<PAGE>   1
                                                                   EXHIBIT 10.16


[CONFIDENTIAL TREATMENT REQUESTED. CONFIDENTIAL PORTIONS OF THIS DOCUMENT HAVE
BEEN REDACTED AND HAVE BEEN FILED SEPARATELY WITH THE COMMISSION]

                       RESEARCH AND DEVELOPMENT AGREEMENT

         THIS RESEARCH AND DEVELOPMENT AGREEMENT dated July 1, 1992 (the
"Agreement"), is made by and between BIOSITE DIAGNOSTICS INCORPORATED, a
Delaware corporation, with principal offices at 11030 Roselle Street, Suite D,
San Diego, California 92121 ("Biosite"), and IXSYS, INC., a Delaware
corporation, with principal offices at 3550 General Atomics Court, Suite L-103,
San Diego, California 92121 ("Ixsys").

                                   BACKGROUND

         Biosite has expertise and proprietary rights in technology relating to
immunochemistry and, more particularly, to biochemical techniques for antibody
screening and immunoassay procedures. Biosite also has expertise relating to
chemical techniques for the development of immunogens and conjugates useful as
antibody targets for the production of, e.g., monoclonal antibodies. Ixsys has
complementary technology and expertise for the production of antibodies. Both
parties wish to share their respective antibody technologies for their mutual
benefit.

                              TERMS AND CONDITIONS

         NOW, THEREFORE, in consideration of the foregoing premises, and the
mutual covenants set forth below, the parties hereby agree as follows:
   
         1.       Definitions

                  1.1 "Biosite Antibodies" means collectively those
immunoglobulin-based molecules developed and produced by or on behalf of
Biosite, without the use of Ixsys Technology or Ixsys Improvements other than
Ixsys cloning or expression vectors, such immunoglobulin-based molecules
including, but not limited to, [CONFIDENTIAL MATERIAL REDACTED AND FILED
SEPARATELY WITH THE COMMISSION].
    
                  1.2 "Biosite Improvement(s)" is any technology developed by
either or both parties on or before the fifth anniversary of the Effective Date
and that represents an improvement of Biosite Technology.

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                  1.3 The "Biosite Project Manager" is Dr. Gunars Valkirs, the
Biosite scientist assigned to the Collaborative Project. The Biosite Project
Manager may be changed from time to time by designation of the President of
Biosite, which change shall be communicated in writing to Ixsys.
   
                  1.4 "Biosite Technology" means all technology, and patent
rights thereto, reduced to practice and owned by Biosite or to which Biosite has
rights, now or in the future before the fifth anniversary of the Effective
Date, relating (a) to the immunoassay screening of monoclonal antibodies, (b)
to the chemical modifications of haptens to make antibody targets, (c) to
methods for coupling haptens and proteins with proteins and solid phase
components, and (d) to immunoassay methods, including but not limited to the
technology described generally on Schedule 1.4A, all to the extent and only to
the extent that Biosite now has, or hereafter before the fifth anniversary of
the Effective Date will have, the right to grant licenses, immunities or other
rights, thereunder, but excluding the specific chemical modifications and
compositions as described on Schedule 1.4B.

                  1.5 "Collaborative Biosite Antibodies" means, collectively,
(a) those immunoglobin-based molecules (including, but not limited to
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION]
identified after the Effective Date by Biosite using Ixsys Technology or Ixsys
Improvements, and (b) those modified Biosite Antibodies of which the 
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] after 
the Effective Date by Biosite using Ixsys Technology or Ixsys Improvements.
    
                  1.6 "Collaborative Project" means the project to clone and
express Collaborative Biosite Antibodies as described generally on Schedule 1.6.

                  1.7 "Collaborative Project Period" means the period commencing
on the Effective Date and continuing until the second anniversary thereof,
unless earlier terminated as provided in the Agreement.

                  1.8 "Effective Date" means July 1, 1992.
   
                  1.9 "Immunoassay Field" means the manufacture or use of
all in vitro diagnostic immunoassays.
    
                  1.10 "Ixsys Improvements(s)" is any technology and patents
thereto for use in the Immunoassay Field, developed by either or both parties on
or before the fifth anniversary of the Effective Date and that represents an
improvement of Ixsys Technology.

                  1.11 The "Ixsys Project Manager" is William D. Huse, the Ixsys
scientist assigned to the Collaborative Project. The Ixsys Project manager may
be changed from time to time by designation of the President of Ixsys, which
change shall be communicated in writing to Biosite.
   
                  1.12 "Ixsys Technology" means all technology, and patent
rights thereto, reduced to practice and owned by Ixsys or to which Ixsys has
rights, now or in the future before the fifth anniversary of the Effective Date,
that relates to methods, techniques, materials or compositions (a) for
developing and screening combinatorial [CONFIDENTIAL MATERIAL REDACTED AND FILED
SEPARATELY WITH THE COMMISSION] libraries for use in the Immunoassay Field, and
(b) for producing and screening [CONFIDENTIAL MATERIAL REDACTED AND FILED
SEPARATELY WITH THE COMMISSION] for use in the Immunoassay Field, [CONFIDENTIAL 
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION], including, but not 
limited to, those patents and patent applications listed on attached Schedule
1.12, together with all divisionals, continuations, continuations-in-part,
reissues, renewals, extensions or additions to any such patents and patent
applications, all to the extent and only to the extent that Ixsys now has, or
hereafter before the fifth anniversary of the Effective Date will have, the
right to grant licenses, immunities or other rights thereunder. 
    

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                  1.13 "Libraries" means heavy and light chain antibody gene
libraries and combinatorial libraries, including DNA constructs, created (a)
solely by Ixsys under the Collaborative Project, (b) jointly by Ixsys and
Biosite under the Collaborative Project or (c) solely by Biosite after the term
of the Collaborative Project.
    
