EXHIBIT 3.1.1

                            CERTIFICATE OF AMENDMENT
                                     OF THE
                AMENDED AND RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                             LYNX THERAPEUTICS, INC.


         Lynx Therapeutics, Inc., a corporation organized and existing under and
by virtue of the General  Corporation Law of the State of Delaware,  DOES HEREBY
CERTIFY:

         FIRST:  The name of the  corporation  is Lynx  Therapeutics,  Inc. (the
"Corporation").

         SECOND:  The date on which  the  Certificate  of  Incorporation  of the
Corporation first was filed with the Secretary of State of the State of Delaware
is February 18, 1992.

         THIRD: The Board of Directors, acting in accordance with the provisions
of Section 242 of the General Corporation Law of the State of Delaware,  adopted
resolutions to amend Article 4 of the Restated  Certificate of  Incorporation of
the Corporation to read in its entirety as follows:

                                       "4.

                  A. This  Corporation  is  authorized  to issue two  classes of
         shares to be  designated,  respectively,  "Common Stock" and "Preferred
         Stock." The total number of shares which the  Corporation is authorized
         to issue is Twenty-two  Million  (22,000,000)  shares.  Twenty  Million
         (20,000,000)  shares shall be Common  Stock,  par value one cent ($.01)
         per share (the "Common Stock") and Two Million (2,000,000) shares shall
         be Preferred Stock, par value one cent ($.01) per share (the "Preferred
         Stock")."

                  B. The shares of  Preferred  Stock may be issued  from time to
         time in one or more series.  The Board of Directors of the  corporation
         is expressly  authorized  to provide for the issue of all or any of the
         shares of Preferred Stock in one or more series,  and to fix the number
         of shares and to determine  or alter for each such series,  such voting
         powers,  full or limited,  or no voting powers,  and such designations,
         preferences, and relative, participating, optional, or other rights and
         such qualifications,  limitations or restrictions  thereof, as shall be
         stated and expressed in the  resolution or  resolutions  adopted by the
         Board of Directors providing for the issue of such shares and as may be
         permitted by the General Corporation Law of the State of Delaware.  The
         Board of Directors is also expressly authorized to increase or decrease
         (but not below the number of shares of such  series  then  outstanding)
         the number of shares of any series

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         subsequent to the issue of shares of that series. In case the number of
         shares  of  any  such  series  shall  be  so   decreased,   the  shares
         constituting  such decrease shall resume the status that they had prior
         to the  adoption  of the  resolution  originally  fixing  the number of
         shares of such series.

         FOURTH: Thereafter, pursuant to a resolution of the Board of Directors,
this  Certificate  of  Amendment  was  submitted  to  the  stockholders  of  the
Corporation  for their approval and approved by the  stockholders  in accordance
with  Sections  228 and  242 of the  General  Corporation  Law of the  State  of
Delaware.

         IN WITNESS WHEREOF, Lynx Therapeutics, Inc. has caused this Certificate
of  Amendment  to be signed by its Chief  Executive  Officer and attested by its
Secretary this 23rd day of December, 1996.

                                           LYNX THERAPEUTICS, INC.


                                           /s/ Sam Eletr
                                           -------------------------------------
                                           Sam Eletr, Ph.D.
                                           Chief Executive Officer


ATTEST:


 /s/ James C. Kitch
----------------------------------
James C. Kitch
Secretary


                                       2.