As filed with the Securities and Exchange Commission on April 7, 2000
                                                    Registration No. 333-

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



                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  -------------

                                    FORM S-8
                             REGISTRATION STATEMENT

                                      UNDER
                           THE SECURITIES ACT OF 1933

                                  -------------

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


             DELAWARE                                           77-0319159
  (State or other jurisdiction                                 (IRS Employer
of incorporation or organization)                            Identification No.)

                             3380 CENTRAL EXPRESSWAY
                              SANTA CLARA, CA 95051
               (Address of principal executive offices) (Zip Code)

                                  -------------

                                AFFYMETRIX, INC.

                         GMS/AFFYMETRIX 1998 STOCK PLAN
                            (Full title of the Plan)

                                  -------------

                                  VERN NORVIEL
         SENIOR VICE PRESIDENT, GENERAL COUNSEL and CORPORATE SECRETARY
                                AFFYMETRIX, INC.
                             3380 CENTRAL EXPRESSWAY
                              SANTA CLARA, CA 95051
                     (Name and address of agent for service)

                                 (408) 731-5000
          (Telephone number, including area code, of agent for service)

                                  -------------


<PAGE>

<TABLE>
<CAPTION>
                                                   CALCULATION OF REGISTRATION FEE
====================================================================================================================================


                                                                          Proposed Maximum     Proposed Maximum
                                                        Amount to be     Offering Price per   Aggregate Offering       Amount of
      Title of Securities to be Registered              Registered(1)         Share(2)             Price(2)        Registration Fee
----------------------------------------------------- ------------------ ------------------- --------------------- -----------------
<S>                                                         <C>               <C>                <C>                    <C>
Options                                                     N/A                  N/A                  N/A                 N/A
Common Stock (par value $.01), together with attached
rights to purchase Series B Junior Participating
Preferred Stock                                             65,828            $37.82509          $2,489,950.34          $657.35

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

<FN>
(1)  This Registration Statement covers shares of Common Stock of Affymetrix, Inc. and the attached rights to purchase Series B
     Junior Participating Preferred Stock of Affymetrix, Inc. which may be offered or sold pursuant to the GMS/Affymetrix 1998
     Stock Plan. This Registration Statement shall also cover any additional shares of Common Stock which become issuable under
     the GMS/Affymetrix 1998 Stock Plan by reason of any stock dividend, stock split, recapitalization or other similar
     transaction effected without the receipt of consideration which results in an increase in the number of the outstanding
     shares of Common Stock of Affymetrix, Inc.

(2)  Calculated solely for purposes of this offering under Rule 457(h) of the Securities Act of 1933, as amended, based upon the
     price at which the options may be exercised. The aggregate exercise price for all shares being registered pursuant to this
     Registration statement is equal to $2,489,950.34, and the weighted exercise price for those shares is $37.82509.
</FN>
</TABLE>

<PAGE>



                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


Item 3.   INCORPORATION OF DOCUMENTS BY REFERENCE

          Affymetrix, Inc. (the "Registrant") hereby incorporates by reference
          into this Registration Statement the following documents previously
          filed with the Securities and Exchange Commission (the "SEC"):

          a.   The Registrant's Annual Report on Form 10-K for the fiscal year
               ended December 31, 1999;

          b.   (1)  The Registrant's Current Report on Form 8-K, filed with the
                    SEC on February 11, 2000;

               (2)  The Registrant's Current Report on Form 8-K, filed with the
                    SEC on April 7, 2000;

          c.   The Registrant's Registration Statement No. 0-28218 on Form 8-A
               filed with the SEC on April 16, 1996 pursuant to Section 12 of
               the Securities Exchange Act of 1934, as amended (the "1934 Act"),
               together with amendments thereto, in which there is described the
               terms, rights and provisions applicable to the Registrant's
               outstanding Common Stock;

         All reports and definitive proxy or information statements filed
pursuant to Section 13(a), 13(c), 14 or 15(d) of the 1934 Act after the date of
this Registration Statement and prior to the filing of a post-effective
amendment which indicates that all securities offered hereby have been sold or
which deregisters all securities then remaining unsold shall be deemed to be
incorporated by reference into this Registration Statement and to be a part
hereof from the date of filing of such documents.