                  1.14 "Net Sales" means, with respect to any Product, the
invoiced sales price of such Product billed to independent third party
customers, less (a) to the extent such amounts are included in the invoiced
sales price, actual credit allowance to such customers for spoiled, damaged,
out-dated and returned Product; (b) actual freight and insurance costs incurred
in transporting such Product to such customers; (c) quantity and other trade
discounts actually allowed and taken; (d) sales, value-added and other direct
taxes incurred; (e) customs duties and surcharges and other governmental charges
incurred in connection with the exportation or importation of such product in
final form and (f) legally mandated rebates.

   
                  1.15 "Novel Product" means those Products which are within the
scope of one or more claims under Patent Rights, which claims cover (a) a
diagnostic assay having a format that would not be feasible at the time the
format was identified or reduced to practice with then-existing technology -
other than Ixsys Technology or Ixsys Improvements ("Novel Assay Products"), or
(b) a Collaborative Biosite Antibody actually identified using Ixsys Technology
or Ixsys Improvements for a target antigen or hapten which is not being assayed
at the time such Collaborative Biosite Antibody is first identified ("Novel 
Target Products"). Any disagreements concerning whether a Product constitutes 
a Novel Product shall be subject to the arbitration provisions of 
Section 15.7 below.
    
                  1.16 "Patent Rights" shall mean (a) all patents and patent
applications heretofore or hereafter filed or having legal force in any country,
owned by or licensed to a party or to which such party otherwise acquires
rights, having one or more claims covering Ixsys Technology or Ixsys
Improvements, on the one hand, or Biosite Technology or Biosite Improvements, on
the other hand as the case may be, and (b) all divisionals, continuations,
continuations-in-part, reissues, renewals, extensions or additions to any such
patents and patent applications.

   
                  1.17 "Future Ixsys Patent Rights" shall mean (a) all patents
and patent applications hereafter filed or having legal force in any country,
owned by or licensed to Ixsys or to which Ixsys otherwise acquires rights,
having one or more claims covering technology for use in the Immunoassay Field,
developed from the fifth anniversary of the Effective Date to the
    

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expiration or earlier termination of the Agreement that represents an
improvement of either Ixsys Technology or Ixsys Improvements, and (b) all
divisionals, continuations, continuations-in-part, reissues, renewals,
extensions or additions to any such patents and patent applications.

                  1.18 "Product" means (a) all Collaborative Biosite Antibodies
and all Assignee Antibodies, (b) all assays, assay kits, other diagnostic kits
or test configurations, the manufacture, sale or use of which utilizes or
contains one or more Collaborative Biosite Antibodies and/or Assignee Antibodies
and (c) all Novel Products.

   
                  1.19 "Royalty Period" means the period commencing on the
Effective Date and continuing until the twentieth anniversary of the Effective
Date; provided, however, that in the event of a Biosite Assignment, the period
shall continue until the last to expire patent within (1) those Ixsys Patent
Rights or (ii) Future Ixsys Patent Rights, provided one or more valid claims of
such patent would be infringed by the making, using or selling of an Assignee
Antibody as provided herein.
    

   
                  1.20 "Assignee Antibodies" means those Collaborative Biosite
Antibodies and those Biosite Antibodies developed or made by Biosite or
Biosite's assignee using Ixsys cloning or expression vectors, wherein at the
date of a Biosite Assignment, such antibodies have not been sold previously by
Biosite hereunder and/or have not been disclosed in a Biosite FDA submission in
the Immunoassay Field.
    

                  1.21 "Biosite Assignment" means the consummated assignment of
this Agreement by Biosite to a third party assignee, directly or indirectly, and
in accordance with Section 15.3 below.

         2.       Collaborative Project

                  2.1 Research and Development. Ixsys and Biosite each shall
conduct their respective duties under the Collaborative Project in good
scientific manner, and in compliance in all material respects with all
requirements of applicable laws and regulations and all applicable good
laboratory practices to attempt to achieve the objectives of the Collaborative
Project efficiently and expeditiously. Ixsys and Biosite each shall proceed
diligently with their respective duties under the Collaborative Project by using
their respective good faith efforts to provide sufficient time, effort,
equipment and facilities to carry out the Collaborative Project, and use of
personnel with sufficient skills and experience as are required to accomplish
the objectives of the Collaborative Project.

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                  2.2        Collaborative Objectives.

                             2.2.1 Collaborative Biosite Antibodies.
Biosite shall use its commercially reasonable efforts to develop and
commercialize Collaborative Biosite Antibodies.

                             2.2.2  Biosite Research and Development Duties.
Biosite shall be primarily responsible for performing the work associated with
achieving Objectives 1-3 on Schedule 1.6, together with the assistance of such
Ixsys personnel as designated by the Ixsys Project Manager and reasonably
requested by Biosite.

                             2.2.3 Ixsys Research and Development Duties.
Ixsys shall be primarily responsible for performing the work associated with
achieving Objectives 4-6 on Schedule 1.6 together with the assistance of such
Biosite personnel as designated by the Biosite Project Manager and reasonably
requested by Ixsys.

                             2.2.4         Reimbursement for Certain Biosite
Expenses. Biosite shall reimburse Ixsys for the cost of all disposable and
reagent materials used by Biosite personnel while working at Ixsys. Such
reimbursement shall be quarterly and based on reasonable acceptable business
records made available to Biosite upon request, which records shall include,
among other things, invoices for the disposable and reagent materials. All
reimbursements shall be paid by Biosite within thirty (30) days of receipt of a
quarterly invoice from Ixsys, which invoice must be mailed to Biosite within
sixty (60) days of the end of each calendar quarter to avoid forfeiture of the
reimbursements for that quarter.

                             2.2.5 Reimbursement for Certain Ixsys
Expenses. Ixsys shall reimburse Biosite for the cost of all disposable and
reagent materials used by Ixsys personnel while working at Biosite. Such
reimbursement shall be quarterly and based on reasonable acceptable business
records made available to Ixsys upon request, which records shall include, among
other things, invoices for the disposable and reagent materials. All
reimbursements shall be paid by Ixsys within thirty (30) days of receipt of a
quarterly invoice from Biosite, which invoice must be mailed to Ixsys within
sixty (60) days of the end of each calendar quarter to avoid forfeiture of the
reimbursement for that quarter.

