1

                                                                  EXHIBIT 10.22

                                MASTER AGREEMENT

         AGREEMENT made this 12th day of April, 1996 (the "Effective Date") by
and between Cambridge Biotech Corporation ("Cambridge"), a corporation
organized and existing under the laws of the State of Delaware, debtor and
debtor in possession, Case No. 94-43054-JFQ, United States Bankruptcy Court for
the District of Massachusetts, Western Division, and having a place of business
at 365 Plantation Street, Biotechnology Research Park, Worcester, MA 01605,
U.S.A., and Calypte Biomedical Corporation ("Calypte") a corporation organized
and existing under the laws of California and having a place of business at
1440 Fourth Street, Berkeley,-California.

         WHEREAS Calypte is the exclusive worldwide licensee of New York
University to the patents (the NYU Patents") listed in Appendix 1 attached
hereto and incorporated herein by reference relating to detecting HIV
antibodies in urine;

         WHEREAS Calypte has developed a microtiter plate EIA (the "Screening
Test") for detection of HIV-1 antibodies in urine using the NYU patents and
Calypte's own technology (the "Calypte Technology");

         WHEREAS Calypte has filed a Product License Application with the
United States Food and Drug Administration ("FDA") for the Screening Test and
believes it is in the final stages of FDA review;

         WHEREAS Cambridge manufactures an HIV-1 Western blot assay licensed by
the FDA to confirm the results of HIV antibody detection assays using serum and
plasma samples (the "Serum Blot");

         WHEREAS Calypte and Cambridge propose by this agreement to develop a
protocol and reagents to use or modify the Serum Blot to confirm the results of
the Screening Test using urine samples (the "Urine Confirmation System"), and
to seek FDA licensure or marketing approval thereof; and

         WHEREAS Calypte and Cambridge propose by this agreement to assign
rights and responsibilities for the commercialization of the resulting product;

         NOW THEREFORE, and in consideration of the mutual covenants and
undertakings set forth herein, the parties agree as follows:


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1 KIT CONFIGURATION Calypte and Cambridge will agree on the optimal Urine
Confirmation System, taking into account manufacturing and QC efficiencies,
regulatory requirements, marketing advantages, and other relevant criteria.

         1.1     Preferred Kit Configuration Based on information presently
                 available, the parties agree that the preferred Urine
                 Confirmation System (the "Preferred Kit Configuration")
                 consists of (i) a kit (the "Urine Control Kit") consisting of
                 a urine sample panel containing three of each of high
                 positive, low positive and negative controls and a package
                 insert describing the composition of such controls, and
                 referencing their use with the Serum Blot, and (ii) the Serum
                 Blot with a claim permitting use of urine samples,
                 interpretive criteria that the appearance of only a gp160 band
                 is sufficient to declare a positive, and lot release criteria
                 for urine consisting of testing at the kit level of a
                 representative number of kits per lot.  The parties plan to
                 seek marketing approval for the Urine Control Kit from the
                 United States Food and Drug Administration ("FDA") pursuant to
                 an application under Section 510(k) of the Food, Drug and
                 Cosmetic Act, and to seek FDA approval of the urine claim for
                 the Serum Blot under Cambridge's existing Serum Blot product
                 license.  The Urine Control Kit would be manufactured by or on
                 behalf of Calypte and distributed as set forth in this
                 Agreement.  The Serum Blot would continue to BE manufactured
                 by Cambridge, and Calypte would have distribution rights as
                 set forth in this Agreement.

         1.2     Alternate Kit Configurations The parties recognize that
                 alternative kit configurations may include modifications of
                 the Serum Blot in which urine controls are substituted for or
                 included in addition to serum controls, with resulting package
                 insert changes; such configurations are anticipated to require
                 an amendment to the Serum Blot product license, and are
                 referred to herein as the "Urine Blot." The Urine Blot would
                 continue to be manufactured by Cambridge, and Calypte would
                 have distribution rights as set forth in this Agreement.
                 Calypte agrees to reimburse Cambridge for the one-time artwork
                 and/or design costs associated with modifying Cambridge's
                 package insert and/or packaging if the Urine Blot is selected
                 as the Urine Confirmation System.


2        PRODUCT DEVELOPMENT Calypte is responsible for and has commenced
development of the Urine Confirmation System.


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         2.1     Development Kits Cambridge has furnished Calypte free of
                 charge twenty-four (24) Serum Blot kits for use in carrying
                 out the development plan, and Calypte intends to purchase
                 approximately twenty-eight (28) additional kits (including
                 kits purchased to date) at a price of      per kit.  Cambridge
                 will endeavor to supply the foregoing kits from three or four
                 different manufacturing lots.  In the event the FDA requires
                 the conduct of clinical trials necessitating the use of
                 substantially more Serum Blots, Cambridge will supply the
                 additional Serum Blots at a cost of      per kit.

         2.2     Development Effort Calypte will, at its expense, prepare any
                 necessary urine controls and other reagents necessary to
                 enable the Serum Blot to use urine samples and to complete
                 development of the Urine Confirmation System, and shall
                 provide Cambridge free of charge with sufficient Urine Control
                 Kits to enable Cambridge to validate its lot release protocol.

         2.3     Draft Report Calypte will prepare a draft report, in a form
                 agreeable to Cambridge, suitable for submission to the FDA in
                 support of proposed regulatory submissions.

         2.4     Clinical Trials Calypte will at its expense carry out all
                 clinical trials required for regulatory approval of the Urine
                 Confirmation System.

         2.5     Cambridge obligations Cambridge will make its regulatory and
                 product development personnel reasonably available to Calypte
                 for consultation regarding development of the Urine
                 Confirmation System.  Calypte shall reimburse Cambridge only
                 for reasonable out-of-pocket costs approved in advance.

         2.6     Review of Data Calypte shall make available to Cambridge
                 regulatory and product development personnel ALL relevant pre-
                 clinical, clinical and other evaluation data regarding the
                 Screening Test and the Urine Confirmation System, and all
                 relevant information relating to the manufacture and
                 validation of the Urine Control Kit.


3        U.S. REGULATORY PLAN Calypte and Cambridge have agreed on a regulatory
plan for obtaining FDA approval and/or licensure of .the Urine Confirmation
System, including clinical trial design and regulatory strategy.

         3.1     Preferred Kit Configuration On June 9, 1995, the FDA indicated
                 verbally that the parties may proceed with


Confidential portion has been omitted and filed separately with the Commission

                                     - 3 -
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                 the Preferred Kit Configuration.  Accordingly, the parties
                 have proceeded with the Preferred Kit Configuration, and the
                 following provisions apply:

                 3.1.1    The current regulatory strategy is set forth in
                          Appendix 2, a letter dated May 3, 1995 from Cindy
                          Green of Calypte to Jay Epstein of the FDA.

                 3.1.2    Calypte has at its expense prepared and filed on its
                          behalf an application for 510(k) approval.

                 3.1.3    Cambridge has at its expense prepared and filed a
                          supplement to its Serum Blot product license to
                          permit use of urine samples.  Cambridge shall include
                          a reference to Calypte as licensor of the urine
                          testing technology, or some other appropriate
                          reference to Calypte, if inclusion of such reference
                          is permitted by the FDA and is not likely to
                          significantly delay regulatory approval.

         3.2     Alternative Kit Configurations In the event the FDA changes
                 the position it took verbally on June 9, 1995 and the Urine
                 Confirmation System is in the configuration of the Urine Blot,
                 then the parties shall assess the costs and resources
                 necessary to satisfy the FDA requirements, and attempt to
                 negotiate in good faith an acceptable means of sharing this
                 burden.  If the parties fail to reach agreement within ninety
                 (90) days after receipt of final notice from the FDA that the
                 Preferred Kit Configuration is not approved, then either party
                 may terminate this agreement without further recourse.

         3.3     Joint Meetings Each party shall offer the other party the
                 greatest possible advance notice of and the opportunity to be
                 present at any meeting and participate in any telephone
                 conference with the FDA regarding the Urine Confirmation
                 System.

         3.4     FDA Questions The parties will prepare responses to FDA
                 questions with the same approximate allocation of
                 responsibilities as prevailed in the conduct of the clinical
                 trials and the preparation of the original submission.

         3.5     Inspections Each party shall make its facilities reasonably
                 available for audit by the FDA.  In

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                 addition, each party shall, upon not less than ten (10)
                 working days prior notice make its facilities available for
                 audit by the other party, or the other party's designee (to
                 whom the audited party shall have no reasonable objection),
                 but only with respect to the utilization of Good manufacturing
                 Practices for the Urine Confirmation System.


4        Commercialization

         4.1     License Simultaneous with the execution and delivery of this
                 Agreement, Calypte will grant Cambridge a license in the form
                 of Appendix 3 attached hereto and incorporated herein-by
                 reference, to make, use and sell Western Blot confirmatory
                 assays under the NYU Patents and the Calypte Technology.
                 Calypte represents and warrants that it has the right and
                 power to grant such license and such license shall be
                 enforceable in accordance with its terms.

         4.2     Distribution Distribution (including in each case the right to
                 appoint sub-distributors) of the Urine Confirmation System
                 shall be accomplished in accordance with Sections 4.3 and 4.4.
                 The parties agree to make commercially reasonable efforts to
                 cooperate with each other to accommodate unforeseen
                 distribution problems due to unanticipated kit configurations
                 or marketing conditions.

         4.3     Preferred Kit Configuration In the event the Urine
                 Confirmation System is in the Preferred Kit Configuration, the
                 following provisions shall apply:

                 4.3.1    Calypte shall have a non-exclusive right to
                          distribute the Serum Blot to its Screening Assay
                          customers in Asia (as defined in Exhibit 2 of
                          Appendix 4).  At the request of Calypte, Cambridge
                          (or its designee) shall meet with Calypte during the
                          three month period following the Effective Date to
                          discuss extending Calypte's distribution rights to
                          other customers.  During such period (and, if longer,
                          for thirty (30) days after the initial meeting of the
                          parties), Cambridge shall not appoint any other
                          distributors for the Serum Blot in Asia.  Unless
                          Cambridge shall have notified Calypte otherwise
                          within three months after the Effective Date, then,
                          commencing three (3) months after the Effective Date,
                          Calypte

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                          shall also have the nonexclusive right to distribute
                          the Serum Blot to any other of its customers in Asia,
                          provided, however, that Cambridge may, on ninety (90)
                          days prior written notice to Calypte, reduce
                          Calypte's distribution rights, on a
                          country-by-country basis, so that Calypte may resell
                          the Serum Blot only to its Screening Assay customers.
                          To embody these distribution rights, Calypte and
                          Cambridge shall, within thirty (30) days after FDA
                          approval, execute and deliver a distribution
                          agreement in substantially the form set forth in
                          Appendix 4. Cambridge shall have no right to
                          distribute the Urine Control Kit in Asia.


