Document:

<PAGE>   1
                                                                   EXHIBIT 10.23

          Confidential Materials omitted and filed separately with the
        Securities and Exchange Commission. Asterisks denote omissions.

       SIXTH AMENDMENT TO PROGRESS SOFTWARE APPLICATION PARTNER AGREEMENT

SIXTH AMENDMENT to the Progress Software Corporation Application Partner
Agreement is effective as of the 26th day of October, 1999 ("Effective Date"),
by and between Progress Software Corporation, a Massachusetts corporation with
its principal place of business at 14 Oak Park, Bedford, Massachusetts 01730
("PSC") and RSA Security Inc. (formerly known as Security Dynamics Inc.), a
Massachusetts corporation with its principal place of business at 20 Crosby
Drive, Bedford, Massachusetts 01730 ("AP").

         WHEREAS, PSC and AP entered into a Progress Software Application
Partner Agreement effective as of December 5, 1994 (the "Agreement"); and

         WHEREAS, PSC and AP previously amended the Agreement by entering into
the Progress Software Application Partner Agreement Addendum effective as of
December 5, 1994 (the "Addendum") and a subsequent amendment to the Agreement
dated as of October 19, 1995 (the "Amendment");

         WHEREAS, PSC and AP entered into a Second Amendment to the Agreement
dated as of November 29, 1995 (the "Second Amendment") which completely
superseded the terms and conditions of the earlier Addendum and Amendment and
specified new special pricing and distribution terms and conditions in an
Attachment A relating to certain PSC products distributed by AP or AP's
distributors in conjunction with AP's PROGRESS(R)-based applications; and

         WHEREAS, PSC and AP entered into a Third Amendment to the Agreement
dated as of November 15, 1996 (the "Third Amendment") specifying certain
additional modifications to the terms and conditions of the Agreement and
replacing the Attachment A incorporated by reference into the Second Amendment
with a new Attachment A including modified special pricing and distribution
terms and conditions relating to certain PSC products distributed by AP or AP's
distributors in conjunction with AP's PROGRESS(R)-based applications; and

         WHEREAS, PSC and AP entered into a Fourth Amendment to the Agreement
dated as of April 1, 1998 (the "Fourth Amendment") identifying the PSC products
that AP has the right to distribute to accomplish the AP customer configuration
for AP's PROGRESS(R)-based application and specifying additional modifications
to the special pricing and distribution terms and conditions set forth in
Attachment A to the Third Amendment; and

         WHEREAS, PSC and AP entered into a Fifth Amendment to the Agreement
dated as of February 18, 1999 (the "Fifth Amendment") whereby PSC granted, and
AP accepted, a license to use, distribute, OEM and sub-license the Progress
Database in AP's Public Key Infrastructure ("PKI") Products; and

         WHEREAS, PSC and AP desire to further amend the terms and conditions of
the Agreement and the prior Amendments to specify certain additional terms and
conditions pertaining to AP's ordering of additional quantities of PSC products,
and AP's use and distribution of said PSC products,

         NOW, THEREFORE, for good and valuable consideration, the receipt and
adequacy of which is hereby acknowledged, the parties hereto agree as follows:

<PAGE>   2

          Confidential Materials omitted and filed separately with the
        Securities and Exchange Commission. Asterisks denote omissions.

1.       Subject to the existing requirements as set forth in the previous
         Amendments and the Agreement and in consideration for AP paying to PSC,
         according to the payment terms as further specified herein, the
         non-refundable sum of [**] PSC agrees to provide AP with an [**]
         allowance against license and maintenance fees for deployment licenses,
         on HPUX, AIX, NT and Solaris platforms, for the following Progress
         product configuration:

         Progress ProVISION (up to 16 users)
         Progress Enterprise Database
         Progress Client Networking
         Progress Server Networking
         Progress E/SQL

         PSC warrants that the PSC products listed above, in versions 8.3 or
         above and on HPUX, AIX, NT and Solaris platforms, are Year 2000 Ready
         as specified in the Year 2000 Warranty listed in Exhibit A attached
         hereto and made a part hereof.