                             2.2.6 Compensation of Personnel.  Each of
Ixsys and Biosite shall be solely responsible for the payment of all salary and
other compensation of their respective personnel.

                  2.3 Insurance. Biosite shall maintain product liability
insurance with respect to the development, manufacture

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and sales of Products by Biosite in such amount as is customary in the industry
for other companies engaged in similar activities. Ixsys shall be named as an
additional insured on any such insurance policies. Biosite shall maintain such
insurance for so long as it continues to develop, manufacture or sell any
Products, and thereafter for so long as Biosite maintains insurance for itself
covering such development, manufacture or sales.

                  2.4        Records and Reports

                             2.4.1 Records. Each party shall maintain complete
records, in sufficient detail and manner as the Ixsys Project Manager and the
Biosite Project Manager mutually shall determine, and in good scientific manner
for patent purposes, which shall be complete and accurate and shall fully and
properly reflect all work done by such party and results achieved in the
performance of the Collaborative Project (including all data in the form
required under all applicable laws and regulations).

                             2.4.2 Inspection of Records. Each party shall have
the right, during normal business hours and upon reasonable notice, to inspect
and copy all such records of the other party regarding work performed under the
Collaborative Project. Each party shall maintain such records and the
information of the other party contained therein in confidence in accordance
with Section 9 below, and shall not use such records or information except to
the extent otherwise permitted by the Agreement.

                             2.4.3 Quarterly Development Reports. Within thirty
(30) days following the end of each calendar quarter during the Collaborative
Project Period, Biosite shall prepare and deliver to Ixsys a reasonably detailed
written summary report which shall (a) describe the work performed to date under
the Collaborative Project, (b) evaluate the work performed in relation to the
objectives of the Collaborative Project and (c) state any determinations of
Biosite regarding the nature and extent of future research and development
activities under the Collaborative Project.

                             2.5 Term of Collaborative Project. The
Collaborative Project shall continue for the duration of the Collaborative
Project Period unless terminated earlier as

provided below.

         3.       Exchange of Information

                  3.1 Ixsys Technology. During the Collaborative Project Period,
Ixsys shall provide to Biosite, on a continuing basis as it becomes available,
such information, training and technical assistance regarding Ixsys Technology
and Ixsys

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Improvements as reasonably necessary to enable Biosite to perform its duties
under the Collaborative Project, to achieve the objectives of the Collaborative
Project and to manufacture, use and sell Products and Biosite Antibodies.

                  3.2 Biosite Technology. During the Collaborative Project
Period, Biosite shall provide to Ixsys, on a continuing basis as it becomes
available, hybridomas producing Biosite Antibodies, and such information,
training and technical assistance regarding Biosite Technology and Biosite
Improvements as reasonably necessary to enable Ixsys to perform its duties under
the Collaborative Project, to achieve the objectives of the Collaborative
Project, as reasonably necessary for the use of such Biosite Antibodies or as
useful for the practice of Ixsys Technology.

                  3.3 Improvements. From the Effective Date to the [CONFIDENTIAL
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] thereof, Ixsys and
Biosite, as applicable, shall provide to the other party all information
regarding Biosite Improvements developed by Ixsys and Ixsys Improvements
developed by Biosite.

                  3.4 Availability of Employees. During the Collaborative
Project Period, each party shall make its employees (designated by the Ixsys
Project Manager or the Biosite Project Manager, as the case may be) and relevant
reports of nonemployee consultants available, at no cost to the other party,
upon reasonable notice during normal business hours, at their respective places
of employment to consult with the other party, regarding use of the Ixsys
Technology or Ixsys Improvements, or the Biosite Technology or Biosite
Improvements, as the case may be, on issues arising during the Collaborative
Project, and in connection with any request from any regulatory agency
(including regulatory, scientific, technical and clinical testing issues).

         4.       Ownership of Technology and Improvements

                  4.1 Ixsys Technology. Ixsys is, and at all times hereafter
shall be, the sole and exclusive owner or licensee of all Ixsys Technology and
all Ixsys Improvements, whether conceived or developed solely by Ixsys
personnel, solely by Biosite personnel or jointly by Ixsys and Biosite
personnel. Biosite shall assign to Ixsys any rights which it has or obtains in
all Ixsys Technology and Ixsys Improvements.

                  4.2 Biosite Technology. Biosite is, and at all times hereafter
shall be, the sole and exclusive owner or licensee of all Biosite Technology and
all Biosite Improvements, whether conceived or developed solely by Biosite
personnel, solely by Ixsys personnel or jointly by Biosite and Ixsys

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personnel. Ixsys shall assign to Biosite any rights which it has or obtains in
all Biosite Technology and Biosite Improvements.

                  4.3 Biosite Antibodies and Libraries. Subject to the ownership
rights set forth in Sections 4.1 and 4.2 above, Biosite is, and at all times
hereafter shall be, the sole and exclusive owner of all Biosite Antibodies,
Collaborative Biosite Antibodies and all Libraries. Ixsys is not granted any
right to use or sell Biosite Antibodies, Collaborative Biosite Antibodies or
Libraries, unless expressly provided under the Agreement.

         5.       Patents

                  5.1 Patents. The decision as to whether to seek patent
protection, including the decision as to whether to file applications for patent
term extension, and the decision as to where to seek and maintain such
protection shall be in the sole discretion of (a) Ixsys with respect to Ixsys
Technology, Ixsys Improvements and Future Ixsys Patent Rights, and (b) Biosite
with respect to Biosite Technology, Biosite Improvements, Biosite Antibodies,
Collaborative Biosite Antibodies and Libraries. Except as expressly set forth in
this Section 5.1, each party shall manage the filing, prosecution and
maintenance of, and shall bear all costs incurred in connection with, the
filing, prosecution and maintenance of its own patent applications and patents.
Each party shall cause its employees and agents to take all actions and to
execute, acknowledge and deliver all instruments or agreements reasonably
requested by the other party, and necessary for the perfection, maintenance or
enforcement of the other party's rights as set forth above.

