  any  officer,  director  or  employee  of  the  Company  has  been
permanently  or  temporarily  enjoined  by any order,  judgment or decree of any
court or any other  Governmental  Entity  from  engaging  in or  continuing  any
conduct or practice in connection with the business, assets or properties of the
Company nor, to the Company's knowledge, is the Company or any officer, director
or  employee of the  Company  under  investigation  by any  Governmental  Entity
related to the conduct of the Company's business.  There is not in existence any
order, judgment or decree of any court or other tribunal or other agency that is
specifically  applicable  to the Company  enjoining or requiring  the Company to
take any action of any kind with respect to its business, assets or properties.


<PAGE> 17

                  Section  3.11  Employee  Benefit  Plans;  ERISA.  (a)  Section
3.11(a) of the Company  Disclosure  Letter  contains a true and complete list of
each employment,  bonus, deferred compensation,  incentive  compensation,  stock
purchase,  stock option, SAR or stock-based incentive,  severance or termination
pay,  hospitalization  or other medical,  life or other insurance,  supplemental
unemployment  benefits,  profit-sharing,  pension,  or retirement plan, program,
agreement  or  arrangement,  and each  other  employee  benefit  plan,  program,
agreement or arrangement, sponsored, maintained or contributed to or required to
be  contributed  to by the Company or by any trade or  business,  whether or not
incorporated  (an "ERISA  Affiliate"),  that  together with the Company would be
deemed a "single  employer"  within the  meaning of  section  4001(b)(1)  of the
Employee  Retirement Income Security Act of 1974, as amended,  and the rules and
regulations  promulgated thereunder ("ERISA") within the last six years, for the
benefit of any current or former  employee or director of the  Company,  whether
formal or  informal  and  whether  legally  binding  or not  (collectively,  the
"Plans").  Section 3.11(a) of the Company  Disclosure  Letter identifies each of
the Plans that is an  "employee  welfare  benefit  plan," or  "employee  pension
benefit plan" as such terms are defined in sections 3(1) and 3(2) of ERISA (such
plans being hereinafter referred to collectively as the "ERISA Plans").  Neither
the Company nor any ERISA  Affiliate has any formal plan or commitment,  whether
legally  binding or not, to create any  additional  Plan or modify or change any
existing  Plan that would  affect any current or former  employee or director of
the Company,  except as contemplated  by this Agreement.  Section 3.11(a) of the
Company Disclosure Letter contains a true and complete list of all Company Stock
Options issued and outstanding as of the date hereof.

                           (b)      With  respect to each of the Plans,  the 
Company has heretofore  delivered to Baxter true and complete  copies of each of
the  following  documents:  (i) copies of the Plans  (including  all  amendments
thereto) or a written  description of any Plan that is not otherwise in writing;
(ii) a copy of the annual report,  if required under ERISA, with respect to each
ERISA Plan for the last three years;  (iii) a copy of the actuarial  report,  if
required under ERISA,  with respect to each ERISA Plan for the last three years;
(iv) a copy of the most recent Summary Plan Description  ("SPD"),  together with
all  Summaries  of Material  Modification  issued  with  respect to such SPD, if
required under ERISA, with respect to each ERISA Plan; (v) if the Plan is funded
through  a trust or any  other  funding  vehicle,  a copy of the  trust or other
funding  agreement  (including all amendments  thereto) and the latest financial
statements  thereof;  (vi) all  contracts  relating to the Plans with respect to
which the  Company or any ERISA  Affiliate  may have any  liability,  including,
without  limitation,  insurance  contracts,  investment  management  agreements,
subscription and  participation  agreements and record keeping  agreements;  and
(vii) the most  recent  determination  letter  received  from the  Service  with
respect to each Plan that is intended to be qualified  under  section  401(a) of
the Code.

                           (c)     Neither the Company nor any current or former
ERISA Affiliate is currently or has ever been the sponsor of or required to make
contributions  to any  "employee  benefit  plan" (as defined in Section  3(3) of
ERISA)  subject  to  Title  IV  of  ERISA  (including   without  limitation  any
"multiemployer  plan" (as  defined  in  Section  3(37) of ERISA  and a  multiple
employer plan within the meaning  Section 413(c) of the Code)),  and neither the
Company nor any ERISA Affiliate has at any time incurred any liability, directly
or  indirectly   (including,   without   limitation,   any  material  contingent
liability), with respect to any such employee benefit plan.

                           (d)      Neither the Company,  any ERISA  Affiliate, 
any of the  ERISA  Plans,  any  trust  created  thereunder  nor any  trustee  or
administrator  thereof  has engaged in a  transaction  or has taken or failed to
take any action in connection with which the Company,  any ERISA Affiliate,  any
of the ERISA Plans, any such trust, any trustee or administrator thereof, or any
party  dealing with the ERISA Plans or any such trust could be subject to either
a civil  penalty  assessed  pursuant  to section 409 or 502(i) of ERISA or a tax
imposed pursuant to section 4975, 4976 or 4980B of the Code.


<PAGE> 18

                           (e)      Full  payment  has been made,  or will be 
made in accordance with section  404(a)(6) of the Code, of all amounts which the
Company or any ERISA Affiliate is required to pay under the terms of each of the
ERISA Plans,  and all such  amounts  properly  accrued  through the Closing with
respect to the current plan year thereof will be paid by the Company on or prior
to the Closing or will be properly recorded on the Company's balance sheet.

                           (f)      Each of the Plans has been operated and  
administered  in  all  material  respects  in  accordance  with  its  terms  and
applicable laws, including, but not limited to, ERISA and the Code.

                           (g)      Each of the ERISA Plans that is intended to 
be "qualified" within the meaning of section 401(a) of the Code is so qualified.
The  Company  has  timely  applied  for  and  received  a  currently   effective
determination letter from the Service with respect to each such plan.

                           (h)      Each of the ERISA  Plans  that is  intended 
to satisfy the  requirements  of section  501(c)(9) of the Code has so satisfied
such requirements.

                           (i)      No  amounts  payable  under  any  of  the  
Plans or any other  agreement or  arrangement  with respect to which the Company
has or may have any liability  could give rise to the payment of any amount that
would fail to be deductible for federal income tax purposes by virtue of Section
162(m) or Section 280G of the Code.

                           (j)      No  "leased  employee"  (as  defined in  
section  414(n) of the Code)  performs  services  for the  Company  or any ERISA
Affiliate.

                           (k)      No  Plan  provides  benefits,  including  
without  limitation  death or medical  benefits  (whether or not insured),  with
respect to current or former employees after retirement or other  termination of
service other than (i) coverage  mandated by applicable law, (ii) death benefits
or  retirement  benefits  under  any  "employee  pension  plan," as that term is
defined in Section 3(2) of ERISA, (iii) deferred  compensation  benefits accrued
as  liabilities  on the books of the  Company or the ERISA  Affiliates,  or (iv)
benefits,  the full cost of which is borne by the current or former employee (or
his beneficiary).

                           (l)     With  respect to each Plan that is funded  
wholly or partially through an insurance  policy,  there will be no liability of
the  Company or any ERISA  Affiliate,  as of the  Closing  Date,  under any such
insurance policy or ancillary agreement with respect to such insurance policy in
the nature of a retroactive rate adjustment,  loss sharing  arrangement or other
actual  or  contingent  liability  arising  wholly  or  partially  out of events
occurring prior to the Closing Date.

                           (m)      Except as provided by this  Agreement,  the 
consummation of the transactions  contemplated  hereunder will not result in the
payment, vesting, acceleration or enhancement of any benefit under any Plan.

                           (n)      Except as set forth in Section 3.11(n) of 
the Company  Disclosure  Letter,  the Company has no severance  and  termination
policy and the  Company's  employees are not entitled to severance pay under any
current Company arrangement.


<PAGE> 19

                           (o)      There are rights to purchase an  aggregate 
of 8,675 shares of Company Common Stock, outstanding,  on the date hereof, under
the ESPP  assuming (i) a purchase  price of $4.0375 per share of Company  Common
Stock and (ii) no changes in the amount of employees' withholding.

                  Section 3.12  Environmental  Matters.  (a) The business of the
Company and its former Subsidiaries has been, and the business of the Company is
in,  material  compliance  with all federal,  state,  local and foreign laws and
regulations  relating  to  pollution  or  protection  of  human  health  or  the
environment,  including, without limitation,  ambient air, surface water, ground
water,  land  surface or  subsurface  strata and  natural  resources  (together,
"Environmental  Laws" and including,  without  limitation,  laws and regulations
relating to emissions, discharges, releases or threatened releases of chemicals,
pollutants,  contaminants,  wastes,  toxic or  hazardous  substances  or wastes,
petroleum  and  petroleum  products,   polychlorinated  biphenyls  ("PCBs"),  or
asbestos  or   asbestos-containing   materials   (collectively,   "Materials  of
Environmental  Concern"), or otherwise relating to the manufacture,  processing,
distribution,  use,  treatment,  storage,  disposal,  transport  or  handling of
Materials of Environmental  Concern);  such material compliance includes, but is
not limited to, the possession by the Company of all Governmental Entity permits
and other  authorizations  required for the operation of its business  under all
applicable  Environmental  Laws,  and  material  compliance  with the  terms and
conditions  thereof.  All Governmental  Entity permits and other  authorizations
held by the Company as of the date hereof pursuant to the Environmental Laws are
identified on Schedule 3.12(a) of the Company Disclosure Letter.

                           (b)      Since July 1, 1995, the Company has not 
received  any  communication  (written  or oral),  whether  from a  Governmental
Entity, citizens group, employee or otherwise,  that alleges that the Company is
not in  compliance  with any  Environmental  Laws.  The Company has  provided to
Baxter  all  information  that is in the  possession  of the  Company  regarding
environmental  matters  pertaining  to or  the  environmental  condition  of the
business or real  property  of the  Company,  or the  Company's  compliance  (or
noncompliance) with any Environmental Laws.

                           (c)      There is no claim, action,  cause of action,
investigation or notice (written or oral) (together,  "Environmental  Claim") by
any  person  or  entity  alleging  potential   liability   (including,   without
limitation,   potential  liability  for  investigatory   costs,  cleanup  costs,
governmental  response  costs,  natural  resources  damages,  property  damages,
personal injuries,  or penalties) arising out of, based on or resulting from (i)
the presence, or release into the environment,  of any Material of Environmental
Concern at any location, whether or not owned or operated by the Company or (ii)
circumstances forming the basis of any violation,  or alleged violation,  of any
Environmental Law, that in either case is pending against the Company or against
any person or entity whose liability for any Environmental Claim the Company has
retained or assumed either contractually or by operation of law.

                           (d)      There  are no  past  or  present  actions,  
activities,  events or incidents,  including,  without limitation,  the release,
emission,  discharge,  presence  or disposal  of any  Material of  Environmental
Concern,  that,  to the best  knowledge  of the Company  after due  inquiry,  is
reasonably  likely  to form the basis of any  Environmental  Claim  against  the
Company or against any person or entity whose  liability  for any  Environmental
Claim the Company has retained or assumed either  contractually  or by operation
of law.

                           (e)      Without in any way limiting the  generality 
of the foregoing,  (i) all on-site and off-site  locations where the Company has
(previously  or  currently)  stored,  disposed or arranged  for the  disposal of
Materials of  Environmental  Concern are  identified  in Section  3.12(e) of the
Company Disclosure Letter,  (ii) all underground storage tanks, and the capacity
and contents of such tanks, located on any property owned,  leased,  operated or
controlled  by the  Company  are  identified  in Section  3.12(e) of the Company
Disclosure  Letter,  (iii) there is no asbestos  contained in or forming part of
any  building,  building  component,  structure or office  space owned,  leased,
operated or controlled by the Company and (iv) no PCBs or  PCB-containing  items
are used or stored at any property owned, leased,  operated or controlled by the
Company.


<PAGE> 20

                  Section 3.13  Compliance  with  Applicable  Laws.  The Company
holds all material licenses, permits and authorizations necessary for the lawful
conduct of its business,  as now conducted,  and such business is not being, and
the Company has not received any notice since July 1, 1996 from any authority or
person that such  business  has been or is being,  conducted in violation of any
law, ordinance or regulation,  including, without limitation, any law, ordinance
or  regulation   relating  to  (a)  the  conduct  of  medical  research  or  (b)
occupational  health and safety,  except for possible  violations which,  either
singly or in the aggregate, have not resulted and are not reasonably expected to
result in a Material Adverse Effect.

                  Section  3.14  Material  Contracts.  (a)  Section  3.14 of the
Company  Disclosure  Letter  sets forth a true and  correct  list of any and all
executory agreements, contracts, purchase or installment agreements, indentures,
leases, mortgages,  licenses, plans, arrangements,  commitments (whether written
or oral) and instruments (collectively, "contracts") in existence as of the date
hereof,  that  are,  as of the date  hereof,  material  to the  Company  (each a
"Material  Contract"),  including  without  limitation,  the following  types of
contracts to which the Company is a party:

                                    (i)     any contract which is not terminable
by the Company upon 30 days' or less notice and which involves  annual  payments
of more than $100,000;
                                    (ii) any oral contract which involves annual
payments in excess of $50,000 or an  aggregate  payment in excess of $200,000 or
any  written  contract,  in  either  case for the  employment  of any  director,
officer,  consultant  or other  person or  entity  who is not an  employee  on a
full-time,  part-time,  consulting  or other basis,  including  any severance or
other termination provisions with respect to such employment;

                                    (iii) any  noncompetition  agreement,  other
than customary agreements with employees who are not officers,  directors or key
employees,  or any other  contract  that in any way  restricts  the Company from
carrying on its business any place in the world; and

                                    (iv)    any contract between the Company and
any of its affiliates or any of its officers,  directors or key employees. 

True and complete copies of each written Material Contract, or form thereof, and
true and complete  written  summaries of each oral  Material  Contract have been
made available to Baxter by the Company prior to the date hereof.

                           (b)      Each Material  Contract is a valid,  binding
and enforceable  agreement of the Company and, to the Company's  knowledge,  the
other parties thereto and will, subject to the satisfaction of the conditions in
Article VIII,  continue to be valid,  binding and enforceable  immediately after
the  Closing,  except (i) as such  enforcement  may be  subject  to  bankruptcy,
insolvency  or similar laws now or hereafter  in effect  relating to  creditors'
rights,   (ii)  general   principles  of  equity  (regardless  of  whether  such
enforcement  is considered in a proceeding at law or in equity) and (iii) as the
remedy of specific  performance  and  injunctive  and other  forms of  equitable
relief may be subject to equitable  defenses and to the  discretion of the court
before which any proceeding therefor may be brought; and

                           (c)      There has not  occurred,  (i) since June 30,
1997, any material  default (or event which upon provision of notice or lapse of
time or both would become such a default)  or, (ii) prior to June 30, 1997,  any
uncured  default  (or event which upon  provision  of notice or lapse of time or
both would become such a default) under any Material Contract on the part of the
Company, except for violations or defaults that individually or in the aggregate
would not be reasonably expected to have a Material Adverse Effect.

                  Section 3.15  Intellectual  Property  Rights.  (a) The Company
owns or possesses  adequate rights to use all  intellectual and similar property
of every kind and nature  relating to or used or necessary  in the  operation of
the  Company's  business,   including,   without  limitation,  (i)  patents  and
trademarks  associated with the Company's  business  (including all Governmental
Entity  trademarks,  service marks,  logos and designs,  all  registrations  and
recordings thereof,  and all applications in the United States or with any other
Governmental Entity, all goodwill symbolized thereby or associated therewith and
all extensions or renewals  thereof) which are set forth on Schedule 3.15 of the
Company Disclosure Letter, (ii) copyrights  associated solely with the Company's
business,  including  all  copyrights,   United  States  and  foreign  copyright
registrations,  and applications to register copyrights,  which are set forth on
Schedule 3.15 of the Company  Disclosure  Letter,  (iii)  inventions,  formulae,
processes,  designs,  know-how,  show-how  or other  data or  information,  (iv)
confidential or proprietary  technical and business  information,  processes and
trade secrets,  (v) computer software,  (vi) technical manuals and documentation
made or used in  connection  with any of the  foregoing  and (vii)  licenses and
rights with respect to the  foregoing or property of like nature  (collectively,
"Company Intellectual Property").


<PAGE> 21

                           (b)     (i) Schedule  3.15 of the Company  Disclosure
Letter sets forth a complete and  accurate  list of all  registered  copyrights,
patents  and  trademarks  owned  by or under  obligation  of  assignment  to the
Company,  or  otherwise  licensed  to and  currently  used in the conduct of the
Company's  business  and  related  to  the  Company's   recombinant   hemoglobin
technology;

                                    (ii)    each  owner, as of the date  hereof,
listed on  Schedule  3.15 of the  Company  Disclosure  Letter,  is listed in the
records of the appropriate Governmental Entity as the sole owner of record;

                                    (iii)   Schedule   3.15   of   the   Company
Disclosure  Letter sets forth a complete  and  accurate  list of all  agreements
between the  Company,  on the one hand,  and any person,  on the other hand,  in
existence  on the date hereof  granting  any right to use or practice any rights
under  any  Company  Intellectual  Property,   including,   without  limitation,
marketing rights, royalty rights or distribution rights;

                                    (iv) there is no material encumbrance on the
right of the Company to transfer any of the Company Intellectual Property;

                                    (v)     no trade secret, formula, process,  
invention, design, know-how or any other confidential information of the Company
has been  disclosed or authorized  to be disclosed to any Person,  except in the
ordinary  course of business or pursuant  to an  obligation  of  confidentiality
binding upon said Person;

                                    (vi) there are no pending  proceedings by or
before Governmental Entities, including oppositions, interferences,  proceedings
or suits involving the Company,  relating to the Company Intellectual  Property,
and, to the Company's knowledge,  no such proceedings are threatened against the
Company;

                                    (vii)  to  the  Company's   knowledge,   the
conduct of the Company's business does not infringe upon or otherwise violate in
a material respect intellectual property rights of any Person;

                                    (viii) to the Company's knowledge, no Person
is infringing  upon or otherwise  violating any patents  comprising a portion of
Company Intellectual Property;

                                    (ix) since July 1, 1995, the Company has not
received  written  notice of any claims  and there are no pending  claims of any
Persons involving the Company relating to the scope,  ownership or use of any of
the Company Intellectual Property; and

                                    (x)     each copyright registration,  patent
and registered trademark and application therefor, is listed on Schedule 3.15 of
the Company  Disclosure  Letter,  and is in proper form,  not disclaimed and has
been duly  maintained,  including the  submission  of all  necessary  filings in
accordance  with the legal and  administrative  requirements  of the appropriate
jurisdictions except with respect to use requirements as to trademarks.

                  Notwithstanding  the foregoing,  no  representation is made by
the Company with respect to any intellectual property of Baxter.


<PAGE> 22

                  Section 3.16 Insurance. Section 3.16 of the Company Disclosure
Letter lists each of the insurance policies relating to the Company which are in
effect as of the date  hereof.  The  Company  has  provided  Baxter with a true,
complete  and  correct  copy of each such  policy or the binder  therefor.  With
respect to each such  insurance  policy or binder  neither  the  Company nor any
other party to the policy is in breach or default thereunder (including, without
limitation,  with  respect to the payment of premiums or the giving of notices),
and the Company does not know of any  occurrence or any event which (with notice
or the  lapse of time or both)  would  constitute  such a breach or  default  or
permit  termination,  modification or acceleration under the policy,  except for
such breaches or defaults  which,  individually  or in the aggregate,  would not
result in a Material  Adverse  Effect.  Section  3.16 of the Company  Disclosure
Letter  describes any  self-insurance  arrangements  affecting the Company.  The
insurance  policies  listed on Section  3.16 of the  Company  Disclosure  Letter
include all policies which are required in connection  with the operation of the
business of the Company,  as currently  conducted,  by  applicable  laws and all
agreements  relating  to the  Company.  All  such  policies,  in  the  Company's
judgment,  provide coverage in reasonably  sufficient  amounts to insure against
all risks customarily  insured against for the business  currently  conducted by
the Company.  All such  policies  are, as of the date hereof,  in full force and
effect,  all premiums due with  respect  thereto  covering all periods up to and
including  the Closing Date will have been paid as of such date and no notice of
cancellation  or  termination  has been  received  prior to the date hereof with
respect to any such policy.  All policies of insurance or  replacements  thereof
will remain in full force and effect through and after the Closing Date.

                  Section  3.17 Opinion of  Financial  Advisor.  The Company has
received the opinion of Lehman Brothers Inc. ("Lehman Brothers"),  the Company's
financial  advisor,  to the effect that,  as of February  23,  1998,  the Merger
Consideration to be received by the Company's stockholders in the Merger is fair
to the  Company's  stockholders  from a financial  point of view. A draft of the
written   confirmation   of  such  opinion  has  been  provided  to  Baxter  for
informational purposes only.

                  Section 3.18 Rights  Agreement;  Takeover  Laws. The execution
and delivery of this Agreement will not (i) cause any rights issued  pursuant to
the Rights Agreement (each, a "Right") to become exercisable or to separate from
the stock  certificates to which they are attached,  (ii) cause Baxter or any of
its affiliates to be an Acquiring  Person (as such term is defined in the Rights
Agreement)  or (iii)  trigger  any other  provisions  of the  Rights  Agreement,
including  giving  rise to a  Distribution  Date (as such term is defined in the
Rights  Agreement).  The Company and the Board of  Directors of the Company have
each  taken  all  action  required  to be taken by it in  order to  exempt  this
Agreement, and the transactions contemplated hereby from, and this Agreement and
the  transactions  contemplated  hereby are exempt from, the requirements of any
"moratorium," "control share," "fair price," "affiliate  transaction," "business
combination" or other antitakeover laws and regulations of any state, including,
without limitation,  the State of Delaware,  and including,  without limitation,
Section 203 of the DGCL.

                  Section 3.19 Company Disclosure. No representation or warranty
by  the  Company  in  this  Agreement   (including,   without  limitation,   the
representation  concerning Company SEC Reports),  the Company Disclosure Letter,
any schedule or  certificate  furnished or to be furnished by the Company or any
of its  representatives  pursuant to the provisions hereof or in connection with
the transactions  contemplated hereby, contains as of the date hereof any untrue
statement of a material  fact or omits to state any material  fact  necessary in
order  to  make  the  statements  herein  or  therein,   in  the  light  of  the
circumstances under which they were made, not misleading.


<PAGE> 23

                  Section 3.20 Labor Matters.  Except as would not be reasonably
likely to have a Material Adverse Effect, (i) there is no labor strike, dispute,
slowdown,  work  stoppage  or  lockout  actually  pending  or, to the  Company's
knowledge, threatened against or affecting the Company and, during the past five
years,  there  has not  been  any such  action;  (ii) no  union  or other  labor
organization represents or claims to represent the employees of the Company and,
to the  Company's  knowledge,  no  union  or  other  labor  organizing  activity
currently is occurring among and no question of representation exists concerning
such  employees;  the Company is neither a party to nor bound by any  collective
bargaining or similar  agreement with any labor  organization,  or work rules or
practices  agreed  to  with  any  labor  organization  or  employee  association
applicable  to employees of the  Company;  (iii) there are no written  personnel
policies,  rules or procedures applicable to employees of the Company other than
such  policies,  rules and  procedures,  copies of which have been  delivered to
Baxter;  (iv) the Company is in material  compliance  with all  applicable  laws
concerning  employment  and  employment  practices,   terms  and  conditions  of
employment,  immigration,  wages,  hours of work  and  occupational  safety  and
health,  and is not  engaged in any unfair  labor  practices  (as defined in the
National Labor Relations Act or other applicable law,  ordinance or regulation);
(v)  there  is no  grievance  or  arbitration  proceeding  arising  out  of  any
collective bargaining or similar agreement or other grievance procedure relating
to the  Company;  (vi) to the  Company's  knowledge,  no charges  or  complaints
relating  to the Company are  pending  before the Equal  Employment  Opportunity
Commission or any other  corresponding  state agency; and (vii) to the Company's
knowledge,  no federal, state or local agency responsible for the enforcement of
labor or employment laws, immigration laws,  occupational health and safety laws
or any other law affecting  the  employees of the Company  intends to conduct or
currently  is  conducting  an  investigation  with respect to or relating to the
Company,  and no such  agencies  have  threatened  to or have filed any  claims,
charges, complaints or citations against the Company.

                  Section  3.21 WARN  Act.  Since the  enactment  of the  Worker
Adjustment and Retraining Notification Act of 1988 ("WARN Act"), the Company has
not  effectuated  (i) a plant  closing  as  defined  in the WARN  Act (a  "Plant
Closing") affecting any site of employment or one or more operating units within
any site of employment  of the Company,  or (ii) a mass layoff as defined in the
WARN Act (a "Mass  Layoff")  affecting  the  Company;  nor has the Company  been
affected by any  transaction  or engaged in layoffs or  employment  terminations
sufficient in number to trigger  application  of any similar state or local law.
None of the employees of the Company has suffered an employment  loss as defined
in the WARN Act (an "Employment Loss") during the ninety-day period prior to the
Closing Date.

                  Section 3.22  Transactions  with Related  Parties.  No Related
Party (i) has borrowed  money or loaned  money to the Company;  (ii) has made or
threatened  any  contractual or other claim of any kind  whatsoever  against the
Company; (iii) has any interest in any property or assets used by the Company in
its  business;  or (iv) has  been  engaged  in any  other  transaction  with the
Company,  except for transactions  which are not required to be disclosed in the
Company SEC Reports.


<PAGE> 24

                  Section 3.23 Absence of Certain Payments.  None of the Company
nor its officers,  directors nor, to the Company's  knowledge,  any of its other
affiliates  nor any of the  Company's  employees  or agents or others  acting on
behalf of any of them have (i) engaged in any activity  prohibited by the United
States  Foreign  Corrupt  Practices  Act of  1977  or  any  other  similar  law,
regulation,  decree,  directive  or order of any other  country and (ii) without
limiting the generality of the preceding clause (i), used any corporate or other
funds for unlawful contributions,  payments, gifts or entertainment, or made any
unlawful  expenditures relating to political activity to government officials or
others.  None of the Company nor its officers,  directors  nor, to the Company's
knowledge,  any of its other  affiliates  nor any of the Company's  employees or
agents or others  acting on behalf of any of them,  has accepted or received any
unlawful contributions, payments, gifts or expenditures.

                  Section  3.24  Title  to  Properties;  Absence  of  Liens  and
Encumbrances;  Condition of Equipment.  (a) The Company has good and valid title
to, or in the case of leased  properties and assets,  valid leasehold  interests
in, all of its tangible properties and assets, real, personal and mixed, used in
its business, free and clear of any liens, charges,  pledges, security interests
or other  encumbrances,  except as reflected in the Company's  audited financial
statements or except for such  imperfections of title and encumbrances,  if any,
which are not  substantial  in  character,  amount or  extent,  and which do not
materially  detract from the value as reflected  in the  Company's  December 31,
1997  balance  sheet,  or  materially  interfere  with the  present  use, of the
property subject thereto or affected thereby.

                           (b)     The equipment owned or leased by the Company 
is, taken as a whole, (i) adequate, in all material respects, for the conduct of
the Company's business, (ii) suitable, in all material respects, for the uses to
which it is currently employed, (iii) in good operating condition (ordinary wear
and tear excepted),  (iv) regularly and properly  maintained,  (v) not obsolete,
dangerous  or  in  need  of  renewal  or  replacement,  except  for  renewal  or
replacement  in the ordinary  course of business and (vi) free from any defects,
except,  with  respect to clauses  (i) through  (vi) above,  as would not have a
Material Adverse Effect.


<PAGE> 25


                  Section 3.25 FDA Matters.  The Company is in  compliance  with
all statutes,  rules and regulations of the U.S. Food and Drug Administration or
similar  domestic state authority  ("FDA") with respect to the  manufacturing of
all of its products, to the extent that the same are applicable to the Company's
business as it is currently  conducted,  except for such violations as would not
be reasonably expected to have a Material Adverse Effect. The Company adheres to
"Good  Laboratory  Practices" and "Good Clinical  Practices," as required by the
FDA,  except for such  deviations as would not be reasonably  expected to have a
Material Adverse Effect. The Company has all requisite FDA permits, approvals or
the like to conduct the  Company's  business as it is currently  conducted.  The
Company  has  previously  delivered  to  Baxter  an  index  of  all  information
concerning all  Investigational  New Drug  Applications  obtained by the Company
from the FDA or  required  in  connection  with  the  conduct  of the  Company's
business  as it is  currently  conducted  and  has  made  all  such  information
available to Baxter. There are no pending or threatened actions,  proceedings or
complaints  by the FDA,  which  would  prohibit  or impede  the  conduct  of the
Company's  business as it is  currently  conducted.  Section 3.25 of the Company
Disclosure Letter contains a list of all  communication  between the Company and
the FDA from January 17, 1990 through the date hereof.

                  Section    3.26     Registration     Statement    and    Proxy
Statement/Prospectus. The information supplied or to be supplied by the Company,
for inclusion in (a) a  registration  statement on Form S-4  (together  with all
amendments   thereto,   the   "Registration   Statement")  in  which  the  Proxy
Statement/Prospectus  shall be included as a prospectus,  in connection with the
registration  under the  Securities Act of the shares of Baxter Common Stock and
the CPRs to be issued  pursuant to the Merger  will not,  either at the time the
Registration  Statement is filed with the Commission,  at the time any amendment
thereof or supplement  thereto is filed with the  Commission,  or at the time it
becomes  effective under the Securities Act,  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  and (b) the Proxy
Statement/Prospectus  will  not,  either  at the date  mailed  to the  Company's
stockholders or at the time of the Special Meeting, 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 the  light of the
circumstances   under  which  they  were  made,   not   misleading.   The  Proxy
Statement/Prospectus,  as to information supplied by the Company, will comply in
all material  respects with all applicable  provisions of the Securities Act and
the Exchange Act and the rules and regulations promulgated thereunder.