         Except for Progress ProVISION, AP's distribution of such PSC products
         shall not be limited to any certain number of users, provided that, for
         each deployment of the above-mentioned Progress product configuration,
         or portion thereof, to an AP customer in conjunction with the AP
         Progress-based applications described herein, the number of users
         authorized to use such PSC products shall not exceed the number of
         users authorized to use AP's Progress-based application(s).
         Furthermore, and consistent with, PSC's then-current maintenance
         policies and procedures, and so long as AP purchases maintenance in
         conjunction with its distribution of such PSC products, PSC will
         provide to AP new releases of the above listed PSC products in
         accordance with the provisions specified in Section 4 of Attachment A
         to the Third Amendment.

         Payment terms shall be as follows:

         [**]              due by [**]
         [**]              due by [**]
         [**]              due by [**]

         AP shall have the right to distribute all or part of the above Progress
         products for each AP customer license for any one or more of the AP
         Progress-based applications currently identified as follows:

                  ACE/Server
                  RSA Keon Certificate Server
                  RSA Advanced Public Key Infrastructure ("PKI")
                  Keon Unix Platform Security

2.       The license and maintenance royalties from any balance remaining of the
         prior [**] allowance as specified in the Fourth Amendment shall
         continue to be calculated at the same license and maintenance royalty
         rates outlined in such Fourth Amendment. Once AP has completely used
         all of the [**] allowance mentioned above, the royalty percentage rate
         for the [**] pre-paid allowance described herein shall be set at a
         license royalty rate of [**] and a maintenance royalty rate also of
         [**].

<PAGE>   3

          Confidential Materials omitted and filed separately with the
        Securities and Exchange Commission. Asterisks denote omissions.

3.       The parties agree that, upon depletion of this initial [**] allowance,
         AP may either:

         a.       extend the term of this Sixth Amendment for an additional term
                  of [**] for the same product royalty rate of [**] and the same
                  maintenance royalty rate also of [**], provided AP pays to PSC
                  an up-front, non-refundable, pre-payment of an additional
                  [**], and provided such pre-payment occurs either prior to
                  expiration of this Sixth Amendment or upon the depletion of
                  this initial [**], whichever occurs first; or

         b.       if, after the depletion of this initial [**] allowance, AP has
                  not extended the term of this Sixth Amendment as described in
                  3(a) above, then, the product and maintenance royalty rates
                  shall revert back to the rates as specified in the Fourth
                  Amendment of [**] for product licenses and [**] for
                  maintenance. Payment to PSC for such additional royalties in
                  the absence of an extension of this Sixth Amendment will be
                  due and payable to PSC upon receipt of AP's required monthly
                  deployment report. Payment to PSC would only be required for
                  AP products licensed that contain the PSC products identified
                  herein. AP's right to distribute the PSC products pursuant to
                  this option 3(b) would commence on the expiration of this
                  Sixth Amendment or upon depletion of the [**] allowance,
                  whichever occurs first, and would expire [**] from such date.
                  After such [**] period, AP's right to distribute PSC's
                  products referenced hereunder shall be subject to PSC's
                  then-current prices, practices and policies regarding the
                  distribution of PSC's products, and subject to the provisions
                  specified in Section 6 of the Third Amendment.

4.       AP will continue to provide to PSC monthly deployment reports detailing
         the number of licenses sold and maintenance dates as required under the
         previous Amendments and the Agreement. PSC will continue to accrue
         against AP's pre-paid royalties upon receipt of such reports.

5.       Subject to the extensions provisions specified in Section 3(a) above,
         the term of this Sixth Amendment shall commence as of the Effective
         Date defined above, and shall continue in force for a period of four
         (4) years.

6.       Except as specifically modified or amended by this Sixth Amendment, the
         terms and conditions of the Agreement (as previously amended by the
         Fifth, Fourth, Third and Second Amendments thereto) shall remain in
         full force and effect until the termination of the Agreement. No other
         modifications or additions are made to the Agreement. The Agreement,
         Sixth, Fifth, Fourth, Third, Second and First Amendments constitutes
         the entire agreement between the parties with respect to the subject
         matter hereof. In the event of any conflict among the terms and
         conditions of the Agreement, the Second Amendment, Third Amendment,
         Fourth Amendment, Fifth Amendment or this Sixth Amendment, the order of
         precedence shall be: first, this Sixth Amendment, second the Fifth
         Amendment, third the Fourth Amendment, fourth, the Third Amendment,
         fifth, the Second Amendment (which completely supersedes the earlier
         Addendum and Amendment) and sixth and finally, the Agreement.

