UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 SCHEDULE 13G/A

                  UNDER THE SECURITIES EXCHANGE ACT OF 1934
                        (AMENDMENT NO. 1 - EXIT FILING)*

                                  NANOGEN, INC.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                    COMMON STOCK, PAR VALUE $0.001 PAR SHARE
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                   630075 10 9
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                                DECEMBER 31, 2004
--------------------------------------------------------------------------------
            (Date of Event Which Requires Filing of this Statement)


Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

|_|  Rule 13d-1(b)

[X]  Rule 13d-1(c)

|_|  Rule 13d-1(d)


       *The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which could
alter the disclosures provided in a prior cover page.

       The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).



                                Page 1 of 9 Pages






                                      13G/A

----------------------                                --------------------------
CUSIP NO. 630075 10 9                                      PAGE 2 OF 9 PAGES
----------------------                                --------------------------


--------------------------------------------------------------------------------
 1   NAME OF REPORTING PERSON
     S.S. or I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

           Sage Capital Growth, Inc.

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

 2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                           (a)  |X|
                                                           (b)  |_|

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

 3   SEC USE ONLY

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

 4   CITIZENSHIP OR PLACE OF ORGANIZATION

           New York

--------------------------------------------------------------------------------
                  5  SOLE VOTING POWER
NUMBER OF    
SHARES               0
BENEFICIALLY      --------------------------------------------------------------
OWNED BY          6  SHARED VOTING POWER
EACH         
REPORTING            142,993 shares of Common Stock
PERSON            --------------------------------------------------------------
WITH              7  SOLE DISPOSITIVE POWER
             
                     0
                  --------------------------------------------------------------
                  8  SHARED DISPOSITIVE POWER

                     See Row 6 above
--------------------------------------------------------------------------------

 9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           See Row 6 above

--------------------------------------------------------------------------------
 10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*[_]   

--------------------------------------------------------------------------------
 11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

     0.4% as of December 31, 2004. (Based on 33,892,892 shares of Common
     Stock issued and outstanding as reported in the Issuer's Quarterly
     Report on Form 10-Q dated November 11, 2004.)

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

 12  TYPE OF REPORTING PERSON *

           CO

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



                               Page 2 of 9 Pages




                                      13G/A

----------------------                                 -------------------------
CUSIP NO. 630075 10 9                                      PAGE 3 OF 9 PAGES
----------------------                                 -------------------------



--------------------------------------------------------------------------------
 1   NAME OF REPORTING PERSON
     S.S. or I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

           Mainfield Enterprises, Inc.

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

 2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                           (a)  |X|
                                                           (b)  |_|

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

 3   SEC USE ONLY

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

 4   CITIZENSHIP OR PLACE OF ORGANIZATION

           British Virgin Island

--------------------------------------------------------------------------------
                  5  SOLE VOTING POWER
NUMBER OF    
SHARES               0
BENEFICIALLY      --------------------------------------------------------------
OWNED BY          6  SHARED VOTING POWER
EACH         
REPORTING            142,993 shares of Common Stock
PERSON            --------------------------------------------------------------
WITH              7  SOLE DISPOSITIVE POWER
             
                     0
                  --------------------------------------------------------------
                  8  SHARED DISPOSITIVE POWER

                     See Row 6 above
--------------------------------------------------------------------------------

 9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           See Row 6 above

--------------------------------------------------------------------------------
 10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*[_]   

--------------------------------------------------------------------------------
 11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

     0.4% as of December 31, 2004. (Based on 33,892,892 shares of Common
     Stock issued and outstanding as reported in the Issuer's Quarterly
     Report on Form 10-Q dated November 11, 2004.)

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

 12  TYPE OF REPORTING PERSON*

           CO

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


                               Page 3 of 9 Pages


This is the final amendment to this Schedule 13G and an exit filing with respect
to each Reporting Person listed in Item 2(a).

ITEM 1.

      (a)   Name of Issuer

            NANOGEN, INC.

      (b)   Address of Issuer's Principal Executive Offices:

            10398 Pacific Center Court

            San Diego, CA 92121

ITEM 2.