                 4.3.2    In the United States, Cambridge shall have no right
                          to distribute the Urine Control Kit, and Calypte
                          shall have no right to distribute the Serum Blot
                          except to those accounts which are listed by name in
                          Exhibit 2 of Appendix 4.  Elsewhere in the United
                          States, Calypte shall make available the Urine
                          Control Kit to its Screening Assay customers and
                          notify them of the availability of the Serum Blot
                          from Cambridge or its designated distributors.

                 4.3.3    Cambridge shall have no right to distribute the Urine
                          Control Kit in the rest of the world.  Calypte shall
                          have the exclusive right to distribute the Urine
                          Control Kit in the rest of the world.  In addition,
                          Calypte shall have the nonexclusive right to
                          distribute the Serum Blot to its Screening Assay
                          customers in the rest of the world (except for Italy,
                          Spain and Portugal), which right shall be exercised
                          by Calypte only in those regions in which, in
                          Calypte's reasonable opinion, the Urine Confirmation
                          System is not being made available to its Screening
                          Assay customers in a manner consistent with local
                          regulations and prevailing commercial conditions.  To
                          embody Calypte's Serum Blot distribution rights,
                          Calypte and Cambridge shall, within thirty (30)
                          days after FDA approval, execute and deliver a
                          distribution agreement in substantially the form set
                          forth in Appendix 4. Calypte shall notify its
                          Screening Assay customers of the availability of the
                          Urine

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                          Confirmation System from Cambridge or its designated
                          distributors.

                 4.3.4    Calypte, either directly or by arrangement with its
                          vendors, shall supply Cambridge free of charge with
                          Urine Control Kits, for use by Cambridge in the
                          manufacture of the Serum Blot, including use for lot
                          release testing.  Such Urine Control Kits shall be
                          manufactured in accordance with Good Manufacturing
                          Practices and shall be shipped with a certificate of
                          analysis on which Cambridge may rely.  Calypte (or
                          its vendor) shall permit Cambridge, upon not less
                          than ten (10) working days prior notice, to inspect
                          Calypte's (or the vendor's) facility with respect to
                          utilization of Good Manufacturing Practices in
                          manufacturing the Product.  Cambridge shall not be
                          deemed in default of its supply obligations if
                          Calypte shall be unable to arrange to supply
                          Cambridge with Urine Control Kits.

                 4.3.5    Cambridge and Calypte agree to share, for so long as
                          the Distribution Agreement shall be in effect, the
                          cost of additional lot release testing of the Serum
                          Blot for use with urine samples.  Cambridge estimates
                          that this cost will be approximately         per
                          year. in any given calendar quarter in which
                          Cambridge sells 150 or fewer Serum Blot kits for
                          urine testing, Calypte will reimburse Cambridge
                               .  In any given calendar quarter in which
                          Cambridge sells between 151 and 300 Serum Blot kits
                          for urine testing, Calypte will reimburse Cambridge
                               .  In any given calendar quarter in which
                          Cambridge sells 301 to 450 Serum Blot kits for urine
                          testing, Calypte will reimburse Cambridge      .  In
                          any given calendar quarter in which Cambridge sells
                          more than 450 Serum Blot kits for urine testing, no
                          reimbursement will be due.  Cambridge will invoice
                          Calypte quarterly for the reimbursement, which
                          Calypte will pay within 30 days.  Cambridge will
                          review its lot release testing costs annually and
                          provide Calypte with the results of the review; at
                          the request of either party, the reimbursement rate
                          may be adjusted in light of such review.


Confidential portion has been omitted and filed separately with the Commission

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         4.4     Urine-Blot In the event the Urine Confirmation System is not
                 in the Preferred Kit Configuration, the parties will negotiate
                 distribution of the Urine Confirmation System following the
                 guidelines set forth below:

                 4.4.1    Calypte shall have an exclusive right to distribute
                          the Urine Blot to its Screening Test customers in
                          Asia and to any other customers in Asia, provided,
                          however, that Cambridge may restrict Calypte's
                          distribution rights to Calypte's Screening Assay
                          customers on ninety (90) days prior written notice.
                          To embody these distribution rights, Calypte and
                          Cambridge shall, within thirty (30) days after FDA
                          approval, execute and deliver a distribution
                          agreement in substantially the form set forth in
                          Appendix 4.


                 4.4.2    In the United States, Cambridge shall have the
                          exclusive right to distribute the Urine Blot
                          provided, however, that Calypte shall have the
                          non-exclusive right to distribute the Urine Blot to
                          its Screening Assay customers in the United States
                          which are listed by name in Exhibit 2 of Appendix 4.
                          Calypte shall notify its Screening Assay customers of
                          the availability of the Urine Blot from Cambridge.

                 4.4.3    Cambridge shall have the exclusive right to
                          distribute the Urine Blot in the rest of the world,
                          provided, however, that Calypte shall have the
                          nonexclusive right to distribute the Urine Blot to
                          its Screening Assay customers in the rest of the
                          world (except for Italy, Spain and Portugal), which
                          right shall be exercised by Calypte only in those
                          regions in which, in Calypte's reasonable opinion,
                          the Urine Confirmation System is not being made
                          available to its Screening Assay customers in a
                          manner consistent with local regulations and
                          prevailing commercial conditions.  To embody these
                          distributions rights, Calypte and Cambridge shall,
                          within thirty (30) days after FDA approval, execute
                          and deliver a distribution agreement in substantially
                          the form set forth in Appendix 4. Calypte shall
                          notify its Screening Assay customers of the
                          availability of the Urine Blot from Cambridge.

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                 4.4.4    Calypte shall make reasonable efforts to supply
                          Cambridge, either directly or by arrangement with
                          Calypte's vendors, with bulk urine controls
                          manufactured in accordance with Good Manufacturing
                          Practices, on terms to be negotiated in good faith,
                          for use by Cambridge in the manufacture of the Urine
                          Blot.  Cambridge shall not be deemed in default of
                          any of its supply obligations if Calypte shall be
                          unable to arrange to supply Cambridge with bulk urine
                          controls.

5        OTHER AGREEMENTS

         5.1     HIV-2 Cambridge is willing to enter into A similar arrangement
                 for an HIV-2 or HIV-1/2 Western blot, assuming a reasonable
                 market exists and economic terms can be agreed, but neither
                 party, shall be obligated to enter into such an arrangement,
                 and the failure of the parties to reach agreement shall not
                 constitute a breach of this agreement.

         5.2     Manufacture of Screening Test Cambridge is willing to discuss
                 manufacturing or having manufactured an HIV-1/2 Screening
                 Assay for distribution by Calypte, and Calypte is willing to
                 discuss with Cambridge distribution rights and/or patent
                 licenses to the HIV1/2 Screening Assay, but neither party
                 shall be obligated to enter into such an arrangement, and the
                 failure of the parties to reach agreement shall not constitute
                 a breach of this agreement.  Terms may include upfront license
                 fees, which may be payable in A combination of cash and stock.

6        GOVERNING LAW AND ARBITRATION; VENUE

         6.1     Law This Agreement shall be deemed made under, governed by and
                 construed in accordance with the laws of the Commonwealth of
                 Massachusetts, without giving effect to conflict of laws
                 provisions thereof.

         6.2     Arbitration Any controversy or claim arising out of OR
                 relating to this Agreement or the breach thereof shall be
                 settled by arbitration in accordance with the laws of the
                 Commonwealth of Massachusetts, such arbitration to be
                 conducted in California, if arbitration is initiated BY
                 Cambridge, and in Massachusetts, if arbitration is initiated
                 by Calypte, and judgment upon the award rendered by the
                 arbitrators may be enforced in any court of competent
                 jurisdiction.  Nothing contained herein shall prevent the
                 parties from seeking

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                 injunctive or other equitable relief in any court of competent
                 jurisdiction prior to arbitration, but nothing herein shall be
                 construed as an admission that injunctive or other equitable
                 relief may be appropriate.

7         General

         7.1     Termination/Survival The provisions of Section 4 (except for
                 Subsections 4.3.4 and 4.3.5) shall be superseded and be of no
                 further force and effect upon the execution and delivery of
                 the license and distribution agreements in the forms of
                 Appendix 3 and Appendix 4, respectively.  The provisions of
                 Subsections 4.3.4 and 4.3.5 and Section 5 shall be terminated
                 and have no further force and effect upon the termination of
                 said license and distribution agreements.  Except as set forth
                 herein, this Agreement may be terminated only in accordance
                 with Section 3.2 or by agreement of the parties.  Sections 6
                 and 7 shall survive any termination of this Agreement.

         7.2     Attorneys' Fees  In the event any proceeding is commenced to
                 enforce this Agreement or otherwise relating to this
                 Agreement, the prevailing party shall be entitled to
                 reasonable attorneys' fees and costs incurred in connection
                 therewith.

         7.3     Counterparts  This Agreement may be executed in one or more
                 counterparts, each of which shall be deemed an original, but
                 all of which together shall constitute one and the same
                 instrument; however, this Agreement shall be of no force or
                 effect until executed by both parties.

         7.4     Captions  Captions and Sections and Subsection headings used
                 herein are for convenience only, are not a part of this
                 Agreement, and shall not be used in construing it.  Appendices
                 to this Agreement are incorporated herein by reference.

         7.5     Further Assurances  Each of the parties agrees to execute and
                 deliver such further documents and to cooperate in such manner
                 as may be necessary to implement and give effect to the
                 agreements contained herein.

         7.6     Successors  This Agreement shall be binding upon and shall
                 inure to the benefit of each party, its successors and
                 permitted assigns.  Neither party may assign this Agreement
                 without the prior written consent

                                     - 10 -
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                 of the other party, which consent shall not be unreasonably
                 withheld or delayed, provided, however, that either party may
                 assign this agreement to the purchaser of the business unit to
                 which this Agreement pertains, or substantially all of the
                 assets of such business unit.

         7.7     Invalidity If any provision of this Agreement, or the
                 application thereof, is held to be invalid or unenforceable,
                 the remainder of the Agreement shall continue in full force
                 and effect.

         7.8     Authority The parties executing this Agreement warrant that
                 they have the requisite authority to do so.  Each parties
                 represents and warrants that it has, or expects to have within
                 six months after the date hereof, the ability to manufacture
                 under current Good Manufacturing Practices in FDA-licensed or
                 otherwise approved facilities the products which it may be
                 required to manufacture hereunder.