<PAGE>   4

         IN WITNESS WHEREOF, this Sixth Amendment has been executed under seal
for and on behalf of each of the parties hereto by their duly authorized
representative as of the date first set forth above.

PROGRESS SOFTWARE CORPORATION                        RSA SECURITY INC.

By:  /s/ David Vesty                        By:  /s/ Arthur W. Coviello, Jr.
Name: David Vesty                           Name: Arthur W. Coviello, Jr.
Title:  VP of Worldwide Sales               Title:  President

<PAGE>   5

                                    EXHIBIT A

Year 2000 Warranty: PSC warrants that the Software (as hereinafter defined) is
capable of accurately processing, providing and/or receiving date data from,
into, and between the twentieth and twenty-first centuries, provided that (a)
the Software is used in accordance with the documentation accompanying the
Software and PSC's Year 2000 documentation generally available at the time of
delivery of the Software, (b) all software, hardware and firmware used in
conjunction with the Software supply date data to the Software and retrieve date
data from the Software in accordance with the requirements specified in the
documentation accompanying the Software and the Year 2000 documentation
generally available at the time of delivery of the Software, (c) there have been
no unauthorized modifications to the Software, (d) AP is using the most current
version of 8.3 or above of the Software, (e) AP is not currently in default of
any of its material obligations hereunder, and (f) the Software is under PSC's
maintenance program (the "Year 2000 Warranty"). In no event, shall the Year 2000
Warranty apply to claims of noncompliance arising from: (i) the design of a
particular software application created using the Software, (ii) the misuse of
the Software in connection with development or implementation of any software
application, or (iii) the AP's underlying operating system, file system,
database, hardware or firmware, or any software not supplied by PSC.

Software Covered: For the purposes of this Section, the term "Software" shall
mean the following PSC products, in version 8.3 and above, on HPUX, AIX, NT and
Solaris platforms:

         Progress ProVISION
         Progress Enterprise Database
         Progress Client Networking
         Progress Server Networking
         Progress E/SQL

Prerequisites for Claim of Breach: PSC shall be in breach of the Year 2000
Warranty only if:

         (a)      AP provides PSC with written notice via certified mail of a
                  claim that the Software (or any updates or new releases
                  thereto) fail to conform to the Year 2000 Warranty within one
                  hundred eighty (180) days of initial delivery of the Software
                  or one hundred eighty (180) days of the delivery of any
                  updates or new releases thereto;

Cooperation: AP agrees to provides reasonable assistance to PSC in identifying
and remedying any non-conformance, including, without limitation, providing hard
copy documentation of the non-conformance, providing PSC with remote dial-in
access, conducting additional computer runs to duplicate the non-conformance,
allowing PSC access to data files, listing and console logs.

Remedies/Limits of Liability: The remedies available to AP for breach of the
Year 2000 Warranty shall be limited to PSC's commercially reasonable efforts to
repair or replacement of any Software or part thereof whose non-conformance with
the Year 2000 Warranty is discovered and made known to PSC in accordance with
the notice requirements specified in subpart (a) above, or in the event, in
PSC's reasonable opinion, such repair or replacement is not reasonably
practicable, PSC shall refund to AP the license fees paid by AP for the Software
which is the subject of the claimed breach.

Notwithstanding anything to the contrary herein, the Year 2000 Warranty shall
apply only to the initial copy of the Software, and to any updates or new
releases to the Software, delivered to AP. The purchase of additional licenses
of the same version of the Software by AP shall not extend the term of the Year
2000 Warranty. The completion of upgrades to the Software, such as increased
user or agent counts, machine transfers, or operating platform transfers, shall
not extend the term of the Year 2000 Warranty unless such upgrades result in the
delivery of a different version of the Software to AP.<PAGE>   1

EXHIBIT 4.2

NEITHER THESE SECURITIES NOR THE SECURITIES ISSUABLE UPON EXERCISE HAVE BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY APPLICABLE STATE
SECURITIES LAWS. SUCH SECURITIES MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR
HYPOTHECATED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT WITH RESPECT
TO THE SECURITIES UNDER SUCH ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE
COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED OR UNLESS SOLD PURSUANT TO RULE
144 OF SUCH ACT. ANY SUCH TRANSFER MAY ALSO BE SUBJECT TO APPLICABLE STATE
SECURITIES LAWS.