<PAGE>



Item 4.  DESCRIPTION OF SECURITIES

         Not Applicable.

Item 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

         Not Applicable.

Item 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporation law empowers a Delaware
corporation to indemnify any persons who are, or are threatened to be made,
parties to any threatened, pending or completed legal action, suit or
proceedings, whether civil, criminal, administrative or investigative (other
than by or in the right of such corporation), by reason of the fact that such
person was an officer or director of such corporation, or is or was serving at
the request of such corporation as a director, officer, employee or agent of
another corporation or enterprise. Then indemnity may include expenses
(including attorneys' fees), judgements, fines and amounts paid in settlement
actually and reasonably incurred by such person in connection with such action,
suit or proceeding, provided that such officer or director acted in good faith
and in a manner he reasonably believed to be in or not opposed to the
corporation's best interests, and, for criminal proceedings, had no reasonable
cause to believe his conduct was illegal. A Delaware corporation may indemnify
officers and directors in an action by or in the right of the corporation under
the same conditions, except that no indemnification is permitted without
judicial approval if the officer or director is adjudged to be liable to the
corporation in the performance of his duty. Where an officer or director is
successful on the merits or otherwise in the defense of any action referred to
above, the corporation must indemnify he or she against the expenses which such
officer or director actually and reasonably incurred.

         In accordance with Delaware law, Registrant's restated certificate of
incorporation contains a provision to limit the personal liability of
Registrant's directors for violations of their fiduciary duty as a director.
This provision eliminates each director's liability to Registrant or
Registrant's stockholders for monetary damages except (i) for any breach of the
director's duty of loyalty to Registrant or Registrant's stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the Delaware General
Corporation law providing for liability of directors for unlawful payment of
dividends or unlawful stock purchases or redemptions, or (iv) for any
transaction from which a director derived an improper personal benefit. The
effect of this provision is to eliminate the personal liability of directors for
monetary damages for actions involving a breach of their fiduciary duty of care,
including any such actions involving gross negligence.

         Registrant's restated certificate of incorporation and bylaws provide
for indemnification of its officers and directors to the fullest extended
permitted by applicable law.

         Registrant has entered into indemnification agreements with each
director and executive officer which provide indemnification to such directors
and executive officers under certain circumstances for acts or omissions which
may not be covered by directors' and officers' liability insurance.

Item 7.  EXEMPTION FROM REGISTRATION CLAIMED

         Not Applicable.

Item 8.  EXHIBITS


     Exhibit Number     Exhibit
     --------------     -------

            4           Instrument Defining Rights of Stockholders. Reference is
                        made to Registrant's Registration Statement No. 0-28218
                        on Form 8-A, together with amendments thereto, which is
                        incorporated herein by reference pursuant to Item 3(e)
                        of this Registration Statement.



