<PAGE>   1
                                             * TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                          UNDER 17 C.F.R. SECTIONS 200.80(b)(4),
                                                            200.83 AND 240.24b-2



                                  EXHIBIT 10.44




                                LICENSE AGREEMENT

                                     BETWEEN

                                XENOMETRIX, INC.

                                       AND

                                AFFYMETRIX, INC.


                                        1
<PAGE>   2
                                LICENSE AGREEMENT

This Agreement is made this 30th day of September 1998 (the "Effective Date"),
by and between Xenometrix, Inc. ("XENO"), a Delaware corporation with principal
offices at 2425 55th Street, Boulder, CO 80301-5700 and Affymetrix, Inc.
("AFFYMETRIX"), a Delaware corporation with principal offices at 3380 Central
Expressway, Santa Clara, CA 95051 to license certain technology.

                                    RECITALS

WHEREAS, XENO is the owner or exclusive licensee of the XENO Patents relating to
certain assays, technology and intellectual property further described herein,
and desires to non-exclusively license the same to AFFYMETRIX; and

WHEREAS, AFFYMETRIX seeks to obtain certain non-exclusive license rights under
the XENO Patents, according to the terms contained herein (the "Agreement");

Now, therefore, in consideration of the foregoing and the covenants and promises
contained herein the parties agree as follows:

1. DEFINITIONS

   1.1.  "Affiliate" means any corporation or other business entity controlled
         by, or in common control of an entity. Control, as used in the context
         of a business entity, means the ownership directly or indirectly of
         fifty percent (50%) of the voting securities of the person,
         corporation, or other entity or a fifty percent (50%) or greater
         interest in a) the income of such corporation or other entity or b) the
         ability otherwise of the entity to secure that the affairs of such
         person, corporation or other entity are managed in accordance with the
         such entity's wishes.

   1.2.  "Confidential Information" means all information, compounds, data, and
         Materials received by either party from the other party pursuant to
         this Agreement including, without limitation, technology of each party,
         subject to the exceptions set forth in Section 5.1.

   1.3.  "Control" or "Controlled" means, in the context of intellectual
         property, possession by a party of the ability to grant a license or
         sublicense in accordance with the terms of this Agreement, and without
         violating the terms of any agreement by such party with any Third


                                       2
<PAGE>   3
         Party.

   1.4.  "Field" means [*].

   1.5.  "Harvard License Agreement" means the license agreement between the
         President and Fellows of Harvard College and Venmark Ltd., now XENO,
         executed on January 17, 1992 attached hereto as Exhibit B.

   1.6.  "Licensed Product(s)" means products or components thereof claimed in
         Xeno Patents or products or components thereof made in accordance with
         or by means of Licensed Processes.

   1.7.  "Licensed Process(es)" means the processes claimed in XENO Patents.

   1.8.  "Materials" means any biological or chemical entity for screening or
         assays, including reagents, cells, promoters, enhancers, vectors,
         plasmids, proteins and fragments thereof, peptides, antigens,
         antibodies, antagonists, agonists, inhibitors, and chemicals.

   1.9.  "Net Sales" means the amounts received for sales or use of Licensed
         Products or Licensed Processes less: a) reasonable credits or
         allowances, if any, actually granted on account of price adjustments,
         recalls, rejections, or return of items previously sold, b) excises,
         sales taxes, value added taxes, consumption taxes, duties, or other
         taxes imposed upon and paid with respect to such sales (excluding
         income or franchise taxes of any kind) and c) separately itemized
         insurance and transportation costs incurred in shipping Licensed
         Products to such third parties. Net Sales shall not include any
         transfer between AFFYMETRIX and any of its Affiliates for resale when
         such Affiliate pays royalties upon such resale. If AFFYMETRIX or its
         Affiliate sells Licensed Products or Processes to or through a
         distributor (which is not an Affiliate), Net Sales shall be the gross
         revenues from the sales to such distributor. In the event that
         AFFYMETRIX or any of its Affiliates shall make any transfer to third
         parties for other than monetary value in whole or in part, such
         transfer shall be considered a sale hereunder for accounting and
         royalty purposes. Net Sales for any such non-monetary transfers shall
         be determined on a country-by-country basis and shall be the average
         price of arms length sales by AFFYMETRIX or its Affiliates in such
         country during the royalty reporting period in which such transfer
         occurs, or if no such arms length sales occurred in such country during
         such period, during the last period in which such arms length sales
         occurred. If no arms length sales have occurred in a particular
         country, Net Sales for 