                             GENOMETRIX INCORPORATED
                                     WARRANT

         FOR VALUE RECEIVED, GENOMETRIX INCORPORATED, a Delaware corporation
(the "Company"), hereby certifies that ______________ (the "Holder", which term
shall include any subsequent holder hereof) is entitled to purchase from the
Company fully paid and nonassessable shares (subject to adjustment as provided
below) of the Capital Stock (as defined below), determined as provided herein.

         This Warrant has been issued pursuant to a Note and Warrant Purchase
Agreement of dated as of January 24, 1996 between the Company and the Holder
(the "Agreement"). Hereinafter, (i) "Capital Stock," "Conversion Date",
"Financing" and "Purchase Price" shall have the respective meanings set forth in
the Convertible Note (the "Convertible Note") issued contemporaneously herewith,
and (ii) the shares of Capital Stock purchasable hereunder are referred to as
the "Warrant Shares," (iii) the aggregate purchase price payable for the Warrant
Shares hereunder is referred to as the "Aggregate Warrant Price," and (iv) the
price payable for each of the Warrant Shares hereunder is referred to as the
"Per Share Warrant Price."

         1.       EXERCISE OF WARRANT.

         (a) This Warrant may be exercised, in whole at any time or in part from
time to time by the Holder commencing on the Conversion Date and prior to 5:00
p.m., The Woodlands, Texas time, on the later of (1) [THREE YEARS FROM DATE OF
ISSUE] or (2) the first (1st) anniversary of the Conversion Date, by the
surrender of this Warrant (with the subscription form at the end hereof duly
executed) at the address set forth in Section 8 hereof, together with proper
payment of the Aggregate Warrant Price made by certified or official bank check
payable to the order of the Company.

         (b) This Warrant shall be exercisable for that number of shares as
equals six tenths

                                      -1-

<PAGE>   2

(.6) times the number of shares of Capital Stock determined by dividing (i) the
sum of the outstanding principal amount of the Convertible Note and all accrued
but unpaid interest thereon as of the Conversion Date by (ii) the Purchase Price
per such share of Capital Stock, subject to adjustment as provided herein, and
the Per Share Warrant Price shall be equal to the Purchase Price per share,
subject to adjustment as provided herein.

         (c) If this Warrant is exercised in part, this Warrant must be
exercised for a number of whole shares of the Capital Stock, and the holder is
entitled to receive a new Warrant covering the Warrant Shares as to which this
Warrant has not been exercised. Upon exercise of this Warrant, the Company will
(i) issue a certificate or certificates in the name of the holder for the
largest number of whole shares of the Capital Stock to which the holder shall be
entitled, and (ii) deliver the other securities and properties receivable upon
the exercise of this Warrant.

         2. RESERVATION OF WARRANT SHARES. The Company agrees that, prior to the
expiration of this Warrant, the Company will at all times have authorized and in
reserve, and will keep available, solely for issuance or delivery upon the
exercise of this Warrant, the shares of the Capital Stock and other securities
and properties as from time to time shall be receivable upon the exercise of
this Warrant, free and clear of all restrictions on sale or transfer and free
and clear of all preemptive rights and rights of first refusal.

         3. ADJUSTMENTS OF PER SHARE WARRANT PRICE.

         (a) In case the Company shall, after the Conversion Date (i) pay a
dividend or make a distribution on its Capital Stock in shares of Capital Stock,
(ii) subdivide its outstanding shares of Capital Stock into a greater number of
shares (by a stock split or otherwise), (iii) combine its outstanding shares of
Capital Stock into a smaller number of shares (by a reverse stock split or
otherwise) or (iv) issue by reclassification of its Capital Stock any shares of
capital stock of the Company (whether or not Capital Stock), the Per Share
Warrant Price shall be adjusted so that the holder upon the exercise hereof
shall be entitled to receive the number of shares of Capital Stock or other
capital stock of the Company which it would have owned immediately following
such action had such Warrant been exercised immediately prior thereto. An
adjustment made pursuant to this Section 3(a) shall become effective on the
record date in the case of a dividend or distribution and shall become effective
on the effective date in the case of a subdivision, combination or
reclassification.