                  5.2 Notification of Infringement. Each party shall notify the
other party of any infringement known to such party of any Patent Rights of the
other party and shall provide the other party with the available evidence, if
any, of such infringement.

                  5.3 Enforcement of Patent Rights. If Ixsys or Biosite has
actual notice of infringement of Patent Rights in the Immunoassay Field, the
respective officers of Ixsys and Biosite shall confer to determine in good faith
an appropriate course of action to enforce such Patent Rights or otherwise abate
the infringement thereof. Ixsys, at its sole expense, shall have the right to
determine the appropriate course of action to enforce Ixsys Patent Rights or
otherwise abate the infringement thereof, to take (or refrain from taking)
appropriate action to enforce Ixsys Patent Right, to control any litigation or
other enforcement action and to enter into, or permit, the settlement of any
such litigation or other enforcement action with respect to Ixsys Patent Rights,
and shall consider, in good faith, the interests of Biosite in so

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doing. All monies recovered upon the final judgment or settlement of any action
undertaken by Ixsys to enforce Ixsys Patent Rights shall be retained by Ixsys.
Biosite, at its sole expense, shall have the right to determine the appropriate
course of action to enforce Biosite Patent Rights or otherwise abate the
infringement thereof, to take (or refrain from taking) appropriate action to
enforce Biosite Patent Rights, to control any litigation or other enforcement
action and to enter into, or permit, the settlement of any such litigation or
other enforcement action with respect to Biosite Patent Rights, and shall
consider, in good faith, the interests of Ixsys is doing so. All monies
recovered upon the final judgment or settlement of any action undertaken by
Biosite to enforce Biosite Patent Rights shall be retained by Biosite; provided,
however, that in the event of a Biosite Assignment, after reimbursement of costs
from the litigation Biosite's assignee shall pay to Ixsys royalties under
Sections 7.1 and 7.2 below on all monies representing royalty-bearing sales of
Products or Biosite Antibodies recorded after the assignment, or royalties or
other fees from third parties on sales of Biosite Antibodies developed or made
using Ixsys cloning or expression vectors and Collaborative Biosite Antibodies
in accordance with Section 6.3 below. Notwithstanding the foregoing, Ixsys and
Biosite shall fully cooperate with each other in the planning and execution of
any action to enforce the other party's Patent Rights.

         6.       Licenses

   
                  6.1 License Grant to Ixsys. Biosite grants a worldwide
nonexclusive license to Ixsys (a) to make, have made, use and sell those Biosite
Antibodies and Collaborative Biosite Antibodies identified prior to the fifth
anniversary of the Effective Date and which may be useful in the practice of
Ixsys Technology and Ixsys Improvements, but specifically excluding antibodies
directed to the targets identified in Schedule 1.4B, and (b) to use Biosite
Technology and Biosite Improvements, including the right to grant sublicenses
(on the terms and subject to the conditions of the Agreement) to the extent it
may be useful in the practice of Ixsys Technology and Ixsys Improvements. This
license to Ixsys shall not permit the use of Biosite Antibodies, Collaborative
Antibodies, Biosite Technology or Biosite Improvements by Ixsys or its
sublicensees in commercial in vitro diagnostic products or their manufacture.
    
   
                  6.2 License Grant to Biosite. Ixsys grants to Biosite a
worldwide nonexclusive license under the Ixsys Technology and the Ixsys
Improvements, without the right to grant further sublicenses, (a) to make, use
or sell Products in the Immunoassay Field and (b) to make Biosite Antibodies
solely for use in the Immunoassay Field.
    

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                  6.3 Third Party Sale or Production. Notwithstanding anything
to the contrary in this Agreement, Biosite shall have the right, in connection
with the sale to a third party of Biosite Antibodies or Collaborative Biosite
Antibodies, to grant to such third party the right to produce and sell such
Biosite Antibodies and Collaborative Biosite Antibodies from hosts provided by
Biosite; provided, however, that any such third party shall have no right,
title or license under the Ixsys Technology or the Ixsys Improvements.
    

   
                  6.4 Third Party Licenses. If, on or before the fifth
anniversary of the Effective Date, any third party grants or assigns to Ixsys
any rights in the Immunoassay Field which constitute Ixsys Technology or Ixsys
Improvements, or grants or assigns to Biosite any rights in the Immunoassay
Field which constitute Biosite Technology or Biosite Improvements, then Ixsys or
Biosite, as the case may be, shall grant a sublicense under such rights to the
other party at the option of the other party, to the extent that Ixsys or
Biosite, as the case may be, has a right under, and on such terms and conditions
as provided by, such third party agreement to grant such sublicense. For
example, Ixsys hereby sublicenses Biosite under the agreement between Ixsys and
Stratacyte Corporation effective November 7, 1991, a copy of which is attached
hereto as Appendix A.
    

                  6.5        Biosite License Options.

   
                  6.5.1 If Ixsys elects in its sole discretion to broadly
license (in terms of number of intended licensees) a Future Ixsys Patent Right,
Biosite shall have the option to obtain a world-wide non-exclusive license from
Ixsys under such Future Patent Rights, without the right to grant further
sublicenses, (a) to make, use, or sell Products in the Immunoassay Field and (b)
to make Biosite Antibodies for use solely in the Immunoassay Field, on such
terms and conditions as the parties mutually shall agree. If Ixsys grants a
license under any Future Ixsys Patent Right to any third party (other than an
Affiliate of Ixsys) at a royalty rate or on other financial terms more
favorable to such third party than those set forth in the license granted to
Biosite under this Section 6.5.1, Ixsys promptly shall notify Biosite thereof.
If Biosite gives written notice to Ixsys of its election to substitute the more
favorable financial terms within thirty (30) days of Ixsys's notice to Biosite,
then the license granted to Biosite under this Section 6.5.1 automatically
shall be amended and adjusted to include all of the financial terms and
conditions (including all less favorable terms and conditions) of such third
party license taken as a whole.
    