                                       3

* CERTAIN CONFIDENTIAL MATERIAL CONTAINED IN THIS DOCUMENT HAS BEEN OMITTED AND 
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 
24b-2 OF THE SECURITIES AND EXCHANGE COMMISSION ACT OF 1934, AS AMENDED.
<PAGE>   4
         such transfer shall be the average price of arms length sales in all
         countries. Notwithstanding the foregoing, no transfer of products or
         services for evaluation testing or as samples shall be considered a
         sale hereunder for accounting and royalty purposes unless such transfer
         is for value. If a Licensed Product or Process is sold as part of a
         system, package, or combination product or process (including
         combinations of a product and a process), Net Sales shall be calculated
         by multiplying the Net Sales of the combination product or process by
         the fraction A/B where "A" is the average unit price of the licensed
         product or process when sold separately and "B" is the average unit
         price of the combination product or process. If the product or process
         is not sold separately, the Parties shall negotiate in good faith the
         appropriate percentage of the unit price of the combination product or
         process. Net Sales shall not include technology access, support fees,
         or service fees paid in partial consideration for access to nucleic
         acid arrays, provided that a material profit is derived from the sale
         of such nucleic acid arrays. It is assumed for the purposes of this
         Agreement that the business model of AFFYMETRIX provides for the
         derivation of profits primarily or substantially through the sale of
         nucleic acid arrays licensed hereunder, or processes using such nucleic
         acid arrays. In the event that AFFYMETRIX modifies its business
         strategy such that derivation of profits is substantially or primarily
         through another vehicle (such as the licensing of software or sale of
         Systems) the Parties will meet and confer to negotiate in good faith a
         substitute definition of Net Sales that will provide XENO with a
         substantially equivalent royalty payment as if such business model was
         not modified. In the event that the Parties cannot agree upon an
         alternate definition of Net Sales, the Parties shall resolve the issue
         by prompt, binding arbitration by the rules of the ICC.


   1.10. "XENO Patents" means the U.S. patents and patent applications listed on
         Exhibit A hereto, any patent applications filed prior or subsequent to
         the Effective Date that claim the benefit of an early filing date of
         any of the patent applications listed in Exhibit A, and any reissues,
         extensions, substitutions, confirmations, re-registrations,
         re-examinations, continuations, divisionals or continuations-in-part of
         the foregoing patents and patent applications, as well as all foreign
         counterparts or equivalents thereof.

   1.11. "Third Party" means any entity other than (i) AFFYMETRIX and any of its
         Affiliates, and (ii) XENO and any of its Affiliates.

2. LICENSES


                                       4
<PAGE>   5
   2.1.  Grant of Licenses Under the XENO Patents from XENO to AFFYMETRIX.

         2.1.1.   Non-Exclusive License to XENO Patents. XENO hereby grants to
                  AFFYMETRIX and its Affiliates a non-exclusive, worldwide
                  license in the Field, without the right to sublicense under
                  XENO's ownership interest in the XENO Patents to make, use,
                  have made, sell, have sold, offer for sale, import, export or
                  otherwise exploit any process, composition of matter or other
                  invention claimed in the XENO Patents. Licensed Products shall
                  enjoy the benefit of this license for any Third Party who
                  purchases Licensed Product, however, the license shall only
                  apply to those Licensed Products that are purchased by the
                  Third Party from Affymetrix.