                  Section 3.27 Brokers.  Other than Lehman Brothers,  no broker,
finder or investment banker is entitled to any brokerage,  finder's or other fee
or commission in connection with the Merger based upon  arrangements  made by or
on behalf of the Company.


<PAGE> 26

                                   ARTICLE IV

             REPRESENTATIONS AND WARRANTIES OF BAXTER AND MERGER SUB

                  Except  as  otherwise  disclosed  to the  Company  in a letter
delivered  to it prior to the  execution  hereof  (which  letter  shall  contain
appropriate  references  to identify  the specific  section  herein to which the
information in such letter relates) (the "Baxter  Disclosure  Letter") or as set
forth in the Baxter  SEC  Reports  (as  defined  herein),  Baxter and Merger Sub
represent and warrant to the Company as follows:

                  Section 4.1  Organization.  Each of Baxter and Merger Sub is a
corporation duly organized, validly existing and in good standing under the laws
of the State of Delaware and has the requisite  corporate power and authority to
own,  use or lease  properties  and to carry on its  business as it is now being
conducted and as it is now proposed to be conducted. Merger Sub has delivered to
the Company a complete and correct copy of its certificate of incorporation  and
bylaws, each as currently in effect. Neither Baxter nor Merger Sub is in default
in any respect in the  performance,  observation or fulfillment of any provision
of its certificate of incorporation or bylaws.

                  Section 4.2  No Ownership of Company  Common Stock.  Neither  
Baxter nor Merger  Sub owns any  shares of Company  Common  Stock as of the date
hereof.

                  Section 4.3  Capitalization.  The authorized  capital stock of
Baxter  consists of  350,000,000  shares of Baxter Common Stock and  100,000,000
shares of preferred  stock, no par value per share ("Baxter  Preferred  Stock"),
including, 3,500,000 shares of Series A Junior Participating Stock, no par value
per share  ("Series A  Preferred").  As of December  31, 1997,  (i)  287,701,247
shares of Baxter Common Stock were issued and  outstanding,  of which  7,662,187
shares of Baxter Common Stock were held in treasury,  (ii) no shares of Series A
Preferred  were  outstanding,  (iii) no shares of Baxter  Preferred  Stock  were
issued and outstanding  and (iv)  27,070,672  shares of Baxter Common Stock were
reserved  under all employee  benefit plans of Baxter.  The  authorized  capital
stock of Merger Sub consists of 1,000 shares of Common Stock, par value $.01 per
share,  all of  which  are  validly  issued  and  outstanding,  fully  paid  and
nonassessable and are owned by Baxter.

                  Section 4.4  Authority.  Each of Baxter and Merger Sub has all
requisite  corporate  power and  authority  to execute and deliver  each of this
Agreement,  the CPR Agreement and the CPRs and to  consummate  the  transactions
contemplated  hereby or  thereby.  The  execution  and  delivery of each of this
Agreement,  the  CPR  Agreement  and  the  CPRs  and  the  consummation  of  the
transactions contemplated hereby or thereby on the part of Baxter and Merger Sub
have been duly and validly  authorized by the  respective  Board of Directors of
Baxter and of Merger Sub and by Baxter as the sole stockholder of Merger Sub and
no other  corporate  proceedings on the part of Baxter or Merger Sub as a matter
of law or otherwise are necessary to authorize this Agreement, the CPR Agreement
and the CPRs or to consummate the transactions  contemplated  hereby or thereby.
This  Agreement  has been duly and validly  executed and delivered by Baxter and
Merger Sub and, assuming the due  authorization,  execution and delivery of this
Agreement by the Company,  constitutes a valid and binding  agreement of each of
Baxter and Merger Sub,  enforceable  against each of them in accordance with its
terms,  except to the extent that the enforcement  thereof may be limited by (i)
bankruptcy,  insolvency,  reorganization,  moratorium,  fraudulent conveyance or
other  similar  laws now or hereafter in effect  relating to  creditors'  rights
generally,  (ii)  general  principles  of equity  (regardless  of  whether  such
enforcement  is  considered  in a proceeding  at law or in equity) and (iii) the
remedy of specific  performance  and  injunctive  and other  forms of  equitable
relief  may be  subject  to  the  discretion  of  the  court  before  which  any
enforcement proceeding therefor may be brought.


<PAGE> 27

                 Section 4.5  Baxter  Stockholder  Approval.  Neither the 
execution of this Agreement nor the consummation of the Merger requires approval
by the stockholders of Baxter.

                  Section 4.6 Consent and Approvals; No Violation. The execution
and  delivery of each of this  Agreement  the CPR  Agreement  and the CPRs,  the
consummation of the transactions contemplated hereby or thereby, and each of the
performance  by  Baxter  and  Merger  Sub  of  their  obligations  hereunder  or
thereunder will not:

                           (a)      conflict  with or result in a breach of any
provision  of the  certificate  of  incorporation  or  bylaws  of  Baxter or the
certificate of incorporation or bylaws of Merger Sub;

                           (b)      require any consent, approval, authorization
or permit of, or filing with or notification to, any Governmental Entity, except
(i) the filing of a pre-merger notification and report form by Baxter and Merger
Sub, as  applicable,  under the HSR Act, (ii) the filing with the  Commission of
(x) the Proxy  Statement/Prospectus  as contemplated by this Agreement,  if such
approval is required by law, and (y) the Registration  Statement relating to the
offer and sale of the CPRs and shares of Baxter Common Stock as  contemplated by
this Agreement, if such filing is required by law, (iii) the qualification under
the Trust  Indenture Act of 1939, as amended (the "Trust  Indenture Act") of the
CPR  Agreement,  if such filing is  required by law,  and (iv) the filing of the
Certificate of Merger with the Secretary of State of the State of Delaware;

                           (c)      result in any  violation  of or the  breach 
of or constitute a default (with notice or lapse of time or both) under (or give
rise to any right of  termination,  cancellation  or  acceleration or guaranteed
payments under or to, a loss of a material  benefit or result in the creation or
imposition  of a lien under) any of the terms,  conditions  or provisions of any
note,  lease,  mortgage,  indenture,  license,  agreement or other instrument or
obligation to which Baxter or Merger Sub is a party or by which Baxter or Merger
Sub or any of their  respective  properties  or assets may be bound,  except for
such violations,  breaches, defaults, or rights of termination,  cancellation or
acceleration,  or losses as to which  requisite  waivers or  consents  have been
obtained or will be obtained prior to the Effective Time or which,  individually
or in the  aggregate,  would  not (i)  have a  material  adverse  effect  on the
business,  results  of  operations  or  financial  condition  of Baxter  and its
subsidiaries,  taken as a whole,  other  than as a result  of  general  economic
conditions or conditions  affecting  the health care  products  supply  industry
generally (a "Baxter  Material  Adverse  Effect"),  (ii)  materially  impair the
ability of either Baxter or Merger Sub to perform its obligations  under the CPR
Agreement or this  Agreement  or (iii)  prevent the  consummation  of any of the
transactions contemplated by the CPR Agreement or this Agreement;

                           (d)      violate the provisions of any order,  writ,
injunction,  judgment,  decree, statute, rule or regulation applicable to Baxter
or Merger Sub, in such a manner as to (i) have a Baxter Material Adverse Effect,
(ii) materially impair the ability of either Baxter or Merger Sub to perform its
obligations  under the CPR  Agreement  or this  Agreement  or (iii)  prevent the
consummation  of any of the  transactions  contemplated  by the CPR Agreement or
this Agreement; or


<PAGE> 28

                          (e)      result in the creation of any lien,  charge 
or encumbrance upon any shares of capital stock,  properties or assets of Baxter
or Merger Sub under any agreement or instrument to which Baxter or Merger Sub is
a party or by which Baxter or Merger Sub is bound.

                  Section 4.7 Merger Sub's Operations. The Merger Sub was formed
solely for the purpose of engaging in the transactions  contemplated  hereby and
has not engaged in any business  activities  or conducted any  operations  other
than in connection with the transactions contemplated hereby.

                  Section  4.8  Baxter  SEC  Reports.  Baxter has filed with the
Commission,  and has heretofore  made available to the Company true and complete
copies  of,  each  form,  registration  statement,  report,  schedule,  proxy or
information  statement and other  document  (including  exhibits and  amendments
thereto),  including  without  limitation  its Annual  Reports  to  Stockholders
incorporated by reference in certain of such reports,  required to be filed with
the Commission since December 31, 1995 under the Securities Act, or the Exchange
Act  (collectively,  the "Baxter SEC Reports").  As of the respective dates such
Baxter SEC Reports were filed or, if any such Baxter SEC Reports  were  amended,
as of the date  such  amendment  was  filed,  each of the  Baxter  SEC  Reports,
including  without  limitation  any financial  statements or schedules  included
therein, (a) complied in all material respects with all applicable  requirements
of the  Securities  Act  and the  Exchange  Act,  as the  case  may be,  and the
applicable rules and regulations promulgated thereunder, and (b) did not contain
any  untrue  statement  of a  material  fact or omit to  state a  material  fact
required  to be stated  therein  or  necessary  in order to make the  statements
therein,  in the light of the  circumstances  under  which they were  made,  not
misleading.

                  Section 4.9 Baxter  Disclosure.  No representation or warranty
by Baxter or Merger Sub in this  Agreement  and no  statement  contained  in any
document (including,  without limitation,  the Baxter SEC Reports),  schedule or
certificate  furnished or to be furnished by Baxter or Merger Sub to the Company
or any of its representatives pursuant to the provisions hereof or in connection
with the transactions  contemplated  hereby,  contains as of the date hereof any
untrue  statement of material fact or omits to state any material fact necessary
in  order  to make  the  statements  herein  or  therein,  in the  light  of the
circumstances under which they were made, not misleading.

                  Section 4.10 Baxter Financial Statements.  Each of the audited
consolidated  financial statements and unaudited  consolidated interim financial
statements of Baxter  (including any related notes and  schedules)  included (or
incorporated  by reference)  in its Annual  Reports on Form 10-K for each of the
three fiscal years ended  December  31,  1994,  1995 and 1996 and its  Quarterly
Reports on Form 10-Q for all interim  periods  during such period and subsequent
thereto (collectively,  the "Financial Statements") have been prepared from, and
are in  accordance  with,  the books and records of Baxter and its  consolidated
subsidiaries,  comply  in  all  material  respects  with  applicable  accounting
requirements and with the published rules and regulations of the Commission with
respect  thereto,  have been  prepared  in  accordance  with GAAP  applied  on a
consistent  basis  (except as may be indicated in the notes thereto and subject,
in the case of quarterly financial statements,  to normal and recurring year-end
adjustments) and fairly present,  in all material  respects,  in conformity with
GAAP  applied on a  consistent  basis  (except as may be  indicated in the notes
thereto),  the consolidated financial position of Baxter and its subsidiaries as
of the date thereof and the  consolidated  results of operations  and cash flows
(and changes in financial  position,  if any) of Baxter and its subsidiaries for
the periods  presented  therein (subject to normal year-end  adjustments and the
absence of financial  footnotes in the case of any unaudited  interim  financial
statements).


<PAGE> 29

                  Section    4.11     Registration     Statement    and    Proxy
Statement/Prospectus.  The  information  supplied or to be supplied by Baxter or
Merger Sub for inclusion in (a) the  Registration  Statement will not, either at
the time the  Registration  Statement is filed with the Commission,  at the time
any amendment thereof or supplement thereto is filed with the Commission, at the
time the Registration Statement becomes effective under the Securities Act or at
the Effective Time,  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 and (b) the Proxy  Statement/Prospectus  will
not,  either at the date mailed to the Company's  stockholders or at the time of
the Company Meeting,  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 the light of the  circumstances  under  which they were
made, not misleading. The Proxy Statement/Prospectus, as to information supplied
by Baxter or Merger Sub,  will comply as to form in all material  respects  with
all  applicable  provisions of the  Securities  Act and the Exchange Act and the
rules and regulations  promulgated  thereunder,  and the Registration Statement,
other than as to  information  supplied by the  Company or its  representatives,
will comply in all material  respects with the  provisions of the Securities Act
and the rules and regulations promulgated thereunder.

                  Section 4.12  Brokers.  Other than Credit  Suisse First Boston
Corporation, no broker, finder, investment banker or other person is entitled to
any  brokerage,  finder's  or other fee or  commission  in  connection  with the
transactions contemplated by this Agreement or the CPR Agreement or the issuance
of the CPRs,  based upon  arrangements  made by or on behalf of Baxter or Merger
Sub.

                  Section 4.13 Shares.  The shares of Baxter Common Stock,  when
issued in accordance with the terms of this Agreement,  will be duly authorized,
validly issued,  fully paid and nonassessable and not issued in violation of any
preemptive rights.

                                    ARTICLE V

                            COVENANTS OF THE COMPANY

                  Section  5.1  Ordinary   Course.   Except  as  (i)   otherwise
specifically provided in this Agreement, (ii) as set forth in Section 5.1 of the
Company  Disclosure Letter or (iii) otherwise  consented to in writing by Baxter
and Merger Sub,  from the date of this  Agreement  to the  Effective  Time,  the
Company  will  conduct its  operations  only in the ordinary and usual course of
business  and will  preserve  intact its  present  business  organization,  take
reasonable  efforts to keep  available  the  services of its  present  officers,
employees  and  consultants  and to  preserve  its  present  relationships  with
licensors,   licensees,   suppliers,  and  others  with  whom  the  Company  has
significant  business  relationships.  Without  limiting the  generality  of the
foregoing,  and except (x) as otherwise  specifically provided in this Agreement
or (y) as set forth in Section 5.1 of the Company Disclosure Letter, the Company
will  not  directly  or  indirectly,  from  the  date of this  Agreement  to the
Effective Time, without the prior written consent of Baxter and Merger Sub:


<PAGE> 30

                           (a)      propose  or adopt any  amendment  to or  
otherwise change the Certificate of Incorporation or the Bylaws;

                           (b)      authorize for issuance,  sale,  pledge,  
disposition  or  encumbrance,  or issue,  sell,  pledge,  dispose of or encumber
(except (x) pursuant to the exercise of Company Stock  Options,  outstanding  on
the date  hereof,  under the Company  Stock Option Plans and (y) the issuance of
shares  pursuant to the ESPP in accordance with past practice or as contemplated
by Section 2.2) any of its shares or any of its other securities or any interest
relating to or whose value is dependent  on the value of any equity  interest in
the  Company  or issue any  securities  convertible  into or  exchangeable  for,
options,  warrants  to  purchase,  scrip,  rights  to  subscribe  for,  calls or
commitments of any character whatsoever relating to, or enter into any contract,
understanding  or arrangement with respect to the issuance of, any of its shares
or any of its other  securities,  or enter into any arrangement or contract with
respect to the  purchase  or voting of shares of its shares,  or adjust,  split,
reacquire,  redeem,  combine or reclassify  any of its  securities,  or make any
other changes in its capital structure;

                           (c)      (i)     except in the  ordinary  course of  
business,  incur  (contingently  or otherwise)  any material  liability or other
material obligation including, without limitation, any indebtedness for borrowed
money,  enter into any  guarantee of any such  obligation  of another  person or
mortgage,  pledge or subject to any lien,  charge or other  encumbrance of their
assets,  properties  or  business,  or (ii) make any loans,  advances or capital
contributions  to, or  investments  in, any other person other than  advances to
employees, for reasonable expenses, related to Company business, in the ordinary
course of business;

                           (d)      enter into any transaction,  commitment, 
contract,  agreement,  license or lease,  amend or affirmatively  renew any such
contracts,  commitments,  licenses  or leases  other than those that are (i) not
material  or  (ii)  in the  ordinary  course  of  business  and  do not  involve
affiliates of the Company;

                           (e)      sell or otherwise  dispose of or lease any 
material part of its properties or assets, including but not limited to the sale
or license of any real estate or Intellectual Property, or purchase or otherwise
acquire or lease material  properties or assets (including real estate),  except
purchases,  sales and other  dispositions  in the  ordinary  course of  business
(excluding  sales or other  dispositions  of  assets  held for sale in excess of
$100,000 per item),  or acquire or agree to acquire by merging or  consolidating
with, or by purchasing  all, or  substantially  all, of the assets of, or by any
other  manner,  any business or any  corporation,  partnership,  joint  venture,
association or other business organization or division thereof;

                           (f)      declare,  set  aside or pay any  dividends  
on, or make any distributions in respect of, its outstanding shares;

                           (g)      (i) (A) make any change, other than in the 
ordinary course of business, in the compensation payable or to become payable to
any of its  employees,  agents  or  consultants  or (B) make any  change  in the
compensation  payable or to become  payable to any of its officers or directors,
(ii) enter into or amend any employment,  consulting,  severance, termination or
similar  agreement;  (iii) adopt any new Plan or amend any existing  Plan;  (iv)
make  any  loans  to  any of  its  officers,  directors,  employees,  agents  or
consultants or any changes in its existing borrowing or lending arrangements for
or on  behalf of any of such  persons,  whether  contingent  on the  Closing  or
otherwise; or (v) except to the extent permitted by Section 2.2 hereof, take any
action to cause to be  exercisable  any  otherwise  unexercisable  Company Stock
Option under the Company Stock Option Plans;


<PAGE>  31

                           (h)      make any material changes in the type or 
amount of its insurance coverages;

                           (i)      make  any  material  tax  election  (unless
required by law) or settle or  compromise  any material  income tax liability of
the Company,  except if such action is taken in the ordinary  course of business
and Baxter shall have been provided reasonable prior notice thereof. The Company
shall  consult with Baxter before filing or causing to be filed any material Tax
Return  of the  Company  or before  executing  or  causing  to be  executed  any
agreement or waiver  extending  the period for  assessment  or collection of any
material Taxes of the Company;

                           (j)      cancel any debts or waive,  release or 
relinquish any material  contract  rights or other material rights other than in
the ordinary course of business;

                           (k)  knowingly  take or agree or  commit  to take any
action that would result in any of the Company's  representations  or warranties
hereunder qualified as to materiality being untrue and any such  representations
and warranties that are not so qualified  being untrue in any material  respect;
or

                           (l)      make,  or commit  to make,  any  capital  
expenditure  in  excess  of  $100,000  including,  without  limitation,  for the
purchase of real estate.

                  Section 5.2 Rule 145 Affiliates. At least 30 days prior to the
Effective  Time,  the  Company  shall cause to be  delivered  to Baxter a letter
identifying all Persons who, at the time of the Special  Meeting,  may be deemed
to be  "affiliates" of the Company for purposes of Rule 145 under the Securities
Act (each such Person, a "Securities Act Affiliate").  The Company shall use its
reasonable  efforts to cause each person who is identified  as a Securities  Act
Affiliate to deliver,  to Baxter,  at least 15 days prior to the Effective Time,
an agreement substantially in the form of Annex B to this Agreement.

                  Section 5.3 No Solicitation.  (a) Prior to the Effective Time,
the Company  agrees (x) that  neither  the  Company,  nor any of its  directors,
officers, legal counsel, or financial advisors, will, and that the Company shall
make reasonable efforts to cause its other affiliates,  employees and agents not
to,  directly  or  indirectly,  (i)  solicit or  initiate  (including  by way of
furnishing or disclosing non-public  information) any inquiries or the making of
any  proposal  with  respect  to any  merger,  consolidation  or other  business
combination  involving  the Company or the  acquisition  of all or a substantial
part of the assets or capital stock of the Company (an  "Acquisition  Proposal")
or (ii) negotiate,  knowingly  encourage or otherwise engage in discussions with
any person  (other  than  Baxter and its  representatives)  with  respect to any
Acquisition Proposal and (y) that the Company will not enter into any agreement,
arrangement or understanding with respect to any such Acquisition Proposal which
would require it to abandon,  terminate or fail to consummate  the Merger or any
other transaction  contemplated by this Agreement;  provided,  however, that (1)
the Company may, in response to an  unsolicited  written  proposal  from a third
party  regarding a Superior  Proposal  (as defined in Section  5.3(b)),  furnish
information to (and enter into a confidentiality  or similar agreement with) and
negotiate or otherwise  engage in  discussions  with,  such third party,  if the
Board of Directors of the Company  determines in good faith,  after consultation
with its outside counsel that such action is required for the Board of Directors
of the Company to comply with its fiduciary  duties under applicable law and (2)
concurrently  with compliance with Section  9.1(c)(i),  the Company,  upon three
days  prior  written  notice  to  Baxter,  may  accept  and may  enter  into any
definitive agreement relating to such Superior Proposal.


<PAGE> 32

                           (b)      The  Company  agrees  that  neither  the  
Company,  nor  any of its  directors,  officers,  legal  counsel,  or  financial
advisors shall, and the Company shall make reasonable efforts to cause its other
affiliates,  employees  and  agents  to,  immediately  cease  and  cause  to  be
terminated any existing activities,  discussions or negotiations with any person
(other than Baxter and its representatives) conducted heretofore with respect to
any  Acquisition  Proposal.  The Company agrees to promptly advise Baxter of (i)
any inquiries or proposals  received by, any  non-public  information  requested
from, or any  negotiations  or  discussions  sought to be initiated or continued
with,  the Company and (ii) any  inquiries or proposals  known by the Company to
have been received by, any non-public  information  known by the Company to have
been requested from, or any  negotiation or discussions  known by the Company to
have been sought to be initiated or continued with, its affiliates or any of the
respective  directors,  officers,  employees,  agents or  representatives of the
foregoing,   in  each  case  from  a  person   (other   than   Baxter   and  its
representatives)  with respect to an Acquisition  Proposal,  and (iii) the terms
thereof, including the identity of such third party and the general terms of any
financing   arrangement  or  commitment  in  connection  with  such  Acquisition
Proposal,  and the Company agrees to promptly  update Baxter on an ongoing basis
of the status thereof.  As used herein,  "Superior  Proposal" means a bona fide,
written and  unsolicited  proposal or offer made by any person (or group) (other
than  Baxter  or any of its  representatives)  with  respect  to an  Acquisition
Proposal on terms which the Board of Directors of the Company determines in good
faith (based on the written advice of  independent  financial  advisors),  to be
more  favorable  to the  Company  and its  stockholders  than  the  transactions
contemplated hereby; provided,  however, that such a proposal or offer shall not
be deemed to be a  "Superior  Proposal"  unless  the Board of  Directors  of the
Company  reasonably  determines  that any financing  required to consummate  the
transaction contemplated by such proposal or offer is capable of being obtained.

                           (c)  Nothing  contained  in this  Section  5.3  shall
prohibit the Company from taking and  disclosing to its  stockholders a position
contemplated  by 14d-9 or Rule  14e-2(a)  promulgated  under the Exchange Act or
from making any disclosure to the Company's  stockholders  if, in the good faith
judgment of the Board of  Directors  of the  Company,  after  consultation  with
outside  counsel,  failure  so  to  disclose  would  be  inconsistent  with  its
obligations  under any  applicable  law,  rule or  regulation or any duty of the
Company's Board of Directors.

                  Section  5.4 No WARN Act  Activities.  From  the  date  hereof
through the Closing Date,  the Company shall not  effectuate (i) a Plant Closing
affecting any site of employment  or one or more  facilities or operating  units
within any site of employment or facility of the Company's  business,  or (ii) a
Mass Layoff  affecting  any site of  employment  or  facility  of the  Company's
business  without  giving all  notices  required by the WARN Act, or any similar
state law or  regulation,  and the Company  shall assume all  liability  for any
alleged  failure to give such notice and indemnify and hold harmless  Baxter for
any and all  claims  asserted  under  the WARN Act or any  similar  state law or
regulation  because of a Plant  Closing or a Mass Layoff  occurring on or before
the Closing  Date.  For  purposes  of this  Agreement,  the Closing  Date is the
"effective date" for purposes of the WARN Act.


<PAGE> 33

                  Section 5.5 Stockholders'  Meeting. The Company shall call the
Special  Meeting  to be held as  promptly  as  practicable  for the  purpose  of
considering  and  voting  upon  this  Agreement  and the  Merger.  The  Board of
Directors of the Company shall  recommend that the  stockholders  of the Company
approve  and adopt  this  Agreement  and the  Merger.  Notwithstanding  anything
contrary  contained in this Section 5.5 or elsewhere in this  Agreement,  at any
time prior to the obtaining  such approval of the  Company's  stockholders,  the
Board of  Directors  of the Company,  to the extent that it  determines  in good
faith,  after  consultation  with outside  counsel,  that failure to do so would
create a risk of  liability  for breach its  fiduciary  duties to the  Company's
stockholders  under  applicable  law,  may  withdraw  or modify its  approval or
recommendation of this Agreement or the Merger.

                  Section  5.6 Rights  Plan.  The  Company  shall,  prior to the
Effective  Time,  cause the Rights to be  redeemed  pursuant to the terms of the
Rights Agreement, as in effect on the date hereof.

                  Section 5.7 Company  Stock Option  Plans.  The Company  shall,
prior to the Effective Time,  cause the ESPP, and the Company Stock Option Plans
and the agreements governing the Company Stock Options to be amended in order to
effectuate the  transactions  contemplated by this Agreement.  The Company shall
not open a new Purchase Period under the ESPP after June 30, 1998.

                                   ARTICLE VI

                       COVENANTS OF BAXTER AND MERGER SUB

                  Section  6.1  Directors'  and  Officers'  Indemnification  and
Insurance.   (a)  Baxter  and  Merger  Sub   acknowledge   that  all  rights  to
indemnification or exculpation now existing in favor of the directors, officers,
employees  and  agents  of  the  Company  as  provided  in  the  Certificate  of
Incorporation,  the Bylaws or  written  indemnity  agreements  or  otherwise  in
effect,  as of the date hereof,  with respect to matters  occurring prior to the
Effective  Time shall  survive  the Merger and shall  continue in full force and
effect. The certificate of incorporation and bylaws of the Surviving Corporation
shall contain  provisions with respect to  indemnification  and exculpation from
liability as set forth in the Certificate of Incorporation and Bylaws, as of the
date of this  Agreement,  which  provisions  will not be  amended,  repealed  or
otherwise  modified  for a period of six years after the  Effective  Time in any
manner that would  adversely  affect the rights  thereunder  of any  Indemnified
Party (as defined  below).  After the Effective  Time,  Baxter shall  indemnify,
defend and hold harmless the present and former officers,  directors,  employees
and agents of the  Company  (each an  "Indemnified  Party")  against all losses,
claims, damages,  liabilities,  fees and expenses (including reasonable fees and
disbursements of counsel and judgments,  fines, losses, claims,  liabilities and
amounts paid in settlement (provided,  that any such settlement is effected with
the prior  written  consent of  Baxter))  arising  out of  actions or  omissions
occurring at or prior to the Effective Time to the full extent  permitted  under
the laws of the State of  Delaware,  the  Certificate  of  Incorporation  or the
Bylaws,  in each  case,  as in effect at the date of this  Agreement,  including
provisions  therein  relating to the  advancement  of  expenses  incurred in the
defense of any action or suit.


<PAGE> 34

                           (b)      Baxter  shall  maintain  in effect  for not 
fewer  than six  years  from and  after  the  Effective  Time  the  policies  of
directors' and officers'  liability  insurance  most recently  maintained by the
Company  (provided,  that (i) Baxter  may,  consistent  with  Baxter's  existing
policies,  substitute  therefor its self insurance  program and/or policies with
reputable and financially sound carriers,  in either case providing at least the
same coverage and containing  terms and conditions no less  advantageous as long
as such  substitution does not result in gaps or lapses in coverage with respect
to claims  arising from or related to matters  occurring  prior to the Effective
Time) and (ii) with respect to any insurance  (including self insurance) that is
substituted  for the policies of directors'  and officers'  liability  insurance
most recently maintained by the Company, Baxter shall ensure that such insurance
does not contain  limitations  of the type contained in Rule 145(b) of the DGCL,
public policy  limitations or any other limitations in excess of the limitations
contained in such directors' and officers' liability insurance maintained by the
Company);  provided,  that in no event  shall  Baxter be required to expend more
than an amount  per year (the  "Premium  Amount")  equal to 200% of the  current
annual  premiums paid by the Company to maintain or procure  insurance  coverage
pursuant to this Section 6.1(b); provided,  further, that if Baxter is unable to
obtain the insurance called for this Section 6.1(b), Baxter shall obtain as much
comparable insurance as is available for the Premium Amount per year.

                           (c)      Baxter  and  Merger  Sub  jointly  and  
severally  agree to pay all expenses,  including  attorneys'  fees,  that may be
incurred  by the  Indemnified  Parties  in  enforcing  the  indemnity  and other
obligations provided for in this Section 6.1.

                           (d)      In the event Baxter or any of its successors
or assigns (i)  consolidates  with or merges into any other person and shall not
be the continuing or surviving  corporation or entity of such  consolidation  or
merger or (ii) transfers all or  substantially  all of its properties and assets
to any person,  then, and in each such case,  proper provisions shall be made so
that the successors and assigns of Baxter shall assume Baxter's  obligations set
forth in this Section 6.1.

                           (e)      The  provisions  of this Section 6.1 are 
intended to be for the benefit of, and shall be enforceable by, each Indemnified
Party, his or her heirs and his or her personal representatives.

                  Section  6.2  Blue  Sky.  Baxter  shall  use its  commercially
reasonably  efforts  to obtain  prior to the  Effective  Time all  approvals  or
permits  required  to  carry  out the  transactions  contemplated  hereby  under
applicable  blue sky laws in connection with the issuance of the CPRs and shares
of Baxter  Common  Stock in the Merger and as  contemplated  by this  Agreement;
provided,  however, that with respect to such qualifications  neither Baxter nor
the Company shall be required to register or qualify as a foreign corporation or
to take any action  which  would  subject  it to  general  service of process or
taxation in any  jurisdiction  where any such entity is not now so subject.  The
Company shall cooperate with Baxter in the making of all required  filings under
applicable  blue sky laws in connection with the issuance of the CPRs and shares
of Baxter Common Stock in the Merger in accordance with this Agreement.