         7.9     No Waiver The failure of either party at any time or times to
                 require performance of any provisions hereof shall in no
                 manner affect the right at a later time to enforce the same.
                 No waiver by either party of any condition, or of any breach
                 of any term, covenant, representation, or warranty contained
                 in this Agreement, in any one or more instances,.shall be
                 deemed to be construed as a further breach or a waiver of any
                 other condition or of any breach of any other term, covenant,
                 representation, or warranty.

         7.10    Prior Performance The parties recognize that, during the time
                 in which this Agreement was negotiated, each party performed
                 many of its respective obligations required hereunder.
                 Execution of this Agreement shall not constitute an
                 undertaking by either party to reperform any obligation
                 satisfied during the period of negotiations.

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be executed under seal and in duplicate as of the Effective Date as stated
hereunder by their duly authorized representatives.

CAMBRIDGE BIOTECH CORPORATION              CALYPTE BIOMEDICAL CORPORATION

By: /s/                                    By:  /s/  JACK DAVIS
   ----------------------------                ----------------------------
                                                Jack Davis, President & CEO

Name/Title President & CEO                      Name/Title 
 


                                     - 11 -
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                                   APPENDIX I

                                  NYU PATENTS


"Method for Detecting Antibodies to Human Immunodeficiency Virus" United States
Patent Nos. 4,865,966 and 5,122,446, and any divisions, continuations, or
continuations-in-part based thereon, and any patents which may issues therefrom
and any reissues, re-examinations, or extensions therefor; and any and all
foreign patents and patent applications corresponding to any of the foregoing
patents and applications.





                                     - 12 -
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                                   APPENDIX 2

                              REGULATORY STRATEGY


calyptebomedical

1440 FOURTH STREET
BERKELEY, CALIFORNIA 94710
(510) 526-2541 FAX (510)526-5381


         May 3, 1 995

         Jay S. Epstein, M.D.
         Food and Drug Administration
         Center for Biologics Evaluation and Research 
         Document Control Center
         Office of Blood Research and Review 
         Division of Blood Applications (HFM-30)
         Woodmont Office Center, Suite 20ON
         1401 Rockville Pike
         Rockville, MD 20852-1448

         RE:     PLA Reference Number 92-0670 
         
         Dear Dr. Epstein,
         
         In response to a request from Mr. Howard Balick, I am submitting an
         application strategy and proposal for an HIV-1 confirmatory product to
         the Document Center as an official request for consideration.  Over
         the past several months, I have had phone conversations with both Mr.
         Balick and Dr. Gary Riordan regarding Calypte's plan to proceed with
         the submission of a HIV-1 confirmatory test using urine as a sample
         in support of the Calypte HIV-1 Urine EIA test kit currently under
         review.  On March 6, 1995, a faxed letter was sent to Dr. Riordan to
         document the strategy for this application. In this letter, we
         requested a meeting with the reviewing committee, Calypte Biomed1cal
         and Cambridge Biotech (our partner for the confirmatory test) to
         review our preliminary data, the clinical plan and regulatory
         strategy.

         Background Information
         
         Calypte submitted the PLA/ELA for the HIVA Urine EIA test kit In
         September, 1992.  In November, 1993, Calypte was notified of the need
         to aggressively pursue a confirmatory test to support the HIV-1 Urine
         EIA approval.  Calypte contacted all licensed manufacturers (and a
         number of unlicensed manufacturers) of HIV confirmatory tests.  After
         several lengthy and unsuccessful attempts to come to terms with one of
         the manufacturers, a business agreement was finally reached in March,
         1995, with Cambridge Biotech

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         to bring a urine based confirmatory product to market Cambridge
         Biotech has had a licensed serum based HIV confirmatory test on the
         U.S. market since January, 1991.

         The proposed urine confirmatory test will be performed using the
         currently licensed Cambridge HIV Western Blot test kit There will be
         no changes to the assay components.  The urine test samples will be
         substituted for the plasma/serum samples.  The interpretation will be
         based on the reactivity of the serum controls currently included in
         the Cambridge kit.  They will be run diluted with diluent provided in
         the kit using incubations which have been extended to accommodate the
         reduced titre.  Laboratories wishing to confirm reactive ELISA urine
         samples will run the currently licensed Western blot and its serum
         controls In conjunction with an accessory HIV-1 Urine Control Kit In
         the accessory kit, there will be three levels: a negative, low
         positive and high positive.  The urine controls will be heat
         inactivated and preserved with 0.1% azide.  The Reactivity of the
         samples will be compared to the diluted low positive serum control
         with respect to the band intensity.  A positive sample will require a
         band at 160kd of equal or greater intensity to the p24 band on the
         Reactive Control Strip using the diluted serum control material
         supplied in the Cambridge kit If the 160kd band is of lesser intensity
         than the p24 band or if there are other bands not meeting the criteria
         for positive, but visible, the interpretation will be indeterminate.
         If there are no bands, the sample Interpretation will be negative.

         There are other examples where the kit control material is dissimilar
         from the specimens being tested. In the area of HIV testing, the most
         noteworthy is the dried blood spot.  It is our understanding that
         this example (dissimilar controls and specimens) has been approved for
         use by several manufacturers and furthermore, that there are several
         other examples of dissimilar controls/specimens under review by CBER.

         One purpose of kit controls is to demonstrate assay validity.  The
         serum controls have been shown to be effective in accomplishing this,
         as shown during the four years which the Cambridge kit has been on the
         market.  The other purpose of the kit controls is to provide a
         "calibrated" visual reference to determine positivity.  Following
         dilution, this can also be accomplished with the Cambridge controls
         provided for the urine assay.  The current instructions allow the user
         to visually compare the p24 band intensity to ANY of the other bands
         observed on the test sample.  This visual comparison can be equally
         successful comparing the urine bands to this p24 band of the diluted
         Cambridge control.  The Calypte HIV-1 Urine Control Kit can provide
         the user with the added security of running controls with the same
         specimen-type and will assist the laboratory in meeting CUA
         requirements.




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         In the event there are concerns regarding the lot release testing or
         CBER's control of the test kit for urines, we feel these concerns can
         be satisfied by the standard lot release testing currently performed
         on the Cambridge kit.  The serum controls will be tested and released
         according to the standard procedure.

         Currently there are several control kits for HIV and Hepatitis which
         have been approved by the 510(K) approval process.  We would not
         expect that replacing urine for serum/plasma would make this approval
         any different than those previously cleared.

         The Urine Control kit would include the urine control materials along
         with Instructions for running the patient samples (urine) and controls
         (serum) with the Cambridge Western Blot kit Therefore, the controls
         would be intended for use only with this specific kit.  The
         instructions would Include interpretation criteria specific for urine
         reactivity.  The criterion we are intending to use is a reactive 160kd
         band with intensity equal to or greater than the p24 band on the
         diluted low positive Cambridge serum control.  This criterion is the
         same (160kd reactive band) as was used in both sets of clinical
         studies conducted by Calypte where the Western blots run on urine were
         a modified procedure using the BioRad Western Blot assay.

         In support of the urine application to the Cambridge Western blot,
         Cambridge would submit a labeling transmittal form with the change in
         intended use such that urine would be added as an alternative sample
         to serum/plasma.  The Instructions would direct the user to use the
         Urine Control lot in conjunction with the kit serum controls provided
         in the currently licensed Cambridge kit.

         Clinical Study Plan

         The clinical study plan includes the evaluation of a total of 600
         patient samples collected under the IND filed for the Calypte
         "extended study".  These samples have been well characterized by
         urine.  ETA, urine Western blot (BloRad assay modified for use with
         urine), and paired serum ETA and Western blot The samples chosen are
         distributed as follows:

         200 normal, low risk
         200 moderate or unknown risk 100 high risk, positive
         100 special disease state (10 from each of 1O categories)
             liver disease, kidney disease, autoimmune disorders, IVDA, etc.
         5 individual samples from seropositive individuals run in a 
           dilutional series

         We feel It is appropriate to run this study in-house (using Calypte
         personnel since the consistency of performance of both the Cambridge
         Western blot as well as the modified BioRad urine Western blot
         procedures have been well


                                       3
   16
         documented in the clinical trial data submitted by both Calypte and/or
         the blot manufacturers as well as FDA 's own release testing.  The
         questions posed by the Calypte modified procedure should not require
         challenging the assay by evaluating site to site, operator to
         operator, lot to lot, or other parameters since these questions have
         already been satisfactorily addressed.  Likewise, the more fundamental
         questions of whether or not there are antibodies in urine or how the
         antibodies react in a Western blot assay have been demonstrated in the
         numerous data submitted with both of Calypte's clinical trials.  The
         samples chosen for testing are based on those populations which we
         assume are of greatest concern to the reviewers and those samples
         which may have potential problems in a urine based assay.

         In summary, the clinical trial strategy Is based on an application
         validation, since from Calypte's point of view the sample matrix
         change is a minor one.

         We are most anxious to resolve this issue and begin the studies.
         Since the proposed study is a retrospective one with samples collected
         under an IND, we are requesting a waiver for the filing of an IND and
         associated 30 day waiting period.  Please let us know if there are
         suggested changes to the study plan and or submission strategy so that
         we can begin these critically important studies.  With the plan
         described herein, we feel confident that the studies could
         be completed rapidly, the data assembled, and the submission filed
         with coincident approval with the HIV-1 Urine EIA.  Since the
         submission is an application only and very minor in comparison to a
         standard PLA, we would except to have a review and approval within a
         90 day period, if not before.  As you know, it would be extremely
         beneficial to have both tests approved together.

         In past discussions, it has been indicated to Calypte that the
         requirement for the Urine EIA approval is contingent ONLY on the
         demonstration of clinical data for use an urine in a confirmatory
         assay with a commitment to aggressively move toward approval of this
         chosen confirmatory test.  We have been told clearly that the approval
         of the confirmatory test is NOT a requirement for the HIV-1 Urine EIA
         approval.  Therefore, although our clear preference is for
         simultaneous approval of both the EIA and the confirmatory assay, we
         do not want approval of the confirmatory assay to in any way delay the
         approval of the EIA.  Please confirm with us that this is still the
         case.

         We thank you in advance for your prompt reply to this request and your
         careful consideration of the proposal described.