         2.1.2.   Non-Exclusive Sublicense to XENO Patents under the Harvard
                  License Agreement. XENO hereby grants to AFFYMETRIX and its
                  Affiliates a non-exclusive, worldwide sublicense in the Field,
                  without the right to sublicense, under XENO's right to
                  sublicense the XENO Patents in the Harvard License Agreement
                  to make, use, have made, sell, have sold, offer for sale,
                  import, export or otherwise exploit any process, composition
                  of matter or other invention claimed in the XENO Patents.
                  AFFYMETRIX acknowledges the Harvard License Agreement and
                  XENO's and AFFYMETRIX's duties and obligations thereunder.
                  Licensed Products shall enjoy the benefit of this license for
                  any Third Party who purchases Licensed Product, however, the
                  license shall only apply to those Licensed Products that are
                  purchased by the Third Party from Affymetrix.

3. COMPENSATION

   3.1.  Compensation for the XENO Patents License.

         3.1.1.   XENO Patent Licenses and Rights.

                  3.1.1.1 Payments As consideration for the licenses and rights
                  granted to AFFYMETRIX herein, AFFYMETRIX has, or will pay to
                  XENO:

                        (a) [*];

                        (b) [*] payment of $[*] fee and for i) access to the
                        technology licensed hereunder; and ii) assistance from
                        XENO to Affymetrix in toxicity chip 


                                       5


* CERTAIN CONFIDENTIAL MATERIAL CONTAINED IN THIS DOCUMENT HAS BEEN OMITTED AND 
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 
24b-2 OF THE SECURITIES AND EXCHANGE COMMISSION ACT OF 1934, AS AMENDED.
<PAGE>   6
                        design. The chip design assistance component shall be
                        negotiated in good faith between the parties after the
                        conclusion of this Agreement, but shall provide for
                        technical assistance [*];

                        (c) an earned royalty of [*] percent [*] for sales in a
                        specific country which has patents that cover the
                        Licensed Products and which have issued [*]. It is
                        understood that no earned royalty is payable on products
                        and processes not specifically designed, labeled or
                        marketed for use in the Field.

The [*] fee paid above shall be considered [*] to constitute an up-front
payment for technology hereunder. [*].

                        3.1.1.2 Duration of Compensation
                         
                        Compensation for the XENO Patents License will be due by
                        AFFYMETRIX to XENO until the termination of this
                        Agreement and at the most until the last expiration date
                        of all XENO Patents.



         3.1.2.   Royalty Reports, and Payments. Beginning on the Effective
                  Date, AFFYMETRIX shall make non-audited written reports (even
                  if there are no sales) and earned royalty payments to within
                  sixty (60) days after the end of the each calendar quarter.
                  These reports shall state the Net Sales of Licensed Product(s)
                  and Licensed Service(s) during such completed calendar
                  quarter, and resulting calculations of royalty payment due
                  XENO for such completed calendar quarter. Concurrent with the
                  making of each such report, AFFYMETRIX shall include payment
                  due XENO of royalties for the calendar quarter covered by such
                  report. The royalty will be solely due for the countries where
                  there is an issued XENO Patent and where a valid claim is in
                  effect.

         3.1.3.   [*].

         3.1.4.   Accounting. AFFYMETRIX agrees to keep and maintain records for
                  a period of three (3) years showing the manufacture, sale,
                  use, Net Sales and other income 


                                       6


* CERTAIN CONFIDENTIAL MATERIAL CONTAINED IN THIS DOCUMENT HAS BEEN OMITTED AND 
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 
24b-2 OF THE SECURITIES AND EXCHANGE COMMISSION ACT OF 1934, AS AMENDED.
<PAGE>   7
                  according to this Agreement. Such records will include general
                  ledger records showing cash receipts and expenses, and records
                  that include sufficient detail to enable the royalties payable
                  hereunder by AFFYMETRIX to be determined. AFFYMETRIX further
                  agrees to permit its relevant books and records to be examined
                  by XENO confidentially pursuant to the provisions herein, from
                  time to time from three (3) years from the date of a
                  transaction to the extent necessary to verify reports provided
                  for above. Such examination is to be made by XENO or its
                  designee, at the expense of XENO except in the event that the
                  results of a definitive audit reveal an underreporting of
                  royalties due XENO of five percent (5%) or more in any
                  calendar year, then the audit costs shall be paid by
                  AFFYMETRIX.