                  Section 6.3 CPR  Agreement.  Baxter shall,  at or prior to the
Effective  Time,  cause the CPR  Agreement to be duly  authorized,  executed and
delivered by Baxter and,  assuming due authorization and delivery thereof by the
Trustee,  the CPR  Agreement  shall be a valid and binding  agreement of Baxter,
enforceable in accordance with its terms except the  enforceability  thereof may
be limited by (a)  applicable  bankruptcy,  insolvency,  moratorium,  fraudulent
transfer or similar laws affecting creditors' rights generally,  (b) the general
principles of equity (whether enforcement is considered at law or in equity) and
(c) the discretion of a court considering enforcement thereof.


<PAGE> 35

                  Section  6.4 NYSE  Listing.  Baxter  shall use its  reasonable
efforts to cause the shares of Baxter Common Stock to be issued in the Merger in
accordance  with this  Agreement  to be listed on the NYSE and on each  national
securities  exchange on which shares of Baxter  Common Stock may at such time to
be admitted for trading or listed, subject to official notice of issuance, prior
to the Effective Time.

                  Section 6.5  Employment Matters.  (a) Baxter shall cause the
Surviving  Corporation to offer employment to persons  specified in Schedule
6.5  ("Key  Existing  Employees")  of the  Company  Disclosure  Letter  on terms
specified therein.

                           (b)      Following the Closing,  Baxter intends to 
provide  employees  of the  Company  who become and  continue  to be employed by
Baxter or its  subsidiaries  with  total  compensation  benefits  comparable  to
similarly situated Baxter employees. Each employee of the Company who becomes an
employee of Baxter or its  subsidiaries  shall receive full credit (A) under the
applicable welfare benefit plans of Baxter in which such employee is eligible to
participate  for his or her time of service to the Company,  (B) for eligibility
and vesting (but not for benefit  accrual) under Baxter's  qualified  retirement
plans for his or her time of service to the Company and (C) under the  vacation,
sick leave and paid-time off policies of Baxter applicable to such employee, for
all  accrued and unused  vacation,  sick leave and  paid-time  off to which such
employee  is entitled as of the Closing  Date.  Notwithstanding  the  foregoing,
employees will begin to receive service credit for retiree  medical  benefits as
of the Closing Date. Baxter shall waive any pre-existing  condition  limitations
or waiting periods under such employee benefit plans.


                                   ARTICLE VII

                                MUTUAL COVENANTS

                  Section 7.1 Access to Information; Confidentiality. Subject to
the existing confidentiality agreement,  executed as of August 20, 1997, between
the Company and Baxter Healthcare Corporation (the "Confidentiality Agreement"),
between the date of this  Agreement  and the  Effective  Time,  upon  reasonable
notice the Company shall (i) give Baxter,  its affiliates  and their  respective
officers,  employees,  accountants,  counsel, financing sources and other agents
and  representatives  reasonable  access,  during normal  business hours, to all
plants, offices, warehouses and other facilities and to all contracts,  internal
reports,  data processing files and records,  federal,  state, local and foreign
tax returns and records, commitments, books, records and affairs of the Company,
whether  located on the premises of the Company or at another  location,  during
normal business hours;  (ii) furnish promptly to Baxter or its affiliates a copy
of each report,  schedule,  registration  statement and other  document filed or
received  by it during  such  period  pursuant  to the  requirements  of federal
securities laws or  regulations;  (iii) permit Baxter or its affiliates to make,
during normal business hours,  such inspections as they may reasonably  require;
(iv) cause its  officers  to furnish  Baxter and its  affiliates  such  existing
financial,  operating,  technical  and product data and other  information  with
respect  to  the  business  and  properties  of the  Company  as  Baxter  or its
affiliates  from  time  to  time  may  reasonably  request,   including  without
limitation  financial  statements  and  schedules;  (v)  allow  Baxter  and  its
affiliates the  opportunity  to interview such employees and other  personnel of
the Company with the Company's prior written consent, which consent shall not be
unreasonably  withheld;  and (vi)  assist  and  cooperate  with  Baxter  and its
affiliates in the development of integration plans for  implementation by Baxter
and its affiliates and the Surviving  Corporation  following the Effective Time;
provided,  however, that no investigation pursuant to this Section 7.1 or notice
pursuant to Section 7.6 shall  affect or be deemed to modify any  representation
or warranty  made by the Company  herein.  Until the Effective  Time,  materials
furnished to Baxter or its  affiliates  pursuant to this Section 7.1 may be used
by Baxter or its affiliates  solely for continued  evaluation of the Company and
integration   planning  purposes  relating  to  accomplishing  the  transactions
contemplated hereby and for compliance with the applicable  securities laws, and
shall  be  kept  in  confidence   by  Baxter   pursuant  to  the  terms  of  the
Confidentiality Agreement.


<PAGE> 36

                  Section 7.2 HSR Act. The Company,  Baxter and Merger Sub shall
take  all  reasonable   actions   necessary  to  file  as  soon  as  practicable
notifications under the HSR Act and to respond as promptly as practicable to any
inquiries  received from the Federal Trade Commission and the Antitrust Division
of the Department of Justice for additional  information or documentation and to
respond as promptly as practicable  to all inquiries and requests  received from
any state  attorney  general or other  Governmental  Entity in  connection  with
antitrust matters.

                  Section  7.3  Consents  and  Approvals.  Each of the  Company,
Baxter and  Merger  Sub will take all  reasonable  actions  necessary  to comply
promptly with all legal  requirements which may be imposed on it with respect to
this  Agreement and the  transactions  contemplated  hereby (which actions shall
include without limitation furnishing all information required under the HSR Act
and in  connection  with  approvals  of or filings  with any other  Governmental
Entity) and will promptly  cooperate with and furnish  information to each other
in  connection  with  any  such  requirements  imposed  on  it  or  any  of  its
subsidiaries,  if any, in connection  with this  Agreement and the  transactions
contemplated  hereby. Each of the Company,  Baxter and Merger Sub will, and will
cause its  respective  subsidiaries,  if any,  to, take all  reasonable  actions
necessary  to obtain  (and will  cooperate  with each  other in  obtaining)  any
consent,  authorization,  order  or  approval  of,  or  any  exemption  by,  any
Governmental  Entity or other  public or  private  third  party  required  to be
obtained or made by Baxter,  Merger Sub, the Company or any of their  respective
subsidiaries,  if any, in connection with the Merger or the taking of any action
contemplated thereby or by this Agreement.

                  Section 7.4 Publicity. So long as this Agreement is in effect,
neither the Company,  Baxter nor any of their respective  affiliates shall issue
or cause the publication of any press release or other announcement with respect
to the Merger,  this  Agreement or the other  transactions  contemplated  hereby
without the prior  consultation with the other party,  except as may be required
by law or by any listing agreement with a national securities exchange.

                  Section 7.5 Filings  with the  Commission.  (a) As promptly as
practicable after the execution of this Agreement, the Company shall prepare and
file  with the  Commission  the Proxy  Statement/Prospectus,  and  Baxter  shall
prepare and file with the Commission the Registration Statement.  Each of Baxter
and  the  Company  (i)  shall  cause  the  Proxy  Statement/Prospectus  and  the
Registration  Statement to comply as to form in all material  respects  with the
applicable  provisions of the Securities Act, the Exchange Act and the rules and
regulations  thereunder,  (ii) shall use commercially reasonable efforts to have
or cause the Registration Statement to become effective and the CPR Agreement to
become  qualified  under the Trust Indenture Act, as promptly as practicable and
(iii)  shall take all or any action  required  under any  applicable  federal or
state securities laws in connection with the issuance of shares of Baxter Common
Stock and the CPRs pursuant to the Merger.  The Company and Baxter shall furnish
to the other all information  concerning the Company and Baxter as the other may
reasonably  request in connection with the preparation of the documents referred
to herein.  As promptly as practicable  after the  Registration  Statement shall
have become  effective and the CPR Agreement has been qualified  under the Trust
Indenture  Act,  the Company  shall mail the Proxy  Statement/Prospectus  to its
stockholders.


<PAGE> 37

                           (b)      The  information  supplied by each of the 
Company and Baxter for  inclusion in the  Registration  Statement  and the Proxy
Statement/Prospectus  shall not, at (i) the time the  Registration  Statement is
declared  effective,  (ii)  the  time  the  Proxy  Statement/Prospectus  (or any
amendment thereof or supplement  thereto) is first mailed to the stockholders of
the Company,  (iii) the time of the Special Meeting, or (iv) the Effective Time,
contain any untrue  statement  of a material  fact or omit to state any material
fact required to be stated  therein or necessary in order to make the statements
therein not  misleading.  If, at any time prior to the Effective Time, any event
or circumstance  relating to the Company,  Baxter,  any subsidiary of Baxter, or
their respective officers or directors, should be discovered by such party which
should  be set  forth  in an  amendment  or a  supplement  to  the  Registration
Statement or the Proxy  Statement/Prospectus,  such party shall promptly  inform
the other thereof and take appropriate action in respect thereof.

                  Section  7.6 Advice of Changes.  The Company and Baxter  shall
each  promptly  give  notice  to the  other  party  upon  becoming  aware of any
representation  or warranty of the Company or Baxter contained in this Agreement
becoming  untrue or  inaccurate  in any  material  respect or the failure by the
Company or Baxter to timely  comply  with or satisfy  any  material  covenant or
agreement to be complied with or satisfied by it under this  Agreement and shall
use its  reasonable  best efforts to prevent or promptly  remedy same. No notice
given  hereunder  shall  affect or be deemed to  modify  any  representation  or
warranty made by the Company or Baxter herein.

                  Section 7.7  Additional  Agreements.  Subject to the terms and
conditions  herein  provided,  each  of the  parties  hereto  agrees  to use all
reasonable efforts to take, or cause to be taken, all action and to do, or cause
to be done, all things necessary,  proper or advisable under applicable laws and
regulations to consummate and make effective the  transactions  contemplated  by
this Agreement,  including using all reasonable  efforts to obtain all necessary
waivers, consents and approvals in connection with any governmental requirements
set forth in  Section  3.4 and 4.6 of the  Agreement,  to effect  all  necessary
registrations  and  filings.  In case at any time after the  Effective  Time any
further  action is  necessary  or  desirable  to carry out the  purposes of this
Agreement,  the proper  officers  and/or  directors of Baxter and the  Surviving
Corporation and the former  officers and/or  directors of the Company shall take
all such necessary action.

                  Section 7.8 Tax Matters.  Concurrently  with the  execution of
this  Agreement,  and again on the  Closing  Date,  Baxter  and Merger Sub shall
execute and deliver to the Company and the Company  shall execute and deliver to
Baxter and Merger Sub, a certificate  in the form  heretofor  agreed upon by the
parties  (the "Tax Matters  Certificate").  Neither  Baxter,  Merger Sub nor the
Company shall take any action which would cause its respective  representations,
warranties  and  covenants in the Tax Matters  Certificate  to become  untrue or
breached in any material respect.

                                  ARTICLE VIII
                    CONDITIONS TO CONSUMMATION OF THE MERGER

                  Section 8.1  Conditions  to Each Party's  Obligation to Effect
the Merger. The respective  obligations of each party to effect the Merger shall
be subject to the  satisfaction  or waiver,  on or prior to the Closing Date, of
the following conditions:

                           (a)      Governmental Approvals. All authorizations,
consents, orders or approvals of, or declarations or filings with, or expiration
of waiting periods imposed by, and federal, state, local or foreign Governmental
Entity  necessary  for the  consummation  of the  Merger  and  the  transactions
contemplated by this Agreement shall have been filed,  occurred or been obtained
and shall be in effect at the Effective Time.


<PAGE> 38

                           (b)      Legal  Action.  No  temporary  restraining  
order, preliminary injunction or permanent injunction or other order precluding,
restraining, enjoining, preventing or prohibiting the consummation of the Merger
shall  have  been  issued  by  a  federal,  state  or  foreign  court  or  other
Governmental Entity and remain in effect.

                           (c)  Statutes.  No federal,  state,  local or foreign
statute,  rule or  regulation  shall  have  been  enacted  which  prohibits  the
consummation of the Merger or would make the consummation of the Merger illegal.

                           (d)      Stockholder Approval. This Agreement and the
transactions  contemplated  hereby  shall have been  approved and adopted by the
requisite vote of the stockholders of the Company in accordance with and subject
to applicable law.

                           (e)      Registration  Statement.  The  Registration 
Statement shall have been declared  effective under the Securities Act and shall
not be the subject of any stop order or proceedings seeking a stop order.

                           (f) CPR Agreement.  The CPR Agreement shall have been
duly qualified under the Trust Indenture Act.

                           (g)      Change in Tax Law. There shall have occurred
no amendment to the Code or promulgation of a Treasury Regulation  thereunder or
a judicial interpretation thereof published, after the date of the Agreement, by
a Federal  Court (a  "Change  in Tax Law")  that  would  cause  the  Merger,  if
consummated  after the  effective  date of such  Change  in Tax Law,  to fail to
qualify as a reorganization under Section 368 of the Code.

                           (h) Listing.  The shares of Baxter Common Stock to be
issued pursuant to this Agreement shall have been listed on the NYSE, subject to
official notice of issuance.

                  Section 8.2  Conditions  of  Obligations  of Baxter and Merger
Sub.  The  obligation  of Baxter  and Merger Sub to effect the Merger is further
subject to the  satisfaction  at or prior to the Closing  Date of the  following
conditions, unless waived by Baxter and Merger Sub:

                           (a)      The  representations  and warranties of the 
Company set forth in this Agreement (i) shall, when made, be true and correct in
all  material  respects  and (ii) shall be true and correct as if made as of the
Closing Date (unless such representation or warranty is, by its terms, made only
as of a specific  other date and time),  except,  in the case of (ii),  for such
inaccuracies  as would not be  reasonably  expected  to have a Material  Adverse
Effect.

                           (b)      The Company shall have performed,  in all 
material respects, and complied, in all material respects,  with all obligations
and  covenants  required  to be  performed  or  complied  with by it under  this
Agreement at or prior to the Closing Date.

                           (c)      The Company shall have obtained all 
consents, approvals, authorizations and permits referred to in Section 8.2(c) of
the Company Disclosure Letter.


<PAGE> 39

                           (d) Baxter and  Merger Sub shall have  received  from
the Company an  officer's  certificate,  executed on behalf of the Company by an
authorized officer confirming,  to such officers' knowledge, that the conditions
set forth in Sections 8.2(a) and (b) have been complied with.

                           (e)  From  the  date of this  Agreement  through  the
Effective Time, no event shall have occurred which shall be reasonably likely to
result or shall have resulted in a Material Adverse Effect.

                           (f) Baxter and  Merger  Sub shall  have  received  an
opinion from Cooley Godward LLP,  special counsel to the Company,  substantially
in the  form  of  Annex C  attached  hereto,  subject  to  such  exceptions  and
qualifications as are customary for such counsel and opinions of such type.

                           (g)  Such  Key  Existing   Employees   designated  in
paragraphs  (A) and (B) on Schedule 6.5 of the Company  Disclosure  Letter shall
have entered into  employment  or other  agreements  for the periods and on such
other terms substantially as set forth in the Company Disclosure Letter.

                           (h) The aggregate  number of shares of Company Common
Stock  constituting  Dissenting  Shares shall be less than seven  percent of the
outstanding  shares of Company Common Stock  immediately  prior to the Effective
Time.

                  Section 8.3  Conditions  of  Obligations  of the Company.  The
obligations  of the  Company to effect the  Merger  are  further  subject to the
satisfaction at or prior to the Closing Date of the following conditions, unless
waived by the Company:

                           (a)      The representations and warranties of Baxter
and Merger Sub set forth in this  Agreement  (i) shall,  when made,  be true and
correct in all  material  respects and (ii) shall be true and correct as if made
as of the Closing Date (unless such representation or warranty is, by its terms,
made only as of a specific  other date and time),  except,  in the case of (ii),
for such  inaccuracies  which would not be reasonably  expected to have a Baxter
Material Adverse Effect.

                           (b)      Baxter and Merger Sub shall have  performed 
and  complied,  in all material  respects,  with all  obligations  and covenants
required to be  performed  or complied  with by them under this  Agreement at or
prior to the Closing Date.

                           (c)      Baxter and Merger Sub shall have obtained   
all consents, approvals, authorizations and permits referred to in Section 4.6.

                           (d) The Company  shall have  received from Baxter and
Merger Sub an officer's certificate executed on behalf of each of Baxter and the
Merger Sub by an authorized  officer  confirming,  to such officer's  knowledge,
that the conditions  set forth in Sections  8.3(a) and 8.3(b) have been complied
with.

                           (e)      The Company shall have received an opinion 
from Thomas J. Sabatino,  Jr.,  Corporate Vice President and General  Counsel of
Baxter,  substantially in the form of Annex D attached  hereto,  subject to such
exceptions and  qualifications as are customary for such counsel and opinions of
such type.

                           (f)  From  the  date of this  Agreement  through  the
Effective Time, no event shall have occurred which shall be reasonably likely to
result or shall have resulted in a Baxter Material Adverse Effect.


<PAGE> 40

                                   ARTICLE IX

                        TERMINATION, AMENDMENT AND WAIVER

                  Section 9.1  Termination.  Anything herein or elsewhere to the
contrary notwithstanding, this Agreement may be terminated and the Merger may be
abandoned  at any time  prior to the  Effective  Time,  whether  before or after
stockholder approval thereof:

                           (a)      By Mutual Consent.  By mutual consent of the
Board of Directors of Baxter and the Board of Directors of the Company.

                           (b)      By Baxter and Merger Sub or the Company.  By
the Board of Directors of Merger Sub, Baxter or the Company:

                                    (i)     if the Merger shall not have been  
consummated on or prior to July 31, 1998; provided,  however,  that the right to
terminate this Agreement under this Section  9.1(b)(i) shall not be available to
any party whose failure to fulfill any material  obligation under this Agreement
has  been  the  cause  of or  resulted  in,  the  failure  of the  Merger  to be
consummated on or prior to such date; or

                                    (ii) if a court of competent jurisdiction or
other Governmental  Entity shall have issued an order, decree or ruling or taken
any other action (which order, decree, ruling or other action the parties hereto
shall  use  their  reasonable   efforts  to  lift),  in  each  case  permanently
restraining,  enjoining, or otherwise prohibiting the transactions  contemplated
by this  Agreement  and such order,  decree,  ruling or other  action shall have
become final and non-appealable.

                                    (iii) if (a) the Special Meeting  (including
any  adjournments  thereof) shall have been held and completed and the Company's
stockholders  shall have taken a final vote on a proposal  to approve  and adopt
this  Agreement and to approve the Merger,  and (b) the adoption and approval of
this  Agreement  and the  approval of the Merger by the holders of a majority of
the shares of  Company  Common  Stock  outstanding  on the  record  date for the
Special Meeting shall not have been obtained.

                           (c) By the Company.  By the Board of Directors of the
Company:

                                    (i)     if, prior to the  Effective  Time, 
the Company shall have (A) accepted a Superior  Proposal in compliance  with the
terms of Section  5.3 hereof and (B) paid or caused to be paid the fee  provided
for in Section 10.1(b) hereof; or

                                    (ii) if, prior to the  Effective  Time,  (A)
the Company is not in material  breach of this  agreement,  (B) Baxter or Merger
Sub breaches or fails in any  material  respect to perform or comply with any of
its covenants and agreements  contained  herein or breaches its  representations
and warranties in a manner which would cause any of the conditions  contained in
Sections  8.3(a) or 8.3(b) not to be satisfied,  and (C) such breach or failure,
if  curable,  shall not have been cured in all  material  respects  by Baxter or
Merger Sub within thirty days following receipt by Baxter of written notice from
the Company describing such breach or failure.

                           (d)      By Baxter.  By the Board of Directors of
Baxter:


<PAGE> 41

                                    (i)     if (A)  neither  Baxter nor Merger  
Sub is in material breach of this Agreement and (B) prior to the Effective Time,
the Board of  Directors  of the  Company  shall have  withdrawn,  or modified or
changed (including by amendment to the Proxy  Statement/Prospectus)  in a manner
adverse to Baxter or Merger Sub its approval or  recommendation of the Merger or
this Agreement, or shall have recommended a Superior Proposal; or

                                    (ii) if prior  to the  Effective  Time,  (A)
neither Baxter nor Merger Sub is in material breach of this  Agreement,  (B) the
Company  breaches or fails in any material respect to perform or comply with any
of its covenants and agreements contained herein or breaches its representations
and  warranties  in a manner  which  would  result in any of the  conditions  in
Section 8.2(a) or 8.2(b) not being satisfied, and (C) such breach or failure, if
curable,  shall not have been  cured in all  material  respects  by the  Company
within thirty days  following  receipt by the Company of written notice from the
Baxter or Merger Sub describing such breach or failure.

                  Section  9.2 Effect of  Termination  and  Abandonment.  In the
event of termination of this Agreement as provided in Section 9.1 above, written
notice thereof shall forthwith be given to the other party or parties specifying
the  provision  hereof  pursuant  to which such  termination  is made,  and this
Agreement shall  forthwith  become null and void and there shall be no liability
or  obligation  on the part of Baxter and  Merger  Sub,  or any of them,  or the
Company, or their respective  officers,  directors or employees,  except (a) for
fraud or for material  willful  breach of this Agreement and (b) as set forth in
this Section 9.2, in Section 10.1 hereof and in the  Confidentiality  Agreement.
No  termination of this  Agreement  shall affect the  obligations of the parties
contained  in the  Confidentiality  Agreement,  all of which  obligations  shall
survive termination of this Agreement in accordance with their terms.

                                    ARTICLE X

                               GENERAL PROVISIONS

                  Section 10.1 Fees and Expenses.  (a) Except as contemplated by
this  Agreement,  including  Section  10.1(b)  hereof,  all costs  and  expenses
incurred  in  connection  with  this  Agreement  and  the  consummation  of  the
transactions  contemplated  hereby  shall be paid by the  party  incurring  such
expenses.

                           (b)      If (A) this Agreement is validly  terminated
by the  Company  pursuant  to  Section  9.1(c)(i)  and  (B) at the  time of such
termination,  neither Baxter nor Merger Sub shall be in breach of this Agreement
in any material  respect and there shall not have occurred and continue to exist
a Baxter Material Adverse Effect, then, concurrently with such termination,  the
Company  shall pay or cause to be paid to Baxter  (by wire  transfer)  an amount
equal to $5.0 million.

                           (c) If (A) this  Agreement is validly  terminated  by
Baxter pursuant to Section  9.1(d)(i),  and (B) at the time of such termination,
neither Baxter nor Merger Sub shall be in breach in any material respect of this
Agreement  and there  shall not have  occurred  and  continue  to exist a Baxter
Material   Adverse  Effect,   then,   within  three  business  days  after  such
termination,  the  Company  shall  pay or  cause to be paid to  Baxter  (by wire
transfer) an amount equal to $5.0 million.

                           (d)      If (A) this Agreement is validly terminated 
by the Company or by Baxter pursuant to Section 9.1(b)(iii),  (B) an Acquisition
Proposal shall have been made and publicly  announced at or prior to the Special
Meeting  (or  any  adjournment  or  postponement  thereof),  (C) an  Acquisition
Proposal  shall  have been  consummated  within  six  months of the date of such
termination  and (D) at the time of termination  of this  Agreement  pursuant to
Section  9.1(b)(iii),  neither  Baxter  nor Merger Sub shall be in breach in any
material  respect  of this  Agreement  and  there  shall not have  occurred  and
continue to exist a Baxter Material Adverse Effect,  then, upon  consummation of
such Acquisition  Proposal,  the Company shall pay or cause to be paid to Baxter
(by wire transfer) an amount equal to $5.0 million.


<PAGE> 42

                  Section 10.2 Amendment and Modification. Subject to applicable
law, this  Agreement may be amended,  modified and  supplemented  in any and all
respects,  whether before or after any vote of the  stockholders  of the Company
contemplated  hereby,  by written  agreement of the parties  hereto,  based upon
action taken by their respective  Boards of Directors,  at any time prior to the
Effective  Time with  respect to any of the terms  contained  herein;  provided,
however,  that after the approval of this Agreement by the  stockholders  of the
Company,  no such amendment,  modification or supplement  shall reduce or change
the Merger Consideration.

                  Section 10.3   Nonsurvival of Representations and Warranties. 
None of the  representations  and warranties in this Agreement shall survive the
Effective Time.

                  Section  10.4  Notices.  All notices and other  communications
hereunder shall be in writing and shall be deemed given upon personal  delivery,
facsimile  transmission (which is confirmed),  telex or delivery by an overnight
express courier service  (delivery,  postage or freight charges prepaid),  or on
the  fourth  day  following  deposit  in the  United  States  mail  (if  sent by
registered or certified mail,  return receipt  requested,  delivery,  postage or
freight charges  prepaid),  addressed to the parties at the following  addresses
(or at such other address for a party as shall be specified by like notice):

                           (a)      If to Baxter or Merger Sub, to:

                                    c/o Baxter International Inc.
                                    One Baxter Parkway
                                    Deerfield, Illinois  60015
                                    Telecopy No.:  (847) 940-6271
                                    Attention:  General Counsel

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

                                    Skadden, Arps, Slate, Meagher & Flom LLP
                                    300 South Grand Avenue, Suite 3400
                                    Los Angeles, California 90071-3144
                                    Telecopy No.: (213) 687-5600
                                    Attention: Joseph J. Giunta

                           (b)      if to the Company, to:

                                    Somatogen, Inc.
                                    2545 Central Avenue, Suite FD1
                                    Boulder, CO  80301-2857
                                    Telecopy No.:  (303) 440-3013
                                    Attention:  President and Chief Executive 
                                    Officer

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

                                    Cooley Godward LLP
                                    2595 Canyon Boulevard, Suite 250
                                    Boulder, Colorado  80302-6737
                                    Telecopy No.:  (303) 546-4099
                                    Attention:  James C.T. Linfield


<PAGE> 43

                  Section  10.5  Definitions;  Interpretation.  As  used in this
Agreement,  the term  "affiliate(s)"  shall have the  meaning  set forth in Rule
12b-2 of the  Exchange  Act.  When a reference  is made in this  Agreement to an
Article,  Section or Schedule, such reference shall be to an Article, Section or
Schedule to this Agreement  unless  otherwise  indicated.  The words  "include,"
"includes" and  "including"  when used herein shall be deemed in each case to be
followed by the words "without  limitation."  The table of contents and headings
contained in this Agreement are for reference purposes only and shall not affect
in any way the meaning or interpretation of this Agreement.

                  Section 10.6  Specific  Performance.  In addition to any other
remedies  available at law, or in equity, it is agreed that the parties shall be
entitled to an injunction or injunctions  to prevent  breaches of this Agreement
and to enforce  specifically  the terms and  provisions of this Agreement in any
court of the United States located in the State of Delaware or in Delaware state
court. In addition,  each of the parties hereto (a) consents to commit itself to
the personal  jurisdiction of any Federal court located in the State of Delaware
or any  Delaware  state  court  in the  event  any  dispute  arises  out of this
Agreement or any of the transactions  contemplated by this Agreement, (b) agrees
that it will not attempt to deny or defeat such personal  jurisdiction by motion
or other  request for leave from any court and (c) agrees that it will not bring
any action relating to this Agreement or any of the transactions contemplated by
this  Agreement  in any court other than  federal or state court  sitting in the
State of Delaware.

                  Section 10.7  Counterparts.  This Agreement may be executed in
one or more  counterparts,  each of which shall be  considered  one and the same
agreement and shall become  effective  when two or more  counterparts  have been
signed  by each of the  parties  and  delivered  to the  other  party,  it being
understood that all parties need not sign the same counterpart.

                  Section 10.8 Entire Agreement;  No Third-Party  Beneficiaries.
This Agreement  (including the documents and the instruments referred to herein)
and the  Confidentiality  Agreement  (a)  constitute  the entire  agreement  and
supersede all prior agreements and understandings,  both written and oral, among
the  parties  with  respect to the subject  matter  hereof,  and (b),  except as
provided in Section  6.1(d)  hereof,  are not intended to confer upon any person
other than the parties hereto any rights or remedies hereunder.

                  Section 10.9 Severability. If any term, provision, covenant or
restriction of this Agreement is held by a court of competent jurisdiction or to
another authority to be invalid,  void,  unenforceable or against its regulatory
policy,  the remainder of the terms,  provisions,  covenants and restrictions of
this  Agreement  shall  remain in full  force and  effect and shall in no way be
affected, impaired or invalidated.

                  Section 10.10  Governing Law. This Agreement shall be governed
and  construed  in  accordance  with the laws of the State of Delaware  (without
giving effect to the conflicts of laws principles thereof).

                  Section 10.11  Assignment.  Neither this  Agreement nor any of
the rights,  interests or obligations  hereunder shall be assigned by any of the
parties  hereto  (whether by  operation of law or  otherwise)  without the prior
written consent of the other parties,  except that Merger Sub may assign, in its
sole discretion,  any or all of its rights,  interests and obligations hereunder
to Baxter or to any,  direct or  indirect,  wholly owned  subsidiary  of Baxter.
Subject to the preceding sentence, this Agreement will be binding upon, inure to
the benefit of and be enforceable by the parties and their respective successors
and assigns.



<PAGE> 44



IN WITNESS WHEREOF,  each of Baxter,  Merger Sub and the Company has caused this
Agreement to be executed on its behalf by its duly authorized officers hereunder
all as of the date first above written.

                                   BAXTER INTERNATIONAL INC.



                                   By:    Harry M. Jansen Kraemer, Jr.
                                   Name:  Harry M. Jansen Kraemer, Jr.
                                   Title:    President



                                   RHB1 ACQUISITION CORP.