         Sincerely,

         /s/  CINDY GREEN
         ----------------------------
         Cindy Green, RAC
         Director, Regulatory/QA


                                       4
   17
APPENDIX 3                LICENSE

         AGREEMENT made this     day of       1996 (the "Effective Date") by and
between Cambridge Biotech Corporation ("Cambridge"), a corporation organized and
existing under the laws of the State of Delaware, debtor and debtor in
possession, Case No. 94-43054-JFQ, United States Bankruptcy Court for the
District of Massachusetts, Western Division, and having a place of business at
365 Plantation Street, Biotechnology Research Park, Worcester, MA 01605, U.S.A.,
and Calypte Biomedical Corporation ("Calypte"), a corporation organized and
existing under the laws of the State of California, and having a place of
business at 1440 Fourth Street, Berkeley, CA 94710, U.S.A.

                                   BACKGROUND

         In the course of research at New York University "NYU" certain
inventions were made relating to-the ability to detect antibodies to Human
Immunodeficiency Virus in urine samples.  NYU is the owner of these inventions,
and has been granted two United States patents, numbered 4,885,966 and
5,122,446, entitled "Method for Detecting Antibodies to Human Immunodeficiency
Virus".  The patents were granted September 12, 1989, and June 16, 1992,
respectively.

         Calypte is the exclusive, worldwide licensee of these inventions and
the issued patent and pending patent applications by way of an exclusive
license agreement from NYU and has the right to grant sublicenses thereunder,
subject to the limitations set forth in the NYU agreement attached hereto as
Exhibit A, for the making, using or selling of the inventions which have been
disclosed and claimed in the issued patent and pending patent applications.
This Agreement is subject and subordinate to the NYU Agreement attached hereto
as Exhibit A and any conflicts between this Agreement and the NYU Agreement
shall be resolved in favor of the interpretation and meaning set forth in the
NYU Agreement.


                                    RECITALS

         WHEREAS, Calypte is the exclusive worldwide licensee of patents
4,865,966 and 5,122,446 and any reissues, renewals, divisions, continuations,
continuations-in-part, substitutes, divisions or extensions thereof, related to
the detection of antibodies to Human Immunodeficiency Virus ("HIV") using urine
samples;

         WHEREAS, Cambridge manufactures and distributes a Western Blot Assay
(as hereinafter defined) for the detection of human
   18
antibodies to a variety of HIV proteins and glycoproteins on nitrocellulose
strips using serum and plasma; and

         WHEREAS, Cambridge desires to adapt its Western Blot Assay for use
with urine samples, and to license Calypte's Licensed Processes (as hereinafter
defined) and Licensed Patent Rights (AS hereinafter defined) to enable it to
manufacture and distribute the resulting Western Blot Assay in the Field of USE
(as hereinafter defined) and to enable its customers to practice the Licensed
Processes in the Field of Use.

         NOW, THEREFORE, and in consideration of the mutual covenants and
undertaking set forth herein, the parties agree as follows:

         1.      DEFINITIONS

                 1.1      LICENSED PATENT RIGHTS shall mean U.S. Patents No.
4,865,966 and 5,122,446 issued September 12, 1989, and June 6, 1992,
respectively, and any divisions, continuations, or continuations-in-part based
thereon, and any patents which may issue therefrom and any reissues,
re-examinations, or extensions thereof; and any and all foreign patents and
patent applications corresponding to any of the foregoing patents and
applications, as well as such other patents or patent applications listed in
Exhibit B effective as of the date said patents or patent applications are
granted or filed, as the case may be, and the inventions described or claimed
therein.

                 1.2      FIELD OF USE shall mean only use in diagnostic
applications and use for research purposes utilizing urine samples.  The
diagnostic field of use is limited to methods for detecting antibodies to HIV
utilizing HIV lysates immobilized on nitrocellulose strips in a Western Blot
format.

                 1.3      LICENSED PRODUCT(S) shall mean HIV diagnostic Western
Blot finished goods covered by or made in accordance with LICENSED PATENT
RIGHTS OR finished goods on which LICENSED PROCESSES are practiced.  The term
"finished goods" as used herein shall mean any and all products in any form for
use BY an end user.

                 1.4      LICENSED PROCESSES shall mean processes claimed OR
otherwise included in the LICENSED PATENT RIGHTS or using Calypte's proprietary
know-how or other technical information and techniques disclosed by Calypte to
Cambridge.  For purposes of example only, and not by way of limitation LICENSED
PROCESSES may include (1) services for providing a test result utilizing the
methods of assay covered under the LICENSED PATENT RIGHTS, or (2) services for
providing test results utilizing the LICENSED PRODUCTS.


                                       2
   19
                 1.5      NET SALES shall mean the amount invoiced by Cambridge
on sales of LICENSED PRODUCTS and/or on sales of services utilizing LICENSED
PROCESSES which amount shall not include:

                          (a)     Amounts repaid or credited by reason of
rejection or return;

                          (b)     Shipping and handling charges, to the extent
separately invoiced; and

                          (c)     Taxes levied on either the Licensed Products
or Licensed Processes, or other governmental charges assessed on the
production, sale, transportation, delivery or use; provided, however, such
taxes or charges are separately stated on purchase orders, invoices or other
documents of sale and are clearly identifiable, and provided further that such
taxes and charges are actually paid by or on behalf of Cambridge.

                 1.6      FIRST USE shall mean the date of the initial transfer
by Cambridge of any LICENSED PRODUCTS to any third party or date of the first
commercial application of the LICENSED PROCESSES, in each case in the Field of
Use, whichever is earlier, in exchange for consideration of any kind to which
value can reasonably be assigned for purposes of determining Net SALES.

                 1.7      EARNED ROYALTIES shall mean royalties paid or payable
by Cambridge to Calypte calculated on the basis of NET SALES.

                 1.8      EFFECTIVE DATE shall mean the date first set forth
above.

                 1.9      PRIME LICENSE shall mean the exclusive license
agreement between NYU and Calypte, as amended, dated August 12, 1993.

                 1.10     CAMBRIDGE shall mean Cambridge Biotech Corporation,
the Delaware corporation.  An AFFILIATE of Cambridge shall mean any corporation
or other business entity controlled BY, controlling, or under common control
with Cambridge.  For this purpose, "control" shall mean direct or indirect
beneficial OR legal ownership of at least fifty percent (50%) interest in such
corporation or business entity.

                 1.11     WESTERN BLOT OR WESTERN BLOT ASSAY shall mean the
Cambridge HIV Western Blot which is FDA licensed as of the date of execution of
this Agreement, and/or replacements or improved versions thereof.  The Western
Blot kit currently consists of nitrocellulose strips onto which HIV I lysate
has been

                                       3
   20
electrophoretically separated and immobilized plus the ancillary buffers,
conjugates, chromagens and other materials customarily provided in the FDA
licensed kit.

                 1.12     MASTER AGREEMENT shall mean that certain Agreement
dated April 12, 1996, by and between Cambridge and Calypte with respect to the
development of a protocol and reagents for use or modification of the Serum
Blot for purposes of confirming the results of the Screening Test using urine
samples.

                 1.13     DISTRIBUTION AGREEMENT shall mean the distribution
agreement which is Appendix 4 to the Master Agreement.

         2.      GRANT OF LICENSE

                 2.1      Subject to the terms and conditions of this Agreement
and the Prime License, Calypte hereby grants to Cambridge an exclusive royalty
bearing license, with no right to sublicense, to make, use, and sell LICENSED
PRODUCTS and to practice the LICENSED PROCESSES under LICENSED PATENT RIGHTS in
the FIELD OF USE throughout the patent and non-patent countries as listed in
Exhibit C.

                 2.2      If and to the extent there are divisionals,
continuations or continuation-in-part based on or relating to the
LICENSED PATENT RIGHTS, and any patents which may issue therefrom and an AND
ANY reissues, re-examinations or extensions thereof, as WELL as any and all
foreign patents and patent applications corresponding thereto or to the
LICENSED PATENT RIGHTS, Calypte shall notify Cambridge of such developments and
shall deliver AN amended Exhibit B to Cambridge to reflect any such changes or
additions to the LICENSED PATENT RIGHTS.

                 2.3      Notwithstanding any provisions to the contrary, end
users of the Licensed Product shall have an implied license to practice the
Licensed Processes in conjunction with their rendering of testing services
related to the detection of antibodies to HIV using urine samples.

         3.      ROYALTIES.  In consideration of the rights granted hereunder,
Cambridge shall make the following payments to Calypte when the same are due:

                 3.1      Cambridge shall pay to Calypte EARNED ROYALTIES of
                                on the NET SALES of all LICENSED PRODUCTS sold
by Cambridge for use in the FIELD OF USE to its customers and distributors
within the patent countries (Exhibit B) and                                
within non-patent countries.


Confidential portion has been omitted and filed separately with the Commission


                                       4
   21
                 3.2      Cambridge shall pay to Calypte EARNED ROYALTIES of
                                calculated on NET SALES of all services
utilizing LICENSED PROCESSES sold by Cambridge.

                 3.3      Calypte and Cambridge recognize that the Western Blot
Assay may be used by customers for use with samples other than urine, and agree
that royalties shall be payable hereunder only with respect to sales of Western
Blots used with urine samples.  In view of the difficulty of determining the
quantity of Western Blot Assays used with urine samples in any given royalty
reporting period, the parties hereby agree to calculate quantities subject to
royalties as follows:

                          (i)     Calypte plans to sell a Urine Control Kit, as
                 defined in the Master Agreement, containing three 10 ml vials
                 each of high positive, low positive and negative control.  The
                 parties estimate that, for each Urine Control Kit sold,
                 approximately 270 Western Blot Assays (10 27-strip kits) will
                 be run by customers.  Calypte agrees to promptly report to
                 Cambridge after the end of each calendar quarter, the number
                 of Urine Control Kits sold, and for each Urine Control Kit
                 sold, Cambridge shall pay a royalty on 10 Western Blot Assay
                 kits (based on an average net selling price of ALL of its
                 Western Blot Assays, calculated in accordance with Net Sales);
                 provided, however, that (a) no royalty shall be due with
                 respect to sales attributable to the first So Urine Control
                 Kits sold by Calypte each calendar year; and (b) a royalty
                 adjustment shall be made with respect to expired Urine Control
                 Kits with respect to which a royalty was previously paid.
                 Calypte shall report to Cambridge, within 30 days after the
                 end of each calendar year, the number of such expired Urine
                 Control Kits in the inventory of its distributors and if
                 known, its customers.

                          (ii)    Either party may request a review of the
                 above method of calculating royalties by delivering notice on
                 or before December I of any year.  In such event, the parties
                 shall negotiate in good faith a method or methods which
                 adequately and reasonably approximate the number of Western
                 Blot Assays used with urine samples.  Such new method, if any,
                 shall be effective for the following calendar year and



Confidential portion has been omitted and filed separately with the Commission

                                       5
   22
                 thereafter unless changed in accordance with this section.