4. REPRESENTATIONS AND WARRANTIES

   4.1.  Representations and Warranties of AFFYMETRIX and XENO.

         Each party hereby represents and warrants:

         Corporate Power. Such party is duly organized and validly existing and
         in good standing under the laws of the state and/or country of its
         incorporation and has all requisite corporate power and authority to
         enter into this Agreement and to carry out the provisions hereof.

         Due Authorization. Such party is duly authorized to execute and deliver
         this Agreement and to perform its obligations hereunder.

         Binding Agreement. This Agreement is a legal and valid obligation
         binding upon it and enforceable in accordance with its terms. The
         execution, delivery and performance of this Agreement by such party
         does not conflict with any agreement, instrument or understanding, oral
         or written, to which it is a party or by which it may be bound, nor
         violate any law or regulation of any court, governmental body or
         administrative or other agency having jurisdiction over it.

   4.2   Harvard License Agreement. XENO represents and warrants that the
         Harvard License Agreement has not at the date hereof expired, been
         terminated by either XENO or the President and Fellows of Harvard
         College and that XENO has not at the date hereof received 


                                       7
<PAGE>   8
         nor given notice of termination for breach of the Harvard License
         Agreement. XENO represents and warrants to use best efforts to maintain
         the Harvard License Agreement, including, but not limited to complying
         with its obligations to pay the compensation due for the Harvard
         License Agreement. XENO agrees to notify AFFYMETRIX of any allegation
         by Harvard of XENO having breached the Harvard License Agreement. XENO
         warrants that to the best of its knowledge after reasonable inquiry it
         has the right under the Harvard License Agreement to make the grants
         herein.

   4.3   XENO represents and warrants that, under the non-Harvard owned patents
         referred to herein that it has the right to make the grants herein.
         XENO represents that it is not aware of patents owned or controlled by
         XENO other than those licensed herein which are needed or desirable to
         practice the methods licensed hereunder.



   4.4   Negation of Warranties

         Except as expressly set forth in this Agreement, XENO MAKES NO
         REPRESENTATIONS AND EXTENDS NO WARRANTIES OF ANY KIND, EITHER EXPRESS
         OR IMPLIED. THERE ARE NO EXPRESS OR IMPLIED WARRANTIES OF
         MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, OR THAT THE USE OF
         THE LICENSED PRODUCTS OR SERVICES WILL NOT INFRINGE ANY PATENT,
         COPYRIGHT, TRADEMARK, OR OTHER RIGHTS OR ANY OTHER EXPRESS OR IMPLED
         WARRANTIES.

   4.5   Infringement. AFFYMETRIX hereby agrees to notify XENO immediately of
         any claim it receives for alleged patent infringement by AFFYMETRIX of
         Third Party patents through and specifically directed to use of XENO
         Patents Licenses and Rights.


                                       8
<PAGE>   9
5. CONFIDENTIALITY

   5.1.  Confidential Information. Except as expressly provided herein, the
         parties agree that, for the Term and five (5) years thereafter, the
         receiving party shall keep completely confidential and shall not
         publish or otherwise disclose to another party and shall not use for
         any purpose other than to perform the purposes contemplated by this
         Agreement any Confidential Information furnished to it by the
         disclosing party hereto pursuant to this Agreement, except that to the
         extent that it can be established by the receiving party by competent
         proof that such Confidential Information:

                  was already known to the receiving party, other than under an
                  obligation of confidentiality, at the time of disclosure;

                  was generally available to the public or otherwise part of the
                  public domain at the time of its disclosure to the receiving
                  party;

                  became generally available to the public or otherwise part of
                  the public domain after its disclosure and other than through
                  any act or omission of the receiving party in breach of this
                  Agreement; or

                  was lawfully disclosed to the receiving party by a person
                  other than a party hereto, or was independently developed by
                  the receiving party.

   5.2.  Permitted Use and Disclosures. Each party hereto may use or disclose
         Confidential Information disclosed to it by the other party to the
         extent such use or disclosure is reasonably necessary in filing or
         prosecuting patent applications, prosecuting or defending litigation,
         complying with applicable law, governmental regulation or court order,
         submitting information to tax or other governmental authorities, making
         a permitted sublicense or otherwise exercising its rights hereunder,
         provided that if a party is required to make any such disclosure of
         another party's Confidential Information, other than pursuant to a
         confidentiality agreement, it will give reasonable advance notice to
         the latter party of such disclosure and, save to the extent
         inappropriate in the case of patent applications, will use reasonable
         efforts to secure confidential treatment of such information prior to
         its disclosure (whether through protective orders or otherwise).