                                   By:    John F. Gaither, Jr.
                                   Name:  John F. Gaither, Jr.
                                   Title:    Vice President



                                   SOMATOGEN, INC.



                                   By:    Andre de Bruin
                                   Name:  Andre de Bruin
                                   Title: President and CEO



<PAGE> 45




                            Baxter International Inc.

No.                             Certificate for ____  Contingent Payment Rights


                  This certifies that, or registered assigns (the "Holder"), is
the registered  holder of the number of Contingent  Payment Rights  ("CPRs") set
forth above. Each CPR entitles the Holder,  subject to the provisions  contained
herein and in the Agreement  referred to on the reverse hereof, to payments from
Baxter International Inc., a Delaware corporation (the "Company"),  in an amount
and in the form  determined  pursuant to the provisions set forth on the reverse
hereof and as more fully  described in the Agreement  referred to on the reverse
hereof.  Such payment  shall be made on each  Payment  Date or, if earlier,  the
Redemption  Date or the Default  Payment Date,  each as defined in the Agreement
referred to on the reverse hereof.

                  Payment of any amounts pursuant to this CPR Certificate  shall
be made only to the registered  Holder (as defined in the Agreement) of this CPR
Certificate. Such payment shall be made in the Borough of Manhattan, The City of
New York,  or at any other office or agency  maintained  by the Company for such
purpose, in such coin or currency of the United States of America as at the time
is legal tender for the payment of public and private debts; provided,  however,
the  Company  may pay such  amounts by wire  transfer  or check  payable in such
money. First Trust National  Association has been initially  appointed as Paying
Agent in the Borough of Manhattan, The City of New York.

                  Reference is hereby made to the further provisions of this CPR
Certificate set forth on the reverse hereof,  which further provisions shall for
all purposes have the same effect as if set forth at this place.

                  Unless the certificate of authentication  hereon has been duly
executed by the Trustee  referred to on the reverse hereof by manual  signature,
this CPR  Certificate  shall not be entitled to any benefit under the Agreement,
or be valid or obligatory for any purpose.



<PAGE> 46


                  IN WITNESS WHEREOF,  the Company has caused this instrument to
be duly executed.


Dated:                                      Baxter International Inc.



                                            By______________________________







Attest:



___________________________

Authorized Signature







<PAGE> 47




                      [Form of Reverse of CPR Certificate]

                  This CPR  Certificate  is issued under and in accordance  with
the Contingent  Payment Rights  Agreement,  dated as of [insert date], 1998 (the
"Agreement"),  between  the  Company and First  Trust  National  Association,  a
national  association,  as  trustee  (the  "Trustee,"  which term  includes  any
successor  Trustee  under  the  Agreement),  and is  subject  to the  terms  and
provisions contained in the Agreement,  to all of which terms and provisions the
Holder of this CPR Certificate  consents by acceptance  hereof. The Agreement is
hereby  incorporated  herein by reference  and made a part hereof.  Reference is
hereby made to the  Agreement  for a full  statement of the  respective  rights,
limitations of rights,  duties,  obligations  and  immunities  thereunder of the
Company,  the Trustee and the holders of the CPRs. All capitalized terms used in
this CPR  Certificate  without  definition  shall have the  respective  meanings
ascribed to them in the  Agreement.  Copies of the  Agreement can be obtained by
contacting the Trustee.

                  Subject to  extension  or earlier  redemption  as  hereinafter
provided,  until March 15, 2008,  the Company  shall pay to the Holder hereof on
March 15 and  September  15 of each year (or if such day is not a Business  Day,
without accruing any interest,  on the next succeeding Business Day),  beginning
March 15,  1999,  or if such day is not a Business  Day,  without  accruing  any
interest, on the next Business Day (as the same may be extended, each a "Payment
Date"),  for each CPR represented  hereby,  a pro rata portion of the Contingent
Payment with respect to the Payment  Measuring Period ended immediately prior to
such Payment Date,  unless the CPR(s)  represented by this CPR Certificate shall
have been redeemed as provided for herein;  provided, that in no event shall the
aggregate of all Contingent Payments with respect to each CPR exceed two dollars
($2.00) and, provided,  further,  that in no event shall the Company be required
to a make a payment on any Payment Date in an amount less than $0.05 per CPR and
such amounts which would  otherwise be payable on such Payment Date shall (x) be
aggregated  with the amount  payable with respect to the next Payment  Measuring
Period and (y) not bear interest except on a Default Payment Date.

                  The   "Contingent   Payment,"  with  respect  to  any  Payment
Measuring Period,  equals five percent of the Net Sales that are attributable to
the commercial sale of Products.

                  "Net  Sales"  means the actual  gross  amount  invoiced by the
Company,  its Affiliates,  licensees or distributors for the sale of Products to
any  third  parties  during  a  Payment   Measuring   Period  less:  (a)  direct
transportation  charges,  including  insurance;  (b) trade,  quantity  and other
discounts and rebates  actually allowed and taken to the extent customary in the
trade; and (c) allowances or credits,  including but not limited to,  allowances
or credits to  customers  on account  of  rejection  or return of the  Products;
provided  that (i) a sale or transfer to an  Affiliate of the Company for resale
by such  Affiliate  shall  not be  considered  a sale  for the  purpose  of this
provision,  but the resale by such Affiliate  shall be a sale for such purposes,
and the term "sale" shall include a transfer or other disposition to a customer;
(ii) Net Sales shall not include  reserves for bad debts or allowances,  credits
or rebates not covered  above;  and (iii) a sale of Products  shall occur at the
earlier of (a) the  transfer  of title in such  Products to a third party or (b)
the shipment of such Products from the manufacturing or warehouse  facilities of
the manufacturer of such Products to a third party.


<PAGE> 48

                  Net Sales  shall not  include  license  fees or other  advance
payments  received by the Company from a licensee or distributor of the Products
which is not derived from sales of Products,  but shall include the Net Sales of
such licensee or distributor.

                  "Payment  Measuring  Period"  means  (i) the  period  from the
Effective Date to December 31, 1998 and (ii) each six month period ended June 30
and December 31 thereafter, through and including the Final Payment Date.

                  "Products" shall mean all products in which the primary active
ingredient  is  human  hemoglobin,  or  derivatives,  mutants  or  modifications
thereof, which have been produced in culture of microbial cells (including yeast
cells)  which  have  been  modified  using  Somatogen   Recombinant   Hemoglobin
Technology  (other than clinical  indications  for any such Products that are in
clinical trials as of the date of the Merger Agreement).

                  "Somatogen  Recombinant  Hemoglobin Technology" shall mean all
technology  owned by or licensed to Somatogen on or prior to the Effective Date,
which involves the use of recombinant DNA techniques.

                  If for any reason the Contingent  Payment has not been finally
determined as of the Payment Date,  then the Payment Date will be  automatically
extended until the date that is the seventh Business Day after the date of which
the Contingent Payment has been finally determined.

                  The CPRs will be redeemable,  in whole or in part, at any time
and from time to time,  at the option of the Company at a  redemption  price for
each CPR  represented  hereby equal to $2 less all  Contingent  Payments made or
provided for,  through the Redemption  Date. The Agreement does not prohibit the
Company from otherwise acquiring CPRs.

                  The Contingent  Payment, if any, and interest thereon, if any,
shall be payable by the Company in such coin or currency of the United States of
America  as at the time is legal  tender for the  payment of public and  private
debts; provided,  however, the Company may pay such amounts by its check or wire
transfer  payable in such  money.  First  Trust  National  Association  has been
initially appointed as Paying Agent in the Borough of Manhattan, The City of New
York.

                  If an Event of Default  occurs and is  continuing,  either the
Trustee may or if the Holders  holding an aggregate of at least fifty percent of
the  Outstanding  CPRs,  by notice to the Company and to the Trustee shall bring
suit to recover all amounts then due and payable,  with  interest at the Default
Interest Rate from the Default  Payment Date through the date payment is made or
duly provided for.


<PAGE> 49

                  In the event that, it is finally  determined that no amount is
payable on the CPRs to the Holder on any Payment  Date,  the Company  shall give
the Trustee notice of such determination. The failure to give such notice or any
defect therein shall not affect the validity of such determination.

                  The  Agreement  permits,  with certain  exceptions  as therein
provided,  the  amendment  thereof  and  the  modification  of  the  rights  and
obligations  of the  Company  and the  rights of the  holders  of CPRs under the
Agreement  at any time by the Company  and the  Trustee  with the consent of the
holders of a majority of the CPRs at the time outstanding.

                  No reference  herein to the Agreement and no provision of this
CPR  Certificate or of the Agreement shall alter or impair the obligation of the
Company,  which is absolute  and  unconditional,  to pay any amounts  determined
pursuant  to the terms  hereof  and of the  Agreement  at the  times,  place and
amount,  and  in  the  manner,  herein  prescribed.   The  Holder  of  this  CPR
Certificate,  by acceptance hereof, agrees that the Company has no obligation to
initiate or continue research,  development or commercialization activities with
respect to Products or any of the Somatogen  Recombinant  Hemoglobin  Technology
and, in its sole  subjective  discretion,  the  Company  may abandon  efforts to
research, develop or commercialize such technology or Products.

                  The  Agreement  provides  that the  Trustee  shall  receive an
Officers'   Certificate,   on  or  before  each  Payment  Date,  certifying  the
Consolidated  Revenues from sales of Products.  The Agreement also provides that
The  Company  shall not  transfer  (other than  transfers  to  Subsidiaries  and
Affiliates)  the  Somatogen   Recombinant   Hemoglobin   Technology  unless  the
transferor agrees to be bound by the Agreement to the same extent as the Company
is then  bound  thereby,  whereupon  the  Company  shall  be  released  from any
obligation under the Agreement.

                  As   provided  in  the   Agreement   and  subject  to  certain
limitations  therein set forth, the transfer of the CPRs represented by this CPR
Certificate is registrable on the Security Register,  upon surrender of this CPR
Certificate for  registration of transfer at the office or agency of the Company
maintained  for such purpose in the Borough of Manhattan,  The City of New York,
duly  endorsed by, or  accompanied  by a written  instrument of transfer in form
satisfactory  to The Company and the Security  Registrar  duly  executed by, the
Holder hereof or his attorney duly  authorized in writing,  and thereupon one or
more new CPR  Certificates,  for the same amount of CPRs,  will be issued to the
designated  transferee or transferees.  The Company hereby initially  designates
the office of First Trust National  Association  [insert  address of trustee] as
the office for registration of transfer of this CPR Certificate.

                  As   provided  in  the   Agreement   and  subject  to  certain
limitations  therein set forth,  this CPR Certificate is exchangeable for one or
more CPR  Certificates  representing  the same number of CPRs as  represented by
this CPR Certificate as requested by the Holder surrendering the same.

                  No  service  charge  will be  made  for  any  registration  of
transfer  or exchange  of CPRs,  but the  Company  may require  payment of a sum
sufficient to cover all documentary, stamp or similar issue or transfer taxes or
other  governmental  charges  payable in  connection  with any  registration  of
transfer or exchange.



<PAGE> 50


                  Prior to the time of due presentment of this CPR Certificate 
for  registration  of transfer,  the  Company,  the Trustee and any agent of the
Company or the Trustee  may treat the Person in whose name this CPR  Certificate
is registered as the owner hereof for all purposes, and neither the Company, the
Trustee nor any agent shall be affected by notice to the contrary.

                  Neither the Company nor the Trustee has any duty or obligation
to the holder of this CPR  Certificate,  except as expressly set forth herein or
in the Agreement.



<PAGE> 51




                     TRUSTEE'S CERTIFICATE OF AUTHENTICATION

this is one of the CPR Certificates referred to in the within-mentioned 
Agreement.


                                              FIRST TRUST NATIONAL
                                              ASSOCIATION,
                                              Trustee and Transfer
                                              Agent and Registrar



Dated: ____________________

                                              By _____________________________
                                                      Authorized Signatory







<PAGE> 52




                                                                        ANNEX B
                            FORM OF AFFILIATE LETTER



                                     [Date]



Baxter International Inc.
One Baxter Parkway
Deerfield, Illinois  60015
Attention: General Counsel

Ladies and Gentlemen:

                  I have  been  advised  that  as of the  date  of  this  letter
agreement I may be deemed to be an  "affiliate"  of Somatogen,  Inc., a Delaware
corporation  (the  "Company"),  as such  term is (i)  defined  for  purposes  of
paragraphs (c) and (d) of Rule 145 of the rules and regulations  (the "Rules and
Regulations") of the Securities and Exchange Commission (the "Commission") under
the Securities Act of 1933, as amended (the  "Securities  Act"), or (ii) used in
and for purposes of Accounting  Series Releases 130 and 135, as amended,  of the
Commission.  Pursuant to the terms of the Agreement and Plan of Merger, dated as
of February 23, 1998 (the "Merger Agreement"), by and among Baxter International
Inc., a Delaware  corporation  ("Baxter"),  RHB1  Acquisition  Corp., a Delaware
corporation ("Merger Sub"), and the Company,  Merger Sub will be merged with and
into the Company (the "Merger").

                  Pursuant  to the Merger all of the shares of capital  stock of
the Company owned by the undersigned will be converted into the right to receive
a certain number of shares of Common Stock, par value $1.00 per share, of Baxter
("Baxter  Shares"),  and the right to  receive a  Contingent  Payment  Right (as
described  in the  Merger  Agreement)  pursuant  to  the  terms  of  the  Merger
Agreement.

                  I represent, warrant and covenant to Baxter that, with respect
to all Baxter Shares received as a result of the Merger:

                  (a) I shall not make any sale,  transfer or other  disposition
of the  Baxter  Shares or the  Contingent  Payment  Rights in  violation  of the
Securities Act or the Rules and Regulations.

                  (b) I have carefully read this letter and the Merger Agreement
and the  Contingent  Payment  Rights  Agreement and have had an  opportunity  to
discuss the requirements of such documents and any other applicable  limitations
upon my ability to sell,  transfer or otherwise  dispose of Baxter Shares or the
Contingent Payment Rights with my counsel or counsel for the Company.

                  (c) I have been advised that the issuance of Baxter  Shares to
me  pursuant to the Merger has been  registered  with the  Commission  under the
Securities Act.  However,  I have also been advised that,  since at the time the
Merger was submitted  for a vote of the  stockholders  of the Company,  I may be
deemed to have been an  affiliate of the Company and the  distribution  by me of
the Baxter Shares or the Contingent Payment Rights has not been registered under
the Securities Act,  therefore I may not sell,  transfer or otherwise dispose of
Baxter Shares or the Contingent Payment Rights issued to me in the Merger unless
(i) such sale,  transfer or other  disposition has been registered under the Act
or is made in conformity  with Rule 145 under the Securities Act, or (ii) in the
opinion of counsel reasonably  acceptable to Baxter or pursuant to a "no action"
letter obtained by the undersigned from the staff of the Commission,  such sale,
transfer or other  disposition is otherwise exempt from  registration  under the
Securities Act.


<PAGE> 53

                  (d) I understand that, except as provided for under the Merger
Agreement,  Baxter is under no  obligation  to register  under the Act the sale,
transfer or other disposition of Baxter Shares or the Contingent  Payment Rights
by me or on my  behalf or to take any other  action  necessary  in order to make
compliance with an exemption from such registration available.

                  (e)  I  understand   that  Baxter  will  give  stop   transfer
instructions  to Baxter  transfer  agents with respect to the Baxter  Shares and
Contingent  Payment  Rights  received  by me pursuant to the terms of the Merger
Agreement  and that the  certificates  for such  Baxter  Shares  and  Contingent
Payment Right issued to me, or any  substitutions  therefor,  will bear a legend
substantially to the following effect:

         "THE  SECURITIES  REPRESENTED  BY THIS  CERTIFICATE  WERE  ISSUED  IN A
         TRANSACTION TO WHICH RULE 145 UNDER THE SECURITIES ACT OF 1933 APPLIES.
         THE SECURITIES  REPRESENTED BY THIS CERTIFICATE MAY ONLY BE TRANSFERRED
         IN ACCORDANCE WITH THE TERMS OF AN AGREEMENT,  DATED [ ], 1998, BETWEEN
         THE REGISTERED HOLDER HEREOF AND BAXTER  INTERNATIONAL  INC., A COPY OF
         WHICH  AGREEMENT  IS  ON  FILE  AT  THE  PRINCIPAL  OFFICES  OF  BAXTER
         INTERNATIONAL INC."

                  (f) I also understand that unless the transfer by me of Baxter
Shares or Contingent Payment Rights received pursuant to the terms of the Merger
Agreement  has been  registered  under the  Securities  Act or is a sale made in
conformity with the provisions of Rule 145, Baxter reserves the right to place a
legend  substantially to the following effect on the certificates  issued to any
transferee:

         "THE  SECURITIES   REPRESENTED  BY  THIS   CERTIFICATE  HAVE  NOT  BEEN
         REGISTERED  UNDER THE  SECURITIES  ACT OF 1933 AND WERE ACQUIRED FROM A
         PERSON WHO RECEIVED SUCH  SECURITIES IN A TRANSACTION TO WHICH RULE 145
         UNDER THE  SECURITIES  ACT OF 1933 APPLIES.  THE  SECURITIES MAY NOT BE
         SOLD, PLEDGED OR OTHERWISE  TRANSFERRED EXCEPT PURSUANT TO AN EFFECTIVE
         REGISTRATION  STATEMENT OR IN  ACCORDANCE  WITH AN  EXEMPTION  FROM THE
         REGISTRATION REQUIREMENTS OF THE SECURITIES ACT OF 1933."

                  It is  understood  and agreed  that the  legends  set forth in
paragraphs 5 and 6 above shall be removed by delivery of substitute certificates
without  such  legend  if  such  legend  is not  required  for  purposes  of the
Securities  Act.  It is  understood  and agreed  that such  legends and the stop
orders referred to above will be removed if (i) a sale is effected in compliance
with the provisions of Rule 145(d)(1), (ii) one year shall have elapsed from the
date the  undersigned  acquired  the Baxter  Shares and the  Contingent  Payment
Rights  received in the Merger and the  provisions  of Rule  145(d)(2)  are then
available to the  undersigned,  (iii) two years shall have elapsed from the date
the  undersigned  acquired the Baxter Shares and the  Contingent  Payment Rights
received in the Merger and the  provisions of Rule  145(d)(3) are then available
to the  undersigned  or (iv) Baxter has  received  either an opinion of counsel,
which opinion and counsel shall be  reasonably  satisfactory  to Baxter or a "no
action" letter obtained by the undersigned from the staff of the Commission,  to
the effect that the restrictions imposed by Rule 145 under the Securities Act no
longer apply to the undersigned.

                  Execution of this letter should not be considered an admission
on my part that I am an  "affiliate"  of the Company as  described  in the first
paragraph of this letter.

                  Baxter agrees that, for a period of at least three years after
the  effective  date  of  the  Merger,  it  will  make  publicly  available  the
information  required by, and in the manner  specified  by, Rule 144(c),  or any
successor rule thereto, under the Securities Act.


                                                Sincerely,



                                                _____________________________
                                                Name:

Accepted this __ day of __________ , 1998:

BAXTER INTERNATIONAL INC.



By:________________________________
         Name:
         Title:



<PAGE> 54




                                                                      ANNEX C
                               FORM OF OPINION OF
                               COOLEY GODWARD LLP

                  1. The Company has been duly organized and is validly existing
and in good  standing  under the laws of the State of Delaware.  The Company has
the requisite  corporate power to own its property and assets and to conduct its
business as it is currently  being  conducted and, to the best of our knowledge,
is  qualified to do business  and is in good  standing as a foreign  corporation
under  the  laws of each  jurisdiction  in which  the  conduct  of its  business
requires such qualification, other than jurisdictions in which the failure to be
so qualified would not be reasonably expected to have a Material Adverse Effect.

                  2. The Company has the corporate power and corporate authority
to execute,  deliver and perform all of its obligations under the Agreement. The
execution and delivery of the Agreement and the  consummation  by the Company of
the Merger have been duly  authorized by all requisite  corporate  action on the
part of the Company.

                  3. Assuming the due  authorization,  execution and delivery of
the  Agreement  by each of Merger Sub and Baxter,  the  Agreement is a valid and
binding obligation of the Company, enforceable against the Company in accordance
with its terms,  except (a) to the extent  that the  enforcement  thereof may be
limited by (i) bankruptcy,  insolvency,  reorganization,  moratorium, fraudulent
conveyance  or other  similar  laws  now or  hereafter  in  effect  relating  to
creditors' rights generally,  and (ii) general  principles of equity (regardless
of whether such enforcement is considered in a proceeding at law or in equity).

                  4. The  execution and delivery by the Company of the Agreement
and the  performance by the Company of its obligations  under the Agreement,  in
accordance  with its  terms,  does not (i)  conflict  with  the  Certificate  of
Incorporation  or the Bylaws,  (ii) constitute a violation of or a default under
or require any consent or waiver under any Applicable  Contracts (as hereinafter
defined),  (iii)  conflict  with or result  in a  violation  of an order,  writ,
judgment  or decree  known to us which  the  Company  is a party or is  subject.
"Applicable  Contracts"  means those  agreements  or  instruments  identified in
Sections 3.14 of the Company Disclosure Letter.

                  5.  Neither  the  execution,  delivery or  performance  by the
Company of the  Agreement  nor the  compliance by the Company with the terms and
provisions   thereof   contravene  any  provision  of  any  Applicable  Law  (as
hereinafter  defined).  "Applicable  Laws"  shall mean the DGCL and those  laws,
rules and  regulations  of the State of  Colorado  and of the  United  States of
America  which,  in  such  counsel's  experience,  are  normally  applicable  to
transactions of the type contemplated by the Agreement.

                  6. No Governmental  Approval (as hereinafter  defined),  which
has not been obtained or taken and is not in full force and effect,  is required
to  authorize  or is required in  connection  with the  execution or delivery or
performance of the Agreement by the Company.  "Governmental  Approval" means any
consent, approval, license, authorization or validation of, or filing, recording
or registration  with, any regulatory or governmental  authority (other than the
FDA, as to which such counsel need  express no opinion)  pursuant to  Applicable
Laws.


<PAGE> 55

                  7. The  Proxy  Statement/  Prospectus,  as of its date and the
date of the Special  Meeting  insofar as they describe the Company,  appeared on
its  face  to be  appropriately  responsive  in  all  material  respects  to the
requirements  of the Securities Act and the General Rules and  Regulations  (the
"Rules and Regulations") of the Commission under the Securities Act, except that
such counsel need not assume any responsibility  for the accuracy,  completeness
or fairness of the statements contained in the Proxy Statement/Prospectus.

                  8. Such  counsel  does not know of any  contracts or documents
required  to be filed  as  exhibits  to the  Company  SEC  Reports  required  to
described  therein  which were not so filed or described  as required,  and such
contracts  and  documents  as are  required by the Act to be so described in the
Company SEC Reports were fairly described in all material respects.

                  9. The authorized capital stock of the Company is as set forth
in Section 3.2 of the Agreement,  and to the best of such  counsel's  knowledge,
except as set forth in the Agreement and the Company  Disclosure  Letter,  there
are no options,  warrants,  conversion  privileges,  preemptive  rights or other
rights  presently  outstanding  to purchase any of the  authorized  but unissued
capital stock of the Company.

                  10.  To  such  counsel's   knowledge,   there  is  no  action,
proceeding or investigation pending or threatened against the Company before any
court or administrative agency that questions the validity of the Agreement.


<PAGE> 56





                                  
                                                                      ANNEX D
                           FORM OF OPINION
                     THOMAS J. SABATINO, JR.
       CORPORATE VICE PRESIDENT AND GENERAL COUNSEL OF BAXTER


                  1. Each of Baxter and Merger Sub have been duly  organized and
are  validly  existing  and in good  standing  under  the  laws of the  State of
Delaware.

                  2. Each of Baxter and Merger Sub have the corporate  power and
corporate authority to enter into the Agreement,  the CPRs and the CPR Agreement
and to consummate the transactions contemplated thereby.

                  3. All  requisite  corporate  action  on the part of Baxter or
Merger Sub, as  applicable,  to authorize  the execution and delivery of each of
the Agreement, the CPRs and the CPR Agreement and the consummation by Baxter and
Merger Sub, as applicable,  of the transactions  contemplated  thereby have been
duly and validly taken.

                  4. The  Agreement  has  been  duly and  validly  executed  and
delivered  by  Baxter  and  Merger  Sub,  and  assuming  the due  authorization,
execution and delivery of the Agreement by the Company, the Agreement is a valid
and binding  obligation  of each of Baxter and Merger Sub,  enforceable  against
each of Baxter and Merger Sub in accordance with its terms, except to the extent
that the  enforcement  thereof  may be  limited by (i)  bankruptcy,  insolvency,
reorganization,  moratorium,  fraudulent conveyance or other similar laws now or
hereafter in effect relating to creditors'  rights  generally,  and (ii) general
principles of equity  (regardless of whether such enforcement is considered in a
proceeding at law or in equity).

                  5. The CPR  Agreement  has been duly and validly  executed and
delivered by Baxter, and assuming the due authorization,  execution and delivery
of the CPR  Agreement by the Trustee,  the CPR  Agreement is a valid and binding
obligation of Baxter,  enforceable  against Baxter in accordance with its terms,
except  to the  extent  that  the  enforcement  thereof  may be  limited  by (i)
bankruptcy,  insolvency,  reorganization,  moratorium,  fraudulent conveyance or
other  similar  laws now or hereafter in effect  relating to  creditors'  rights
generally,  and (ii) general  principles of equity  (regardless  of whether such
enforcement  is considered  in a proceeding at law or in equity);  and the CPRs,
when  authenticated  in  accordance  with the  terms of CPR  Agreement,  will be
entitled to the benefit of the CPR Agreement and  enforceable  against Baxter in
accordance with their terms,  except to the extent that the enforcement  thereof
may  be  limited  by (i)  bankruptcy,  insolvency,  reorganization,  moratorium,
fraudulent  conveyance or other similar laws now or hereafter in effect relating
to  creditors'  rights  generally,   and  (ii)  general   principles  of  equity
(regardless of whether such  enforcement is considered in a proceeding at law or
in equity).

                  6. Upon issuance of shares of Baxter Common Stock  pursuant to
the  Agreement,  such  shares of Baxter  Common  Stock will be duly  authorized,
validly issued,  fully paid and  nonassessable and not subject to any preemptive
rights.








                                   CONTINGENT PAYMENT RIGHTS AGREEMENT

                                              by and between


                                        BAXTER INTERNATIONAL, INC.


                                                   and


                                     FIRST TRUST NATIONAL ASSOCIATION



                                          Dated as of [ ], 1998























<PAGE> 2
<TABLE>
<CAPTION>

                                            TABLE OF CONTENTS

<S>           <C>                                                                                         <C>

RECITALS OF THE COMPANY..................................................................................  5

                                                ARTICLE 1
                         DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

Section 1.1   Definitions................................................................................  5
Section 1.2   Compliance and Opinions....................................................................  9
Section 1.3   Form of Documents Delivered to Trustee.....................................................  9
Section 1.4   Acts of Holders............................................................................ 10
Section 1.5   Notices, etc., to Trustee and Company...................................................... 10
Section 1.6   Notice to Holders; Waiver.................................................................. 11
Section 1.7   Conflict with Trust Indenture Act.......................................................... 11
Section 1.8   Effect of Headings and Table of Contents................................................... 11
Section 1.9   Successors and Assigns..................................................................... 11
Section 1.10  Benefits of Agreement...................................................................... 11
Section 1.11  Governing Law.............................................................................. 11
Section 1.12  Legal Holidays............................................................................. 11
Section 1.13  Separability Clause........................................................................ 12
Section 1.14  No Recourse Against Others................................................................. 12
Section 1.15  Counterparts............................................................................... 12

                                                ARTICLE 2
                                              SECURITY FORMS

Section 2.1   Forms Generally............................................................................ 12

                                                ARTICLE 3
                                              THE SECURITIES

Section 3.1   Title and Terms............................................................................ 12
Section 3.2   Registrable Form........................................................................... 13
Section 3.3   Execution, Authentication, Delivery and Dating............................................. 13
Section 3.4   Temporary Securities....................................................................... 14
Section 3.5   Registration, Registration of Transfer and Exchange........................................ 14
Section 3.6   Mutilated, Destroyed, Lost and Stolen Securities........................................... 15
Section 3.7   Presentation of CPR Certificate............................................................ 15
Section 3.8   Persons Deemed Owners...................................................................... 15
Section 3.9   Cancellation............................................................................... 15

                                                ARTICLE 4
                                               THE TRUSTEE

Section 4.1   Certain Duties and Responsibilities........................................................ 16
Section 4.2   Certain Rights of Trustee.................................................................. 16
Section 4.3   Not Responsible for Recitals or Issuance of Securities..................................... 17
Section 4.4   May Hold Securities........................................................................ 17
Section 4.5   Money Held in Trust........................................................................ 17
Section 4.6   Compensation and Reimbursement............................................................. 18
Section 4.7   Disqualification; Conflicting Interests.................................................... 18
Section 4.8   Corporate Trustee Required; Eligibility.................................................... 18
Section 4.9   Resignation and Removal; Appointment of Successor.......................................... 18
Section 4.10  Acceptance of Appointment of Successor..................................................... 20
Section 4.11  Merger, Conversion, Consolidation or Succession to Business................................ 20
Section 4.12  Preferential Collection of Claims Against Company.......................................... 20

<PAGE> 3

                                                ARTICLE 5
                            HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

Section 5.1   Company to Furnish Trustee Names and Addresses of Holders.................................. 21
Section 5.2   Preservation of Information; Communications to Holders..................................... 21
Section 5.3   Reports by Trustee......................................................................... 21
Section 5.4   Reports by Company......................................................................... 21

                                                ARTICLE 6
                                                AMENDMENTS

Section 6.1   Amendments Without Consent of Holders...................................................... 22
Section 6.2   Amendments with Consent of Holders......................................................... 23
Section 6.3   Execution of Amendments.................................................................... 23
Section 6.4   Effect of Amendments; Notice to Holders.................................................... 24
Section 6.5   Conformity with Trust Indenture Act........................................................ 24
Section 6.6   Reference in Securities to Amendments...................................................... 24

                                                ARTICLE 7
                                                COVENANTS

Section 7.1   Payment of Amounts, if any, to Holders..................................................... 24
Section 7.2   Maintenance of Office or Agency............................................................ 24
Section 7.3   Money for Security Payments to Be Held in Trust............................................ 25
Section 7.4   Certain Purchases and Sales................................................................ 25
Section 7.5   Reports.................................................................................... 25
Section 7.6   Audits..................................................................................... 26
Section 7.7   Non-Monetary Consideration for Licensed Products........................................... 26
Section 7.8   Foreign Exchange........................................................................... 26
Section 7.9   Notice of Default.......................................................................... 26

                                                ARTICLE 8
                                   REMEDIES OF THE TRUSTEE AND HOLDERS
                                           ON EVENT OF DEFAULT

Section 8.1   Event of Default Defined; Acceleration of Maturity; Waiver of Default...................... 27
Section 8.2   Collection of Indebtedness by Trustee; Trustee May Prove Debt.............................. 28
Section 8.3   Application of Proceeds.................................................................... 29
Section 8.4   Suits for Enforcement...................................................................... 30
Section 8.5   Restoration of Rights on Abandonment of Proceedings........................................ 30
Section 8.6   Limitations on Suits by Holders............................................................ 31
Section 8.7   Unconditional Right of Holders to Institute Certain Suits.................................. 31
Section 8.8   Powers and Remedies Cumulative; Delay or Omission
                   Not Waiver of Default................................................................. 31
Section 8.9   Control by Holders......................................................................... 31
Section 8.10  Waiver of Past Defaults...................................................................  32
Section 8.11  Trustee to Give Notice of Default, But May Withhold in
                    Certain Circumstances................................................................ 32
Section 8.12  Right of Court to Require Filing of Undertaking to Pay Costs............................... 32

                                                ARTICLE 9
                                CONSOLIDATION, MERGER, SALE OR CONVEYANCE

Section 9.1   Company May Consolidate, etc., on Certain Terms............................................ 33
Section 9.2   Successor Person Substituted............................................................... 33
Section 9.3   Opinion of Counsel to Trustee.............................................................. 33

                                                ARTICLE 10
                                                REDEMPTION

Section 10.1  Right of Redemption........................................................................ 34
Section 10.2  Notices to Trustees........................................................................ 34
Section 10.3  Selection of CPR Certificates to Be Redeemed............................................... 34
Section 10.4  Notice of Redemption....................................................................... 34
Section 10.5  Effect of Notice of Redemption............................................................. 35
Section 10.6  Deposit of Redemption Price................................................................ 35
Section 10.7  CPR Certificates Redeemed in Part.......................................................... 35

- ----------------
Annex A - Form of CPR Certificate


*Note:  This  table of  contents  shall  not,  for any  purpose,  be  deemed  to
 be a part of this Agreement.