   
                  6.5.2 If the parties mutually agree, Ixsys shall produce, for
use by Biosite solely in the Immunoassay Field, such heavy and light chain
antibody gene libraries and combinatorial libraries on such terms and conditions
as the parties mutually shall agree.
    

                  6.6 Ixsys License Options. The parties hereby agree

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to negotiate in good faith a separate license agreement covering the making,
using or selling by Ixsys of Collaborative Biosite Antibodies for therapeutic
indications on reasonable royalty rates and other terms and conditions.

         7.       Royalties

   
                  7.1 Royalty Rate. In consideration for the license granted to
Biosite herein, during the Royalty Period, Biosite shall pay to Ixsys a single
royalty on any Product equal to (a) with respect to all Products, the lesser of
(i) [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION]
per each different Collaborative Biosite Antibody in a Product sold by Biosite
to third parties, or (ii) [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY
WITH THE COMMISSION] per each different target to which more than one
Collaborative Biosite Antibody is directed in each assay in a Product sold by
Biosite to third parties; or (b) if greater in any calendar year with respect to
Novel Products only, [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH
THE COMMISSION]of Net Sales of Novel Target Products or with respect to Novel
Assay Products: (i) [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH
THE COMMISSION] of Net Sales of Novel Assay Products up to [CONFIDENTIAL
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] in any calendar
year, (ii) [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION] of Net Sales of Novel Assay Products in excess of [CONFIDENTIAL
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] and up to
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] in any
calendar year, (iii) [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH
THE COMMISSION] of Net Sales of Novel Assay Products in excess of [CONFIDENTIAL
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] and up to
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] in any
calendar year, and (iv) [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY
WITH THE COMMISSION] of Net Sales of Novel Assay Products in excess of
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] in any
calendar year. Notwithstanding anything to the contrary in this Section 7.1,
Biosite shall pay to Ixsys [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY
WITH THE COMMISSION] of that portion of royalties and other fees actually
received by Biosite and specifically attributable to the use or sale by a third
party, in accordance with Section 6.3, of Collaborative Biosite Antibodies or
those Biosite Antibodies developed or made by Biosite using Ixsys cloning or
expression vectors. The determination of the attributable portion of royalties
and fees in a third party agreement shall be made in accordance with generally
accepted accounting principles. No royalty shall accrue to Ixsys hereunder with
respect to Biosite's or a third party's manufacture, use or sale of Biosite
Antibodies produced from
    

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hybridomas or otherwise without use of Ixsys Technology and Ixsys Improvements.

   
                  7.2 Assignee Royalty Rate. In the event of a Biosite
Assignment, Biosite's assignee shall pay to Ixsys on Assignee Antibodies during
the Royalty Period and instead of the royalty specified in Section 7.1(a) above,
but subject to the provisions of Section 7.1(b) above, a single royalty equal
to: the greater of [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION] of Net Sales of Products containing Assignee Antibodies or (ii)
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] of the
Net Sales, wherein Net Sales for combination Products containing more than one
different antibody shall be calculated by applying to the Net Sales (as defined
in Section 1.14) of the combination Products a fractional multiplier having as
its numerator the number of different Assignee Antibodies in the combination
Product and as its denominator the total number of different antibodies
utilized in the combination product. All other provisions of Section 7.1 shall
remain in full force and effect.
    

   
                  7.3 Royalty Reports. For each calendar quarter during the
Royalty Period, Biosite shall furnish to Ixsys a quarterly written report
showing in reasonably specific detail (a) the gross sales of all Products sold
by Biosite and its sublicensees during the reporting period, (b) the number and
composition of Collaborative Biosite Antibodies in the Products, (c) the
calculation of Net Sales from gross sales (if applicable), and (d) the
calculation of royalties payable to Ixsys which shall have accrued hereunder
based upon sales of Products, (e) the gross sales of Biosite Antibodies
developed or made using Ixsys cloning or expression vectors and Collaborative
Biosite Antibodies by third parties in accordance with Section 6.3, (f) the
calculation of royalties and other fees actually received by Biosite in
connection with the use or sale thereof by third parties, and (g) the
calculation of royalties to Ixsys which shall have accrued hereunder based upon
the use or sale thereof by third parties. Such royalty reports shall be due on
the sixtieth (60th) day following the close of each calendar quarter Biosite
shall keep complete and accurate records in sufficient detail to properly
reflect all gross sales and Net Sales and to enable the royalties payable
hereunder to be determined.
    

                  7.4 Payment Terms. All royalties shown to have accrued by each
royalty report provided for under Section 7.3 above shall be due and payable on
the date such royalty report

                                      -12-

   
<PAGE>   13
is due. Payment of royalties in whole or in part may be made in advance of such
due date.

                  7.5        Minimum Royalties.

                             7.5.1 On the Effective Date and on the first day of
each January thereafter, Biosite shall pay to Ixsys minimum annual royalties for
each calendar year equal to [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY
WITH THE COMMISSION] in connection with the [CONFIDENTIAL MATERIAL REDACTED AND
FILED SEPARATELY WITH THE COMMISSION] constituting part of the Ixsys Technology,
and [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] in
connection with the [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH
THE COMMISSION] constituting part of the Ixsys Technology; provided, however,
that (i) the initial minimum annual royalty payments under this section will be
prorated from the Effective Date until December 31, 1992; and (ii) the minimum
annual royalty payments due after the initial payment on the [CONFIDENTIAL
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] or the [CONFIDENTIAL
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] shall accrue but
shall not be due, with respect to each part of the technology, until the date
such part of the technology has been actually reduced to practice. For purposes
of this Section 7.5.1. "reduced to practice" shall mean the achievement of (a)
objective 1 or 2 on Schedule 1.6 with respect to the [CONFIDENTIAL MATERIAL
REDACTED AND FILED SEPARATELY WITH THE COMMISSION], and (b) objective 3 on
Schedule 1.6 with respect to the [CONFIDENTIAL MATERIAL REDACTED AND FILED
SEPARATELY WITH THE COMMISSION]. If at the end of the Collaborative Project
Period either the [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION] or the [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION] has not been actually reduced to practice by Biosite, Ixsys shall
reimburse Biosite for that portion of the initial minimum annual royalty
payments made under this section which relates to any such technology not
actually reduced to practice.