                                       9
<PAGE>   10
   5.3.  Confidential Terms. Except as expressly provided herein, each party
         agrees not to disclose any material or financial terms of this
         Agreement to another party without the consent of the other party, not
         to be unreasonably withheld; provided, however, each party reserves the
         right to make reasonable disclosures (including the redaction of
         material or financial terms) as required by securities or other
         applicable laws, or to actual or prospective investors or corporate
         partners (including licensees and acquirers), or to accountants,
         attorneys and other professional advisors on a need-to-know basis under
         circumstances that ensure the confidentiality thereof, or to the extent
         required by law.

   5.4.  Press Release. Notwithstanding the foregoing, the parties shall agree
         upon a press release to announce the execution of this Agreement.
         Thereafter, XENO and AFFYMETRIX may each disclose to Third Parties the
         information contained in such press release without the need for
         further approval by the other.

6. TERMINATION

   6.1.  This Agreement shall continue until the last expiration date of all
         patents licensed under this Agreement.

   6.2.  Either party shall have the right to terminate this Agreement at any
         time for a material breach of this Agreement by the other party,
         provided that the non-breaching party shall have first given ninety
         (90) days prior written notice (thirty (30) days in the event of
         non-payment of any amounts due under this Agreement) to the breaching
         party describing such breach and stating the non-breaching party's
         intention to terminate this Agreement if such breach remains uncured,
         and the breaching party thereafter fails to cure same within thirty
         (30) days.

   6.3.  AFFYMETRIX may terminate this Agreement without cause at any time by
         providing written notice to XENO of such termination and such
         termination will be effective ninety (90) days thereafter. Any
         termination pursuant to Section 6.1.3 shall not relieve AFFYMETRIX of
         any obligation or liability accrued hereunder prior to such
         termination, including AFFYMETRIX's obligation to pay royalties accrued
         or accruable. The licenses granted under this agreement shall terminate
         in the event the Agreement is terminated by AFFYMETRIX or terminated by
         an arbitrator for an uncured breach by AFFYMETRIX.


7. MISCELLANEOUS
                                       10
<PAGE>   11

   7.1.  Binding Effect; Assignment. This Agreement shall be binding upon the
         parties' respective successors and permitted assigns. Neither party may
         assign this Agreement or any of its rights or obligations hereunder
         without the prior written consent of the other party (not to be
         unreasonably withheld), and any such attempted assignment shall be
         void; provided, that AFFYMETRIX and XENO may assign this Agreement as
         part of a merger or consolidation in which the surviving entity assumes
         all of AFFYMETRIX's and XENO's rights and obligations hereunder or a
         sale of substantially all of the assets of such party to which this
         Agreement relates. The parties agree that in the event of the
         termination of the Harvard License Agreement, the President and Fellows
         of Harvard College shall have the option of having rights in this
         Agreement as it relates to the Harvard License Agreement assigned to it
         or terminating the license from Harvard granted herein.

   7.2.  Effect of Waiver. No waiver of any default, condition, provisions or
         breach of this Agreement shall be deemed to imply or constitute a
         waiver of any other like default, condition, provision or breach of
         this Agreement.

   7.3.  Limitation of Liability. NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
         ANY SPECIAL, CONSEQUENTIAL, INCIDENTAL, OR INDIRECT DAMAGES ARISING OUT
         OF THIS AGREEMENT, HOWEVER CAUSED, UNDER ANY THEORY OF LIABILITY.