         4.      PAYMENTS AND REPORTS

                 4.1      Cambridge agrees to notify Calypte in writing within
                   three (3) business days after the date of the FIRST USE.

                 4.2      Beginning with the date of FIRST USE, Cambridge SHALL
remit to Calypte EARNED ROYALTIES within thirty (30) DAYS after the close of
each calendar quarter, which is commonly known as the last. day of March, June,
September, and December or within thirty (30) days following receipt of
Calypte's Urine Control Kit report, whichever is later.  Any EARNED ROYALTIES
not paid within the thirty (30) day time period shall be deemed past due
royalties.  Past due royalties shall bear-interest at the rate of the lesser of
                  per annum or the maximum rate permitted by applicable law,
which interest shall accrue commencing on the date the-payment was originally
scheduled to be paid and shall continue to accrue until paid in full.

                 4.3      Cambridge shall also prepare for each calendar
quarter after the date of FIRST USE, a written report in form and substance
acceptable to Calypte setting forth, among other things (1) the NET SALES and
the EARNED ROYALTIES payable thereon, including a detailed listing of all
LICENSED PRODUCTS sold and all deductions or exclusions from NET SALES, if any
and (2) the NET SALES and the EARNED ROYALTIES payable thereon, including a
detailed listing of the services provided utilizing LICENSED PROCESSES and of
all deductions or exclusions from NET SALES.   The reports required by this
Agreement shall be certified by an officer of Cambridge to be correct to the
best of Cambridge's knowledge and information.

                 4.4      All amounts payable to Calypte shall be in United
States Dollars.  In the event that any LICENSED PRODUCT or services utilizing
LICENSED PROCESSES shall be sold for funds other than in United States Dollars
the NET SALES of such product shall first be determined in the foreign funds
and then converted into the equivalent United States Dollars at:

                          (a)     The rate applicable to the transfer of funds
arising from royalty payments as established by the exchange control
authorities of the country of which such funds are the national currency, for
the last business day of the accounting period for which payment is thus made;
or

                          (b)     If there is no rate so applicable, that the
buying rate for such foreign funds as published by the Wall


Confidential portion has been omitted and filed separately with the Commission

                                       6
   23
Street Journal on the last business day of such calendar accounting period.

         5.      BOOKS AND RECORDS

                 5.1      Cambridge shall keep complete and accurate books and
records of all business activities relating to the subject matter of this
Agreement including records of EARNED ROYALTIES on LICENSED PROCESSES and
LICENSED PRODUCTS made, used, and sold under this Agreement for a period of at
least three (3) years following a given reporting period.  These books and
records shall be available during normal business hours for inspection at the
expense of Calypte by a representative selected by Calypte and reasonably
acceptable to Cambridge, after providing ten days' prior written notice to
Cambridge, for the sole purpose of verifying and authenticating reports and
payments hereunder.  The representative of Calypte shall disclose to Calypte
only such financial information of Cambridge as necessary for Calypte TO be
assured of the accuracy of the reports submitted and payments made under this
Agreement.

         6.      NOTICE

                 6.1      Any notice required by this Agreement shall be sent
by registered or certified mail, postage prepaid, telex, facsimile, courier
service or personal delivery at the addresses designated below or-to another
address as may be designated BY written notice.  Unless otherwise so specified,
any notices given hereunder shall be effective as of the date of the date of
dispatch.

for Calypte:

Calypte Biomedical Corporation
1440 Fourth Street
Berkeley, CA 94710
Attn: President

For Cambridge:

Cambridge Biotech Corporation
365 Plantation Street
Worcester, MA 01605
Attn: President

         7.      TERM AND TERMINATION


                 7.1      The term of this Agreement, unless sooner terminated
as provided herein, shall extend from the EFFECTIVE DATE until the expiration
of the last of the patents included in LICENSED PATENT RIGHTS.

                 7.2      Upon any breach of, OR default under, this Agreement,
Calypte may terminate this Agreement BY giving ninety (90) days' written notice
to Cambridge of such termination and identifying the nature of the breach or
default; such termination shall take effect at the end of the ninety-day
period, unless



                                       7
   24
during such ninety-day period Cambridge cures such breach or default to
Calypte's reasonable satisfaction.  If the Master Agreement or the Distribution
Agreement is terminated by Calypte for cause pursuant to the terms set forth
therein, this Agreement shall automatically terminate concurrently with the
termination of such other agreements.  In the event the Distribution Agreement
is terminated for any other reason (other than for cause by Calypte) or expires
without renewal, the license granted under this Agreement shall become
non-exclusive for the duration of the remaining term of this Agreement,
subject: to early termination as provided for hereunder.  Furthermore,, in the
event this Agreement becomes non-exclusive as provided above, Calypte shall
have no obligation to support or share in the cost of insurance as set forth in
Section 12.14 nor shall it have any obligations whatsoever to share in the
costs set forth in Section 4.3.5 of the Master Agreement relative to testing of
Serum Blot.  Upon notice of termination of this Agreement, Cambridge will
immediately undertake such actions as may be required by the United States Food
and Drug Administration to remove the urine application from Product labeling
and report to Calypte a timeline for completion of same.

                 7.3      Cambridge has the right to terminate this Agreement
by giving twenty-four (24) months, prior written notice to Calypte.

                 7.4      Termination of this Agreement shall not affect any
rights or obligations accrued prior to the date of termination, including
Cambridge's obligation to pay all earned Royalties and Cambridge's obligation
to indemnify Calypte, provided however, that Cambridge's obligation to
indemnify Calypte shall extend for a period of ten (10) years after such
termination.  Upon termination of this Agreement, all unpaid earned Royalties
due to Calypte shall become due and payable upon delivery of the next'
quarterly report pursuant to section 4.3 hereof.

                 7.5      Waiver by Calypte of a single default or breach or a
succession of defaults or breaches shall not deprive Calypte of any right to
terminate this Agreement pursuant to the terms hereof upon the occurrence of
any subsequent default or breach.

                 7.6      This Agreement shall automatically expire or
terminate on the termination or expiration of the Prime License,
notwithstanding the fact that Calypte shall exert its best efforts to avoid
termination of the Prime License for cause. In the event that the Prime License
is converted from an exclusive to a nonexclusive license, Cambridge may at its
option extend the duration of this Agreement with Calypte on terms and
conditions mutually agreeable to both parties.

                                       8
   25

         8.      NEGATION OF WARRANTIES AND INDEMNITY.

                 8.1     Calypte makes no representations or warranties as to
the validity or scope of any LICENSED PATENT RIGHTS.

                 8.2     Calypte makes no representations or warranties that the
manufacture, use, sale or other disposal of the LICENSED PRODUCTS or the
practice of the LICENSED PROCESSES is or will BE free from infringement of
patents of third parties.

                 8.3     Calypte's liability for any claim or demand BY
Cambridge shall be limited to and based SOLELY on any material breach of
representation or warranty as set forth therein.  EXCEPT AS OTHERWISE SET FORTH
HEREIN CALYPTE HEREBY DISCLAIMS ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE.  THE SOLE AND ENTIRE MAXIMUM LIABILITY FOR ANY AND ALL
LOSS CLAIM, DAMAGE OR LIABILITY OF ANY KIND SHALL CONSIST OF REPLACEMENT OF THE
LICENSED PRODUCT.  IN NO EVENT SHALL CALYPTE BE LIABLE FOR ANY INCIDENTAL OR
CONSEQUENTIAL DAMAGES.  Cambridge shall make no statements,-representations or
warranties whatsoever to any third parties which are inconsistent with the above
disclaimer.

                 8.4     Cambridge shall defend indemnity, and hold harmless
Calypte and NYU, their directors, officers, employees and agents from and
against any and all claims, demands, damages, losses and expenses of any nature,
including attorney's fees, for but not limited to death, personal injury,
illness, property damage or product liability arising from or in connection with
any one or more of the following:

                         (a)     the use by Cambridge of any method or process
related to the LICENSED PATENT RIGHTS; or

                         (b)     any use, sale or other disposition of any of
the LICENSED PRODUCTS by Cambridge, or any statement.  representation or
warranty made BY Cambridge WITH RESPECT thereto; or

                         (c)     the use of the LICENSED PRODUCTS or LICENSED
PROCESSES by any person.

         Calypte shall reasonably cooperate with Cambridge in defending any
such claim, provided Cambridge and/or its insurance carrier shall reimburse
Calypte for all out of pocket expenses incurred in connection therewith.
Calypte shall be entitled to receive information regarding the status of any
such matter upon reasonable notice and shall be entitled to retain counsel on
its



                                       9
   26
own behalf and at its own expense to monitor the litigation or if Calypte is
not satisfied with the defense provided by Cambridge for any reason.  The
rights and obligations of this paragraph shall survive termination or
expiration of this Agreement.  Cambridge shall have the exclusive right to
control the defense of any such claim; provided, however, that Cambridge shall
not settle any such claim without first consulting with Calypte.

         9.      LAWS AND REGULATIONS.

                 9.1      Cambridge shall comply with all foreign and United
States federal, state, and local laws regulations, rules and orders applicable
to the testing, production, transportation, packaging, labeling, sale and use of
the LICENSED PRODUCTS and services utilizing LICENSED PROCESSES.

         10.     USE OF NAMES.

                 10.1     Cambridge shall not use the names "NYU" "New York
University," the names of the inventors, or the name "Calypte Biomedical
Corporation" or any other name or mark by which NYU or Calypte may be identified
for any purpose without prior written consent obtained from the respective
parties.

         11.     PATENT NOTICE.

                 11.1     Cambridge shall apply the patent marking notices
required by the laws of the United States and relevant countries or as
reasonably requested by Calypte.

         12.     MISCELLANEOUS PROVISIONS.

                 12.1     This Agreement-constitutes the entire understanding
between the parties with respect to the subject matter hereof and supersedes and
replaces all prior agreements, understandings, writings and discussions between
the parties related to said subject matter.

                 12.2     This Agreement may be amended only by a written
instrument executed by the parties.

                 12.3     Except as otherwise set forth herein, without prior
written approval of Calypte, which approval shall not be unreasonably withheld,
this Agreement may not be assigned or transferred, in whole or in part, BY
Cambridge to any other party However on a one-time-only basis, Cambridge shall
be entitled to assign this license, but only under and pursuant to the
following terms and conditions: (i) such assignment.shall be made only to a
business entity that acquires from Cambridge its entire diagnostics division
and business; and (ii) Cambridge and




                                       10
   27
Cambridge's assignee shall execute an "Assignment Agreement" in the form
satisfactory to NYU and a copy thereof shall be provided to NYU for review.  In
the event Cambridge only divests the Western Blot part but not all of its
diagnostics division and business then Cambridge's right to assign shall be
subject to Calypte's and NYU's approval, which approval shall not be
unreasonably withheld.