                                      II-2

<PAGE>




            5           Opinion and consent of Sullivan & Cromwell

          23.1          Consent of Ernst & Young LLP Independent Auditors

          23.2          Consent of Sullivan & Cromwell is contained in
                        Exhibit 5.

           24           Power of Attorney. Reference is made to page II-4 of
                        this Registration Statement.

          99.1          Genetic MicroSystems, Inc. 1998 Stock Option Plan

          99.2          Amendment of the Genetic MicroSystems, Inc. 1998 Stock
                        Option Plan

Item 9.  UNDERTAKINGS

              A. The undersigned Registrant hereby undertakes: (1) to file,
         during any period in which offers or sales are being made, a
         post-effective amendment to this Registration Statement (i) to include
         any prospectus required by Section 10(a)(3) of the 1933 Act, (ii) to
         reflect in the prospectus any facts or events arising after the
         effective date of this Registration Statement (or the most recent
         post-effective amendment thereof) which, individually or in the
         aggregate, represent a fundamental change in the information set forth
         in this Registration Statement and (iii) to include any material
         information with respect to the plan of distribution not previously
         disclosed in this Registration Statement or any material change to such
         information in this Registration Statement; provided, however, that
         clauses (1)(i) and (1)(ii) shall not apply if the information required
         to be included in a post-effective amendment by those paragraphs is
         contained in periodic reports filed by the Registrant pursuant to
         Section 13 or Section 15(d) of the 1934 Act that are incorporated by
         reference into this Registration Statement; (2) that for the purpose of
         determining any liability under the 1933 Act each such post-effective
         amendment shall be deemed to be a new registration statement relating
         to the securities offered therein and the offering of such securities
         at that time shall be deemed to be the initial bona fide offering
         thereof and (3) to remove from registration by means of a
         post-effective amendment any of the securities being registered which
         remain unsold at the termination of the Registrant's 1998 Stock
         Incentive Plan.

              B. The undersigned Registrant hereby undertakes that, for purposes
         of determining any liability under the 1933 Act, each filing of the
         Registrant's annual report pursuant to Section 13(a) or Section 15(d)
         of the 1934 Act that is incorporated by reference into this
         Registration Statement shall be deemed to be a new registration
         statement relating to the securities offered therein, and the offering
         of such securities at that time shall be deemed to be the initial bona
         fide offering thereof.

              C. Insofar as indemnification for liabilities arising under the
         1933 Act may be permitted to directors, officers or controlling persons
         of the Registrant pursuant to the indemnification provisions summarized
         in Item 6 or otherwise, the Registrant has been advised that, in the
         opinion of the SEC, such indemnification is against public policy as
         expressed in the 1933 Act, and is, therefore, unenforceable. In the
         event that a claim for indemnification against such liabilities (other
         than the payment by the Registrant of expenses incurred or paid by a
         director, officer or controlling person of the Registrant in the
         successful defense of any action, suit or proceeding) is asserted by
         such director, officer or controlling person in connection with the
         securities being registered, the Registrant will, unless in the opinion
         of its counsel the matter has been settled by controlling precedent,
         submit to a court of appropriate jurisdiction the question whether such
         indemnification by it is against public policy as expressed in the 1933
         Act and will be governed by the final adjudication of such issue.



                                      II-3

<PAGE>



                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8, and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Santa Clara, State of California on this 7th
day of April 2000.

                                            AFFYMETRIX,  INC.


                                            By:  /s/ Vern Norviel
                                                -------------------------
                                                Vern Norviel
                                                Senior Vice President, General
                                                Counsel and Corporate Secretary




                                      II-4

<PAGE>
                                POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS:

         That the undersigned officers and directors of Affymetrix, Inc., a
Delaware corporation, do hereby constitute and appoint Stephen P.A. Fodor and
Vern Norviel, and either of them, the lawful attorneys-in-fact and agents with
full power and authority to do any and all acts and things and to execute any
and all instruments which said attorneys and agents, and either one of them,
determine may be necessary or advisable or required to enable said corporation
to comply with the Securities Act of 1933, as amended, and any rules or
regulations or requirements of the Securities and Exchange Commission in
connection with this Registration Statement. Without limiting the generality of
the foregoing power and authority, the powers granted include the power and
authority to sign the names of the undersigned officers and directors in the
capacities indicated below to this Registration Statement, to any and all
amendments, both pre-effective and post-effective, and supplements to this
Registration Statement, and to any and all instruments or documents filed as
part of or in conjunction with this Registration Statement or amendments or
supplements thereof, and either of the undersigned hereby ratifies and confirms
all that said attorneys and agents, or either one of them, shall do or cause to
be done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

         IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated.

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

Signature                                   Title                        Date
---------                                   -----                        ----

/s/ Stephen P.A. Fodor
---------------------------  Chief Executive Officer and Chairman     March 2000
Stephen P.A. Fodor, Ph.D.    of the Board

/s/ Edward Hurwitz
---------------------------  Vice President and Chief Financial       March 2000
Edward M. Hurwitz            Officer (Principal Financial and
                             Accounting Officer)

/s/ Paul Berg
---------------------------  Director                                 March 2000
Paul Berg, Ph.D.