   7.4.  Indemnification. AFFYMETRIX will defend, indemnify and hold XENO, its
         officers, directors, employees, Affiliates and agents harmless against
         any and all liability, loss, damage, claim or expense (including
         attorney's fees) arising out of a suit by a Third Party from the
         performance under this Agreement by AFFYMETRIX; except to the extent
         such claim is caused by the negligence or willful misconduct of XENO or
         a breach of a representation of XENO. XENO will defend, indemnify and
         hold AFFYMETRIX, its officers, directors, employees, Affiliates and
         agents harmless against any and all liability, loss, damage, claim or
         expense (including attorney's fees) arising out of a suit by a Third
         Party from the performance under this Agreement by XENO; except to the
         extent such claim is caused by the negligence or willful misconduct of
         AFFYMETRIX or a breach of a representation of AFFYMETRIX.

   7.5.  Patent Defense Costs. XENO will use reasonable efforts, at its
         discretion to defend XENO patents at its own expense against any Third
         Party infringement. AFFYMETRIX at its 


                                       11
<PAGE>   12
         option may elect to join in any prosecution of Third Party infringer
         initiated by XENO at AFFYMETRIX's expense. In the event that AFFYMETRIX
         is sued by a Third Party for infringement of a Third Party's patent,
         XENO hereby agrees, if AFFYMETRIX so requests, to provide AFFYMETRIX
         with all reasonable advice or technical support that AFFYMETRIX may
         reasonably request at AFFYMETRIX's expense.

   7.6.  Patent Marking. AFFYMETRIX agrees reasonably to mark Licensed
         Product(s), covered by a product claim in the XENO device patents, (or
         their containers, labels or associated materials) made, sold, or
         otherwise disposed of by it under the license granted in this Agreement
         with issued Licensed Patent Numbers covering the Licensed Product(s).
         XENO shall from time to time provide AFFYMETRIX with issued Licensed
         Patent numbers and AFFYMETRIX will make reasonable efforts to adopt
         such markings within a reasonable time frame from such notice.

   7.7.  Diligence. AFFYMETRIX agrees to use best efforts to fulfill the
         obligations of the express due diligence provision of the Harvard
         License Agreement as it applies to a sublicense under the Harvard
         License Agreement.

   7.8.  Force Majeure. Neither party shall lose any rights hereunder or be
         liable to the other party for damages or losses (except for payment
         obligations) on account of failure of performance by the defaulting
         party if the failure is occasioned by war, strike, fire, act of God,
         earthquake, flood, lockout, embargo, governmental acts or orders or
         restrictions, failure of suppliers, or any other reason where failure
         to perform is beyond the reasonable control and not caused by the
         negligence or intentional conduct or misconduct of the nonperforming
         party, and such party has exerted all reasonable efforts to avoid or
         remedy such force majeure; provided, however, that in no event shall a
         party be required to settle any labor dispute or disturbance.

   7.9.  Amendment. No modification, supplement to or waiver of this Agreement
         or any Addendum hereto or any of their provisions shall be binding upon
         a party hereto unless made in writing and duly signed by an authorized
         representative of both XENO and AFFYMETRIX. In no event may the terms
         of this Agreement be changed, deleted, supplemented or waived by any
         notice, purchase order, receipt, acceptance, bill of lading or other
         similar form of document. A failure of either party to exercise any
         right or remedy hereunder, in whole or in part, or on one or more
         occasions, shall not be deemed either a waiver of such right or remedy
         to the extent not exercised, or of any other right or remedy, on such
         occasion or a waiver of any right or remedy on any succeeding occasion.


                                       12
<PAGE>   13
   7.10. Entire Agreement. This Agreement, and each Exhibit attached hereto, and
         each supplemental written agreement contemplated hereunder, sets forth
         the entire understanding and agreement of the parties as to the subject
         matter thereof, and there are no other understandings, representations
         or promises, written or verbal, not set forth herein or on which either
         party has relied. If any provisions of any such Addendum or
         supplemental written agreement conflict with any provisions set forth
         in this Agreement, the provisions of this Agreement shall take
         precedence, unless such Addendum or supplemental written agreement
         expressly refers to the specific provision(s) of this Agreement that it
         is intended to replace or modify (and which shall be limited in force
         and effect to such Addendum or supplemental written agreement only).