                 12.4     This Agreement shall be binding upon and inure to the
benefit of and be enforceable by the parties hereto and their respective
successors and permitted assigns.

                 12.5     This Agreement shall be governed and construed and
interpreted in accordance the laws of the State of California.

                 12.6     If any provisions of this Agreement are or become
invalid, or ruled illegal by any court of competent jurisdiction, or are deemed
unenforceable-under then current applicable from time to time in effect during
the term hereof, it is the intention of the parties that the remainder of this
Agreement shall not be affected thereby.  It is further the intention of the
parties that, in lieu of each such provision which is invalid, illegal or
unenforceable, there be substituted or added as part of this Agreement a
provision which shall be as similar as possible in economic and business
objectives as intended by the parties to such invalid, illegal or unenforceable
provision.

                 12.7     In no event shall either party be liable to the other
for any special, or incidental, or consequential, or indirect damages arising
in any way out of this Agreement, however caused, and on any theory of
liability.  This limitation will apply even if the other party has been advised
of the possibility of such damage.

                 12.8     This Agreement may be executed in counterparts, each
of which shall be deemed an original, but both of which together shall
constitute one and the same instrument.

                 12.9     Cambridge agrees that immediately after the execution
of this Agreement, Calypte may provide a copy of this Agreement to NYU for
their review and consideration.

                 12.10    The parties hereto expressly agree that this
Agreement is subject and subordinate to the Prime License and to the extent
there are provisions set forth herein which are inconsistent or conflicting
with the Prime License, then such provisions shall be revised so as to be
non-conflicting and consistent with the proscription of the Prime License.




                                       11
   28
                 12.11    Cambridge hereby unconditionally agrees that it will
not grant nor attempt to grant any sublicenses of any kind based on the rights
granted hereunder.

                 12.12    Cambridge agrees to obtain and maintain insurance and
to provide evidence thereof directly to NYU and Calypte and to indemnify NYU in
the manner described below.  Cambridge agrees that NYU is an intended third
party beneficiary of this Agreement for the purpose of enforcing such
indemnification and insurance provisions.  NYU shall also have the right to
audit Cambridge's records as they may relate to the subject matter of this
Agreement at its own expense.

                 12.13    Cambridge shall indemnify, defend and hold harmless
NYU and its trustees, officers, medical and professional staff, employees,
students and agents and their respective successors, heirs and assigns (the
"Indemnitees"), against any liability, damage, loss or expense (including
reasonable attorneys, fees and expenses of litigation) incurred by or imposed
upon the Indemnitees or any one of them in connection with any claims, suits,
actions, demands or judgments arising out of the design, production,
manufacture, sale, use in commerce or in human clinical trials, lease, or
promotion by Cambridge of any Licensed Product, Licensed Process or service
relating to or developed pursuant to this Agreement or the Prime License.
Cambridge agrees at its own expense, to provide attorneys reasonably acceptable
to NYU to defend against any actions brought or filed against any Indemnitee
with respect to the subject of indemnity to which such Indemnitee is entitled
under the Prime License, whether or not such actions are rightfully brought.

                 12.14    At such time as the Licensed Products or Licensed
Processes are distributed or practiced, as the case may be, Cambridge shall
procure and maintain policies of comprehensive general liability insurance in
amounts not less than five million dollars (US $5,000,000) per incident and
five million dollars (US $5,000,000) annual aggregate and naming the
Indemnitees and Calypte as additional insureds.  Such comprehensive general
liability insurance shall provide (i) product liability coverage and (ii) broad
form contractual liability coverage for Cambridge's indemnification under the
section above.  The minimum amounts of insurance coverage required under this
section shall not be construed to create a limit of Cambridge's liability with
respect to its indemnification of Indemnitees under the sections indicated
above.  Cambridge shall provide Calypte and NYU with written evidence of such
insurance upon request.  Cambridge shall provide NYU and Calypte with written
notice at least ninety (90) days prior to the cancellation, non-renewal or
material change in such insurance.  If Cambridge does not obtain replacement




                                       12
   29
insurance providing comparable coverage within ninety (90) days of such average
termination, Calypte may terminate this Agreement.  Cambridge shall maintain
such comprehensive general liability insurance during the period that any
product, process or service is being commercially distributed or sold pursuant
to this Agreement, and for a period of seven (7) years after the termination or
expiration of this Agreement.  Calypte and Cambridge shall share any additional
insurance premium cost on a 50/50 basis as a direct result of increasing the
coverage for the Licensed Products or Licensed Processes from Cambridge's
existing policy limit to the $5,000,000 limit set forth above.

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be executed.


Calypte Biomedical Corporation        Cambridge Biotech Corporation



By:                                   By:
       ---------------------------            --------------------------------
      
Name:                                 Name:
       ---------------------------            --------------------------------

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






                                       13
   30
                                   EXHIBIT A
                                   
                                 NYU AGREEMENT
                                 
                                   (omitted]
   31
                                   Exhibit B
                          
                             Licensed Patent Rights

"Method for Detecting Antibodies to Human Immunodeficiency Virus" United States
Patent Nos. 4,865,966 and 5,122,446, and any divisions, continuations, or
continuations-in-part based thereon, and any patents which may issues therefrom
and any reissues, reexaminations, or extensions therefor; and any and all
foreign patents and patent applications corresponding to any of the foregoing
patents and applications.
   32
                                   Exhibit C

                        Patent and Non-Patent Countries

Patent Countries:

United States
Australia
Nigeria
Sri Lanka
Canada (if serial no. 564,232 issues)
Japan (if serial no. 504037/88 issues)
South Korea (if serial no. 7016/88 issues)
             
Non-Patent Countries:

All countries in the world which are not Patent Countries


Confidential portion has been omitted and filed separately with the Commission
   33
                                   APPENDIX 4

NOTE: THIS DRAFT AGREEMENT ASSUMES THAT THE PRODUCT IS THE HIV-1 WESTERN
BLOT CURRENTLY MANUFACTURED BY CAMBRIDGE FOR USE WITH SERUM SAMPLES, AND THAT A
LABEL CHANGE WILL PERMIT THE PRODUCT TO BE USED WITH URINE SAMPLES IN
CONJUNCTION WITH A URINE CONTROL KIT MANUFACTURED BY CALYPTE.  IF THAT ROUTE IS
NOT AVAILABLE FROM A REGULATORY STANDPOINT, AND THE PRODUCT COVERED BY THIS
AGREEMENT IS THEREFORE SPECIFICALLY MANUFACTURED FOR USE WITH URINE SAMPLES,
THEN THIS AGREEMENT WILL BE MODIFIED AS INDICATED BY THE BRACKETED MATERIAL.


                CBC-CALYPTE WESTERN BLOT DISTRIBUTION AGREEMENT

         AGREEMENT made this ___ day of ___________________, 1996 (the
"Effective Date") by and between Cambridge Biotech Corporation ("Cambridge"), a
corporation organized and existing under the laws of the State of Delaware,
debtor and debtor in possession, Case No. 94- 43054-JFQ, United States
Bankruptcy Court for the District of Massachusetts, Western Division, and
having a place of business at 365 Plantation Street, Biotechnology Research
Park, Worcester, MA 01605, U.S.A., and Calypte Biomedical Corporation
("Calypte") a corporation organized and existing under the laws of California
and having a place of business at 1440 Fourth Street, Berkeley, California.

         WHEREAS, Cambridge manufactures and/or markets the HIV-1 Western Blot
Kit described in Exhibit 1 (the "Product");

         WHEREAS, Calypte is developing and plans to manufacture and sell a
screening assay to detect antibodies to HIV-1 in urine samples (the "Screening
Assay") worldwide and

         WHEREAS, Calypte desires to purchase and maintain a stock of the
Product for resale to its customers in the countries listed in Exhibit 2
(collectively, the "Territory");

         NOW THEREFORE, and in consideration of the mutual covenants and
undertakings set forth herein, the parties agree as follows:

1.       APPOINTMENT.

         1.1     Subject to the terms and conditions of this Agreement and the
territorial qualifications set forth in Exhibit 2, Cambridge hereby appoints
Calypte as an authorized distributor of the Product for resale to Calypte's
customers in the Territory for Calypte's own risk, expense and account.




                                       - 1 -
   34
         1.2     Calypte hereby accepts the foregoing appointment as such
authorized distributor and agrees to use reasonable efforts to promote the sale
of and sell the Product in the Territory. (If the Product is the Urine Blot,
"reasonable efforts" will be changed to "best efforts."]

         1.3     Calypte may appoint sub-distributors within the Territory,
provided that (i) such sub-distributors deal directly with Calypte, and Calypte
remains responsible for all dealings with Cambridge, (ii) such sub-distributors
operate in accordance with Calypte's rights and obligations under this
Agreement, and (iii) Calypte shall remain responsible to Cambridge for the
performance of this Agreement.

2.       NONEXCLUSIVITY.

The degree of exclusivity of Product distribution rights shall be as set forth
in Exhibit 2.

3.       CALYPTE'S OBLIGATIONS.

         3.1     Calypte shall use reasonable efforts to distribute, market,
promote and sell the Product in the Territory and to maintain and enhance the
goodwill of the Product in the Territory. [If the Product is the Urine Blot,
"reasonable efforts" will be changed to "best efforts."]

         3.2     For all purchases of Product by Calypte from Cambridge,
Cambridge shall invoice Calypte for the amounts of Product shipped during the
term of this Agreement at the prices therefor set forth on Exhibit 3 and
Calypte shall pay such invoices in full within thirty (30) days after its
receipt of such invoices.

         3.3     Calypte may obtain at its option refunds or credits for
returns of Product equal to the price(s) paid therefor against future purchase
orders for Product, provided that such returns are due to the failure of any
Product to meet its Product Specifications (as defined in Section 7.5 hereof),
upon receipt by Cambridge, within fifteen (15) days after receipt of shipment
of the Product, of documentation provided by Calypte which substantiates such
Product(s) return(s) and the reason(s) therefor.  No Product will be accepted
for return by Cambridge without its authorization made in accordance with its
then-current returned goods authorization system.

         3.4     Calypte may ["shall" if the Product is the Urine Blot]
advertise and promote the Product in a commercially reasonable manner and at
its sole cost and expense, and Cambridge agrees to cooperate with Calypte in
advertising and promoting the Product, provided that Calypte shall submit a
copy of each advertisement and of all other promotional materials and any
changes thereto to Cambridge for review and written approval by a duly
authorized



                                     - 2 -
   35

officer of Cambridge, which approval shall not be unreasonably withheld.
Cambridge's cooperation in advertising and promoting the Product shall not
oblige Cambridge to share the expenses associated with same.