/s/ John D. Diekman
---------------------------  Director                                 March 2000
John D. Diekman, Ph.D.


---------------------------  Director                                 March 2000
Adrian Hennah

/s/ Vernon R. Loucks, Jr.
---------------------------  Director                                March  2000
Vernon R. Loucks, Jr.

/s/ Barry C. Ross
---------------------------  Director                                 March 2000
Barry C. Ross, Ph.D.

/s/ David B. Singer
---------------------------  Director                                 March 2000
David B. Singer

/s/ Lubert Stryer
---------------------------  Director                                 March 2000
Lubert Stryer, M.D.

/s/ John A. Young
---------------------------  Director                                 March 2000
John A. Young

                                      II-5
<PAGE>



                                  EXHIBIT INDEX




     Exhibit Number     Exhibit
     --------------     -------

            4           Instrument Defining Rights of Stockholders. Reference is
                        made to Registrant's Registration Statement No. 0-28218
                        on Form 8-A, together with amendments thereto, which is
                        incorporated herein by reference pursuant to Item 3(e)
                        of this Registration Statement.

            5           Opinion and Consent of Sullivan & Cromwell

          23.1          Consent of Ernst & Young, LLP, Independent Auditors

          23.2          Consent of Sullivan & Cromwell is contained in
                        Exhibit 5.

           24           Power of Attorney. Reference is made to page II-4 of
                        this Registration Statement.

          99.1          Genetic MicroSystems, Inc. 1998 Stock Option Plan

          99.2          Amendment of the Genetic MicroSystems, Inc. 1998 Stock
                        Option Plan
[{"type": "S-8", "sequence": "1", "description": "REGISTRATION STATEMENT ON FORM S-8", "secsgml_size_bytes": 19662}]
{"company-data": {"conformed-name": "AFFYMETRIX INC", "cik": "0000913077", "assigned-sic": "8731", "irs-number": "770319159", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-34320", "film-number": "596252"}, "business-address": {"street1": "3380 CENTRAL EXPRESSWAY", "city": "SANTA CLARA", "state": "CA", "zip": "95051", "phone": "4085226000"}, "mail-address": {"street1": "3380 CENTRAL EXPRESSWAY", "city": "SANTA CLARA", "state": "CA", "zip": "95051"}}
As filed with the Securities and Exchange Commission on April 7, 2000
                                                    Registration No. 333-

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

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  -------------

                                    FORM S-8
                             REGISTRATION STATEMENT

                                      UNDER
                           THE SECURITIES ACT OF 1933

                                  -------------

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

             DELAWARE                                           77-0319159
  (State or other jurisdiction                                 (IRS Employer
of incorporation or organization)                            Identification No.)

                             3380 CENTRAL EXPRESSWAY
                              SANTA CLARA, CA 95051
               (Address of principal executive offices) (Zip Code)

                                  -------------

                                AFFYMETRIX, INC.

                         GMS/AFFYMETRIX 1998 STOCK PLAN
                            (Full title of the Plan)

                                  -------------

                                  VERN NORVIEL
         SENIOR VICE PRESIDENT, GENERAL COUNSEL and CORPORATE SECRETARY
                                AFFYMETRIX, INC.
                             3380 CENTRAL EXPRESSWAY
                              SANTA CLARA, CA 95051
                     (Name and address of agent for service)

                                 (408) 731-5000
          (Telephone number, including area code, of agent for service)

                                  -------------
CALCULATION OF REGISTRATION FEE
====================================================================================================================================

                                                                          Proposed Maximum     Proposed Maximum
                                                        Amount to be     Offering Price per   Aggregate Offering       Amount of
      Title of Securities to be Registered              Registered(1)         Share(2)             Price(2)        Registration Fee
----------------------------------------------------- ------------------ ------------------- --------------------- -----------------
Options                                                     N/A                  N/A                  N/A                 N/A
Common Stock (par value $.01), together with attached
rights to purchase Series B Junior Participating
Preferred Stock                                             65,828            $37.82509          $2,489,950.34          $657.35