   7.11. Notices. All Notices under this Agreement shall be given in writing and
         shall be addressed to the parties at the following addresses:


                  For XENO:

                        President
                        Xenometrix, Inc.
                        2425 North 55th Street
                        Boulder, Colorado 80301-5700

                  For AFFYMETRIX:
                        President
                        Affymetrix, Inc.
                        3380 Central Expressway
                        Santa Clara, CA 95051

         Notices shall be in writing and shall be deemed delivered when
         received, if delivered by a courier, overnight mail service or the
         like, or a week following mailing, if sent by first-class certified or
         registered mail, postage prepaid.

   7.12. Arbitration. The parties recognize that disputes as to certain matters
         may from time to time arise during the term of this Agreement which
         relate to either party's rights and/or obligations hereunder. It is the
         objective of the parties to establish procedures to facilitate the
         resolution 


                                       13
<PAGE>   14
         of disputes arising under this Agreement in an expedient manner by
         mutual cooperation and without resort to arbitration. The parties agree
         that prior to any arbitration concerning this Agreement, XENO's CEO and
         AFFYMETRIX's CEO will meet in person or by video-conferencing in a good
         faith effort to resolve any disputes concerning this Agreement. Within
         thirty (30) days of a formal request by either party to the other, any
         party may, by written notice to the other, have such dispute referred
         to their respective officers designated or their successors, for
         attempted resolution by good faith negotiations, such good faith
         negotiations to begin within thirty (30) days after such notice is
         received. Except as otherwise provided specifically herein, any
         controversy or claim under this Agreement shall be solely settled by
         arbitration by one arbitrator pursuant to the Commercial Arbitration
         Rules of the American Arbitration Association (the "Association");
         provided that the parties shall first use their best efforts to resolve
         such dispute by negotiation. The arbitration shall be conducted in Salt
         Lake City, Utah. The arbitrator shall be selected by the joint
         agreement of the parties, but if they do not so agree within twenty
         (20) days of the date of a request for arbitration, the selection shall
         be made pursuant to the rules of the Association. The decision reached
         by the arbitrator shall be conclusive and binding upon the parties
         hereto and may be filed with the clerk of any court of competent
         jurisdiction, and a judgment confirming such decision may, if desired
         by any party to the arbitration, be entered in such court. Each of the
         parties shall pay its own expenses of arbitration and the expenses of
         the arbitrator(s) shall be equally shared; provided, however, that if
         in the opinion of the arbitrator(s) any claim hereunder or any defense
         or objection thereto was unreasonable, the arbitrator(s) may assess, as
         part of the award, all or any part of the arbitration expenses
         (including reasonable attorneys' fees) against the party raising such
         unreasonable claim, defense or objection. Nothing herein set forth
         shall prevent the parties from settling any dispute by mutual agreement
         at any time.

   7.13. Governing Law. This Agreement shall be governed by and construed in
         accordance with the laws of the State of Colorado, without regard or
         giving effect to its principles of conflict of laws.

   7.14. Severability and Survival. This Agreement is intended to be severable.
         If any provision(s) of this Agreement are or become invalid, are ruled
         illegal by a court of competent jurisdiction or are deemed
         unenforceable under the current applicable law from time to time in
         effect during the term hereof, it is the intention of the parties that
         the remainder of the Agreement shall not be affected thereby and shall
         continue to be construed to the maximum extent permitted by law at such
         time. It is further the intention of the parties that in lieu of each


                                       14
<PAGE>   15
         such provision which is invalid, illegal, or unenforceable, there shall
         be substituted or added as part of this Agreement by such court of
         competent jurisdiction 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, but shall
         be valid, legal and enforceable. Unless expressly stated otherwise, any
         provision intended by its meaning to survive, will survive the
         expiration or any other termination of this Agreement.

   7.15  Independent Contractors. The parties hereto are acting as independent
         contractors and shall not be considered partners, joint venturers or
         agents of the other. Neither shall have the right to act on behalf of,
         or to bind, the other.

   7.16  Headings. Captions and paragraph headings are for convenience only and
         shall not form an interpretative part of this Agreement. Unless
         otherwise specifically provided, all references to an Article
         incorporate all Articles or subsections thereunder. This Agreement
         shall not be strictly construed against either party hereto and maybe
         executed in two or more counterparts, each of which will be deemed an
         original and the same instrument.