         3.5      Calypte warrants and represents to Cambridge that it is not,
and shall not hold itself out as, the representative, agent, commission-sales
agent, commissionaire, servant or employee of Cambridge for any purpose, except
as may be provided from time to time by other written instrument signed by both
parties. This Agreement creates no relationship of joint venture, partnership,
limited partnership or agency between the parties. Neither party has any right
or authority to assume or to create any obligation or responsibility on behalf
of the other party except as may from time to time be provided by other written
instrument signed by both parties.

         3.6      Calypte shall defend, indemnify and hold harmless Cambridge
from and against any and all claims, demands, liability and expenses, including
reasonable attorneys' fees and costs, arising out of or in any way resulting
from any breach of the warranty set forth in Section 3.5 hereof.

4.       ORDERING AND PRICES.

         4.1      Calypte shall, on or before the first day of each month,
deliver to Cambridge a forecast of its projected purchases of Product during the
following twelve (12) months. Projected purchases during the first three (3)
months of such forecast shall constitute firm orders, and the forecast for the
remaining months shall be for planning purposes only. Calypte shall purchase
each year the minimum quantities of Product, if any, specified on Exhibit 3.

         4.2      Calypte shall purchase from Cambridge, and Cambridge shall
sell to Calypte such quantities of the Product as Calypte may order pursuant to
Section 4.1 at the Product purchase prices set forth in Exhibit 3. Cambridge
shall not increase such prices more frequently than once per year, and in no
event shall the price increase, singularly or in the aggregate, be greater than
those imposed by Cambridge on its other customers which purchase similar volume
of Product.

         4.2      There shall be added to the prices for Product amounts equal
to any taxes (including, but not limited to, state and local sales and use
taxes, however designated, levied or based on such prices, this Agreement, or
the Product or their sale or use, exclusive, however, of taxes based on
Cambridge's net income. Any taxes assessable on the Product on or after delivery
shall be borne by Calypte.

                                      - 3 -
   36
         4.4      All invoices rendered by and payments made to Cambridge
hereunder shall be in United States dollars.

5.       TECHNICAL SERVICE AND REGULATORY OBLIGATIONS.

         5.1      With respect to the Product, Calypte shall provide to its
customers all technical training and support required by them. For this purpose,
Calypte shall maintain and use a trained staff of qualified sales and technical
personnel.

         5.2      Calypte shall comply with any and all national, regional and
local legislation, statutory provisions and regulations in effect in every
jurisdiction within the Territory regarding the registration, labeling,
advertising, distribution, use and/or sale of the Product, including without
limitation any and all safety and regulatory compliance rules, and shall make no
representation relative to the performance of any Product except as authorized
by the Cambridge and permitted by law.

6.       TRADEMARKS, SERVICE MARKS AND TRADE NAMES.

         6.1      Cambridge hereby grants Calypte a nonexclusive license within
the Territory (subject to the exceptions set forth in Exhibit 2 hereto) to use
its trademarks, service marks and trade names in connection with any
advertisement and promotion of the Product permitted hereunder. Calypte shall
not use or alter such marks or names in a manner which may jeopardize or
diminish Cambridge's rights to use them, and all notices of rights therein and
all notices of Cambridge's patent and/or patent pending rights to the Product
shall be clearly designated in all written materials in which such marks and/or
names are used.

         6.2      Calypte shall use such marks and/or names only in such manner
as will comply with the provisions of the applicable trademark laws of the
Territory. Any and all trademark applications which are filed in the Territory
shall be filed by Cambridge and Cambridge shall bear all costs incurred in
connection with such trademark applications and registrations. In each and every
use of such marks and/or names on its packaging, tags, catalogs, and advertising
for the Product, Calypte shall indicate if applicable the registration of such
marks and/or names by the marking provided for by such laws.

         6.3      The license granted under Section 6.1 to Calypte shall
terminate upon any termination of this Agreement or, with respect to Calypte's
inventory of Product at the time of termination, six months after such
termination, and thereafter Calypte shall not use Cambridge's trade names,
service marks, or trademarks and shall cooperate to the extent necessary in
notifying the Registrar of Trademarks or other official that it is no longer a
registered user of such marks and/or names, at Calypte's expense.

                                      - 4 -
   37

7.       CAMBRIDGE'S OBLIGATIONS, SPECIFICATIONS AND WARRANTIES.

         7.1      Cambridge shall, from time to time during the term of this
Agreement, provide Calypte with reasonable quantities of its then existing
brochures on its Product.

         7.2      Cambridge will provide Calypte with a list of all countries in
the Territory in which the Product is approved for sale. Calypte shall use
reasonable efforts ("best efforts" if the Product is the Urine Blot] to obtain
all required regulatory and other governmental or agency approvals for Product
from the proper authorities within the significant markets as denoted in Exhibit
2 in which marketing approval has not been previously obtained, and Cambridge
shall cooperate therewith. Upon Calypte's request, Cambridge shall provide
Calypte with any information in Cambridge's possession or control which is
necessary for Calypte's acquiring such approvals of the Product in the
Territory.

         7.3      Cambridge shall use its best efforts to fill orders for
Product within thirty (30) days after the requested delivery date, F.O.B.
Cambridge's plant in Massachusetts or Maryland provided, however, that during
the first three months following the receipt of FDA approval of the use of urine
samples with the Product, Cambridge need only use reasonable efforts to make a
requested delivery date which is less than ninety (90) days after receipt of the
order. Cambridge shall use reasonable efforts, consistent with fulfilling its
obligations to its other customers, to supply Product with the longest possible
shelf life. All Product shall be shipped in finished kits (or bulk packaging if
Cambridge can reasonably accommodate such request) as specified in Calypte's
purchase order. Product shall be in Cambridge's trade dress and bear no
trademarks not owned by either Cambridge or Calypte. [If the Product is the
Urine Blot, the parties will consider a joint Cambridge/Calypte label.] However,
subdistributors may, with prior approval of Cambridge, Calypte and the FDA, afix
a small label identifying themselves as such, provided that such label does not
obscure in any way the trademarks owned by Cambridge or Calypte or any other
text on the packaging. Cambridge shall not be deemed in default of its supply
obligations if Calypte shall be unable to arrange to supply Cambridge with Urine
Control Kits for use in lot release testing of the Product. Notwithstanding any
provision to the contrary, Calypte shall have the right to source substitute
product from a back-up vendor for use only in Calypte's reference laboratory;
such right may be exercised only in the event that Cambridge is unable to supply
Calypte's need for a period exceeding ten (10) business days, and Calypte shall
resume purchases of Product from Cambridge as soon as Cambridge shall have
available sufficient quantities of product to meet Calypte's needs.

                                      - 5 -

   38

         7.4      Cambridge shall notify Calypte immediately should Cambridge
become aware of any defect or condition which may render any of the Product in
violation of the United States Federal Food, Drug, and Cosmetic Act, as amended,
or which may in any way alter the quality or the Product Specifications of any
of the Product. Cambridge shall notify Calypte as far in advance as practical of
any change in the manufacture of the Product which affects the quality or legal
sale of the Product. In the event Cambridge determines that it is necessary to
recall the Product, both parties will cooperate to effect the recall and
Cambridge shall reimburse Calypte for its expenses directly related to the
recall. Cambridge shall permit Calypte (or its designee to whom Cambridge shall
have no reasonable objection), upon not less than ten (10) working days prior
notice, to inspect Cambridge's facility with respect to utilization of Good
Manufacturing Practices in manufacturing the Product.

         7.5      Cambridge warrants and represents that its manufacture of the
Product shall be in accordance with current Good Manufacturing Practices, that
the Product complies with the specifications for the Product set forth in the
package insert accompanying each Product kit and any additional release criteria
specified on Exhibit 4 (the "Product Specifications"), and the Product shall not
be adulterated or misbranded within the meaning of the United States Federal
Food, Drug and Cosmetic Act.

         7.6      THE FOREGOING WARRANTY SET FORTH IN SECTION 7.5 IS IN LIEU OF
ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
Cambridge shall not be liable for any indirect, special, consequential,
incidental or contingent damages incurred by Calypte or any third party due to
any breach of the foregoing warranty. Cambridge's sole liability and Calypte's
exclusive remedy for any breach of the foregoing warranty shall consist of
Cambridge's either replacing the Product or refunding the purchase price
therefor, at Cambridge's sole option.

8.       TECHNICAL ASSISTANCE

         8.1      Cambridge shall provide training to Calypte's technical
personnel regarding the technical use and support of the Product at a mutually
agreeable site and on mutually agreeable date(s) no more than once per calendar
year. Training shall be provided free of charge, provided that Calypte shall pay
all costs of travel, accommodations and meals and other expenses of its
personnel associated therewith. Cambridge shall supply to Calypte at no charge a
reasonable number of copies of its technical or troubleshooting manuals.

                                      - 6 -

   39

         8.2      At the request of Calypte, Cambridge shall use reasonable
efforts to make its technical personnel available in the Territory to assist
Calypte with any technical problems it may encounter with the Product and which
its personnel have not been able to solve, at 50% of Cambridge's then current
terms, rates and charges for such services provided, however, that Cambridge
shall make no charge for reasonable amounts of telephone consultation.

9.       CONFIDENTIALITY.

         Calypte shall safeguard as confidential all price lists, customer
lists, quotations and marketing, business and scientific data and information in
any form concerning the Product, and any other information pertaining to the
Product and designated as confidential, and shall not permit their use or
disclosure in any way without the express prior written consent of Cambridge.
Calypte further agrees to surrender and divulge all such confidential
information to Cambridge either on Cambridge's request or on termination of this
Agreement and thereafter shall not retain copies or memoranda of said
information in any form whatsoever.

10.      ENTIRE AGREEMENT.

         10.1     This Agreement, including Exhibits 1 through 4, sets forth the
entire and only agreement between Cambridge and Calypte pertaining to the
distribution of the Product. Any prior agreements, representations, statements,
negotiations, undertakings, promises or conditions, whether oral or written, are
superseded hereby and shall not be binding upon either party. No waiver,
modification, amendment, addition to or deletion of any of the provisions of
this Agreement shall be effective unless made in writing and signed by an
authorized representative of each of the parties to this Agreement.

         10.2     Catalogs, circulars, brochures and similar materials of
Cambridge are issued for general information purposes only and shall not be
deemed to modify or supersede the provisions of this Agreement.