====================================================================================================================================
(1)  This Registration Statement covers shares of Common Stock of Affymetrix, Inc. and the attached rights to purchase Series B
     Junior Participating Preferred Stock of Affymetrix, Inc. which may be offered or sold pursuant to the GMS/Affymetrix 1998
     Stock Plan. This Registration Statement shall also cover any additional shares of Common Stock which become issuable under
     the GMS/Affymetrix 1998 Stock Plan by reason of any stock dividend, stock split, recapitalization or other similar
     transaction effected without the receipt of consideration which results in an increase in the number of the outstanding
     shares of Common Stock of Affymetrix, Inc.

(2)  Calculated solely for purposes of this offering under Rule 457(h) of the Securities Act of 1933, as amended, based upon the
     price at which the options may be exercised. The aggregate exercise price for all shares being registered pursuant to this
     Registration statement is equal to $2,489,950.34, and the weighted exercise price for those shares is $37.82509.
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.   INCORPORATION OF DOCUMENTS BY REFERENCE

          Affymetrix, Inc. (the "Registrant") hereby incorporates by reference
          into this Registration Statement the following documents previously
          filed with the Securities and Exchange Commission (the "SEC"):

          a.   The Registrant's Annual Report on Form 10-K for the fiscal year
               ended December 31, 1999;

          b.   (1)  The Registrant's Current Report on Form 8-K, filed with the
                    SEC on February 11, 2000;

               (2)  The Registrant's Current Report on Form 8-K, filed with the
                    SEC on April 7, 2000;

          c.   The Registrant's Registration Statement No. 0-28218 on Form 8-A
               filed with the SEC on April 16, 1996 pursuant to Section 12 of
               the Securities Exchange Act of 1934, as amended (the "1934 Act"),
               together with amendments thereto, in which there is described the
               terms, rights and provisions applicable to the Registrant's
               outstanding Common Stock;

         All reports and definitive proxy or information statements filed
pursuant to Section 13(a), 13(c), 14 or 15(d) of the 1934 Act after the date of
this Registration Statement and prior to the filing of a post-effective
amendment which indicates that all securities offered hereby have been sold or
which deregisters all securities then remaining unsold shall be deemed to be
incorporated by reference into this Registration Statement and to be a part
hereof from the date of filing of such documents.
Item 4.  DESCRIPTION OF SECURITIES

         Not Applicable.

Item 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

         Not Applicable.

Item 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporation law empowers a Delaware
corporation to indemnify any persons who are, or are threatened to be made,
parties to any threatened, pending or completed legal action, suit or
proceedings, whether civil, criminal, administrative or investigative (other
than by or in the right of such corporation), by reason of the fact that such
person was an officer or director of such corporation, or is or was serving at
the request of such corporation as a director, officer, employee or agent of
another corporation or enterprise. Then indemnity may include expenses
(including attorneys' fees), judgements, fines and amounts paid in settlement
actually and reasonably incurred by such person in connection with such action,
suit or proceeding, provided that such officer or director acted in good faith
and in a manner he reasonably believed to be in or not opposed to the
corporation's best interests, and, for criminal proceedings, had no reasonable
cause to believe his conduct was illegal. A Delaware corporation may indemnify
officers and directors in an action by or in the right of the corporation under
the same conditions, except that no indemnification is permitted without
judicial approval if the officer or director is adjudged to be liable to the
corporation in the performance of his duty. Where an officer or director is
successful on the merits or otherwise in the defense of any action referred to
above, the corporation must indemnify he or she against the expenses which such
officer or director actually and reasonably incurred.