</TABLE>



<PAGE> 4

<TABLE>
<CAPTION>

Reconciliation  and tie  between  Trust  Indenture  Act of 1939  and  Contingent
Payment Rights Agreement, dated as of [ ], 1998.

Trust Indenture Act Section 
<S>          <C>    <C>    <C>    <C>    <C>                                                  <C>
                                                                                              Agreement Section
Section 310  (a)(1).................................................................................   4.9
             (a)(2).................................................................................   4.9
             (a)(3)..........................................................................   Not Applicable
             (a)(4)..........................................................................   Not Applicable
             (b)...............................................................................   4.7, 4.9
Section 311  (a)...............................................................................        4.13(a)
             (b)...............................................................................        4.13(b)
             (b)(2).......................................................................  5.3(a)(2), 5.3(b)
Section 312  (a)...............................................................................   5.1, 5.2(a)
             (b)................................................................................       5.2(b)
             (c)................................................................................       5.2(c)
Section 313  (a)................................................................................       5.3(a)
             (b)................................................................................       5.3(b)
             (c)............................................................................   5.3(a), 5.3(b)
             (d)....................................................................................   5.3(c)
Section 314  (a)....................................................................................   5.4
             (b).............................................................................   Not Applicable
             (c)(1).................................................................................   1.2
             (c)(2).................................................................................   1.2
             (c)(3)..........................................................................   Not Applicable
             (d)........................................................................ .....  Not Applicable
             (e)....................................................................................   1.2
Section 315  (a)....................................................................................   4.1(a)
             (b)..............................................................................   8.11, 5.3(a)(6)
             (c).....................................................................................  4.1(b)
             (d)....................................................................................   4.1(c)
             (d)(1).................................................................................   4.1(a)(1)
             (d)(2).................................................................................   4.1(c)(2)
             (d)(3).................................................................................   4.1(c)(3)
             (e)................................................................................  8.1, 8.12
Section 316  (a)....................................................................................   1.1
             (a)(1)(A)..............................................................................   8.9
             (a)(1)(B)..............................................................................   8.10
             (a)(2)..........................................................................   Not Applicable
             (b)....................................................................................   8.7
Section 317  (a)(1).................................................................................   8.2
             (a)(2).................................................................................   8.2
             (b)....................................................................................   7.3
Section 318  (a)....................................................................................   1.7
- ---------------
Note:  This reconciliation and tie shall not, for any purpose, be deemed to be a
part of the Agreement.

</TABLE>

<PAGE> 5



         CONTINGENT  PAYMENT  RIGHTS  AGREEMENT,  dated  as  of [ ],  1998  (the
"Agreement"),  by and between BAXTER  INTERNATIONAL INC., a Delaware corporation
(the "Company"),  and FIRST TRUST NATIONAL ASSOCIATION,  a national association,
as trustee (the "Trustee").

                              RECITALS OF THE COMPANY

         WHEREAS,  the Company has duly  authorized  the creation of an issue of
contingent  payment rights (the  "Securities" or "CPRs"),  of substantially  the
tenor and amount  hereinafter set forth, and to provide therefor the Company has
duly authorized the execution and delivery of this Agreement;

         WHEREAS,  pursuant  to the  Agreement  and Plan of Merger,  dated as of
February  23, 1998 (the  "Merger  Agreement"),  by and among the  Company,  RHB1
Acquisition  Corp., a Delaware  corporation  and wholly owned  subsidiary of the
Company, and Somatogen, Inc., a Delaware corporation ("Somatogen"),  the Company
agreed to issue, to the stockholders of Somatogen, the Securities; and

         WHEREAS,  all things  necessary have been done to make the  Securities,
when  executed by the Company and  authenticated  and delivered  hereunder,  the
valid obligations of the Company and to make this Agreement a valid agreement of
the Company, all in accordance with their and its terms.

         NOW,  THEREFORE,  for  and in  consideration  of the  premises  and the
consummation of the transactions referred to above, it is covenanted and agreed,
for the equal and  proportionate  benefit of all Holders (as defined  herein) of
the Securities, as follows:

                               ARTICLE 1

          DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

         Section 1.1 Definitions.  For all purposes of this Agreement, except as
otherwise expressly provided or unless the context otherwise requires:

         (a) the terms  defined in this Article  have the  meanings  assigned to
them in this Article, and include the plural as well as the singular;

         (b) all accounting  terms used herein and not expressly  defined herein
shall have the  meanings  assigned to such terms in  accordance  with  generally
accepted  accounting  principles in the United States,  and the term  "generally
accepted  accounting  principles" or "GAAP" means such accounting  principles as
are generally accepted as they may change from time to time;

         (c) all  other  terms  used  herein  which  are  defined  in the  Trust
Indenture Act (as defined herein), either directly or by reference therein, have
the respective meanings assigned to them therein; and

         (d) the words  "herein,"  "hereof" and  "hereunder"  and other words of
similar  import  refer to this  Agreement  as a whole and not to any  particular
Article, Section or other subdivision.


<PAGE> 6

         "Affiliate" of any specified  Person means any other Person directly or
indirectly  controlling  or  controlled  by or under  direct or indirect  common
control  with  such  specified  Person.  For the  purposes  of this  definition,
"control"  when used with  respect to any  specified  Person  means the power to
direct the  management  and  policies of such  Person,  directly or  indirectly,
whether  through the ownership of voting  securities,  by contract or otherwise;
and the terms  "controlling" and "controlled"  have meanings  correlative to the
foregoing.

         "Agreement" means this instrument as originally  executed and as it may
from  time  to  time be  supplemented  or  amended  pursuant  to the  applicable
provisions hereof.

         "Authorized Newspaper" means The Wall Street Journal (Eastern Edition),
or if The Wall Street Journal (Eastern Edition) shall cease to be published, or,
if the  publication or general  circulation of The Wall Street Journal  (Eastern
Edition)  shall be suspended for whatever  reason,  such other English  language
newspaper  of  general  circulation  in The City of New York,  New  York,  as is
selected by the Company.

         "Board of Directors" means the board of directors of the Company or any
duly authorized committee of that board.

         "Board  Resolution"  means  a copy  of a  resolution  certified  by the
Secretary or an Assistant Secretary of the Company, to have been duly adopted by
the Board of  Directors  and to be in full  force and effect on the date of such
certification, and delivered to the Trustee.

         "Business  Day"  means any day (other  than a Saturday  or a Sunday) on
which  banking  institutions  in The  City of New  York,  New  York or  Chicago,
Illinois are not authorized or obligated by law or executive order to close and,
if the CPRs are listed on a national securities exchange,  such exchange is open
for trading.

         "Commission" means the Securities and Exchange Commission, as from time
to time constituted,  created under the Exchange Act (as defined herein),  or if
at any time  after the  execution  of this  instrument  such  Commission  is not
existing and performing the duties now assigned to it under the Trust  Indenture
Act, then the body performing such duties at such time.

         "Company"  means the Person (as defined  herein) named as the "Company"
in the first  paragraph of this Agreement,  until a successor  Person shall have
become  such  pursuant  to the  applicable  provisions  of this  Agreement,  and
thereafter  "Company" shall mean such successor  Person. To the extent necessary
to  comply  with the  requirements  of the  provisions  of Trust  Indenture  Act
Sections 310 through 317, inclusive,  as they are applicable to the Company, the
term  "Company"  shall include any other obligor with respect to the  Securities
for the purposes of complying with such provisions.

         "Company  Request" or "Company  Order" means a written request or order
signed in the name of the Company by the  chairman of the Board of  Directors or
the president or any vice president,  the controller or assistant controller and
the  treasurer  or  assistant  treasurer  or  the  secretary  or  any  assistant
secretary, and delivered to the Trustee.

         "Contingent  Payment"  means,  with  respect to any  Payment  Measuring
Period,  an amount equal to five percent of the Net Sales that are  attributable
to the commercial sale of Products.

         "Corporate  Trust  Office"  means the office of the Trustee at which at
any  particular   time  its  corporate   trust  business  shall  be  principally
administered, which office at the date of execution of this Agreement is located
at [insert address].

         "CPR Certificate" means a certificate representing any of the CPRs.

         "Default  Interest  Rate" means the 90-day  London  Interbank  Offering
Rate, as published in The Wall Street Journal, as such rate may change from time
to time, plus 200 basis points.

<PAGE> 7


        "Default  Payment  Amount"  means,  with  respect to each CPR,  as of a
Default  Payment Date (as defined  herein),  an amount,  equal to the difference
between (i) $2.00 and (ii) the  aggregate  of all  Contingent  Payments  paid or
provided for, in  accordance  with the terms  hereof,  from the  Effective  Date
through and including such Default Payment Date.

         "Default Payment Date" means the date upon which the Securities  become
due and payable pursuant to Section 8.1.

         "Effective Date" means [               ], 1998.

         "Exchange Act" means the Securities Exchange Act of 1934, as amended.

         "Final Measuring Period" means the six months ending December 31, 2007.

         "Final Payment Date" means March 15, 2008.

         "Holder" means a Person in whose name a Security is registered in the 
Security Register.

         "Net Sales" means the actual gross amount invoiced by the Company,  its
Affiliates,  licensees  or  distributors  for the sale of  Products to any third
parties  during a Payment  Measuring  Period  less:  (a)  direct  transportation
charges,  including  insurance;  (b) trade,  quantity  and other  discounts  and
rebates actually allowed and taken to the extent customary in the trade; and (c)
allowances or credits,  including,  but not limited to, allowances or credits to
customers on account of rejection or return of the Products; provided that (i) a
sale or transfer  to an  Affiliate  of the Company for resale by such  Affiliate
shall not be considered a sale for the purpose of this provision, but the resale
by such Affiliate  shall be a sale for such purposes,  and the term "sale" shall
include a transfer or other disposition to a customer;  (ii) Net Sales shall not
include  reserves  for bad debts or  allowances,  credits or rebates not covered
above;  and  (iii) a sale of  Products  shall  occur at the  earlier  of (a) the
transfer of title in such  Products to a third party or (b) the shipment of such
Products from the  manufacturing or warehouse  facilities of the manufacturer of
such Products to a third party.

                  Net Sales  shall not  include  license  fees or other  advance
payments  received by the Company from a licensee or distributor of the Products
which is not derived from sales of Products,  but shall include the Net Sales of
such licensee or distributor.

         "Officers'  Certificate," when used with respect to the Company means a
certificate signed by the chairman of the Board of Directors or the president or
any vice president,  the controller or assistant controller and the treasurer or
assistant  treasurer or the secretary or any assistant  secretary of the Company
delivered to the Trustee.

         "Opinion of Counsel" means a written opinion of counsel, who may be 
counsel for the Company.

         "Outstanding"  when used with respect to  Securities  means,  as of the
date of determination,  all Securities  theretofore  authenticated and delivered
under this  Agreement,  except:  (a)  Securities  theretofore  cancelled  by the
Trustee or  delivered  to the Trustee for  cancellation;  (b) from and after the
earliest of a Default Payment Date, a Redemption Date or the Final Payment Date,
Securities  for the  payment  of which  money in the  necessary  amount has been
theretofore  deposited  with the  Trustee or any Paying  Agent  (other  than the
Company) in trust,  or set aside and  segregated in trust by the Company (if the
Company shall act as its own Paying  Agent) for the Holders of such  Securities;
and (c)  Securities  in exchange for or in lieu of which other  Securities  have
been authenticated and delivered pursuant to this Agreement, other than any such
Securities  in respect of which there shall have been  presented  to the Trustee
proof  satisfactory to it that such Securities are held by a bona fide purchaser
in whose hands the  Securities are valid  obligations of the Company;  provided,
however,  that in determining  whether the Holders of the requisite  Outstanding
Securities  have  given  any  request,  demand,  direction,  consent  or  waiver
hereunder,  Securities  owned by the Company or any  Affiliate  of the  Company,
whether held as treasury  securities  or  otherwise,  shall be  disregarded  and
deemed not to be  Outstanding,  except that, in determining  whether the Trustee
shall be protected in relying upon any such request, demand, direction,  consent
or waiver,  only  Securities  which the Trustee knows to be so owned shall be so
disregarded.


<PAGE> 8

         "Paying  Agent" means any Person  authorized  by the Company to pay the
amount  determined  pursuant to Section 3.1, if any, on any Securities on behalf
of the Company.

         "Payment  Date" means March 15, 1999 and each  succeeding  March 15 and
September 15, through and including the Final Payment Date.

         "Payment Measuring Period" means (i) the period from the Effective Date
to December  31, 1998 and (ii) each six month  period ended June 30 and December
31 thereafter, through and including the Final Measuring Period.

         "Person" means any individual, corporation, partnership, joint venture,
association,    joint-stock   company,   trust,   limited   liability   company,
unincorporated organization or government or any agency or political subdivision
thereof.

         "Products"  shall  mean  all  products  in  which  the  primary  active
ingredient  is  human  hemoglobin,  or  derivatives,  mutants  or  modifications
thereof, which have been produced in culture of microbial cells (including yeast
cells)  which  have  been  modified  using  Somatogen   Recombinant   Hemoglobin
Technology  (other than clinical  indications  for any such Products that are in
clinical trials as of the date of the Merger Agreement).

         "Redemption  Date" means the date specified in a notice of redemption  
given by the  Company pursuant to Section 10.1

         "Redemption  Price"  means,  with respect to each CVR,  the  difference
between (x) $2.00 and (y) the aggregate  Contingent  Payments  made, or provided
for in  accordance  with the terms hereof,  from the Effective  Date through and
including the Redemption Date.

         "Responsible  Officer"  when used with respect to the Trustee means any
officer  assigned to the Corporate Trust Office and also means,  with respect to
any particular  corporate trust matter, any other officer of the Trustee to whom
such matter is referred  because of his  knowledge of and  familiarity  with the
particular subject.

         "Somatogen Recombinant Hemoglobin Technology" shall mean all technology
owned by or licensed  to  Somatogen  on or prior to the  Effective  Date,  which
involves the use of recombinant DNA techniques.

         "Subsidiary"  means each Person more than 50% of the outstanding Voting
Securities of which is owned, directly or indirectly,  by the Company and/or one
or more Subsidiaries.

         "Trust Indenture Act" means the Trust Indenture Act of 1939, as amended
from time to time.

         "Trustee"  means  the  Person  named  as the  "Trustee"  in  the  first
paragraph of this  Agreement,  until a successor  Trustee shall have become such
pursuant  to  the  applicable  provisions  of  this  Agreement,  and  thereafter
"Trustee" shall mean such successor Trustee.

         "Vice  President" when used with respect to the Company or the Trustee,
means any vice  president,  whether or not  designated  by a number or a word or
words added before or after the title of "vice president."

         "Voting  Securities"  means securities  having ordinary voting power to
elect a majority of the  directors  irrespective  of whether or not stock of any
other class or classes  shall have or might have  voting  power by reason of the
happening of any contingency.

<PAGE> 9

         Section 1.2 Compliance and Opinions. Upon any application or request by
the  Company  to the  Trustee  to take any action  under any  provision  of this
Agreement,  the Company  shall  furnish to the Trustee an Officers'  Certificate
stating that, in the opinion of the signor,  all conditions  precedent,  if any,
provided  for in this  Agreement  relating  to the  proposed  action  have  been
complied  with  and  an  Opinion  of  Counsel  stating,   subject  to  customary
exceptions,  that in the opinion of such counsel all such conditions  precedent,
if  any,  have  been  complied  with,  except  that,  in the  case  of any  such
application  or  request  as to  which  the  furnishing  of  such  documents  is
specifically  required  by any  provision  of this  Agreement  relating  to such
particular  application or request, no additional certificate or opinion need be
furnished.

         Every  certificate  or  opinion  with  respect  to  compliance  with  a
condition  or covenant  provided  for in this  Agreement  shall  include:  (a) a
statement that each individual signing such certificate or opinion has read such
covenant or condition and the definitions  herein relating thereto;  (b) a brief
statement as to the nature and scope of the  examination or  investigation  upon
which the  statements or opinions  contained in such  certificate or opinion are
based; (c) a statement that, in the opinion of each such  individual,  he or she
has made such  examination  or  investigation  as is  necessary to enable him to
express an informed  opinion as to whether or not such covenant or condition has
been complied  with;  and (d) a statement as to whether,  in the opinion of each
such individual, such condition or covenant has been complied with.

         Section 1.3 Form of Documents  Delivered to Trustee.  In any case where
several  matters are required to be  certified  by, or covered by an opinion of,
any specified Person, it is not necessary that all such matters be certified by,
or covered by the opinion of, only one such Person, or that they be so certified
or  covered by only one  document,  but one such  Person may  certify or give an
opinion  with  respect to some  matters and one or more other such Persons as to
other  matters,  and any such  Person may  certify or give an opinion as to such
matters in one or several documents.

         Any  certificate  or opinion of an officer of the Company may be based,
insofar as it relates to legal  matters,  upon a  certificate  or opinion of, or
representations  by, counsel.  Any such certificate or Opinion of Counsel may be
based,  insofar as it relates to factual matters,  upon a certificate or opinion
of, or  representations  by, an officer or officers of the Company  stating that
the information with respect to such factual matters is in the possession of the
Company.

         Any  certificate,  statement or opinion of an officer of the Company or
of counsel may be based,  insofar as it relates to  accounting  matters,  upon a
certificate  or  opinion  of or  representations  by an  accountant  or  firm of
accountants  in the employ of the  Company.  Any  certificate  or opinion of any
independent  firm of public  accountants  filed with the Trustee shall contain a
statement that such firm is independent.

         Where any  Person is  required  to make,  give or  execute  two or more
applications,  requests, consents,  certificates,  statements, opinions or other
instruments  under this Agreement,  they may, but need not, be consolidated  and
form one instrument.


<PAGE> 10

         Section 1.4 Acts of Holders.  (a) Any request,  demand,  authorization,
direction, notice, consent, waiver or other action provided by this Agreement to
be given or taken by Holders  may be embodied  in and  evidenced  by one or more
instruments of  substantially  similar tenor signed by such Holders in person or
by an agent duly appointed in writing; and, except as herein otherwise expressly
provided, such action shall become effective when such instrument or instruments
are delivered to the Trustee and, where it is hereby expressly required,  to the
Company.  Such instrument or instruments  (and the action  embodied  therein and
evidenced  thereby) are herein sometimes referred to as the "Act" of the Holders
signing  such  instrument  or  instruments.  Proof  of  execution  of  any  such
instrument or of a writing appointing any such agent shall be sufficient for any
purpose of this  Agreement  and (subject to Section 4.1)  conclusive in favor of
the Trustee and the Company, if made in the manner provided in this Section. The
Company  may set a record  date for  purposes  of  determining  the  identity of
Holders entitled to vote or consent to any action by vote or consent  authorized
or permitted under this Agreement.  If not set by the Company prior to the first
solicitation of a Holder of Securities made by any Person in respect of any such
action,  or, in the case of any such vote,  prior to such vote,  the record date
for such action  shall be the later of ten days prior to the first  solicitation
of such consent or the date of the most recent list of Holders  furnished to the
Trustee pursuant to Section 5.1 of this Agreement prior to such solicitation. If
a record date is fixed,  those  Persons who were Holders of  Securities  at such
record date (or their duly designated proxies), and only those Persons, shall be
entitled  to take such  action by vote or consent  or,  except  with  respect to
clause (d) below, to revoke any vote or consent previously given, whether or not
such  Persons  continue to be Holders  after such record  date.  No such vote or
consent  shall be valid or  effective  for more than 120 days after such  record
date.

         (b) The  fact  and  date of the  execution  by any  Person  of any such
instrument or writing may be proved in any  reasonable  manner which the Trustee
deems sufficient.

         (c) The  ownership  of  Securities  shall  be  proved  by the  Security
Register.  Neither  the  Company nor the Trustee nor any Agent of the Company or
the Trustee shall be affected by any notice to the contrary.

         (d) At any time prior to (but not after) the evidencing to the Trustee,
as provided in this  Section  1.4, of the taking of any action by the Holders of
the Securities  specified in this Agreement in connection with such action,  any
Holder of a Security  the serial  number of which is shown by the evidence to be
included  among the serial  numbers of the  Securities the Holders of which have
consented to such action may, by filing  written  notice at the Corporate  Trust
Office and upon proof of holding as provided in this  Section  1.4,  revoke such
action so far as concerns such  Security.  Any request,  demand,  authorization,
direction, notice, consent, waiver or other action by the Holder of any Security
shall  bind  every  future  Holder of the same  Security  or the Holder of every
Security  issued  upon the  registration  of  transfer  thereof  or in  exchange
therefor or in lieu thereof, in respect of anything done, suffered or omitted to
be done by the  Trustee,  any Paying  Agent or the Company in reliance  thereon,
whether or not notation of such action is made upon such Security.

         Section 1.5 Notices, etc., to Trustee and Company. Any request, demand,
authorization,  direction,  notice,  consent,  waiver or Act of Holders or other
document  provided or  permitted  by this  Agreement  to be made upon,  given or
furnished to, or filed with:

         (a) the Trustee by any Holder or by the Company shall be sufficient for
every purpose  hereunder if made, given,  furnished or filed, in writing,  to or
with the Trustee at [insert trustee's address]; or

          (b) the  Company by the Trustee or by any Holder  shall be  sufficient
for every  purpose  hereunder  if in writing  and  mailed,  first-class  postage
prepaid,  to the  Company  addressed  to it at One  Baxter  Parkway,  Deerfield,
Illinois 60015,  Attention:  General Counsel, or at any other address previously
furnished in writing to the Trustee by the Company.

 
<PAGE> 11

       Section 1.6 Notice to Holders;  Waiver.  Where this Agreement  provides
for notice to Holders of any event,  such  notice  shall be  sufficiently  given
(unless  otherwise  herein  expressly   provided)  if  in  writing  and  mailed,
first-class  postage  prepaid,  to each Holder  affected  by such event,  at his
address as it appears in the Security Register,  not later than the latest date,
and not  earlier  than the  earliest  date,  prescribed  for the  giving of such
notice.  In any case  where  notice to  Holders  is given by mail,  neither  the
failure to mail such  notice,  nor any  defect in any  notice so mailed,  to any
particular  Holder shall affect the  sufficiency  of such notice with respect to
other  Holders.  Where this  Agreement  provides for notice in any manner,  such
notice may be waived in writing by the Person  entitled to receive  such notice,
either  before or after the event,  and such waiver shall be the  equivalent  of
such notice.  Waivers of notice by Holders shall be filed with the Trustee,  but
such filing  shall not be a condition  precedent  to the  validity of any action
taken in reliance upon such waiver.


         In case by reason of the  suspension  of  regular  mail  service  or by
reason of any other cause, it shall be impracticable to mail notice of any event
as required by any provision of this  Agreement,  then any method of giving such
notice  as  shall  be  satisfactory  to the  Trustee  shall  be  deemed  to be a
sufficient giving of such notice.

         Section 1.7 Conflict with Trust Indenture Act. If any provision  hereof
limits,  qualifies or conflicts with another  provision hereof which is required
to be included in this Agreement by any of the provisions of the Trust Indenture
Act, such required provision shall control.

         Section 1.8 Effect of Headings and Table of  Contents.  The Article and
Section  headings herein and the Table of Contents are for convenience  only and
shall not affect the construction hereof.

         Section 1.9  Successors  and Assigns.  All covenants and  agreements in
this Agreement by the Company shall bind its successors and assigns,  whether so
expressed or not.

         Section 1.10 Benefits of Agreement. Nothing in this Agreement or in the
Securities, express or implied, shall give to any Person (other than the parties
hereto and their  successors  hereunder,  any Paying  Agent and the Holders) any
benefit or any legal or equitable right, remedy or claim under this Agreement or
under any  covenant  or  provision  herein  contained,  all such  covenants  and
provisions being for sole benefit of the parties hereto and their successors and
of the Holders.

         Section 1.11 Governing Law. THIS AGREEMENT AND THE SECURITIES  SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE  WITH THE LAWS OF THE STATE OF NEW YORK,
AS APPLIED TO CONTRACTS  MADE AND  PERFORMED  WITHIN THE STATE OF NEW YORK.  THE
COMPANY HEREBY  IRREVOCABLY  SUBMITS TO THE  JURISDICTION  OF ANY NEW YORK STATE
COURT SITTING IN THE BOROUGH OF MANHATTAN IN THE CITY OF NEW YORK OR ANY FEDERAL
COURT  SITTING IN THE BOROUGH OF MANHATTAN IN THE CITY OF NEW YORK IN RESPECT OF
ANY SUIT, ACTION OR PROCEEDING  ARISING OUT OF OR RELATING TO THIS AGREEMENT AND
THE  SECURITIES,  AND  IRREVOCABLY  ACCEPTS  FOR  ITSELF  AND IN  RESPECT OF ITS
PROPERTY,  GENERALLY AND UNCONDITIONALLY,  JURISDICTION OF THE AFORESAID COURTS.
THE COMPANY  IRREVOCABLY  WAIVES, TO THE FULLEST EXTENT IT MAY EFFECTIVELY DO SO
UNDER  APPLICABLE  LAW, ANY OBJECTION IT MAY NOW OR HEREAFTER HAVE TO THE LAYING
OF THE VENUE OF ANY SUCH SUIT,  ACTION OR  PROCEEDING  BROUGHT IN ANY SUCH COURT
AND ANY CLAIM THAT ANY SUCH SUIT, ACTION OR PROCEEDING BROUGHT IN ANY SUCH COURT
HAS BEEN BROUGHT IN AN INCONVENIENT FORUM.

         Section  1.12  Legal  Holidays.  In the event  that a Payment  Date,  a
Redemption  Date, the Final Payment Date or a Default  Payment Date, as the case
may be, shall not be a Business Day, then (notwithstanding any provision of this
Agreement or the Securities to the contrary)  payment on the Securities need not
be made on such date,  but may be made,  without  the  accrual  of any  interest
thereon,  on the next succeeding  Business Day with the same force and effect as
if made on a Payment  Date,  a  Redemption  Date,  the Final  Payment  Date or a
Default Payment Date, as the case may be.


<PAGE> 12

         Section  1.13  Separability  Clause.  In  case  any  provision  in this
Agreement  or in the CPRs  shall  be  invalid,  illegal  or  unenforceable,  the
validity,  legality and enforceability of the remaining  provisions shall not in
any way be affected or impaired thereby.

         Section 1.14 No Recourse Against Others. A director,  officer, employee
or  stockholder,  as such,  of the  Company  or the  Trustee  shall not have any
liability for any obligations of the Company or the Trustee under the Securities
or the  Agreement  or for any claim based on, in respect of or by reason of such
obligations  or their  creation.  By accepting a Security each Holder waives and
releases  all  such   liability.   The  waiver  and  release  are  part  of  the
consideration for the issue of the Securities.

         Section 1.15 Counterparts. This Agreement shall be signed in any number
of  counterparts  with the same effect as if the signatures to each  counterpart
were  upon a single  instrument,  and all such  counterparts  together  shall be
deemed an original of this Agreement.