      (a)   Name of Persons Filing:

            Sage Capital Growth, Inc. ("Sage")
            Mainfield Enterprises, Inc. ("Mainfield")

      (b)   Address of Principal Business Office:

            Sage:
            660 Madison Avenue, 18th floor
            New York, New York  10021

            Mainfield:
            Icaza, Gonzalez-Ruiz & Aleman (BVI) Trust Limited, Wickhams Cay I,
            Vanterpool Plaza
            P.O. Box 873, Road Town
            Tortolla, British Virgin Islands

      (c)   Citizenship:

            Sage:
            New York

            Mainfield:
            British Virgin Islands

      (d)   Title of Class of Securities:

            Common Stock, par value $0.001 per share

      (e)   CUSIP Number:
            630075 10 9

                               Page 4 of 9 Pages


ITEM 3.   IF THIS STATEMENT IS FILED PURSUANT TO RULE 13D-1(B), OR
          13D-2(B), CHECK WHETHER THE PERSON FILING IS A:

      (a) |_|  Broker or dealer registered under section 15 of the Act (15
               U.S.C. 78o).

      (b) |_|  Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

      (c) |_|  Insurance company as defined in section 3(a)(19) of the Act (15
               U.S.C. 78c).

      (d) |_|  Investment company registered under section 8 of the Investment
               Company Act of 1940 (15 U.S.C 80a-8).

      (e) |_|  An investment adviser in accordance with
               Section 240.13d-1(b)(1)(ii)(E);

      (f) |_|  An employee benefit plan or endowment fund in accordance with
               Section 240.13d-1(b)(1)(ii)(F);

      (g) |_|  A parent holding company or control person in accordance with
               Section 240.13d-1(b)(1)(ii)(G);

      (h) |_|  A savings associations as defined in Section 3(b) of the Federal
               Deposit Insurance Act (12 U.S.C. 1813);

      (i) |_|  A church plan that is excluded from the definition of an
               investment company under section 3(c)(14) of the Investment
               Company Act of 1940 (15 U.S.C. 80a-3);

      (j) |_|  Group, in accordance with Section 240.13d-1(b)(1)(ii)(J).


ITEM 4.     OWNERSHIP

      (a)   Amount Beneficially Owned

            142,993 shares of Common Stock

      (b)   Percent of Class

            0.4% as of December 31, 2004. (Based on 33,892,892 shares of Common
            Stock issued and outstanding as reported in the Issuer's Quarterly
            Report on Form 10-Q dated November 11, 2004.)

      (c)   Number of shares as to which the person has:

            (i) Sole power to vote or direct the vote:

                0

            (ii) Shared power to vote or direct the vote:

                               Page 5 of 9 Pages


                 See Item 4(a) above.

          (iii)  Sole power to dispose or to direct the disposition of:

                 0

           (iv)  Shared power to dispose or to direct the disposition of:

                 See Item 4(a) above.

ITEM 5.     OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

            If this statement is being filed to report the fact that as of the
            date hereof the reporting person has ceased to be the beneficial
            owner of more than five percent of the class of securities, check
            the following |X|.

ITEM 6.     OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON

            Not applicable.

ITEM 7.     IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH
            ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING
            COMPANY

            Inapplicable

ITEM 8.     IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP


            See the Joint Filing Agreement attached hereto as an Exhibit.

ITEM 9.     NOTICE OF DISSOLUTION OF THE GROUP

            Inapplicable

ITEM 10.    CERTIFICATION


                               Page 6 of 9 Pages


            By signing below I certify that, to the best of my knowledge and
            belief, the securities referred to above were not acquired and are
            not held for the purpose of or with the effect of changing or
            influencing the control of the issuer of the securities and were not
            acquired and are not held in connection with or as a participant in
            any transaction having that purpose or effect.



                               Page 7 of 9 Pages







                                    SIGNATURE

      After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


Dated this 14th day of February, 2005


SAGE CAPITAL GROWTH, INC.


By: /s/ Avi Vigder
    ---------------------------------
    Name: Avi Vigder
    Title: Authorized Signatory


MAINFIELD ENTERPRISES, INC.


By: By: /s/ Avi Vigder
    ---------------------------------
    Name: Avi Vigder
    Title: Authorized Signatory



                               Page 8 of 9 Pages




                             JOINT FILING AGREEMENT

       In accordance  with rule  13d-1(k)(1) of the  Securities  Exchange Act of
1934,  as amended,  the  undersigned  hereby agree to the joint filing with each
other of the attached statement on Schedule 13G, and all amendments thereto, and
that such statement,  and all amendments  thereto,  is made on behalf of each of
them.

       IN WITNESS  WHEREOF,  the  undersigned  hereby executed this agreement on
February 14, 2005.

                                         Sage Capital Growth, Inc.

                                           /s/ Avi Vigder
                                         ---------------------------------------
                                         Name:   Avi Vigder
                                         Title:  Authorized Signatory


                                         Mainfield Enterprises, Inc.

                                          /s/ Avi Vigder
                                         ---------------------------------------
                                         Name:   Avi Vigder
                                         Title:  Authorized Signatory


                               Page 9 of 9 Pages