         In accordance with Delaware law, Registrant's restated certificate of
incorporation contains a provision to limit the personal liability of
Registrant's directors for violations of their fiduciary duty as a director.
This provision eliminates each director's liability to Registrant or
Registrant's stockholders for monetary damages except (i) for any breach of the
director's duty of loyalty to Registrant or Registrant's stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the Delaware General
Corporation law providing for liability of directors for unlawful payment of
dividends or unlawful stock purchases or redemptions, or (iv) for any
transaction from which a director derived an improper personal benefit. The
effect of this provision is to eliminate the personal liability of directors for
monetary damages for actions involving a breach of their fiduciary duty of care,
including any such actions involving gross negligence.

         Registrant's restated certificate of incorporation and bylaws provide
for indemnification of its officers and directors to the fullest extended
permitted by applicable law.

         Registrant has entered into indemnification agreements with each
director and executive officer which provide indemnification to such directors
and executive officers under certain circumstances for acts or omissions which
may not be covered by directors' and officers' liability insurance.

Item 7.  EXEMPTION FROM REGISTRATION CLAIMED

         Not Applicable.

Item 8.  EXHIBITS

     Exhibit Number     Exhibit
     --------------     -------

            4           Instrument Defining Rights of Stockholders. Reference is
                        made to Registrant's Registration Statement No. 0-28218
                        on Form 8-A, together with amendments thereto, which is
                        incorporated herein by reference pursuant to Item 3(e)
                        of this Registration Statement.

                                      II-2
5           Opinion and consent of Sullivan & Cromwell

          23.1          Consent of Ernst & Young LLP Independent Auditors

          23.2          Consent of Sullivan & Cromwell is contained in
                        Exhibit 5.

           24           Power of Attorney. Reference is made to page II-4 of
                        this Registration Statement.

          99.1          Genetic MicroSystems, Inc. 1998 Stock Option Plan

          99.2          Amendment of the Genetic MicroSystems, Inc. 1998 Stock
                        Option Plan

Item 9.  UNDERTAKINGS

              A. The undersigned Registrant hereby undertakes: (1) to file,
         during any period in which offers or sales are being made, a
         post-effective amendment to this Registration Statement (i) to include
         any prospectus required by Section 10(a)(3) of the 1933 Act, (ii) to
         reflect in the prospectus any facts or events arising after the
         effective date of this Registration Statement (or the most recent
         post-effective amendment thereof) which, individually or in the
         aggregate, represent a fundamental change in the information set forth
         in this Registration Statement and (iii) to include any material
         information with respect to the plan of distribution not previously
         disclosed in this Registration Statement or any material change to such
         information in this Registration Statement; provided, however, that
         clauses (1)(i) and (1)(ii) shall not apply if the information required
         to be included in a post-effective amendment by those paragraphs is
         contained in periodic reports filed by the Registrant pursuant to
         Section 13 or Section 15(d) of the 1934 Act that are incorporated by
         reference into this Registration Statement; (2) that for the purpose of
         determining any liability under the 1933 Act each such post-effective
         amendment shall be deemed to be a new registration statement relating
         to the securities offered therein and the offering of such securities
         at that time shall be deemed to be the initial bona fide offering
         thereof and (3) to remove from registration by means of a
         post-effective amendment any of the securities being registered which
         remain unsold at the termination of the Registrant's 1998 Stock
         Incentive Plan.

              B. The undersigned Registrant hereby undertakes that, for purposes
         of determining any liability under the 1933 Act, each filing of the
         Registrant's annual report pursuant to Section 13(a) or Section 15(d)
         of the 1934 Act that is incorporated by reference into this
         Registration Statement shall be deemed to be a new registration
         statement relating to the securities offered therein, and the offering
         of such securities at that time shall be deemed to be the initial bona
         fide offering thereof.