                             7.5.2 Minimum royalties paid under Section 7.5.1.
shall be creditable against all royalties shown to have accrued by each royalty
report provided for under Section 7.3 above during such calendar year.

                  7.6 Duration of Royalty Obligations. Royalty obligations shall
continue during the Royalty Period, after which each party's license granted
hereunder shall become a fully paid-up, irrevocable license.

                  7.7 Audits. Upon the written request of Ixsys, Biosite shall
permit an accounting firm selected by Ixsys and reasonably acceptable to Biosite
to have access, up to twice per year, during normal business hours to such of
the records of

                                      -13-

   
<PAGE>   14
   
Biosite as may be reasonably necessary to verify the accuracy of the royalty
reports hereunder. If such audit concludes that additional royalties were owed
during such period, Biosite shall pay the additional royalties within thirty
(30) days of the date Ixsys delivers to Biosite such accounting firm's written
report. The fees charged by such accounting firm shall be paid by Ixsys;
provided, however, if the audit discloses that the royalties payable by Biosite
for the audited period are more than one hundred ten percent (110%) of the
royalties actually paid for such period, then Biosite shall pay the reasonable
fees and expenses of such audit. Biosite shall include in each sublicense
granted pursuant to the Agreement a provision requiring the sublicensee to make
reports to Biosite, to keep and maintain records of sales and to grant access to
such records by Ixsys' accounting firm to the same extent required of Biosite
under the Agreement.
    

         8. License Issue Fee Payments. In consideration for the licenses
granted to Biosite under the Agreement, Biosite shall pay to Ixsys, on or before
the Effective Date, license issue fees in the amount of [CONFIDENTIAL MATERIAL
REDACTED AND FILED SEPARATELY WITH THE COMMISSION] in connection with the
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION]
constituting part of the Ixsys Technology, and [CONFIDENTIAL MATERIAL REDACTED
AND FILED SEPARATELY WITH THE COMMISSION] in connection with the [CONFIDENTIAL
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] constituting part of
the Ixsys Technology.

         9.       Confidentiality.

   
                  9.1 Confidential Information. During the term of the
Agreement, and for a period of ten (10) years following the expiration or
earlier termination hereof, each party shall maintain in confidence all
information (including samples) disclosed by the other party hereto, and shall
not use, disclose or grant the use of such information except on a need-to-know
basis to those affiliates, employees, permitted licensees, permitted assignees
and agents, consultants, clinical investigators or contractors, to the extent
such disclosure is reasonably necessary in connection with such party's
activities as expressly authorized by the Agreement. To the extent that
disclosure is authorized by the Agreement, prior to disclosure, each party
hereto shall obtain agreement of any such person or entity to hold in confidence
and not make use of such information for any purpose other than those permitted
by the Agreement. Each party shall use at least the same standard of care
customarily used by companies engaged in the research, development and
manufacture of biopharmaceutical products to protect its own trade secrets or
proprietary information to ensure that its affiliates, employees, permitted
licensees,
    

                                      -14-

   
<PAGE>   15
permitted assignees and agents, consultants, clinical investigators and
contractors do not disclose or make any unauthorized use of information of the
other party hereto except as permitted by the Agreement. Each party shall notify
the other promptly upon discovery of any unauthorized use or disclosure of the
other party's information.

                  9.2 Permitted Disclosures. The confidentiality obligations
contained in Section 9.1 above shall not apply to the extent that (a) any
receiving party (the "Recipient") is required to disclose information by law,
order or regulation of a governmental agency or a court of competent
jurisdiction, (b) the Recipient is required to disclose information to any
governmental agency for purposes of obtaining approval to test or market a
Product, or (c) the Recipient can demonstrate that (i) the disclosed information
was public knowledge at the time of such disclosure by the Recipient, or
thereafter became public knowledge, other than as a result of actions of the
Recipient, its affiliates, employees, permitted licensees, permitted assignees
and agents, consultants, clinical investigators or contractors in violation
hereof; (ii) the disclosed information was rightfully known by the Recipient,
its affiliates or permitted licensees (as shown by its written records) prior to
the date of disclosure to the Recipient by the other party hereunder; or (iii)
the disclosed information was received by the Recipient or its affiliates or
permitted licensees on an unrestricted basis from a source unrelated to any
party to the Agreement and not under a duty of confidentiality to the other
party.

         10.      Warranties and Representations.

                  10.1 By Ixsys. Ixsys warrants and represents to Biosite as
follows:

                             10.1.1 It is a corporation duly organized, validly
existing, and in good standing under the laws of the jurisdiction of its
incorporation, has full corporate power and authority to own its assets and
carry on its business as presently conducted and to enter into and perform its
obligations under the Agreement, including the Schedules hereto.

                             10.1.2 The execution, delivery and performance by
it of the Agreement, including the Schedules attached hereto, have been duly
authorized by all necessary corporate action on its part, do not require further
approvals or consents of its stockholders or governing body, and will not
contravene any applicable law, government rule, regulation or order binding on
it, or contravene its charter, certificate of incorporation, bylaws, or other
constituent documents or contravene the provisions of, or constitute a default
under, violation of, or conflict with, or result in the creation of any lien
upon any of

                                      -15-

   
<PAGE>   16
its property under, any agreement or other instrument to which it is a party or
by which it or any of its properties is or may be bound or affected.