         (b) In case of any capital reorganization or reclassification, or any
consolidation or merger to which the Company is a party other than a merger or
consolidation in which the Company is the continuing corporation, or in case of
any sale or conveyance to another entity of the property of the Company as an
entirety or substantially as a entirety, or in the case of any statutory
exchange of securities with another corporation (including any exchange effected
in connection with a merger of a third corporation into the Company) (which
consolidation, merger, sale, conveyance and statutory exchange is referred to
below as a "Sale"), the Holder of this Warrant shall have the right thereafter
to receive on the exercise of this Warrant the kind and

                                      -2-
<PAGE>   3

amount of securities, cash or other property which the Holder would have owned
or have been entitled to receive immediately after such reorganization or
reclassification (as if such transaction had already occurred for the Purchase
Price contemplated in such reorganization or reclassification as the value
attributable to each share of Common Stock by the Company's Board of Directors
in the reorganization or reclassification approved thereby) or Sale had this
Warrant been exercised immediately prior to the effective date of such
reorganization, reclassification or Sale and in any such case, if necessary,
appropriate adjustment shall be made in the application of the provisions set
forth in this Section 3 with respect to the rights and interests thereafter of
the Holder of this Warrant to the end that the provisions set forth in this
Section 3 shall thereafter correspondingly be made applicable, as nearly as may
reasonably be, in relation to any shares of stock or other securities or
property thereafter deliverable on the exercise of this Warrant. The above
provisions of this Section 3(b) shall similarly apply to successive
reorganizations, reclassifications or Sales. The issuer of any shares of stock
or other securities or property thereafter deliverable on the exercise of this
Warrant shall be responsible for all of the agreements and obligations of the
Company hereunder. Notice of any such reorganization, reclassification or Sale
and of said provisions so proposed to be made, shall be mailed to the Holder not
less than thirty (30) days prior to such event. In the event of an anticipated
Sale, the Company or the entity assuming the obligations of the Company
hereunder may (i) upon written notice to the Holder, provide that this Warrant
must be exercised, to the extent then exercisable, within thirty (30) days of
the date of such notice, at the end of which period this Warrant shall terminate
(but if and only if such Sale shall be consummated); or (ii) terminate this
Warrant in exchange for a cash payment equal to the excess of the current market
price of the Warrant Shares subject to this Warrant (to the extent then
exercisable) over the Per Share Warrant Price thereof (but if and only if such
Sale shall be consummated).

         (c) If the Board of Directors of the Company shall declare any dividend
or other distribution with respect to any Capital Stock of the Company, the
Company shall mail notice thereof to the Holder not less than fifteen (15) days
prior to the record date fixed for determining stockholders entitled to
participate in such dividend or other distribution.

         (d) If, as a result of an adjustment made pursuant to this Section 3,
the Holder after surrender of this Warrant for exercise shall become entitled to
receive shares of two or more classes of capital stock of the Company, the Board
of Directors (whose determination shall be conclusive and shall be described in
a written notice to the Holder promptly after such adjustment) shall determine
the allocation of the adjusted Per Share Warrant Price between or among shares
or such classes of capital stock.

         4. FULLY PAID STOCK. The Company agrees that the shares of the Capital
Stock represented by each and every certificate for Warrant Shares delivered on
the exercise of this Warrant shall, at the time of such delivery, be validly
issued and outstanding, fully paid and nonassessable, and not subject to
preemptive rights or rights of first refusal, and the Company will take all such
actions as may be necessary to assure that the par value or stated value, if
any, per share of the Capital Stock is at all times equal to or less than the
then Per Share Warrant

                                      -3-
<PAGE>   4

Price.

         5. LOSS, ETC., OF WARRANT. Upon receipt of evidence reasonably to the
Company of the loss, theft, destruction or mutilation of this Warrant, and of
indemnity reasonably satisfactory to the Company, if lost, stolen or destroyed,
and upon surrender and cancellation of this Warrant, if mutilated, the Company
shall execute and deliver to the Holder a new Warrant of like date, tenor and
denomination.