              C. Insofar as indemnification for liabilities arising under the
         1933 Act may be permitted to directors, officers or controlling persons
         of the Registrant pursuant to the indemnification provisions summarized
         in Item 6 or otherwise, the Registrant has been advised that, in the
         opinion of the SEC, such indemnification is against public policy as
         expressed in the 1933 Act, and is, therefore, unenforceable. In the
         event that a claim for indemnification against such liabilities (other
         than the payment by the Registrant of expenses incurred or paid by a
         director, officer or controlling person of the Registrant in the
         successful defense of any action, suit or proceeding) is asserted by
         such director, officer or controlling person in connection with the
         securities being registered, the Registrant will, unless in the opinion
         of its counsel the matter has been settled by controlling precedent,
         submit to a court of appropriate jurisdiction the question whether such
         indemnification by it is against public policy as expressed in the 1933
         Act and will be governed by the final adjudication of such issue.

                                      II-3
SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8, and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Santa Clara, State of California on this 7th
day of April 2000.

                                            AFFYMETRIX,  INC.

                                            By:  /s/ Vern Norviel
                                                -------------------------
                                                Vern Norviel
                                                Senior Vice President, General
                                                Counsel and Corporate Secretary

                                      II-4
POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS:

         That the undersigned officers and directors of Affymetrix, Inc., a
Delaware corporation, do hereby constitute and appoint Stephen P.A. Fodor and
Vern Norviel, and either of them, the lawful attorneys-in-fact and agents with
full power and authority to do any and all acts and things and to execute any
and all instruments which said attorneys and agents, and either one of them,
determine may be necessary or advisable or required to enable said corporation
to comply with the Securities Act of 1933, as amended, and any rules or
regulations or requirements of the Securities and Exchange Commission in
connection with this Registration Statement. Without limiting the generality of
the foregoing power and authority, the powers granted include the power and
authority to sign the names of the undersigned officers and directors in the
capacities indicated below to this Registration Statement, to any and all
amendments, both pre-effective and post-effective, and supplements to this
Registration Statement, and to any and all instruments or documents filed as
part of or in conjunction with this Registration Statement or amendments or
supplements thereof, and either of the undersigned hereby ratifies and confirms
all that said attorneys and agents, or either one of them, shall do or cause to
be done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

         IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated.

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

Signature                                   Title                        Date
---------                                   -----                        ----

/s/ Stephen P.A. Fodor
---------------------------  Chief Executive Officer and Chairman     March 2000
Stephen P.A. Fodor, Ph.D.    of the Board

/s/ Edward Hurwitz
---------------------------  Vice President and Chief Financial       March 2000
Edward M. Hurwitz            Officer (Principal Financial and
                             Accounting Officer)

/s/ Paul Berg
---------------------------  Director                                 March 2000
Paul Berg, Ph.D.

/s/ John D. Diekman
---------------------------  Director                                 March 2000
John D. Diekman, Ph.D.

---------------------------  Director                                 March 2000
Adrian Hennah

/s/ Vernon R. Loucks, Jr.
---------------------------  Director                                March  2000
Vernon R. Loucks, Jr.

/s/ Barry C. Ross
---------------------------  Director                                 March 2000
Barry C. Ross, Ph.D.

/s/ David B. Singer
---------------------------  Director                                 March 2000
David B. Singer

/s/ Lubert Stryer
---------------------------  Director                                 March 2000
Lubert Stryer, M.D.

/s/ John A. Young
---------------------------  Director                                 March 2000
John A. Young

                                      II-5
EXHIBIT INDEX

     Exhibit Number     Exhibit
     --------------     -------

            4           Instrument Defining Rights of Stockholders. Reference is
                        made to Registrant's Registration Statement No. 0-28218
                        on Form 8-A, together with amendments thereto, which is
                        incorporated herein by reference pursuant to Item 3(e)
                        of this Registration Statement.

            5           Opinion and Consent of Sullivan & Cromwell

          23.1          Consent of Ernst & Young, LLP, Independent Auditors

          23.2          Consent of Sullivan & Cromwell is contained in
                        Exhibit 5.

           24           Power of Attorney. Reference is made to page II-4 of
                        this Registration Statement.

          99.1          Genetic MicroSystems, Inc. 1998 Stock Option Plan

          99.2          Amendment of the Genetic MicroSystems, Inc. 1998 Stock
                        Option Plan