                               ARTICLE 2

                            SECURITY FORMS

         Section  2.1  Forms   Generally.   The  Securities  and  the  Trustee's
certificate of  authentication  shall be in substantially the forms set forth in
Annex A, attached hereto and  incorporated  herein by this reference,  with such
appropriate  insertions,  omissions,  substitutions  and other variations as are
required or permitted by this  Agreement and may have such  letters,  numbers or
other marks of identification and such legends or endorsements placed thereon as
may be required to comply with the rules of any securities exchange or as may be
required  by law or any  rule  or  regulation  pursuant  thereto,  all as may be
determined  by the officers  executing  such  Securities,  as evidenced by their
execution of the Securities.  Any portion of the text of any Security may be set
forth on the reverse thereof,  with an appropriate reference thereto on the face
of the Security.

         The definitive Securities shall be typewritten,  printed,  lithographed
or engraved on steel  engraved  borders or produced by any  combination of these
methods or may be produced  in any other  manner  permitted  by the rules of any
securities  exchange on which the  Securities may be listed all as determined by
the officers executing such Securities,  as evidenced by their execution of such
Securities.


                                  ARTICLE 3

                               THE SECURITIES

         Section  3.1  Title  and  Terms.   (a)  The  aggregate  number  of  CPR
Certificates  which may be  authenticated  and delivered under this Agreement is
limited to a number  equal to [insert  number of shares of Company  Common Stock
outstanding  on a  fully  diluted  basis  at the  Effective  Time],  except  for
Securities  authenticated  and delivered upon registration of transfer of, or in
exchange for, or in lieu of, other Securities  pursuant to Section 3.4, 3.5, 3.6
or 6.6.

         (b) The  Securities  shall be known and  designated as the  "Contingent
Payment Rights" of the Company.

         (c) The Company  shall,  on or prior to any Payment Date,  pay, to each
Holder of a CPR on the April 1 or September 1 immediately  prior to such Payment
Date, the Contingent  Payment with respect to the Payment Measuring Period ended
immediately  preceding such Payment Date, plus any amounts deferred  pursuant to
Section 3.1(d).


<PAGE> 13

                  (1) If for any reason the  Contingent  Payment has not finally
been  determined  as of any Payment  Date,  then such Payment  Date shall,  upon
written notice to that effect from the Company to the Trustee,  be automatically
extended  until the date that is the  seventh  Business  Day after the date upon
which the Contingent Payment has finally been determined.

                  (2) The  Company  shall  deliver,  on each  Payment  Date,  an
Officers'  Certificate,  to the Trustee,  setting forth the  calculation  of the
Contingent  Payment,  if any, payable on such Payment Date. The Trustee shall be
protected in relying upon such Officers'  Certificate and shall be under no duty
to investigate the facts underlying such Officers' Certificate.

         (d) In the event that the Contingent  Payment (plus any amount deferred
pursuant to this Section 3.1(d)  otherwise  payable on any Payment Date) is less
than $0.05 per CPR,  then such amount  shall not be payable on such Payment Date
but shall be deferred  (without any accrual of interest  thereon) until the next
following Payment Date.

         (e) In no event shall the aggregate of all Contingent Payments payable,
from the Effective Time to and including the Final Payment Date, with respect to
any CPR, exceed $2.00.

         (f) The Holders of the CPR Certificates,  by acceptance thereof,  agree
that the Company has no obligation to initiate or continue research, development
or  commercialization  activities  with  respect to any  Products  or any of the
Somatogen Recombinant  Technologies and, in its sole and subjective  discretion,
the Company may  abandon  efforts to  research,  develop or  commercialize  such
technologies  or Products.  No joint  venture,  partnership  or other  fiduciary
relationship is created hereby or by the Securities.

         (g)  The  Company  shall  not  transfer,  as an  entirety  (other  than
transfers  to  Subsidiaries  or  Affiliates  of the  Company),  ownership of the
Somatogen  Recombinant  Technology,  unless the transferee agrees to be bound by
the Agreement to the same extent as the Company is then bound by this Agreement,
and the Company  shall be released from any  obligation  hereunder to the extent
the transferee assumes the Company's obligations under this Agreement.

         (h)  Notwithstanding  any  provision  of  this  Agreement  or  the  CPR
Certificates to the contrary,  other than in the case of interest on the Default
Payment Amount,  no interest shall accrue on any amounts payable with respect to
the CPRs.

         (i) In the  event  that  all of the  CPR  Certificates  not  previously
cancelled  shall have been  called for  redemption  by the  Company  pursuant to
Article 10 hereof or shall have  become due and  payable  pursuant  to the terms
hereof,  and the  Company  has paid or caused to be paid or  deposited  with the
Trustee  all  amounts  payable to the Holders  under this  Agreement,  then this
Agreement shall cease to be of further effect and shall be deemed  satisfied and
discharged.  Notwithstanding  the  satisfaction and discharge of this Agreement,
the obligations of the Company under Section 4.6(c) shall survive.

         Section 3.2  Registrable Form.  The Securities shall be issuable only 
in registered form.

         Section  3.3  Execution,  Authentication,   Delivery  and  Dating.  The
Securities  shall be executed  on behalf of the  Company by its  chairman of the
Board of Directors or its president or any vice president or its treasurer,  but
need not be attested.  The signature of any of these  officers on the Securities
may be manual or facsimile.

         Securities  bearing the manual or facsimile  signatures of  individuals
who were,  at the time of  execution,  the proper  officers of the Company shall
bind the  Company,  notwithstanding  that such  individuals  or any of them have
ceased to hold such  offices  prior to the  authentication  and delivery of such
Securities or did not hold such offices at the date of such Securities.

         At any time and from time to time after the  execution  and delivery of
this Agreement,  the Company may deliver  Securities  executed by the Company to
the  Trustee  for  authentication,   together  with  a  Company  Order  for  the
authentication and delivery of such Securities;  and the Trustee,  in accordance
with such Company  Order,  shall  authenticate  and deliver such  Securities  as
provided in this Agreement and not otherwise.


<PAGE> 14

         Each Security shall be dated the date of its authentication.

         No Security shall be entitled to any benefit under this Agreement or be
valid or  obligatory  for any purpose  unless there  appears on such  Security a
certificate of authentication substantially in the form provided for herein duly
executed by the  Trustee,  by manual or  facsimile  signature  of an  authorized
officer,  and such certificate  upon any Security shall be conclusive  evidence,
and the only  evidence,  that  such  Security  has been duly  authenticated  and
delivered  hereunder  and that the Holder is  entitled  to the  benefits of this
Agreement.

         Section 3.4 Temporary Securities. Pending the preparation of definitive
Securities,  the Company may execute,  and upon Company Order, the Trustee shall
authenticate and deliver, temporary Securities which are printed,  lithographed,
typewritten,  mimeographed or otherwise produced,  substantially of the tenor of
the  definitive  Securities  in lieu of which  they  are  issued  and with  such
appropriate  insertions,  omissions,  substitutions  and other variations as the
officers  executing such  Securities  may determine with the  concurrence of the
Trustee.  Temporary  Securities  may contain such reference to any provisions of
this Agreement as may be appropriate. Every temporary Security shall be executed
by the Company and be  authenticated by the Trustee upon the same conditions and
in  substantially  the same  manner,  and with like  effect,  as the  definitive
Securities.

         If temporary  Securities are issued,  the Company will cause definitive
Securities to be prepared without  unreasonable  delay. After the preparation of
definitive  Securities,  the  temporary  Securities  shall be  exchangeable  for
definitive  Securities upon surrender of the temporary  Securities at the office
or agency of the Company  designated  for such purpose  pursuant to Section 7.2,
without charge to the Holder. Upon surrender for cancellation of any one or more
temporary   Securities,   the  Company  shall  execute  and  the  Trustee  shall
authenticate  and  deliver  in  exchange  therefor a like  amount of  definitive
Securities.  Until so exchanged,  the Temporary Securities shall in all respects
be entitled to the same benefits under this Agreement as definitive Securities.

         Section 3.5  Registration,  Registration of Transfer and Exchange.  The
Company  shall  cause to be kept at the office of the  Trustee a  register  (the
register  maintained in such office and in any other office or agency designated
pursuant  to Section 7.2 being  herein  sometimes  referred to as the  "Security
Register") in which, subject to such reasonable regulations as it may prescribe,
the Company shall provide for the registration of Securities and of transfers of
Securities.  The Trustee is hereby initially appointed "Security  Registrar" for
the purpose of  registering  Securities  and  transfers of  Securities as herein
provided.

         Upon  surrender  for  registration  of transfer of any  Security at the
office or agency of the Company designated  pursuant to Section 7.2, the Company
shall execute,  and the Trustee shall  authenticate and deliver,  in the name of
the  designated  transferee  or  transferees,  one or more new CPR  Certificates
representing   the  same  aggregate  number  of  CPRs  represented  by  the  CPR
Certificate  so  surrendered  that are to be  transferred  and the Company shall
execute and the  Trustee  shall  authenticate  and  deliver,  in the name of the
transferor,  one or more new CPR Certificates  representing the aggregate number
of CPRs represented by such CPR Certificate that are not to be transferred.

         At the option of the Holder,  CPR  Certificates  may be  exchanged  for
other CPR  Certificates  that represent in the aggregate the same number of CPRs
as the CPR Certificates  surrendered at such office or agency.  Whenever any CPR
Certificates are so surrendered for exchange, the Company shall execute, and the
Trustee shall  authenticate and deliver,  the CPR Certificates  which the Holder
making the exchange is entitled to receive.

         All Securities  issued upon any registration of transfer or exchange of
Securities  shall be the valid  obligations of the Company,  evidencing the same
rights,  and  entitled  to  the  same  benefits  under  this  Agreement,  as the
Securities surrendered upon such registration of transfer or exchange.

         Every Security presented or surrendered for registration of transfer or
for exchange shall (if so required by the Company or the Security  Registrar) be
duly endorsed,  or be  accompanied  by a written  instrument of transfer in form
satisfactory  to the Company and the Security  Registrar,  duly  executed by the
Holder thereof or his attorney duly authorized in writing.

         No service  charge  shall be made for any  registration  of transfer or
exchange of Securities,  but the Company may require payment of a sum sufficient
to cover any tax or other governmental  charge that may be imposed in connection
with any  registration  of  transfer  or  exchange  of  Securities,  other  than
exchanges pursuant to Section 3.4 or 6.6 not involving any transfer.


<PAGE> 15

         Section 3.6 Mutilated,  Destroyed,  Lost and Stolen Securities.  If (a)
any mutilated Security is surrendered to the Trustee, or (b) the Company and the
Trustee receive evidence to their satisfaction of the destruction, loss or theft
of any  Security,  and there is  delivered  to the Company and the Trustee  such
security or indemnity as may be required by them to save each of them  harmless,
then,  in the absence of notice to the Company or the Trustee that such Security
has been acquired by a bona fide purchaser,  the Company shall execute and, upon
delivery of a Company  Order,  the Trustee shall  authenticate  and deliver,  in
exchange for any such mutilated Security or in lieu of any such destroyed,  lost
or stolen  Security,  a new CPR  Certificate  of like  tenor and amount of CPRs,
bearing a number not contemporaneously outstanding.

         In case any such  mutilated,  destroyed,  lost or stolen  Security  has
become or is to become due and payable  within  fifteen days, the Company in its
discretion may, instead of issuing a new CPR  Certificate,  pay to the Holder of
such Security on a Redemption  Date, the Final Payment Date or a Default Payment
Date, as the case may be, all amounts due and payable with respect thereto.

         Upon the issuance of any new Securities under this Section, the Company
shall pay any tax or other  governmental  charge that may be imposed in relation
thereto and any other expenses  (including the fees and expenses of the Trustee)
connected therewith.

         Every new  Security  issued  pursuant  to this  Section  in lieu of any
destroyed,  lost or stolen  Security  shall  constitute  an original  additional
contractual  obligation of the Company,  whether or not the  destroyed,  lost or
stolen  Security  shall be at any  time  enforceable  by  anyone,  and  shall be
entitled to all benefits of this Agreement equally and proportionately  with any
and all other Securities duly issued hereunder.

         The provisions of this Section are exclusive and shall preclude (to the
extent lawful) all other rights and remedies with respect to the  replacement or
payment of mutilated, destroyed, lost or stolen Securities.

         Section 3.7  Presentation  of CPR  Certificate.  Payment of any amounts
pursuant to the CPRs shall be made only upon presentation by the Holder thereof,
at the  office or agency  of the  Company  maintained  for that  purpose  in the
Borough of  Manhattan,  The City of New York,  and at any other office or agency
maintained  by the  Company  for such  purpose in such coin or  currency  of the
United  States of  America  as at the time is legal  tender  for the  payment of
public and private debts or in debt securities of the Company in accordance with
the provisions of Section 3.1(g).  However,  the Company may pay such amounts by
wire transfer or check payable in such money.

         Section 3.8 Persons Deemed Owners. Prior to the time of due presentment
for  registration  of transfer,  the  Company,  the Trustee and any agent of the
Company  or the  Trustee  may treat the  Person in whose  name any  Security  is
registered as the owner of such Security for the purpose of receiving payment on
such  Security  and for all  other  purposes  whatsoever,  whether  or not  such
Security be overdue,  and neither the Company,  the Trustee nor any agent of the
Company or the Trustee shall be affected by notice to the contrary.

         Section 3.9  Cancellation.  All  Securities  surrendered  for  payment,
registration  of transfer or exchange  shall, if surrendered to any Person other
than the Trustee,  be delivered to the Trustee and shall be promptly canceled by
it. The Company may at any time  deliver to the  Trustee  for  cancellation  any
Securities  previously  authenticated and delivered  hereunder which the Company
may have  acquired in any manner  whatsoever,  and all  Securities  so delivered
shall be promptly canceled by the Trustee.  No Securities shall be authenticated
in lieu of or in  exchange  for any  Securities  canceled  as  provided  in this
Section,  except  as  expressly  permitted  by  this  Agreement.  All  cancelled
Securities  held by the  Trustee  shall be  disposed of as directed by a Company
Order.

<PAGE> 16

                                ARTICLE 4

                               THE TRUSTEE

         Section 4.1 Certain  Duties and  Responsibilities.  (a) With respect to
the Holders of Securities  issued,  the Trustee,  prior to the  occurrence of an
Event of Default with respect to the  Securities and after the curing or waiving
of all Events of Default  which may have  occurred,  undertakes  to perform such
duties and only such duties as are  specifically set forth in this Agreement and
no implied covenants shall be read into this Agreement  against the Trustee.  In
case an Event of Default with respect to the Securities has occurred  (which has
not been cured or waived),  the Trustee  shall  exercise  such of the rights and
powers vested in it by this Agreement, and use the same degree of care and skill
in  their  exercise,  as a  prudent  person  would  exercise  or use  under  the
circumstances in the conduct of his own affairs.

          (b) In the absence of bad faith on its part,  prior to the  occurrence
of an Event of Default  and after the  curing or  waiving of all such  Events of
Default which may have occurred,  the Trustee may  conclusively  rely, as to the
truth of the statements and the correctness of the opinions  expressed  therein,
upon  certificates  or opinions  furnished to the Trustee and  conforming to the
requirements  of this  Agreement;  but in the case of any such  certificates  or
opinions which by any provision hereof are specifically required to be furnished
to the  Trustee,  the  Trustee  shall  be  under a duty to  examine  the same to
determine whether or not they conform to the requirements of this Agreement.

         (c) No  provision of this  Agreement  shall be construed to relieve the
Trustee from liability for its own negligent  action,  its own negligent failure
to act, or its own willful misconduct, except that (i) this Subsection (c) shall
not be construed to limit the effect of Subsections (a) and (b) of this Section;
(ii) the  Trustee  shall not be liable  for any error of  judgment  made in good
faith by a Responsible  Officer,  unless it shall be proved that the Trustee was
negligent  in  ascertaining  the  pertinent  facts;  (iii) no  provision of this
Agreement shall require the Trustee to expend or risk its own funds or otherwise
incur any financial liability in the performance of any of its duties hereunder,
or in the exercise of any of its rights or powers,  if it shall have  reasonable
grounds for believing that repayment of such funds or adequate indemnity against
such risk or  liability  is not  reasonably  assured to it; and (iv) the Trustee
shall not be liable with  respect to any action  taken or omitted to be taken by
it in good faith in  accordance  with the  direction of the Holders  pursuant to
Section 8.9 relating to the time,  method and place of conducting any proceeding
for any  remedy  available  to the  Trustee,  or  exercising  any trust or power
conferred upon the Trustee, under this Agreement.

         (d) Whether or not therein  expressly so provided,  every  provision of
this  Agreement  relating  to the  conduct  or  affecting  the  liability  of or
affording  protection to the Trustee shall be subject to the  provisions of this
Section.

         Section 4.2  Certain Rights of Trustee.  Subject to the provisions of 
Section 4.1:

           (a) the  Trustee  may  rely and  shall  be  protected  in  acting  or
refraining from acting upon any resolution,  certificate, statement, instrument,
opinion,  report, notice, request,  direction,  consent, order, bond, debenture,
note,  other evidence of indebtedness or other paper or document  believed by it
to be  genuine  and to have been  signed or  presented  by the  proper  party or
parties and the Trustee need not  investigate  any fact or matter  stated in the
document;

         (b) any request or direction or order of the Company  mentioned  herein
shall be  sufficiently  evidenced by a Company  Request or Company Order and any
resolution  of the Board of Directors may be  sufficiently  evidenced by a Board
Resolution  and the Trustee shall not be liable for any action it takes or omits
to take in good faith reliance thereon;


<PAGE> 17

         (c) whenever in the  administration of this Agreement the Trustee shall
deem it  desirable  that a matter  be  proved or  established  prior to  taking,
suffering or omitting any action  hereunder,  the Trustee (unless other evidence
be herein specifically prescribed) may, in the absence of bad faith on its part,
rely upon an Officers'  Certificate  and the Trustee shall not be liable for any
action it takes or omits to take in good faith reliance thereon or an Opinion of
Counsel;

         (d) the Trustee may consult with counsel and the written advice of such
counsel or any Opinion of Counsel shall be full and complete  authorization  and
protection in respect of any action  taken,  suffered or omitted by it hereunder
in good faith and in accordance with such advice or Opinion of Counsel;

         (e) the Trustee  shall be under no  obligation  to exercise  any of the
rights or powers  vested in it by this  Agreement at the request or direction of
any of the Holders  pursuant to this  Agreement,  unless such Holders shall have
offered to the  Trustee  reasonable  security  or  indemnity  against the costs,
expenses and  liabilities  which might be incurred by it in compliance with such
request or direction;

         (f) the Trustee shall not be bound to make any  investigation  into the
facts or matters stated in any resolution,  certificate,  statement, instrument,
opinion,  report, notice, request,  consent, order, approval,  appraisal,  bond,
debenture,  note, coupon,  security, or other paper or document, but the Trustee
in its discretion may make such further inquiry or investigation into such facts
or matters as it may see fit,  and if the Trustee  shall  determine to make such
further  inquiry or  investigation,  it shall be  entitled to examine the books,
records and premises of the Company, personally or by agent or attorney;

         (g) the Trustee may  execute any of the trusts or powers  hereunder  or
perform  any  duties  hereunder  either  directly  or by or  through  agents  or
attorneys  and the  Trustee  shall  not be  responsible  for any  misconduct  or
negligence  on the part of any agent or attorney  appointed  with due care by it
hereunder; and

         (h) the Trustee shall not be liable for any action  taken,  suffered or
omitted to be taken by it in good faith and believed by it to be  authorized  or
within the discretion or rights or powers conferred upon it by this Agreement.

         Section 4.3 Not Responsible for Recitals or Issuance of Securities. The
Trustee shall not be accountable  for the Company's use of the Securities or the
proceeds  from  the  Securities.  The  recitals  contained  herein  and  in  the
Securities, except the Trustee's certificates of authentication,  shall be taken
as the statements of the Company,  and the Trustee assumes no responsibility for
their  correctness.  The Trustee makes no  representations as to the validity or
sufficiency of this Agreement or of the Securities.

         Section  4.4 May  Hold  Securities.  The  Trustee,  any  Paying  Agent,
Security  Registrar or any other agent of the Company,  in its individual or any
other capacity,  may become the owner or pledgee of Securities,  and, subject to
Sections 4.7 and 4.12,  may otherwise deal with the Company with the same rights
it would have if it were not Trustee,  Paying Agent,  Security Registrar or such
other agent.

         Section  4.5 Money Held in Trust.  Money  held by the  Trustee in trust
hereunder need not be segregated  from other funds except to the extent required
by law.  The  Trustee  shall be under no  liability  for  interest  on any money
received by it hereunder.


<PAGE> 18

         Section 4.6  Compensation and Reimbursement. The Company agrees:

          (a) to pay to the Trustee  from time to time  reasonable  compensation
for all  services  rendered by it  hereunder  (which  compensation  shall not be
limited by any provision of law in regard to the compensation of a trustee of an
express trust);

         (b) except as otherwise  expressly  provided  herein,  to reimburse the
Trustee upon its request for all reasonable expenses, disbursements and advances
incurred  or made by the  Trustee  in  accordance  with  any  provision  of this
Agreement   (including  the  reasonable   compensation   and  the  expenses  and
disbursements of its agents and counsel), except any such expense,  disbursement
or advance as may be attributable to the Trustee's negligence or bad faith; and

         (c)  to  indemnify  the  Trustee  and  each  of its  agents,  officers,
directors  and  employees  (each an  "indemnitee")  for, and to hold it harmless
against,  any loss, liability or expense (including attorneys fees and expenses)
incurred  without  negligence  or bad  faith on its part,  arising  out of or in
connection  with  the  acceptance  or  administration  of  this  trust  and  the
performance  of its  duties  hereunder,  including  the  costs and  expenses  of
defending  itself against any claim or liability in connection with the exercise
or performance of any of its powers or duties hereunder.  The obligations of the
Company hereunder shall constitute additional  indebtedness hereunder. To secure
the Company's payment obligations in this Section, the Trustee shall have a lien
prior to the  Securities  on all  money or  property  held or  collected  by the
Trustee other than money or property held in trust to pay particular Securities.
The  Company's  payment  obligations  pursuant to this Section shall survive the
termination  of  this  Agreement.  When a  Trustee  incurs  expenses  after  the
occurrence  of an Event of Default  specified  in Section  8.1(c) or 8.1(d) with
respect to the Company,  the expenses  are  intended to  constitute  expenses of
administration under bankruptcy laws.

         Section 4.7 Disqualification; Conflicting Interests. If the Trustee has
or shall  acquire  any  conflicting  interest  within  the  meaning of the Trust
Indenture Act, it shall,  within ninety days after ascertaining that it has such
conflicting  interest,  either eliminate such conflicting  interest or resign to
the extent and in the manner  provided by, and subject to the provisions of, the
Trust Indenture Act and this  Agreement.  The Company shall take prompt steps to
have a successor appointed in the manner provided in this Agreement.

         Section 4.8 Corporate Trustee Required; Eligibility. There shall at all
times be a Trustee  hereunder  which  shall be a  corporation  that is  eligible
pursuant to the Trust  Indenture  Act to act as such and has a combined  capital
and surplus of at least $15 million.  If such corporation  publishes  reports of
condition  at  least  annually,  pursuant  to law or to  the  requirements  of a
supervising or examining  authority,  then for the purposes of this Section, the
combined  capital  and  surplus  of such  corporation  shall be deemed to be its
combined capital and surplus as set forth in its most recent report of condition
so  published.  If at any  time  the  Trustee  shall  cease  to be  eligible  in
accordance with the provisions of this Section,  it shall resign  immediately in
the manner and with the effect hereinafter specified in this Article.

         Section 4.9 Resignation and Removal;  Appointment of Successor.  (a) No
resignation or removal of the Trustee and no appointment of a successor  Trustee
pursuant  to this  Article  shall  become  effective  until  the  acceptance  of
appointment by the successor Trustee under Section 4.10.

         (b) The Trustee,  or any trustee or trustees hereafter  appointed,  may
resign  at any time by giving  written  notice  thereof  to the  Company.  If an
instrument of acceptance by a successor Trustee shall not have been delivered to
the Trustee  within thirty days after the giving of such notice of  resignation,
the resigning  Trustee may petition any court of competent  jurisdiction for the
appointment of a successor Trustee.

          (c) The Trustee may be removed at any time by an act of the Holders of
a majority of the  Outstanding  Securities,  delivered to the Trustee and to the
Company.


<PAGE> 19

          (d)     If at any time:

                  (1) the Trustee  shall fail to comply  with  Section 4.7 after
written  request  therefor  by the  Company or by any Holder who has been a bona
fide Holder of a Security for at least six months, or

                  (2) the Trustee  shall cease to be eligible  under Section 4.8
and shall fail to resign after written request therefor by the Company or by any
such Holder, or

                  (3) the Trustee  shall become  incapable of acting or shall be
adjudged  a  bankrupt  or  insolvent,  or a  receiver  of the  Trustee or of its
property shall be appointed,  or any public officer shall take charge or control
of the Trustee or of its property or affairs for the purpose of  rehabilitation,
conservation or liquidation,

then,  in any case,  (i) the  Company,  by a Board  Resolution,  may  remove the
Trustee, or (ii) the Holder of any Security who has been a bona fide Holder of a
Security  for at least six  months  may,  on behalf of  himself  and all  others
similarly situated, petition any court of competent jurisdiction for the removal
of the Trustee and the appointment of a successor Trustee.

         (e) If the Trustee  shall  resign,  be removed or become  incapable  of
acting,  or if a vacancy shall occur in the office of Trustee for any cause, the
Company, by a Board Resolution,  shall promptly appoint a successor Trustee. If,
within one year after any  removal by Holders of a majority  of the  Outstanding
Securities,  a successor  Trustee  shall be appointed by act of the Holders of a
majority of the Outstanding Securities delivered to the Company and the retiring
Trustee the successor Trustee so appointed shall,  forthwith upon its acceptance
of such  appointment  in  accordance  with Section  4.10,  become the  successor
Trustee and  supersede  the successor  Trustee  appointed by the Company.  If no
successor  Trustee shall have been so appointed by the Company or the Holders of
the  Securities  and accepted  appointment  within sixty days after the retiring
Trustee tenders its resignation or is removed, the retiring Trustee may, or, the
Holder of any  Security  who has been a bona fide Holder for at least six months
may on behalf of himself and all others similarly  situated,  petition any court
of competent jurisdiction for the appointment of a successor Trustee.

         (f) The Company shall give notice of each  resignation and each removal
of the Trustee and each  appointment of a successor  Trustee by mailing  written
notice of such event by first-class  mail,  postage  prepaid,  to the Holders of
Securities as their names and addresses  appear in the Security  Register.  Each
notice shall  include the name of the  successor  Trustee and the address of its
Corporate Trust office. If the Company fails to send such notice within ten days
after  acceptance  of  appointment  by a  successor  Trustee,  it shall not be a
default  hereunder but the successor Trustee shall cause the notice to be mailed
at the expense of the Company.


<PAGE> 20

         Section 4.10  Acceptance of Appointment of Successor.  Every  successor
Trustee  appointed  hereunder  shall  execute,  acknowledge  and  deliver to the
Company and to the retiring  Trustee an instrument  accepting such  appointment,
and thereupon the  resignation  or removal of the retiring  Trustee shall become
effective  and  such  successor  Trustee,  without  any  further  act,  deed  or
conveyance,  shall become vested with all the rights,  powers, trusts and duties
of the  retiring  Trustee;  but,  upon  request of the Company or the  successor
Trustee,  such retiring Trustee shall, upon payment of its charges,  execute and
deliver an instrument  transferring  to such  successor  Trustee all the rights,
powers and trusts of the retiring Trustee,  and shall duly assign,  transfer and
deliver to such  successor  Trustee all property and money held by such retiring
Trustee hereunder. Upon request of any such successor Trustee, the Company shall
execute  any and all  instruments  for more fully and  certainly  vesting in and
confirming to such successor Trustee all such rights, powers and trusts.

         No successor Trustee shall accept its appointment unless at the time of
such  acceptance  such  successor  Trustee shall be qualified and eligible under
this Article.

         Section  4.11  Merger,  Conversion,   Consolidation  or  Succession  to
Business.  Any corporation  into which the Trustee may be merged or converted or
with which it may be consolidated, or any corporation resulting from any merger,
conversion  or  consolidation  to which  the  Trustee  shall be a party,  or any
corporation  succeeding  to all or  substantially  all  of the  corporate  trust
business  of the  Trustee,  shall be the  successor  of the  Trustee  hereunder,
provided such corporation  shall be otherwise  qualified and eligible under this
Article,  without the execution or filing of any paper or any further act on the
part of any of the  parties  hereto.  In case any  Securities  shall  have  been
authenticated,  but not delivered,  by the Trustee then in office, any successor
by merger,  conversion or consolidation to such authenticating Trustee may adopt
such  authentication  and deliver the Securities so authenticated  with the same
effect as if such successor  Trustee had itself  authenticated  such Securities;
and such  certificate  shall have the full  force  which it is  anywhere  in the
Securities or in this  Agreement  provided that the  certificate  of the Trustee
shall have;  provided that the right to adopt the certificate of  authentication
of any  predecessor  Trustee  shall apply only to its successor or successors by
merger, conversion or consolidation.

         Section 4.12 Preferential  Collection of Claims Against Company. If and
when the  Trustee  shall be or shall  become a creditor  of the  Company (or any
other  obligor  upon  the  Securities)  the  Trustee  shall  be  subject  to the
provisions of the Trust Indenture Act regarding the collection of claims against
the Company (or any such other obligor).