         6. WARRANT HOLDER NOT STOCKHOLDER. Except as otherwise provided herein,
this Warrant does not confer upon the Holder any right to vote or to consent to
or receive notice as a stockholder of the Company, as such, in respect of any
matters whatsoever, or any other rights or liabilities as a stockholder, prior
to the exercise hereof.

         7. COVENANTS OF WARRANT HOLDER. By acceptance of this Warrant, the
Holder is hereby deemed to covenant and agree with the Company:

         (a) that it is acquiring this Warrant as an investment and not with a
view to distribution hereof. The holder of this Warrant or any Warrant Shares
may transfer this Warrant or such Warrant Shares only pursuant to applicable
Federal and state laws. Each registered Holder of this Warrant acknowledges that
this Warrant has not been registered under the Securities Act of 1933, as
amended (or any successor legislation) (the "Securities Act") and agrees not to
sell, pledge, distribute, offer for sale, transfer or otherwise dispose of this
Warrant or any Warrant Shares issued upon its exercise in the absence of (i) an
effective registration statement as to this Warrant or such Warrant Shares under
the Securities Act, or (ii) an opinion of counsel reasonably acceptable to the
Company to the effect that such registration is not, under the circumstances,
required. In addition, in order for any transferee of this Warrant or any
Warrant Shares to receive any of the benefits of this Warrant or the Warrant
Shares, as the case may be, the Company must have received notice of such
transfer, at the address set forth in Section 8 below, in the form of assignment
or partial assignment attached hereto. Any transferee other than pursuant to an
effective registration statement under the Securities Act or pursuant to Rule
144 promulgated under the Securities Act must also covenant and agree that it is
acquiring this Warrant or such Warrant Shares as an investment and not with a
view to distribution hereof or thereof, except in accordance with the Securities
Act and applicable state securities law; and

         (b) it will not sell, transfer or otherwise dispose of any securities
of the Company during the period commencing upon the date upon which the Company
files a registration statement with the Securities and Exchange Commission for
the registration of any securities for sale to the public and terminating on the
180th day following the date on which the Company's registration statement with
respect to its initial public offering is declared effective, except pursuant to
any written registration rights agreement with the Company.

         8. NOTICES. All notices, requests, consents and demands shall be made
in writing and shall be mailed postage prepaid, or delivered by hand, to the
Company or to the Holder

                                      -4-
<PAGE>   5

thereof at their respective addresses set forth below or to such other address
as may be furnished in writing to the other party hereto:

                  If to the Holder:     ------------------
                                        ------------------
                                        ------------------
                                        ------------------

                  If to the Company:    Genometrix Incorporated
                                        3608 Research Forest Drive, Suite B7
                                        The Woodlands, TX 77381
                                        Attention:   Mitchell D. Eggers
                                                     President

All notices, requests, consents and other communications hereunder shall be
deemed to have been given either (i) if by hand, at the time of the delivery
thereof to the receiving party at the address of such party set forth above,
(ii) if made by telex, telecopy or facsimile transmission, at the time that
receipt thereof has been acknowledged by electronic confirmation or otherwise,
(iii) if sent by overnight courier,on the next business day following the day
such notice is delivered to the courier service, or (iv) if sent by registered
or certified mail, on the 5th business day following the day such mailing is
made.

         9. HEADINGS. The headings of this Warrant have been inserted as a
matter of convenience and shall not affect the construction hereof.

         10. APPLICABLE LAW. This Warrant shall be governed by and construed in
accordance with the law of the State of Texas without giving effect to the
principles of conflicts of law thereof.

         11. AMENDMENT. The terms of this Warrant may be amended or modified or
waiver of compliance of any term hereof may be obtained only in a writing signed
by the Company and the Holder.

                  [Remainder of Page Left Intentionally Blank]

                                      -5-
<PAGE>   6

                  IN WITNESS WHEREOF, the Company has caused this Warrant to be
signed by its President and its corporate seal to be hereunto affixed and
attested by its Secretary effective as of ________________.