                             10.1.3 The Agreement, including the Schedules
attached hereto, constitutes its legal, valid and binding obligation,
enforceable against it in accordance with its terms, except as such
enforceability may be limited by applicable bankruptcy, insolvency or similar
laws in effect from time to time that affect creditors' rights generally and by
principles of equity.

                             10.1.4 As of the date of the Agreement, Schedule
1.12 is a complete list of all United States and foreign patent applications and
issued patents relating to Ixsys Technology. This schedule will be updated as
necessary to reflect additional filings and issuances.

                  10.2 By Biosite. Biosite warrants and represents to Ixsys as
follows:

                             10.2.1 It is a corporation duly organized, validly
existing, and in good standing under the laws of the jurisdiction of its
incorporation, has full corporate power and authority to own its assets and
carry on its business as presently conducted and to enter into and perform its
obligations under the Agreement, including the Schedules hereto.

                             10.2.2 The execution, delivery and performance
by it of the Agreement, including the Schedules attached hereto, have been duly
authorized by all necessary corporate action on its part, do not require further
approvals or consents of its stockholders or governing body, and will not
contravene any applicable law, government rule, regulation or order binding on
it, or contravene its charter, certificate of incorporation, bylaws, or other
constituent documents or contravene the provisions of, or constitute a default
under, violation of, or conflict with, or result in the creation of any lien
upon any of its property under, any agreement or other instrument to which it is
a party or by which it or any of its properties is or may be bound or affected.

                             10.2.3 The Agreement, including the Schedules
attached hereto, constitutes its legal, valid and binding obligation,
enforceable against it in accordance with its terms, except as such
enforceability may be limited by applicable bankruptcy, insolvency or similar
laws in effect from time to time that affect creditors' rights generally and by
principles of equity.

                  10.3 DISCLAIMER OF WARRANTIES. NOTHING IN THE AGREEMENT SHALL
BE CONSTRUED AS A REPRESENTATION MADE, OR

                                      -16-

   
<PAGE>   17
WARRANTY GIVEN, BY EITHER IXSYS OR BIOSITE THAT ANY PATENT WILL ISSUE BASED UPON
ANY PENDING PATENT APPLICATION WITHIN THE PATENT RIGHTS, THAT ANY PATENT WITHIN
THE PATENT RIGHTS WHICH ISSUES WILL BE VALID, OR THAT THE USE OF ANY LICENSE
GRANTED HEREUNDER OR THAT THE USE OF ANY PATENT RIGHTS WILL NOT INFRINGE THE
PATENT OR PROPRIETARY RIGHTS OF ANY OTHER PERSON OR ENTITY. EACH OF IXSYS AND
BIOSITE DISCLAIMS ALL WARRANTIES WHATSOEVER WITH RESPECT TO THE OWNERSHIP OF THE
PROCESSES, TECHNIQUES, METHODS, MATERIALS OR TECHNOLOGY USED TO MAKE AND USE THE
BIOSITE ANTIBODIES OR COLLABORATIVE BIOSITE ANTIBODIES, EITHER EXPRESS OR
IMPLIED, AND ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, AS TO THE
MERCHANTABILITY OR FITNESS OF THE ANTIBODIES FOR A PARTICULAR PURPOSE.

         11.      Term and Termination.

   
                  11.1 Expiration. Unless terminated earlier pursuant to Section
11.2 below, the Agreement shall expire on the expiration of Biosite's
obligations to pay royalties under the Agreement.
    

   
                  11.2 Termination. The Agreement may be terminated by either
party upon or after the breach of any material provision of the Agreement by the
other party, if the breaching party has not cured such breach within
ninety (90) days after notice thereof by the other party.
    

                  11.3 Effect of Termination. Expiration or termination of the
Agreement shall not relieve the parties of any obligation accruing prior to such
expiration or termination. The provisions of Section 6 shall survive the
expiration of the Agreement. The provisions of Sections 4, 9, 12 and 15.7, as
well as any rights of Ixsys or Biosite arising out of a breach by the other of
any obligations hereunder, shall survive the expiration or earlier termination
of the Agreement.

         12. Indemnification. Each party shall indemnify, defend and hold the
other party, its affiliates and sublicensees harmless, and hereby forever
releases and discharges the other party, its affiliates and sublicensees, from
and against all claims, demands, liabilities, damages and expenses, including
attorneys' fees and costs arising out of the negligence, recklessness or
intentional acts or omissions of the indemnifying party, its affiliates or
sublicensees in connection with the work performed by such party during the
Collaborative Project or the development, manufacture, sale or use of Biosite
Antibodies or Products by such party.

         13. Notices. Any consent, notice or report required or permitted to be
given or made under the Agreement by one of the parties hereto to the other
shall be in writing, delivered

                                      -17-

   
<PAGE>   18
personally or by facsimile (and promptly confirmed by personal delivery, U.S.
first class mail or courier), U.S. first class mail or courier, postage prepaid
(where applicable), addressed to such other party at its address indicated
below, or to such other address as the addressee shall have last furnished in
writing to the addressor and (except as otherwise provided in the Agreement)
shall be effective upon receipt by the addressee.

         Biosite:            Biosite Diagnostics Incorporated
                             11030 Roselle Street, Suite D
                             San Diego, CA 92121
                             Attention: Kim D. Blickenstaff

         Ixsys:              Ixsys, Inc.
                             3550 General Atomics Court, Suite L-103
                             San Diego, CA 92121
                             Attention: Michael J. Hanifin

         With a copy to:

                            Pillsbury Madison & Sutro
                            235 Montgomery Street, 15th Floor
                            San Francisco, CA 94104
                            Attention: Thomas E. Sparks, Jr.

         14. Bankruptcy. All rights and licenses granted under or pursuant to
the Agreement are, and shall otherwise be deemed to be, for purposes of Section
365(n) of the Bankruptcy Code, licenses of rights to "intellectual property" as
defined under Section 101(52) of the Bankruptcy Code. Each of the parties, as a
licensee of certain rights under the Agreement, shall retain and may fully
exercise all of its rights and elections under the Bankruptcy Code.