<PAGE> 21

                                 ARTICLE 5

              HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

         Section 5.1 Company to Furnish  Trustee Names and Addresses of Holders.
The  Company  will  furnish  or  cause  to  be  furnished  to  the  Trustee  (i)
semiannually a list, in such form as the Trustee may reasonably  require, of the
names and  addresses of the Holders as of a recent date,  and (ii) at such times
as the Trustee may request in writing,  within  thirty days after receipt by the
Company of any such request,  a list, in such form as the Trustee may reasonably
require,  of the names and  addresses  of the Holders as of a date not more than
fifteen days prior to the time such list is furnished;  provided,  however, that
if and so long as the Trustee shall be the Security Registrar, no such list need
be furnished.

         Section 5.2 Preservation of Information; Communications to Holders. (a)
The Trustee shall preserve,  in as current a form as is reasonably  practicable,
the names and addresses of Holders  contained in the most recent list  furnished
to the Trustee as provided in Section 5.1 and the names and addresses of Holders
received by the Trustee in its capacity as Security  Registrar.  The Trustee may
destroy any list  furnished  to it as provided in Section 5.1 upon  receipt of a
new list so furnished.

         (b) The rights of the Holders to  communicate  with other  Holders with
respect to their rights under this  Agreement and the  corresponding  rights and
privileges of the Trustee shall be as provided by the Trust Indenture Act.

         (c) Every  Holder of  Securities,  by  receiving  and holding the same,
agrees with the Company and the Trustee that neither the Company nor the Trustee
shall be deemed to be in violation of law or held  accountable  by reason of the
disclosure of any such  information as to the names and addresses of the Holders
made pursuant to the Trust Indenture Act.

         Section 5.3 Reports by Trustee. (a) Within sixty days after December 31
of each year  commencing  with the December 31 following the Effective Date, the
Trustee shall  transmit to all Holders such reports  concerning  the Trustee and
its  actions  under this  Agreement  as may be  required  pursuant  to the Trust
Indenture Act at the time and in the manner provided pursuant thereto.

         (b) A copy of each such report shall, at the time of such  transmission
to the Holders,  be filed by the Trustee with each stock exchange,  if any, upon
which the Securities are listed,  with the Commission and also with the Company.
The Company will promptly  notify the Trustee when the  Securities are listed on
any stock exchange.

         Section 5.4 Reports by Company.  The Company  shall:  (a) file with the
Trustee,  (i) within fifteen days after the Company is required to file the same
with the  Commission,  copies  of the  annual  reports  and of the  information,
documents  and other reports (or copies of such portions of any of the foregoing
as the  Commission  may from  time to time by rules and  regulations  prescribe)
which the  Company  may be  required  to file with the  Commission  pursuant  to
Section 13 or Section  15(d) of the  Exchange  Act (such  required  information,
documents and other reports, generally, the "Exchange Act Documents");  or, (ii)
if the Company is not required to file its Exchange Act Documents, quarterly and
annual financial  information  that would be required  pursuant to Section 13 of
the Exchange Act in respect of a security  listed and  registered  on a national
securities  exchange  as may be  prescribed  from time to time in such rules and
regulations;  and (b)  transmit  by mail to all  Holders,  as  their  names  and
addresses appear in the Security  Register,  within thirty days after the filing
thereof  with the  Trustee,  such  summaries of any  information  documents  and
reports  required to be filed by the Company  pursuant to subsection (a) of this
Section as may be required by rules and regulations prescribed from time to time
by the Commission.

<PAGE> 22

                                ARTICLE 6

                                AMENDMENTS

         Section 6.1 Amendments Without Consent of Holders.  Without the consent
of any Holders,  the Company and the Trustee, at any time and from time to time,
may enter into one or more amendments  hereto or to the  Securities,  for any of
the following purposes:

         (a) to convey, transfer, assign, mortgage or pledge to the Trustee
as  security  for the Securities any property or assets; or

         (b) to evidence the succession of another  Person to the Company,
and the assumption by any such successor of the covenants of the Company herein 
and in the Securities; or

         (c) to add to the covenants of the Company such further covenants,
restrictions, conditions or provisions as its Board of Directors and the Trustee
shall  consider to be for the  protection of the Holders of  Securities,  and to
make the occurrence, or the occurrence and continuance, of a default in any such
additional covenants, restrictions, conditions or provisions an Event of Default
permitting  the  enforcement of all or any of the several  remedies  provided in
this  Agreement  as herein  set  forth;  provided,  that in  respect of any such
additional  covenant,  restriction,  condition or provision  such  amendment may
provide for a  particular  period of grace after  default  (which  period may be
shorter  or  longer  than that  allowed  in the case of other  defaults)  or may
provide for an immediate  enforcement upon such an Event of Default or may limit
the remedies available to the Trustee upon such an Event of Default or may limit
the right of the Holders of a majority of the  Securities to waive such an Event
of Default; or


<PAGE> 23

         (d) to cure any  ambiguity,  or to correct or supplement  any provision
herein or in the  Securities  which may be  defective or  inconsistent  with any
other provision  herein;  provided,  that such  provisions  shall not materially
reduce the benefits of this Agreement or the Securities to the Holders; or

         (e) to make any other  provisions  with respect to matters or questions
arising under this Agreement; provided, that such provisions shall not adversely
affect the interests of the Holders; or

         (f) to make any  amendments or changes  necessary to comply or maintain
compliance with the Trust Indenture Act.

         Promptly following any amendment of this Agreement or the Securities in
accordance  with this Section  6.1, the Trustee  shall notify the Holders of the
Securities  of such  amendment;  provided,  that any  failure  so to notify  the
Holders shall not affect the validity of such amendment.

         Section 6.2 Amendments with Consent of Holders. With the consent of the
Holders of a majority  of the  Outstanding  Securities,  by Act of said  Holders
delivered  to the Company and the Trustee,  the Company  (when  authorized  by a
Board  Resolution) and the Trustee may enter into one or more amendments  hereto
or to the  Securities for the purpose of adding any provisions to or changing in
any manner or  eliminating  any of the  provisions  of this  Agreement or to the
Securities  or of modifying  in any manner the rights of the Holders  under this
Agreement or to the Securities; provided, however, that no such amendment shall,
without the consent of the Holder of each Outstanding Security affected thereby:

         (a) modify the  definition  of  Redemption  Date,  Final  Payment Date,
Default Payment Date,  Default Payment Amount,  Net Sales,  Products,  Somatogen
Recombinant  Hemoglobin  Technology or Default  Payment  Interest  Rate,  modify
Section 3.1(i) or otherwise  extend the maturity of the Securities or reduce the
amounts payable in respect of the Securities or modify any other payment term or
payment date.

         (b) reduce  the  number of CPRs,  the  consent of whose  Holders  is 
required  for any such amendment; or

         (c)  modify any of the  provisions  of this  Section  or Section  8.10,
except  to  increase  any such  percentage  or to  provide  that  certain  other
provisions of this Agreement cannot be modified or waived without the consent of
the Holder of each Security affected thereby.

         It shall not be necessary  for any Act of Holders under this Section to
approve  the  particular  form  of  any  proposed  amendment,  but it  shall  be
sufficient if such Act shall approve the substance thereof.

         Section  6.3  Execution  of  Amendments.  In  executing  any  amendment
permitted by this Article,  the Trustee  shall be entitled to receive  indemnity
reasonably  satisfactory  to it, and  (subject  to  Section  4.1) shall be fully
protected  in relying upon an Opinion of Counsel  stating that the  execution of
such amendment is authorized or permitted by this  Agreement.  The Trustee shall
execute any  amendment  authorized  pursuant to this Article VI if the amendment
does not adversely  affect the Trustee's own rights,  duties or immunities under
this Agreement or otherwise.  Otherwise,  the Trustee may, but need not, execute
such amendment.


<PAGE> 24

         Section 6.4 Effect of Amendments; Notice to Holders. Upon the execution
of any amendment under this Article,  this Agreement and the Securities shall be
modified in accordance  therewith,  and such amendment shall form a part of this
Agreement and the  Securities  for all purposes;  and every Holder of Securities
theretofore or thereafter  authenticated and delivered  hereunder shall be bound
thereby.

         Promptly  after the  execution  by the  Company  and the Trustee of any
amendment  pursuant to the provisions of this Article,  the Company shall mail a
notice  thereof  by first  class  mail to the  Holders  of  Securities  at their
addresses  as they  shall  appear on the  Security  Register,  setting  forth in
general  terms the  substance of such  amendment.  Any failure of the Company to
mail such notice, or any defect therein,  shall not, however,  in any way impair
or affect the validity of any such amendment.

         Section  6.5  Conformity  with Trust  Indenture  Act.  Every  amendment
executed pursuant to this Article shall conform to the requirements of the Trust
Indenture Act.

         Section 6.6  Reference in  Securities  to  Amendments.  If an amendment
changes  the terms of a  Security,  the  Trustee  may  require the Holder of the
Security to deliver it to the Trustee.  Securities  authenticated  and delivered
after the execution of any amendment  pursuant to this Article may, and shall if
required by the Trustee,  bear a notation in form  approved by the Trustee as to
any matter  provided for in such  amendment.  If the Company shall so determine,
new Securities so modified as to conform,  in the opinion of the Trustee and the
Board of  Directors,  to any such  amendment may be prepared and executed by the
Company  and  authenticated  and  delivered  by  the  Trustee  in  exchange  for
Outstanding  Securities.  Failure to make the appropriate notation or to issue a
new Security shall not affect the validity of such amendment.


                                   ARTICLE 7

                                    COVENANTS

         Section 7.1 Payment of Amounts,  if any, to Holders.  The Company  will
duly and  punctually  pay the amounts,  if any, on the  Securities in accordance
with the terms of the  Securities  and this  Agreement.  Such  amounts  shall be
considered  paid on the date due if on such date the Trustee or the Paying Agent
holds in accordance with this Agreement money sufficient to pay all such amounts
then due. Notwithstanding any other provision of this Agreement, the Trustee and
the Paying Agent shall  comply with all U.S.  federal  withholding  requirements
with respect to payments to Holders that the Company,  the Trustee or the Paying
Agent  reasonably  believes are  applicable  under the Internal  Revenue Code of
1986, as amended, and the Treasury regulations  thereunder.  Amounts withheld in
compliance  with such  withholding  requirements  shall,  for  purposes  of this
Agreement,  be  treated  as paid to the Holder  such  withholding  was made with
respect  to.  The  consent  of  Holder  shall  not  be  required  for  any  such
withholding.

         Section  7.2  Maintenance  of Office or  Agency.  As long as any of the
Securities  remain  Outstanding,  the  Company  will  maintain in the Borough of
Manhattan, The City of New York, an office or agency (i) where Securities may be
presented or surrendered for payment,  (ii) where  Securities may be surrendered
for  registration of transfer or exchange and (iii) where notices and demands to
or upon the  Company in  respect of the  Securities  and this  Agreement  may be
served.  The office of the Trustee at [insert  trustees' New York address] shall
be such office or agency of the Company,  unless the Company shall designate and
maintain  some  other  office or agency  for one or more of such  purposes.  The
Company  or any of its  Subsidiaries  may  act as  Paying  Agent,  registrar  or
transfer  agent;  provided  that such Person shall take  appropriate  actions to
avoid the  commingling of funds.  The Company will give prompt written notice to
the Trustee of any change in the  location  of any such office or agency.  If at
any time the Company shall fail to furnish the Trustee with the address thereof,
such presentations, surrenders, notices and demands may be made or served at the
Corporate  Trust  Office of the  Trustee,  and the Company  hereby  appoints the
Trustee as its agent to receive all such presentations,  surrenders, notices and
demands.


<PAGE> 25

        The Company may from time to time  designate  one or more other offices
or agencies (in or outside of The City of New York) where the  Securities may be
presented or surrendered for any or all such purposes, and may from time to time
rescind  such  designation;  provided,  however,  that  no such  designation  or
rescission shall in any manner relieve the Company of its obligation to maintain
an office or agency in the Borough of  Manhattan,  The City of New York for such
purposes. The Company will give prompt written notice to the Trustee of any such
designation  or rescission  and any change in the location of any such office or
agency.

         Section 7.3 Money for  Security  Payments  to Be Held in Trust.  If the
Company or any of its Subsidiaries shall at any time act as the Paying Agent, it
will,  on or before a  Redemption  Date,  the Final  Payment Date or the Default
Payment Date, as the case may be, segregate and hold in trust for the benefit of
the Persons  entitled  thereto a sum  sufficient to pay the amounts,  if any, so
becoming due until such sums shall be paid to such Persons or otherwise disposed
of as herein  provided,  and will  promptly  notify the Trustee of its action or
failure so to act.

         Whenever  the  Company  shall  have one or more  Paying  Agents for the
Securities,  it will, on or before the Final Payment Date, a Redemption  Payment
Date or the Default  Payment  Date,  as the case may be,  deposit  with a Paying
Agent a sum in same day funds sufficient to pay the amount,  if any, so becoming
due;  such sum to be held in trust for the  benefit of the  Persons  entitled to
such  amount,  and (unless  such Paying  Agent is the  Trustee) the Company will
promptly notify the Trustee of such action or any failure so to act.

         The  Company  will cause each  Paying  Agent  other than the Trustee to
execute  and  deliver to the Trustee an  instrument  in which such Paying  Agent
shall agree with the Trustee,  subject to the  provisions of this Section,  that
(A) such  Paying  Agent  will  hold all sums held by it for the  payment  of any
amount  payable on Securities  in trust for the benefit of the Persons  entitled
thereto  until such sums shall be paid to such Persons or otherwise  disposed of
as herein  provided and will notify the Trustee of the sums so held and (B) that
it will give the  Trustee  notice of any failure by the Company (or by any other
obligor on the  Securities) to make any payment on the Securities  when the same
shall be due and payable.

         Any money  deposited with the Trustee or any Paying Agent, or then held
by the Company, in trust for the payment on any Security and remaining unclaimed
for one year after the Final  Payment  Date,  a  Redemption  Payment Date or the
Default  Payment  Date,  as the case may be,  shall  be paid to the  Company  on
Company Request,  or (if then held by the Company) shall be discharged from such
trust; and the Holder of such Security shall thereafter, as an unsecured general
creditor, look only to the Company for payment thereof, and all liability of the
Trustee or such Paying  Agent with  respect to such trust money shall  thereupon
cease.

         Section 7.4 Certain Purchases and Sales. Nothing contained herein shall
prohibit the Company or any of its  Subsidiaries or Affiliates from acquiring in
open market transactions, private transactions or otherwise, the Securities.

         Section 7.5  Reports.  Within  sixty days after the end of each Payment
Measuring  Period,  the Company  shall  furnish to the Trustee a written  report
showing (i) the gross sales of all Products sold by the Company, its Affiliates,
licensees and distributors  during the immediately  preceding  Payment Measuring
Period; and (ii) the reconciliation of gross sales to Net Sales.  Payments shown
to have  accrued by each  report  shall be due and  payable,  subject to Section
3.1(d), to the Holders on the next succeeding Payment Date.


<PAGE> 26

         If any adjustments or inaccuracies in the amounts paid or payable under
this Section 7.5 are determined by the Trustee in its review of the  calculation
of the  Contingent  Payment,  which may be  performed  at the end of any Payment
Measuring  Period,  and the Company agrees to such adjustment,  such adjustments
for the immediately  preceding  Payment  Measuring  Period may be reconciled and
described  in the next due  written  report  and the  payment  then due shall be
adjusted to reflect  such  determination.  The Company  shall keep  complete and
accurate records in sufficient detail to enable the amounts payable hereunder to
be determined by the Trustee,  the Holders and their consultants or professional
advisors.

         Section  7.6  Audits.  (a) Upon the  written  request of either (i) the
Trustee; or (ii) Holders representing at least thirty percent of the outstanding
Securities (a "Requesting  Party") and not more than once in each calendar year,
and upon reasonable  notice,  the Company shall permit an independent  certified
public  accounting  firm  of  nationally  recognized  standing  selected  by the
Requesting  Party and  reasonably  acceptable to the Company,  at the Requesting
Party's  expense,  to have access  during normal  business  hours to such of the
records of the Company as may be reasonably  necessary to verify the accuracy of
the  payment  reports.  No such  request  shall be made  more than  three  years
subsequent  to the  Payment  Measuring  Period that is the subject of such audit
request.  The accounting firm shall disclose to the Requesting Party any matters
directly  related  to their  findings,  to the  extent  necessary  to verify the
accuracy  or  completeness  of the  information  provided  by the Company to the
Requesting  Party. This covenant shall survive the termination of this Agreement
for a period of thirty six months.

         (b) If such accounting firm concludes and, the Company agrees with such
conclusion,  that additional  payments were owed during such period, the Company
shall pay the additional  payments  within thirty  Business Days of the date the
Requesting Party delivers to the Company such accounting  firm's written report;
provided that, if the Company  disagrees with such  conclusion the dispute shall
be submitted to arbitration for settlement.  The fees charged by such accounting
firm shall be paid by the  Requesting  Party,  unless  the amount of  additional
payments  due exceeds the amount  paid for any such  period by ten  percent,  in
which case the Company shall reimburse the Requesting Party for the fees charged
by such accounting firm.

         (c) Upon the  expiration of thirty six months  following the end of any
Payment  Measuring  Period,  the calculation of payments payable with respect to
such Payment  Measuring  Period shall be binding and conclusive upon each party,
and the Company  shall be released  from any  liability or  accountability  with
respect to payments for such Payment Measuring Period.

         (d) Each  person  seeking to receive  information  from the  Company in
connection  with an audit shall enter into, and shall cause its accounting  firm
to enter into, a reasonable and mutually satisfactory  confidentiality agreement
with the Company obligating such party to retain all such financial  information
disclosed  to  such  party  in  confidence  pursuant  to  such   confidentiality
agreement.

         (e) The  Company  shall  not enter  into any  license  or  distribution
arrangement  with respect to the  Somatogen  Recombinant  Hemoglobin  Technology
unless such agreement  contains audit  provisions at least as favorable,  in the
aggregate, as this Section 7.6.

         Section 7.7 Non-Monetary  Consideration for Licensed  Products.  In the
event that the Company shall sell any Product to customers for any consideration
other than cash, such sale shall be deemed to have been made at a price equal to
the average selling price (determined in accordance with industry practice).

         Section 7.8 Foreign  Exchange.  For the  purpose of  computing  the Net
Sales of Products  sold in a currency  other than United  States  Dollars,  such
currency  shall be converted into United States Dollars using the average of the
rates of exchange  published in The Wall Street Journal during the five business
days preceding the close of the Payment Measuring Period.

         Section 7.9 Notice of Default.  The Company shall file with the Trustee
written  notice of the occurrence of any Event of Default or other default under
this  Agreement  within five  business  days of its  becoming  aware of any such
Default or Event of Default.


<PAGE> 27

                                     ARTICLE 8
               REMEDIES OF THE TRUSTEE AND HOLDERS ON EVENT OF DEFAULT

         Section 8.1 Event of Default Defined;  Acceleration of Maturity; Waiver
of Default. "Event of Default" with respect to the Securities, means each one of
the following  events which shall have occurred and be continuing  (whatever the
reason  for  such  Event of  Default  and  whether  it  shall  be  voluntary  or
involuntary  or be effected  by  operation  of law or pursuant to any  judgment,
decree  or  order  of  any  court  or  any  order,  rule  or  regulation  of any
administrative or governmental body):

         (a) default in the payment of all or any part of the amounts payable in
respect  of any of the  Securities  as and when the same  shall  become  due and
payable  either at a Payment Date, a Redemption  Date, the Final Payment Date or
otherwise; or

         (b) default in the performance,  or breach, of any covenant or warranty
of the Company in respect of the  Securities  (other than a covenant or warranty
in respect of the Securities,  a default in whose performance or whose breach is
elsewhere in this Section  specifically  dealt with),  and  continuance  of such
default or breach for a period of ninety  days after  there has been  given,  by
registered  or certified  mail,  to the Company by the Trustee or to the Company
and the  Trustee by the  Holders of at least  fifty  percent of the  Outstanding
Securities,  a written notice specifying such default or breach and requiring it
to be remedied and stating that such notice is a "Notice of Default"  hereunder;
or

         (c) a court having jurisdiction in the premises shall enter a decree or
order for  relief in respect of the  Company  in an  involuntary  case under any
applicable  bankruptcy,  insolvency  or other  similar law now or  hereafter  in
effect, or appointing a receiver,  liquidator,  assignee,  custodian, trustee or
sequestrator (or similar official) of the Company or for any substantial part of
its property or ordering the winding up or liquidation of its affairs,  and such
decree  or order  shall  remain  unstayed  and in  effect  for a period of sixty
consecutive days; or

         (d) the Company shall  commence a voluntary  case under any  applicable
bankruptcy,  insolvency  or other  similar law now or  hereafter  in effect,  or
consent  to the entry of an order for  relief in an  involuntary  case under any
such law, or consent to the  appointment of or taking  possession by a receiver,
liquidator,  assignee,  custodian, trustee or sequestrator (or similar official)
of the Company or for any substantial part of its property,  or make any general
assignment for the benefit of creditors.


<PAGE> 28

         If an Event of Default described above occurs and is continuing,  then,
and in each and every such case, unless all of the Securities shall have already
become due and  payable,  either the  Trustee or the  Trustee  upon the  written
request  of  Holders  of not less than  fifty  percent  of the  Securities  then
Outstanding hereunder by notice in writing to the Company (and to the Trustee if
given by the  Holders),  shall bring suit for any amounts  then due and payable,
which amounts shall bear interest at the Default  Interest Rate until payment is
made to the Trustee.

         The foregoing  provisions,  however,  are subject to the condition that
if, at any time after the  Trustee  shall  have begun such suit,  and before any
judgment or decree for the payment of the moneys due shall have been obtained or
entered as hereinafter provided, the Company shall pay or shall deposit with the
Trustee a sum  sufficient  to pay all amounts  which shall have become due (with
interest  upon such overdue  amount at the Default  Interest Rate to the date of
such  payment  or  deposit)  and such  amount  as shall be  sufficient  to cover
reasonable  compensation to the Trustee, its agents,  attorneys and counsel, and
all other  expenses  and  liabilities  incurred and all  advances  made,  by the
Trustee,  and if any and all Events of Default under this Agreement,  other than
the  non-payment  of the amounts  which  shall have become due by  acceleration,
shall have been cured, waived or otherwise remedied as provided herein, then and
in  every  such  case the  Holders  of a  majority  of all the  Securities  then
Outstanding,  by written notice to the Company and to the Trustee, may waive all
defaults with respect to the  Securities,  but no such waiver or rescission  and
annulment shall extend to or shall affect any subsequent default or shall impair
any right consequent thereof.

         Section 8.2 Collection of  Indebtedness  by Trustee;  Trustee May Prove
Debt. The Company covenants that in case default shall be made in the payment of
all or any part of the  Securities  when  the same  shall  have  become  due and
payable, whether at a Redemption Date, the Final Payment Date, a Default Payment
Date or upon  acceleration  or otherwise,  then upon demand of the Trustee,  the
Company will pay to the Trustee for the benefit of the Holders of the Securities
the whole  amount that then shall have become due and payable on all  Securities
(with  interest  from the date due and payable to the date of such  payment upon
the overdue amount at the Default Interest Rate); and in addition thereto,  such
further  amount  as shall be  sufficient  to cover the  costs  and  expenses  of
collection,   including   reasonable   compensation  to  the  Trustee  and  each
predecessor  Trustee,  their respective agents,  attorneys and counsel,  and any
expenses and  liabilities  incurred,  and all advances  made, by the Trustee and
each predecessor Trustee, except as a result of its negligence or bad faith.

         The  Trustee may in its  discretion  proceed to protect and enforce its
rights and the rights of the Holders by such appropriate judicial proceedings as
the Trustee  shall deem most  effectual  to protect and enforce any such rights,
whether  for the  specific  enforcement  of any  covenant or  agreement  in this
Agreement or in aid of the exercise of any power granted  herein,  or to enforce
any other remedy.

         In case the Company shall fail  forthwith to pay such amounts upon such
demand,  the Trustee,  in its own name and as trustee of an express trust, shall
be entitled and  empowered to institute any action or  proceedings  at law or in
equity for the  collection of the sums so due and unpaid,  and may prosecute any
such action or proceedings to judgment or final decree, and may enforce any such
judgment  or final  decree  against  the  Company  or other  obligor  upon  such
Securities and collect in the manner  provided by law out of the property of the
Company or other obligor upon such  Securities,  wherever  situated,  the moneys
adjudged or decreed to be payable.

         In case there shall be pending  proceedings  relative to the Company or
an other obligor upon the Securities under Title 11 of the United States Code or
any other applicable  Federal or state  bankruptcy,  insolvency or other similar
law, or in case a receiver, assignee or trustee in bankruptcy or reorganization,
liquidator,  sequestrator  or similar  official shall have been appointed for or
taken  possession  of the Company or its property or such other  obligor,  or in
case of any other  comparable  judicial  proceedings  relative to the Company or
other  obligor  upon the  Securities,  or to the  creditors  or  property of the
Company or such other obligor the Trustee, irrespective of whether the principal
of any Securities shall then be due and payable as herein expressed or otherwise
and  irrespective  of whether the Trustee shall have made any demand pursuant to
the provisions of this Section, shall be entitled and empowered, (but shall have
no obligation) by intervention in such proceedings or otherwise:


<PAGE> 29

         (a) to file and prove a claim or claims for the whole  amount owing and
unpaid in respect of the Securities,  and to file such other papers or documents
as may be  necessary  or  advisable  in order to have the claims of the  Trustee
(including  any  claim  for  reasonable  compensation  to the  Trustee  and each
predecessor Trustee, and their respective agents, attorneys and counsel, and for
reimbursement of all expenses and liabilities  incurred,  and all advances made,
by the Trustee and each predecessor Trustee, except as a result of negligence or
bad faith) and of the Holders  allowed in any judicial  proceedings  relative to
the  Company  or other  obligor  upon  the  Securities,  or to their  respective
property;

         (b) unless  prohibited by applicable  law and  regulations,  to vote on
behalf of the  Holders  in any  election  of a trustee  or a standby  trustee in
arrangement,  reorganization,  liquidation  or other  bankruptcy  or  insolvency
proceedings or person performing  similar  functions in comparable  proceedings;
and
         (c) to collect  and  receive  any moneys or other  property  payable or
deliverable  on any such claims,  and to  distribute  all amounts  received with
respect to the claims of the Holders and of the Trustee on their behalf; and any
trustee, receiver, or liquidator,  custodian or other similar official is hereby
authorized by each of the Holders to make  payments to the Trustee,  and, in the
event that the Trustee shall  consent to the making of payments  directly to the
Holders,  to pay to the Trustee  such  amounts as shall be  sufficient  to cover
reasonable  compensation  to the  Trustee,  each  predecessor  Trustee and their
respective agents, attorneys and counsel, and all other expenses and liabilities
incurred,  and all advances made, by the Trustee and each  predecessor  Trustee,
except as a result of its negligence or bad faith,  and all other amounts due to
the Trustee or any  predecessor  Trustee  pursuant to Section 4.6. To the extent
that such payment of reasonable compensation, expenses, disbursements,  advances
and other amounts out of the estate in any such proceedings  shall be denied for
any reason, payment of the same shall be secured by a lien on, and shall be paid
out of,  any and all  distributions,  dividends,  moneys,  securities  and other
property  which the  Holders  may be  entitled  to receive in such  proceedings,
whether in  liquidation  or under any plan of  reorganization  or arrangement or
otherwise.

         Nothing  herein  contained  shall be deemed to authorize the Trustee to
authorize  or  consent to or vote for or accept or adopt on behalf of any Holder
any plan of reorganization, arrangement, adjustment or composition affecting the
Securities,  or the rights of any Holder thereof, or to authorize the Trustee to
vote in  respect of the claim of any Holder in any such  proceeding  except,  as
aforesaid,  to vote for the  election  of a trustee  in  bankruptcy  or  similar
person.

         All rights of action and of asserting  claims under this Agreement,  or
under  any of the  Securities,  may be  enforced  by  the  Trustee  without  the
possession of any of the Securities or the  production  thereof and any trial or
other proceedings  instituted by the Trustee shall be brought in its own name as
trustee  of an express  trust,  and any  recovery  of  judgment,  subject to the
payment of the expenses,  disbursements  and  compensation of the Trustee,  each
predecessor Trustee and their respective agents and attorneys,  shall be for the
ratable benefit of the Holders.

         In any  proceedings  brought by the Trustee  (and also any  proceedings
involving the  interpretation  of any  provision of this  Agreement to which the
Trustee  shall be a  party)  the  Trustee  shall  be held to  represent  all the
Holders,  and it shall not be necessary  to make any Holders of such  Securities
parties to any such proceedings.

         Section  8.3  Application  of  Proceeds.  Any monies  collected  by the
Trustee  pursuant to this Article in respect of any Securities  shall be applied
in the  following  order  at the  date  or  dates  fixed  by  the  Trustee  upon
presentation  of the  several  Securities  in respect of which  monies have been
collected and stamping (or otherwise noting) thereon the payment in exchange for
the presented  Securities if only partially  paid or upon  surrender  thereof if
fully paid:


<PAGE> 30

        FIRST:  To the payment of costs and expenses in respect of which monies
have been collected,  including reasonable  compensation to the Trustee and each
predecessor  Trustee  and  their  respective  agents  and  attorneys  and of all
expenses and  liabilities  incurred,  and all advances  made, by the Trustee and
each predecessor Trustee, except as a result of its negligence or bad faith, and
all other  amounts due to the  Trustee or any  predecessor  Trustee  pursuant to
Section 4.6;

         SECOND:  To the payment of the whole  amount then owing and unpaid upon
all the  Securities,  with  interest  at the Default  Interest  Rate on all such
amounts,  and in case such monies shall be insufficient to pay in full the whole
amount  so due and  unpaid  upon the  Securities,  then to the  payment  of such
amounts without  preference or priority of any security over any other Security,
ratably to the aggregate of such amounts due and payable and such payments shall
be deemed to be Contingent Payments made for purposes of Section 3.1(e); and

         THIRD:  To the payment of the  remainder,  if any, to the  Company or 
any other  person  lawfully entitled thereto.