                                       GENOMETRIX INCORPORATED

                                       By:
                                          --------------------------------------
                                          Mitchell D. Eggers
                                          President

ATTEST:

---------------------------------
         Secretary

[Corporate Seal]

                                      -6-

<PAGE>   7

                                  SUBSCRIPTION

         The undersigned, ___________________, pursuant to the provisions of the
foregoing Warrant, hereby agrees to subscribe for and purchase
____________________ shares (the "Warrant Shares") of ___________, $.__ par
value per share, of Genometrix Incorporated covered by said Warrant, and makes
payment therefor in full at the price per share provided by said Warrant.

         (a) The undersigned represents that the address of the undersigned
furnished below is the undersigned's principal business address.

         (b) The undersigned (i) was not formed for the purpose of investing in
the Company, (ii) is acquiring the Warrant Shares for its own account for
investment and not with a view to or for resale in connection with any
distribution or resale of the Warrant Shares except in accordance with the
Securities Act of 1933, as amended (or any successor statute) (the "Securities
Act") and applicable state securities laws, and (iii) has not offered or sold
any portion of the Warrant Shares and has no present intention of dividing the
Warrant Shares with others or of selling, distributing or otherwise disposing of
any portion of the Warrant Shares either currently or after the passage of a
fixed or determinable period of time or upon the occurrence or non-occurrence of
any predetermined event or circumstance, except in accordance with the
Securities Act and applicable state securities laws.

         (c) The undersigned understands that (i) the sale of the Warrant Shares
has not been registered under the Securities Act or any state securities law in
reliance upon an exemption therefrom for non-public or limited offerings, (ii)
the Warrant Shares must be held indefinitely unless the sale or other transfer
thereof is subsequently registered under the Securities Act or an exemption from
such registration is available at the time, and (iii) the Company has no
obligation to register the Warrant Shares.

         (d) The undersigned understands and agrees that the following
restrictions and limitations are applicable to its purchase and any resales,
pledges, hypothecations or other transfers of the Warrant Shares:

                  (i) The following legend (or a legend in substantially similar
         form) will be placed on any certificate(s) or other document(s)
         evidencing the Warrant Shares, and the undersigned must comply with the
         terms and conditions set forth in such legend prior to any resales,
         pledges, hypothecations or other transfers of the Warrant Shares:

                  "The securities represented by this certificate have not been
                  registered pursuant to the Securities Act of 1933, as amended
                  ("Act"), or any state securities laws, and may not be sold,
                  pledged, hypothecated or otherwise transferred unless (A) the
                  stockholder wishing to transfer such securities provides an
                  opinion of counsel in form and substance reasonably
                  satisfactory to Genometrix Incorporated (the

                                      -7-
<PAGE>   8

                  "Company") stating that the proposed transfer of the Company's
                  securities is exempt from the registration provisions of all
                  applicable federal and state laws; or (B) said securities are
                  registered pursuant to the Act and all applicable state
                  securities laws.

                  (ii) Stop transfer instructions have been or will be placed on
         any certificates or other documents evidencing the Warrant Shares so as
         to restrict the resale, pledge, hypothecation or other transfer thereof
         in accordance with the provisions hereof.

         (e) The undersigned's representations and warranties made herein shall
survive the execution and delivery hereof and of the Warrant Shares.

Dated:                              Signature:
      ------------------                      ----------------------------------

                                    Address:
                                            ------------------------------------

                                      -8-
<PAGE>   9

LIST OF PURCHASERS

PURCHASER                                ISSUE DATE
---------                                ----------

Palmetto Partners, Ltd.                  January 26, 1996

Palmetto Partners, Ltd.                  April 8, 1996

Palmetto Partners, Ltd.                  May 13, 1996

Palmetto Partners, Ltd.                  August 5, 1996

Donald R. Kendall and Dianne S.          January 26, 1996
Kendall, JTWROS

Donald R. Kendall and Dianne S.          April 8, 1996
Kendall, JTWROS

Donald R. Kendall and Dianne S.          May 13, 1996
Kendall, JTWROS

Donald R. Kendall and Dianne S.          August 5, 1996
Kendall, JTWROS

                                      -9-

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00003-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00003-of-00352.parquet"}]]