         15.      Miscellaneous.

                  15.1 Limited License. Nothing herein shall be construed as a
license to a party of any patents or patent applications held by the other party
unless otherwise specifically set forth herein.

                  15.2 Governing Law. The Agreement shall be governed by and
construed in accordance with the laws of the State of California.

   
                  15.3 Assignment. Neither Biosite nor Ixsys shall assign its
rights or obligations under the Agreement without the prior written consent of
the other party hereto; provided, however, that either Biosite or Ixsys may,
without such consent, assign the Agreement and its rights and obligations
hereunder in connection with the transfer or sale of all or substantially all of
its business, or in the event of its merger or consolidation or change in
control or similar transaction. Any permitted assignee shall assume all
obligations of its assignor under the Agreement.
    

                  15.4 Waivers and Amendments. No change,

                                      -18-

   
<PAGE>   19
modification, extension, termination or waiver of the Agreement, or any of the
provisions herein contained, shall be valid unless made in writing and signed by
duly authorized representatives of the parties hereto.

                  15.5 Entire Agreement. The Agreement embodies the entire
understanding between the parties and supersedes any prior understanding and
agreements between and among them respecting the subject matter hereof. There
are no representations, agreements, arrangements or understandings, oral or
written, between the parties hereto relating to the subject matter of the
Agreement which are not fully expressed herein.

                  15.6 Force Majeure. In the event of a delay caused by
inclement weather, fire, flood, strike or other labor dispute, act of God, act
of governmental officials or agencies, or any other cause beyond the control of
Ixsys or Biosite, Ixsys or Biosite, as the case may be, shall be excused from
performance hereunder for the period of time attributable to such delay, which
may extend beyond the time lost due to one or more of the causes mentioned
above.

                  15.7 Arbitration. Any disputes arising between the parties
relating to, arising out of or in any way connected with the Agreement or any
term or condition hereof, or the performance by either party of its obligations
hereunder, whether before or after termination of the Agreement, shall be
finally resolved by binding arbitration. Whenever a party shall decide to
institute arbitration proceedings, it shall give written notice to that effect
to the other party. The party giving such notice shall refrain from instituting
the arbitration proceedings for a period of sixty (60) days following such
notice. Any arbitration hereunder shall be conducted under the rules of the
American Arbitration Association. Each such arbitration shall be conducted by a
panel of three arbitrators appointed in accordance with such rules. Any such
arbitration shall be held in San Diego, California. The arbitrators shall have
the authority to grant specific performance, and to allocate between the parties
the costs of arbitration in such equitable manner as they determine. Judgment
upon the award so rendered may be entered in any court having jurisdiction or
application may be made to such court for judicial acceptance of any award and
an order of enforcement, as the case may be. In no event shall a demand for
arbitration be made after the date when institution of a legal or equitable
proceeding based on such claim, dispute or other matter in question would be
barred by the applicable statute of limitations.

                  15.8 Counterparts. The Agreement may be executed in two or
more counterparts, each of which shall be deemed an

                                      -19-

   
<PAGE>   20
original, but all of which together shall constitute one and the same
instrument.

         IN WITNESS WHEREOF, the parties have caused the Agreement to be duly
executed as of the day and year written below.

BIOSITE DIAGNOSTICS                                 IXSYS, INC.
INCORPORATED                                     
                                                 
By /s/ Gunars E. Valkirs                            By  /s/ Michael J. Hanifen
   -----------------------------                        ------------------------
Title V.P. Research and                             Title  V.P. Business
      -----------------                                    --------------
         Development 7/1/92                                  Development 7/1/92
         ------------------                                  ------------------
                                         
                                      -20-

   
<PAGE>   21
                                  Schedule 1.4A

                               Biosite Technology

1.                Threshold immunoassay methods described in U.S. Patent
                  No. 5,028,535 and related Continuations in Part.

2.                [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY
                  WITH THE COMMISSION]

3.                [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY
                  WITH THE COMMISSION]

                                      -21-

   
<PAGE>   22
                                  Schedule 1.4B

                    Specific Chemical Modifications Excluded

[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION]

Specific derivatives and conjugates as disclosed in the following patent
applications:

                                      -22-

   
<PAGE>   23
                              Schedule 1.4B (cont.)

   
Derivatives of other specific compounds and their conjugates synthesized by
Biosite which are useful as antibody targets for the development and use of
commercial in vitro diagnostic immunoassays for those specific compounds and
their conjugates; but other than derivatives of compounds for use in Ixsys
Technology and Ixsys Improvements as antibody targets for: [CONFIDENTIAL
MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] and (iii)
antibodies for use in Ixsys Technology and Ixsys Improvements as agreed upon by
Biosite and Ixsys.

Hybridomas and other cells producing antibodies that specifically react with
any of the above derivatives and conjugates.
    

                                      -23-

   
<PAGE>   24
                                  Schedule 1.6

   
                               Biosite Objectives

1.      [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
        COMMISSION]

2.      [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
        COMMISSION]

3.      [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
        COMMISSION]

        [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
        COMMISSION]

                                Ixsys Objectives

4.      Develop expertise in antibody purification and characterization.

5.      Develop expertise in technology for hapten and/or protein conjugation to
        other proteins, including protein chemistry.

6.      Develop expertise in the development of reagents for use in antibody
        screening and analysis.

                                Joint Objectives

7.      [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
        COMMISSION]

8.      [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
        COMMISSION]

9.      [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
        COMMISSION]

    

                                      -24-

   
<PAGE>   25
                                  Schedule 1.12


  DOCKET                                         SERIAL NO.         DATE FILED
  NUMBER       TITLE            INVENTOR        (PATENT NO.)         (ISSUED)
 --------     -------          ----------      --------------      ------------
    [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION]

 P31 8699     METHODS OF          HUSE             573,648            8/24/90
              SYNTHESIZING
              OLIGONUCLEOTIDES
              WITH RANDOM
              CONDONS
              _______


[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION]



                                      -25-