         Section  8.4 Suits for  Enforcement.  In case an Event of  Default  has
occurred,  has  not  been  waived  and is  continuing,  the  Trustee  may in its
discretion  proceed  to protect  and  enforce  the  rights  vested in it by this
Agreement by such  appropriate  judicial  proceedings  as the Trustee shall deem
most  effectual to protect and enforce any of such  rights,  either at law or in
equity or in bankruptcy or otherwise,  whether for the specific  enforcement  of
any covenant or agreement  contained in this Agreement or in aid of the exercise
of any  power  granted  in this  Agreement  or to  enforce  any  other  legal or
equitable right vested in the Trustee by this Agreement or by law.

         Section 8.5  Restoration of Rights on Abandonment  of  Proceedings.  In
case the Trustee or any Holder  shall have  proceeded to enforce any right under
this Agreement and such  proceedings  shall have been  discontinued or abandoned
for any reason,  or shall have been  determined  adversely  to the Trustee or to
such  Holder,  then and in every such case the  Company  and the Trustee and the
Holders  shall be restored  respectively  to their former  positions  and rights
hereunder,  and all rights,  remedies and powers of the Company, the Trustee and
the Holders shall continue as though no such proceedings had been taken.


<PAGE> 31

         Section 8.6 Limitations on Suits by Holders.  No Holder of any Security
shall have any right by virtue or by availing of any provision of this Agreement
to institute  any action or  proceeding  at law or in equity or in bankruptcy or
otherwise  upon  or  under  or  with  respect  to  this  Agreement,  or for  the
appointment  of a trustee,  receiver,  liquidator,  custodian  or other  similar
official or for any other remedy hereunder,  unless such Holder previously shall
have  given to the  Trustee  written  notice of default  and of the  continuance
thereof, as hereinbefore  provided, and unless also the Holders of not less than
thirty  percent of the  Securities  then  Outstanding  shall  have made  written
request upon the Trustee to institute such action or proceedings in its own name
as trustee  hereunder  and shall have  offered to the  Trustee  such  reasonable
indemnity as it may require  against the costs,  expenses and  liabilities to be
incurred  therein or thereby and the Trustee for sixty days after its receipt of
such notice,  request and offer of indemnity  shall have failed to institute any
such  action or  proceeding  and no  direction  inconsistent  with such  written
request  shall have been given to the Trustee  pursuant to Section 8.9; it being
understood and intended,  and being expressly covenanted by the taker and Holder
of every Security with every other taker and Holder and the Trustee, that no one
or more  Holders of  Securities  shall have any right in any manner  whatever by
virtue or by availing of any provision of this  Agreement to effect,  disturb or
prejudice  the rights of any other such  Holder of  Securities,  or to obtain or
seek to  obtain  priority  over or  preference  to any other  such  Holder or to
enforce any right under this Agreement, except in the manner herein provided and
for the equal, ratable and common benefit of all Holders of Securities.  For the
protection and  enforcement  of the  provisions of this Section,  each and every
Holder and the Trustee  shall be entitled to such relief as can be given  either
at law or in equity.

         Section 8.7 Unconditional  Right of Holders to Institute Certain Suits.
Notwithstanding  any other  provision in this Agreement and any provision of any
Security,  the right of any Holder of any  Security  to  receive  payment of the
amounts payable in respect of such Security on or after the respective due dates
expressed in such Security, or to institute suit for the enforcement of any such
payment on or after such  respective  dates,  shall not be  impaired or affected
without the consent of such Holder.

         Section  8.8 Powers and  Remedies  Cumulative;  Delay or  Omission  Not
Waiver of Default.  Except as provided in Section 8.6, no right or remedy herein
conferred  upon or  reserved  to the Trustee or to the Holders is intended to be
exclusive of any other right or remedy, and every right and remedy shall, to the
extent  permitted by law, be cumulative and in addition to every other right and
remedy  given  hereunder  or now or  hereafter  existing  at law or in equity or
otherwise.  The  assertion or employment  of any right or remedy  hereunder,  or
otherwise, shall not prevent the concurrent assertion or employment of any other
appropriate right or remedy.

         No delay or omission  of the  Trustee or of any Holder to exercise  any
right or power  accruing upon any Event of Default  occurring and  continuing as
aforesaid  shall  impair any such right or power or shall be  construed  to be a
waiver of any such Event of Default or an acquiescence  therein; and, subject to
Section  8.6,  every power and remedy  given by this  Agreement or by law to the
Trustee or to the Holders may be  exercised  from time to time,  and as often as
shall be deemed expedient, by the Trustee or by the Holders.

         Section  8.9  Control by  Holders.  The  Holders  of a majority  of the
Securities  at the time  Outstanding  shall  have the right to direct  the time,
method,  and place of conducting any proceeding for any remedy  available to the
Trustee,  or exercising any trust or power conferred on the Trustee with respect
to the Securities by this  Agreement;  provided that such direction shall not be
otherwise than in accordance with law and the provisions of this Agreement;  and
provided  further that  (subject to the  provisions  of Section 4.1) the Trustee
shall have the right to decline to follow  any such  direction  if the  Trustee,
being  advised by counsel,  shall  determine  that the action or  proceeding  so
directed  may not lawfully be taken or if the Trustee in good faith by its board
of directors,  the  executive  committee,  or a trust  committee of directors or
responsible  officers  of  the  Trustee  shall  determine  that  the  action  or
proceedings  so directed  would involve the Trustee in personal  liability or if
the Trustee in good faith shall so determine  that the actions or  forebearances
specified in or pursuant to such  direction  would be unduly  prejudicial to the
interests  of  Holders  of the  Securities  not  joining  in the  giving of said
direction,  it being  understood that (subject to Section 4.1) the Trustee shall
have no duty to  ascertain  whether  or not such  actions or  forebearances  are
unduly prejudicial to such Holders.


<PAGE> 32

         Nothing in this Agreement  shall impair the right of the Trustee in its
discretion  to take any action  deemed  proper by the  Trustee  and which is not
inconsistent with such direction or directions by Holders.

         Section  8.10 Waiver of Past  Defaults.  In the case of a default or an
Event of Default specified in clause (b), (c) or (d) of Section 8.1, the Holders
of a majority of all the Securities then  Outstanding may waive any such default
or Event of  Default,  and its  consequences  except a default  in  respect of a
covenant or  provisions  hereof which cannot be modified or amended  without the
consent of the Holder of each Security affected. In the case of any such waiver,
the Company,  the Trustee and the Holders of the Securities shall be restored to
their former positions and rights  hereunder,  respectively;  but no such waiver
shall extend to any  subsequent or other default or impair any right  consequent
thereon.

         Upon any such waiver,  such default  shall cease to exist and be deemed
to have been cured and not to have  occurred,  and any Event of Default  arising
therefrom shall be deemed to have been cured, and not to have occurred for every
purpose of this Agreement;  but no such waiver shall extend to any subsequent or
other default or Event of Default or impair any right consequent thereon.

         Section  8.11  Trustee to Give Notice of Default,  But May  Withhold in
Certain  Circumstances.  The Trustee shall transmit to the Holders, as the names
and addresses of such Holders appear on the Security Register, notice by mail of
all defaults which have occurred and are known to the Trustee, such notice to be
transmitted  within  ninety  days  after the  occurrence  thereof,  unless  such
defaults  shall have been  cured  before  the  giving of such  notice  (the term
"default" or "Defaults" for the purposes of this Section being hereby defined to
mean any event or  condition  which is, or with  notice or lapse of time or both
would become, an Event of Default); provided that, except in the case of default
in the payment of the amounts payable in respect of any of the  Securities,  the
Trustee  shall be  protected  in  withholding  such notice if and so long as the
board of directors,  the executive committee,  or a trust committee of directors
or trustees and/or Responsible  Officers of the Trustee in good faith determines
that the withholding of such notice is in the interests of the Holders.

         Section  8.12 Right of Court to Require  Filing of  Undertaking  to Pay
Costs.  All parties to this Agreement  agree, and each Holder of any Security by
his acceptance thereof shall be deemed to have agreed, that any court may in its
discretion require, in any suit for the enforcement of any right or remedy under
this Agreement or in any suit against the Trustee for any action taken, suffered
or omitted by it as Trustee, the filing by any party litigant in such suit of an
undertaking  to pay the  costs of such  suit,  and that  such  court  may in its
discretion assess reasonable costs, including attorneys' fees, against any party
litigant  in such  suit,  having  due regard to the merits and good faith of the
claims or  defenses  made by such party  litigant;  but the  provisions  of this
Section  shall  not apply to any suit  instituted  by the  Trustee,  to any suit
instituted by any Holder or group of Holders  holding in the aggregate more than
twenty five percent of the Securities  Outstanding or to any suit  instituted by
any Holder for the  enforcement  of the payment of any  Security on or after the
due date expressed in such Security.



<PAGE> 33

                                  ARTICLE 9

                  CONSOLIDATION, MERGER, SALE OR CONVEYANCE

         Section  9.1 Company  May  Consolidate,  etc.,  on Certain  Terms.  The
Company  covenants that it will not merge or consolidate  with or into any other
Person or sell or convey all or  substantially  all of its assets to any Person,
unless (i) the Company  shall be the  continuing  corporation,  or the successor
Person or the Person which acquires by sale or conveyance  substantially all the
assets of the Company shall be a Person  organized  under the laws of the United
States  of  America  or any  State  thereof  and  shall  expressly  assume by an
instrument  supplemental hereto,  executed and delivered to the Trustee, in form
satisfactory  to the Trustee,  the due and punctual  payment of the  Securities,
according to their tenor, and the due and punctual performance and observance of
all of the  covenants  and  conditions  of this  Agreement  to be  performed  or
observed by the Company and (ii) the Company,  or such successor  Person, as the
case may be, shall not, immediately after such merger or consolidation,  or such
sale or  conveyance,  be in default in the  performance  of any such covenant or
condition.

         Section  9.2  Successor  Person  Substituted.   In  case  of  any  such
consolidation,  merger, sale or conveyance, or a transfer to a person other than
a  Subsidiary  or an  Affiliate  of the  Company  of the  Somatogen  Recombinant
Hemoglobin  Technologies  as provided in Section  3.1(g) and  following  such an
assumption by the successor  Person,  such successor Person shall succeed to and
be  substituted  for the  Company  with the same  effect as if it had been named
herein.  Such successor  Person may cause to be signed,  and may issue either in
its own name or in the name of the Company prior to such  succession  any or all
of the  Securities  issuable  hereunder  which  theretofore  shall not have been
signed by the Company and delivered to the Trustee;  and, upon the order of such
successor  corporation  instead  of the  Company  and  subject to all the terms,
conditions  and  limitations  in this  Agreement  prescribed,  the Trustee shall
authenticate  and shall deliver any Securities  which previously shall have been
signed and delivered to the Trustee for authentication, and any Securities which
such successor corporation  thereafter shall cause to be signed and delivered to
the Trustee  for that  purpose.  All of the  Securities  so issued  shall in all
respects  have the same  legal rank and  benefit  under  this  Agreement  as the
Securities theretofore or thereafter issued in accordance with the terms of this
Agreement  as though all of such  Securities  had been issued at the date of the
execution hereof.

         In case of any such  consolidation,  merger,  sale or conveyance,  such
changes  in  phraseology  and  form  (but not in  substance)  may be made in the
Securities thereafter to be issued as may be appropriate.

         In the event of any such sale,  transfer  or  conveyance  (other than a
conveyance  by way of lease) the Company or any Person  which shall  theretofore
have become such in the manner  described  in this Article  shall be  discharged
from all  obligations  and covenants under this Agreement and the Securities and
may be liquidated and dissolved.

         Section 9.3 Opinion of Counsel to Trustee. The Trustee,  subject to the
provisions  of  Sections  4.1 and 4.2,  shall  receive an  Opinion  of  Counsel,
prepared in accordance  with  Sections 1.3 and 1.4, as conclusive  evidence that
any such consolidation, merger, sale or conveyance, and any such assumption, and
any such liquidation or dissolution,  complies with the applicable provisions of
this Agreement.



<PAGE> 34

                                  ARTICLE 10

                                  REDEMPTION

         Section  10.1  Right  of  Redemption.   Redemption  of  Securities,  as
permitted by the provisions of this Agreement,  shall be made in accordance with
such provisions and this Article 10. The Company shall have the right to redeem,
in whole or in part, at any time or from time to time, the Securities.

         Section 10.2 Notices to Trustees.  If the Company  elects to redeem any
Securities,  it shall notify the Trustee in writing of the  Redemption  Date and
the aggregate number of CPR Certificates to be redeemed and whether it wants the
Trustee to give notice of redemption to the Holders.

         The Company shall give each notice to the Trustee  provided for in this
Section 10.2 at least thirty days before the  Redemption  Date (unless a shorter
notice  shall be  satisfactory  to the Trustee and the Paying  Agent).  Any such
notice may be  conditional  and may be  cancelled at any time prior to notice of
such  redemption  being mailed to any Holder and shall thereby be void and of no
effect.

         Section 10.3 Selection of CPR Certificates to Be Redeemed. If less than
all of the CPR Certificates are to be redeemed, the Trustee shall select the CPR
Certificates  to be redeemed by lot or by such other method as the Trustee shall
determine to be appropriate and fair.

                  The Trustee shall make the selection from the CPR Certificates
outstanding  and not previously  called for redemption and shall promptly notify
the Company in writing of the CPR  Certificates  selected for redemption and, in
the case of any CPR Certificate  selected for partial redemption,  the number of
CPRs  thereof to be redeemed.  Provisions  of this  Agreement  that apply to CPR
Certificates  called for redemption  also apply to portions of CPR  Certificates
called for redemption.

         Section  10.4 Notice of  Redemption.  At least twenty days but not more
than sixty days before a  Redemption  Date,  the Trustee  shall mail a notice of
redemption  by first  class mail,  postage  prepaid,  to each  Holder  whose CPR
Certificates  are to be redeemed.  Each notice for redemption shall identify the
CPR Certificates to be redeemed and shall state:

         (a)      the Redemption Date;

         (b)      the Redemption Price;

         (c)      the name, address and telephone number of the Trustee and of 
the Paying Agent;

         (d) that CPR Certificates  called for redemption must be surrendered to
the Trustee at the address  specified  in such notice to collect the  Redemption
Price;

         (e) that, unless the Company defaults in its obligation to deposit with
the Trustee cash in an amount to fund the Redemption  Price,  in accordance with
Section  10.6  hereof  or  such  redemption  payment  is  otherwise  prohibited,
Contingent  Payments on CPR Certificates  called for redemption ceases to accrue
on and after the Redemption  Date and the only remaining right of the Holders of
such CPR  Certificates  is to receive  payment  of the  Redemption  Price,  upon
surrender to the Trustee of the CPR Certificates called for redemption and to be
redeemed;


<PAGE> 35

         (f) if any CPR  Certificate  is being  redeemed in part, the portion of
such CPR  Certificate to be redeemed and that,  after the  Redemption  Date, and
upon  surrender  of  such  CPR  Certificate,   a  new  CPR  Certificate  or  CPR
Certificates equal to the Royalty  Certificates  unredeemed portion thereof will
be issued;

         (g) if less  than  all the CPR  Certificates  are to be  redeemed,  the
identification  of the particular CPR  Certificates  (or portion  thereof) to be
redeemed, as well as the aggregate number of CPR Certificates to be redeemed and
the aggregate  number of CPR  Certificates to be outstanding  after such partial
redemption;

         (h) the CUSIP number of the CPR Certificates to be redeemed; and

         (i) that the notice is being sent  pursuant  to this  Section  10.4 and
pursuant to the optional redemption provisions of the CPR Certificates.

         Section 10.5 Effect of Notice of Redemption.  Once notice of redemption
is  mailed  in  accordance  with  Section  10.4,  CPR  Certificates  called  for
redemption  become due and payable on the Redemption  Date and at the Redemption
Price.  Upon  surrender to the Paying Agent,  such CPR  Certificates  called for
redemption shall be paid at the Redemption Price; provided, that if a Redemption
Date is a  non-Business  Day,  payment  shall  be made  on the  next  succeeding
Business Day and no interest  shall  accrue for the period from such  Redemption
Date to such succeeding Business Day.

         Section 10.6 Deposit of  Redemption  Price.  On or prior to 10:00 a.m.,
New York City time, on the  Redemption  Date, the Company shall deposit with the
Trustee cash sufficient to pay the Redemption  Price of all CPR  Certificates to
be redeemed on such  Redemption  Date (other than CPR  Certificates  or portions
thereof  called  for  redemption  on that date that have been  delivered  by the
Company to the Trustee for  cancellation).  The Trustee shall promptly return to
the Company any cash so  deposited  which is not  required for that purpose upon
the written request of the Company.

         If the Company  complies  with the  preceding  paragraph  and the other
provisions  of this  Article 10 and payment of the CPR  Certificates  called for
redemption is not otherwise  prohibited,  the right to Contingent  Payments with
respect  to the CPR  Certificates  to be  redeemed  will  cease to accrue on the
applicable  Redemption Date,  whether or not such CPR Certificates are presented
for  payment.  Notwithstanding  anything  herein  to the  contrary,  if any  CPR
Certificate  surrendered  for  redemption  in the  manner  provided  in the  CPR
Certificates  shall not be so paid upon surrender for redemption  because of the
failure  of the  Company  to  comply  with  the  preceding  paragraph,  such CPR
Certificates  shall  remain  Outstanding  and shall  continue  to be entitled to
Contingent  Payments  in the manner  provided  in Section 4.1 hereof and the CPR
Certificate.

         Section 10.7 CPR Certificates Redeemed in Part. Upon surrender of a CPR
Certificate  that is to be redeemed in part,  the Trustee  shall execute and the
Trustee shall authenticate and deliver to the Holder,  without service charge to
the Holder, a new CPR Certificate or CPR Certificates  equal in principal amount
to the unredeemed portion of the CPR Certificate surrendered.



<PAGE> 36



                  IN WITNESS  WHEREOF,  the  parties  hereto  have  caused  this
Agreement to be duly executed, all as of the day and year first above written.

                                 BAXTER INTERNATIONAL INC.


                                 By:  ________________________________
                                      Name:
                                      Title:

                                 FIRST TRUST NATIONAL ASSOCIATION, as Trustee


                                 By:  ________________________________
                                      Name:
                                      Title:




<PAGE> 37




                                Baxter International Inc.


No.                           Certificate for        Contingent Payment Rights


                  This certifies that, or registered assigns (the "Holder"), is
the registered  holder of the number of Contingent  Payment Rights  ("CPRs") set
forth above. Each CPR entitles the Holder,  subject to the provisions  contained
herein and in the Agreement  referred to on the reverse hereof, to payments from
Baxter International Inc., a Delaware corporation (the "Company"),  in an amount
and in the form  determined  pursuant to the provisions set forth on the reverse
hereof and as more fully  described in the Agreement  referred to on the reverse
hereof.  Such payment  shall be made on each  Payment  Date or, if earlier,  the
Redemption  Date or the Default  Payment Date,  each as defined in the Agreement
referred to on the reverse hereof.

                  Payment of any amounts pursuant to this CPR Certificate  shall
be made only to the registered  Holder (as defined in the Agreement) of this CPR
Certificate. Such payment shall be made in the Borough of Manhattan, The City of
New York,  or at any other office or agency  maintained  by the Company for such
purpose, in such coin or currency of the United States of America as at the time
is legal tender for the payment of public and private debts; provided,  however,
the  Company  may pay such  amounts by wire  transfer  or check  payable in such
money. First Trust National  Association has been initially  appointed as Paying
Agent in the Borough of Manhattan, The City of New York.

                  Reference is hereby made to the further provisions of this CPR
Certificate set forth on the reverse hereof,  which further provisions shall for
all purposes have the same effect as if set forth at this place.

                  Unless the certificate of authentication  hereon has been duly
executed by the Trustee  referred to on the reverse hereof by manual  signature,
this CPR  Certificate  shall not be entitled to any benefit under the Agreement,
or be valid or obligatory for any purpose.




<PAGE> 38



                  IN WITNESS WHEREOF,  the Company has caused this instrument to
be duly executed.

Dated:                                    Baxter International Inc.



                                          By______________________________






Attest:



_____________________________
Authorized Signature





<PAGE> 39


                       [Form of Reverse of CPR Certificate]

                  This CPR  Certificate  is issued under and in accordance  with
the Contingent  Payment Rights  Agreement,  dated as of [insert date], 1998 (the
"Agreement"),  between  the  Company and First  Trust  National  Association,  a
national  association,  as  trustee  (the  "Trustee,"  which term  includes  any
successor  Trustee  under  the  Agreement),  and is  subject  to the  terms  and
provisions contained in the Agreement,  to all of which terms and provisions the
Holder of this CPR Certificate  consents by acceptance  hereof. The Agreement is
hereby  incorporated  herein by reference  and made a part hereof.  Reference is
hereby made to the  Agreement  for a full  statement of the  respective  rights,
limitations of rights,  duties,  obligations  and  immunities  thereunder of the
Company,  the Trustee and the holders of the CPRs. All capitalized terms used in
this CPR  Certificate  without  definition  shall have the  respective  meanings
ascribed to them in the  Agreement.  Copies of the  Agreement can be obtained by
contacting the Trustee.

                  Subject to  extension  or earlier  redemption  as  hereinafter
provided,  until March 15, 2008,  the Company  shall pay to the Holder hereof on
March 15 and  September  15 of each year (or if such day is not a Business  Day,
without accruing any interest,  on the next succeeding Business Day),  beginning
March 15,  1999,  or if such day is not a Business  Day,  without  accruing  any
interest, on the next Business Day (as the same may be extended, each a "Payment
Date"),  for each CPR represented  hereby,  a pro rata portion of the Contingent
Payment with respect to the Payment  Measuring Period ended immediately prior to
such Payment Date,  unless the CPR(s)  represented by this CPR Certificate shall
have been redeemed as provided for herein;  provided, that in no event shall the
aggregate of all Contingent Payments with respect to each CPR exceed two dollars
($2.00) and, provided,  further,  that in no event shall the Company be required
to a make a payment on any Payment Date in an amount less than $0.05 per CPR and
such amounts which would  otherwise be payable on such Payment Date shall (x) be
aggregated  with the amount  payable with respect to the next Payment  Measuring
Period and (y) not bear interest except on a Default Payment Date.

                  The   "Contingent   Payment,"  with  respect  to  any  Payment
Measuring Period,  equals five percent of the Net Sales that are attributable to
the commercial sale of Products.

                  "Net  Sales"  means the actual  gross  amount  invoiced by the
Company,  its Affiliates,  licensees or distributors for the sale of Products to
any  third  parties  during  a  Payment   Measuring   Period  less:  (a)  direct
transportation  charges,  including  insurance;  (b) trade,  quantity  and other
discounts and rebates  actually allowed and taken to the extent customary in the
trade; and (c) allowances or credits,  including but not limited to,  allowances
or credits to  customers  on account  of  rejection  or return of the  Products;
provided  that (i) a sale or transfer to an  Affiliate of the Company for resale
by such  Affiliate  shall  not be  considered  a sale  for the  purpose  of this
provision,  but the resale by such Affiliate  shall be a sale for such purposes,
and the term "sale" shall include a transfer or other disposition to a customer;
(ii) Net Sales shall not include  reserves for bad debts or allowances,  credits
or rebates not covered  above;  and (iii) a sale of Products  shall occur at the
earlier of (a) the  transfer  of title in such  Products to a third party or (b)
the shipment of such Products from the manufacturing or warehouse  facilities of
the manufacturer of such Products to a third party.


<PAGE> 40

                 Net Sales  shall not  include  license  fees or other  advance
payments  received by the Company from a licensee or distributor of the Products
which is not derived from sales of Products,  but shall include the Net Sales of
such licensee or distributor.

                  "Payment  Measuring  Period"  means  (i) the  period  from the
Effective Date to December 31, 1998 and (ii) each six month period ended June 30
and December 31 thereafter, through and including the Final Payment Date.

                  "Products" shall mean all products in which the primary active
ingredient  is  human  hemoglobin,  or  derivatives,  mutants  or  modifications
thereof, which have been produced in culture of microbial cells (including yeast
cells)  which  have  been  modified  using  Somatogen   Recombinant   Hemoglobin
Technology  (other than clinical  indications  for any such Products that are in
clinical trials as of the date of the Merger Agreement).

                  "Somatogen  Recombinant  Hemoglobin Technology" shall mean all
technology  owned by or licensed to Somatogen on or prior to the Effective Date,
which involves the use of recombinant DNA techniques.

                  If for any reason the Contingent  Payment has not been finally
determined as of the Payment Date,  then the Payment Date will be  automatically
extended until the date that is the seventh Business Day after the date of which
the Contingent Payment has been finally determined.

                  The CPRs will be redeemable,  in whole or in part, at any time
and from time to time,  at the option of the Company at a  redemption  price for
each CPR  represented  hereby equal to $2 less all  Contingent  Payments made or
provided for,  through the Redemption  Date. The Agreement does not prohibit the
Company from otherwise acquiring CPRs.

                  The Contingent  Payment, if any, and interest thereon, if any,
shall be payable by the Company in such coin or currency of the United States of
America  as at the time is legal  tender for the  payment of public and  private
debts; provided,  however, the Company may pay such amounts by its check or wire
transfer  payable in such  money.  First  Trust  National  Association  has been
initially appointed as Paying Agent in the Borough of Manhattan, The City of New
York.

                  If an Event of Default  occurs and is  continuing,  either the
Trustee may or if the Holders  holding an aggregate of at least fifty percent of
the  Outstanding  CPRs,  by notice to the Company and to the Trustee shall bring
suit to recover all amounts then due and payable,  with  interest at the Default
Interest Rate from the Default  Payment Date through the date payment is made or
duly provided for.


<PAGE> 41

                  In the event that, it is finally  determined that no amount is
payable on the CPRs to the Holder on any Payment  Date,  the Company  shall give
the Trustee notice of such determination. The failure to give such notice or any
defect therein shall not affect the validity of such determination.

                  The  Agreement  permits,  with certain  exceptions  as therein
provided,  the  amendment  thereof  and  the  modification  of  the  rights  and
obligations  of the  Company  and the  rights of the  holders  of CPRs under the
Agreement  at any time by the Company  and the  Trustee  with the consent of the
holders of a majority of the CPRs at the time outstanding.

                  No reference  herein to the Agreement and no provision of this
CPR  Certificate or of the Agreement shall alter or impair the obligation of the
Company,  which is absolute  and  unconditional,  to pay any amounts  determined
pursuant  to the terms  hereof  and of the  Agreement  at the  times,  place and
amount,  and  in  the  manner,  herein  prescribed.   The  Holder  of  this  CPR
Certificate,  by acceptance hereof, agrees that the Company has no obligation to
initiate or continue research,  development or commercialization activities with
respect to Products or any of the Somatogen  Recombinant  Hemoglobin  Technology
and, in its sole  subjective  discretion,  the  Company  may abandon  efforts to
research, develop or commercialize such technology or Products.

                  The  Agreement  provides  that the  Trustee  shall  receive an
Officers'   Certificate,   on  or  before  each  Payment  Date,  certifying  the
Consolidated  Revenues from sales of Products.  The Agreement also provides that
The  Company  shall not  transfer  (other than  transfers  to  Subsidiaries  and
Affiliates)  the  Somatogen   Recombinant   Hemoglobin   Technology  unless  the
transferor agrees to be bound by the Agreement to the same extent as the Company
is then  bound  thereby,  whereupon  the  Company  shall  be  released  from any
obligation under the Agreement.

                  As   provided  in  the   Agreement   and  subject  to  certain
limitations  therein set forth, the transfer of the CPRs represented by this CPR
Certificate is registrable on the Security Register,  upon surrender of this CPR
Certificate for  registration of transfer at the office or agency of the Company
maintained  for such purpose in the Borough of Manhattan,  The City of New York,
duly  endorsed by, or  accompanied  by a written  instrument of transfer in form
satisfactory  to The Company and the Security  Registrar  duly  executed by, the
Holder hereof or his attorney duly  authorized in writing,  and thereupon one or
more new CPR  Certificates,  for the same amount of CPRs,  will be issued to the
designated  transferee or transferees.  The Company hereby initially  designates
the office of First Trust National  Association  [insert  address of trustee] as
the office for registration of transfer of this CPR Certificate.

                  As   provided  in  the   Agreement   and  subject  to  certain
limitations  therein set forth,  this CPR Certificate is exchangeable for one or
more CPR  Certificates  representing  the same number of CPRs as  represented by
this CPR Certificate as requested by the Holder surrendering the same.

                  No  service  charge  will be  made  for  any  registration  of
transfer  or exchange  of CPRs,  but the  Company  may require  payment of a sum
sufficient to cover all documentary, stamp or similar issue or transfer taxes or
other  governmental  charges  payable in  connection  with any  registration  of
transfer or exchange.

                  Prior to the time of due  presentment of this CPR  Certificate
for  registration  of transfer,  the  Company,  the Trustee and any agent of the
Company or the Trustee  may treat the Person in whose name this CPR  Certificate
is registered as the owner hereof for all purposes, and neither the Company, the
Trustee nor any agent shall be affected by notice to the contrary.

                  Neither the Company nor the Trustee has any duty or obligation
to the holder of this CPR  Certificate,  except as expressly set forth herein or
in the Agreement.

                  TRUSTEE'S CERTIFICATE  OF AUTHENTICATION

this is one of the CPR Certificates referred to in the within-mentioned 
Agreement.

                                          FIRST TRUST NATIONAL
                                          ASSOCIATION,
                                          Trustee and Transfer
                                          Agent and Registrar

Dated: ____________________

                                          By _____________________________
                                                 Authorized Signatory




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