                                       15
<PAGE>   16
   IN WITNESS WHEREOF, the parties have executed this Agreement.

By: /s/ Stephen J. Sullivan             Date: 9/30/98
    -------------------------------           -------
    Stephen J. Sullivan
    CEO and President
    For Xenometrix, Inc.





By: /s/ Stephen P.A. Fodor              Date: 9/29/98
    -------------------------------           -------
    Stephen P.A. Fodor
    President and CEO
    For Affymetrix, Inc.


                                       16
<PAGE>   17
EXHIBIT A



                            EUKARYOTIC GENE PROFILING

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
    PATENT/         FILING      COUNTRY      ISSUE                TITLE
 APPLICATION #       DATE                     DATE
--------------------------------------------------------------------------------
<S>                 <C>        <C>          <C>         <C>
   08/008,896       1/21/93        US       
--------------------------------------------------------------------------------
   5,811,231        7/21/95        US        9/22/98      METHODS AND KITS FOR
                                                        MAMMALIAN GENE PROFILING
--------------------------------------------------------------------------------
     612434         1/21/94     AUSTRALIA    6/11/98
--------------------------------------------------------------------------------
    E160178         1/21/94      AUSTRIA    11/12/97
--------------------------------------------------------------------------------
   0 680 517        1/21/94      BELGIUM    11/12/97
--------------------------------------------------------------------------------
    2154265         1/21/94      CANADA     
--------------------------------------------------------------------------------
   0 680 517        1/21/94      DENMARK    11/12/97
--------------------------------------------------------------------------------
   0 680 517        1/21/94        EPC      11/12/97
--------------------------------------------------------------------------------
   0 680 517        1/21/94      FRANCE     11/12/97
--------------------------------------------------------------------------------
694 06 772.5-08     1/21/94      GERMANY    11/12/97
--------------------------------------------------------------------------------
   980400301        1/21/94      GREECE     11/12/97
--------------------------------------------------------------------------------
   0 680 517                    HONG KONG   
--------------------------------------------------------------------------------
     E77394         1/21/94      IRELAND    11/12/97
--------------------------------------------------------------------------------
   20035BE/98       1/21/94       ITALY     11/12/97
--------------------------------------------------------------------------------
    6-517147        1/21/94       JAPAN     
--------------------------------------------------------------------------------
   0 680 517        1/21/94    LUXEMBOURG   11/12/97
--------------------------------------------------------------------------------
   0 680 517        1/21/94      MONACO     11/12/97
--------------------------------------------------------------------------------
   0 680 517        1/21/94    NETHERLANDS  11/12/97
--------------------------------------------------------------------------------
   US94/00583       1/21/94        PCT      
--------------------------------------------------------------------------------
   0 680 517        1/21/94     PORTUGAL    1/19/98
--------------------------------------------------------------------------------
   9601405-5        2/13/96     SINGAPORE   
--------------------------------------------------------------------------------
   0 680 517        1/21/94       SPAIN     11/12/97
--------------------------------------------------------------------------------
   0 680 517        1/21/94      SWEDEN     11/12/97
--------------------------------------------------------------------------------
   0 680 517        1/21/94    SWITZERLAND  11/12/97
--------------------------------------------------------------------------------
   0 680 517        1/21/94        UK       11/12/97
--------------------------------------------------------------------------------
</TABLE>


                                       17
<PAGE>   18
                                           
Procaryotic Gene Profiling

EP 651,825, granted January 14, 1998, filed July 6, 1993 
priority July 6, 1992
USSN 08/231,990, filed April 21, 1994, now US 5,585,232, 
issued December 17, 1996 
USSN 08/374,641, filed July 21, 1995, now US 5,589,337 
USSN 07/910,793, filed July 6, 1992 (now abandoned) 
Singapore 9601688-6, filed February 14, 1996
Canada 2,13,9,667, filed July 6, 1993 
Korea 95-700038, filed July 6, 1993
Australia 45884/93, filed July 6, 1993 
Norway 95.0040, filed July 6, 1993.


                                       18
<PAGE>   19
                                    EXHIBIT B
                            HARVARD LICENSE AGREEMENT


                                       19