11.      OTHER TERMS OF SALE.

         11.1     The timely performance of Cambridge's obligations hereunder
shall be limited or excused by events considered "force majeure" including
without limitation acts of war, fire, flood, strike, earthquakes, acts of God,
and permanent Governmental restrictions, and by other events not within the
reasonable control of Cambridge.

                                      - 7 -

   40

         11.2     Cambridge will not change the Product Specifications and
quality of the Product without the prior consent of Calypte, which shall not be
unreasonably withheld.

         11.3     Calypte shall carry and maintain liability insurance with such
policy limits and amounts with respect to coverage for personal injury (per
occurrence and in the aggregate) and property damage (per occurrence and in the
aggregate) and exclusions and deductibles as are reasonably acceptable to
Cambridge. A copy of a certificate of such insurance shall be delivered to
Cambridge forthwith after execution of this Agreement. Calypte shall not cancel
such insurance without Cambridge's written consent unless substitute insurance
is obtained prior thereto and to the satisfaction of Cambridge.

12.      ASSIGNMENT.

         Neither party may assign this Agreement without the prior written
consent of the other party, which consent shall not be unreasonably withheld or
delayed, provided, however, that either party may assign this agreement to the
purchaser of the business unit to which this Agreement pertains, or
substantially all of the assets of such business unit.

13.      TERM OF AGREEMENT.

         13.1     This Agreement is effective for a three (3) year period
("Initial Period") beginning on the Effective Date and shall continue in effect
thereafter ("Subsequent Periods") unless at least eighteen (18) months prior to
(i) expiration of the Initial Period, or (ii) any termination during the
Subsequent Periods, either party gives the other written notice of its desire
not to continue the Agreement and indicate the effective date of such
termination.

         13.2     The provisions in Section 13.1 notwithstanding:

                  (a)      this Agreement may be terminated with immediate
                           effect upon the giving of written notice by either
                           party in the event that:

                           (i)      the other party is declared insolvent, or
                                    becomes subject to a petition in bankruptcy
                                    filed by or against it, or is placed under
                                    the control of a receiver, liquidator, or
                                    committee for the benefit of creditors
                                    (excluding, in the case of Cambridge, such
                                    events arising out of the current bankruptcy
                                    proceeding), or

                           (ii)     the other party breaches any material


                                      - 8 -

   41

                                    obligation imposed upon it by this 
                                    Agreement and fails to cure such breach
                                    within thirty (30) days after the giving of
                                    written notice thereof to such other
                                    party; and

                  (b)      Cambridge may terminate this Agreement with immediate
                           effect upon written notice in the event that Calypte:

                           (i)      assigns or attempts to assign this Agreement
                                    without the prior written consent of 
                                    Cambridge, except as provided in Section 12,
                                    or

                           (ii)     ceases to function as a going concern or
                                    abandons the Territory.

14.      NOTICES.

         Any notice or other communication required to be given hereunder
shall be in writing and be given by air mail, overnight courier or telefax with
a copy by air mail or overnight courier addressed to the parties at their
respective addresses set forth on the first page of this Agreement or to such
other address as any party may designate by written notice to the other party
given in accordance with this Section 14, and shall be deemed to have been given
or rendered upon actual receipt or two (2) days after the date of mailing,
delivery to the courier, or telefax transmission (as the case may be), whichever
is first.

15.      EFFECT OF TERMINATION.

         15.1     Orders received by Calypte before the termination of this
Agreement shall be executed on the same terms and provisions as during the term
of this Agreement, even if the order delivery is to be effected after the
termination of this Agreement.

         15.2     On the termination of this Agreement, Cambridge shall have the
option to purchase from Calypte all Product originally supplied by Cambridge
which may remain unsold and in Calypte's possession at Calypte's purchase price
from Cambridge therefor, provided that such Product are in good and salable
condition with appropriate residual shelf lives. Calypte shall allow inspection
of such Product by Cambridge's personnel for this determination.

16.      GOVERNING LAW AND ARBITRATION; VENUE.

         16.1     This Agreement shall be deemed made under, governed by and
construed in accordance with the laws of the Commonwealth of Massachusetts,
without giving effect to conflict of laws provisions thereof.

                                      - 9 -

   42

         16.2     Any controversy or claim arising out of or relating to this
Agreement or the breach thereof shall be settled by arbitration in accordance
with the laws of the Commonwealth of Massachusetts, such arbitration to be
conducted in California, if arbitration is initiated by Cambridge, and in
Massachusetts, if arbitration is initiated by Calypte, and judgment upon the
award rendered by the arbitrator(s) may be enforced in any court of competent
jurisdiction. Nothing contained herein shall prevent the parties from seeking
injunctive or other equitable relief in any court of competent jurisdiction
prior to arbitration.

17. GENERAL.

         17.1     Sections 3.5, 3.6, 6.3, 7.6, 9, 15.2, 16 and 17 shall survive
any termination of this Agreement.

         17.2     In the event any proceeding is commenced to enforce this
Agreement or otherwise relating to this Agreement, the prevailing party shall be
entitled to reasonable attorneys' fees and costs incurred in connection
therewith.

         17.3     This Agreement may be executed in one or more counterparts,
each of which shall be deemed an original, but all of which together shall
constitute one and the same instrument; however, this Agreement shall be of no
force or effect until executed by both parties.

         17.4     Captions and Sections and Subsection headings used herein are
for convenience only, are not a part of this Agreement, and shall not be used in
construing it. Exhibits to this Agreement are incorporated herein by reference.

         17.5     Each of the parties agrees to execute and deliver such further
documents and to cooperate in such manner as may be necessary to implement and
give effect to the agreements contained herein.

         17.6     This Agreement shall be binding upon and shall inure to the
benefit of each party, its successors and permitted assigns.

         17.7     If any provision of this Agreement, or the application
thereof, is held to be invalid or unenforceable, the remainder of the Agreement
shall continue in full force and effect.

         17.8     The terms of this Agreement shall supersede the terms of any
subsequent invoice, purchase order or confirmation.

         17.9     The parties executing this Agreement warrant that they have
the requisite authority to do so.

                                     - 10 -

   43

         17.10    Calypte shall promptly notify Cambridge of any improper or
unlawful use or infringement of the intellectual property rights of Cambridge
pertaining to the Product which come to its notice. Cambridge will take such
steps and proceedings in respect of said infringements as it may in its sole
discretion think fit and shall have full control of any such proceedings,
including the right to compromise and settle them.

         17.11    The failure of either party at any time or times to require
performance of any provisions hereof shall in no manner affect the right at a
later time to enforce the same. No waiver by either party of any condition, or
of any breach of any term, covenant, representation, or warranty contained in
this Agreement, in any one or more instances, shall be deemed to be construed as
a further breach or a waiver of any other condition or of any breach of any
other term, covenant, representation, or warranty.

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed under seal and in duplicate as of the Effective Date as stated
hereunder by their duly authorized representatives.

Cambridge Biotech Corporation      Calypte Biomedical Corporation

By:_________________________        By:__________________________

____________________________        _____________________________
Name/Title                          Name/Title


                                     - 11 -
   44

                                    EXHXBIT 1

                                     Product

                        HIV-I Western Blot Part No. 98002

[If the Product is the Urine Blot, this will be changed accordingly.]




                                     - 12 -

   45

                                    EXHIBIT 2

                                    TERRITORY

A. Asia (Japan, People's Republic of China, Thailand, South Korea, India,
Australia, Indonesia, New Zealand, Philippines, Bangladesh, Kampuchea, Bhutan,
Taiwan, Vietnam, Myanmar, Laos, Burma, North Korea, Pakistan, Singapore,
Malaysia, Sri Lanka, Nepal and Mongolia):

         (1) If the Product is the Serum Blot, Calypte shall have a
         non-exclusive right to distribute the Product to its Screening Assay
         customers. At the request of Calypte, Cambridge (or its designee) shall
         meet with Calypte during the three month period following the Effective
         Date to discuss extending Calypte's distribution rights to other
         customers. During such period (and, if longer, for thirty (30) days
         after the initial meeting of the parties), Cambridge shall not appoint
         any other distributors for the Product in Asia. Unless Cambridge shall
         have notified Calypte otherwise within three months after the Effective
         Date, then, commencing three (3) months after the Effective Date,
         Calypte shall also have the nonexclusive right to distribute the
         Product to any other of its customers in Asia, provided, however, that
         Cambridge may, on ninety (90) days prior written notice to Calypte,
         reduce Calypte's distribution rights, on a country-by-country basis, so
         that Calypte may resell Product only to its Screening Assay customers.

         (2) If the Product is the Urine Blot, Calypte shall have the exclusive
         right to distribute the Product to its Screening Assay customers, and a
         non-exclusive right, in the case of a Urine Blot with a dual
         serum/urine indication, to distribute the Product to any other customer
         in Asia, provided, however, that Cambridge may, on ninety (90) days
         prior written notice to Calypte, reduce Calypte's distribution rights
         so that Calypte may resell Product only to its Screening Assay
         customers.

B. Rest of World except United States, Italy, Spain and Portugal:

         Calypte shall have the non-exclusive right to distribute the Product to
         its Screening Assay customers, which right shall be exercised by
         Calypte only in those regions in which in Calypte's reasonable opinion,
         the Urine Confirmmation System is not being made available to its
         Screening Assay customers in a manner consistent with local regulations
         and prevailing commercial conditions. In the event Calypte desires to
         exercise such right, it shall give Cambridge ninety (90) days prior
         written notice, during which time the parties


                                     - 13 -

   46

                               EXHIBIT 2 (cont'd)

         shall meet in good faith to explore other means of making the Urine
         Confirmation System adequately available.

C. United States:

         Calypte shall have no distribution rights in the United States except
         to the following accounts: Lab One, Clinical Reference Lab, Osborn
         Labs, GIB, Met Life, Calypte Reference Lab, PharmChem, Risk Assessment,
         MedExpress, Direct Access Diagnostics and Home Access Health Corp.

D. Significant Markets (Section 7.2): Japan,- People's Republic of China,
Thailand, South Korea. India, Australia, Indonesia


                                     - 14 -

   47

                                    EXHIBIT 3

                             PRODUCT PURCHASE PRICES

                                         
                                         
                                         
                                         
                                         

Pricing is based on the current 27-test kit configuration. In the event that a
different configuration is introduced, the per strip price will remain as above.

Minimums: [None if the Product is the Serum Blot]:


Confidential portion has been omitted and filed separately with the Commission

                                     - 15 -

   48

                                    EXHIBIT 4

                                 SPECIFICATIONS

Additional Release Criteria (section 7.5): (None if the Product is the Serum 
Blot]




                                     - 16 -