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                                                               Exhibit 10.40(1a)

                  FIRST AMENDMENT TO THE 15 % SECURED NOTE

          FIRST AMENDMENT, dated as of April 3, 2000 (this "First
Amendment"), to the 15% Secured Note issued by Bio-Plexus, Inc. (the
"Company") to Appaloosa Investment Limited Partnership I (the "Holder") on
January 5, 2000 (as such Note may be amended and restated from time to
time, the "Note")

                            W I T N E S S E T H:
                            -------------------

          WHEREAS, the Company has issued the Note to the Holder;

          WHEREAS, the Company has requested that the Holder amend certain
provisions of the Note;

          WHEREAS, the Holder is willing to agree to the requested
amendments, but upon the terms and conditions set forth herein;

          NOW, THEREFORE, in consideration of the premises and mutual
covenants contained herein, the Company and the Holder hereby agree as
follows:

          1. Defined Terms. Unless otherwise defined herein, capitalized
terms which are defined in the Note are used herein as therein defined.

          2. Amendment to Note.

          (a) Subsection 4.4 of the Note is amended by deleting the date at
the end of the first clause of the first sentence thereof and substituting
in lieu therefor "April 30, 2000".

          (b) Subsection 5.1(d) of the Note is amended by deleting all
references therein to "February 28, 2000" and substituting in lieu therefor
"April 30, 2000".

          (c) Subsection 6.1 of the Note is amended by deleting clause (i)
thereof in its entirety and substituting in lieu therefore the following:

               (i) the Convertible Note Purchase Agreement attached to the
First Amendment to this Note as Exhibit A (the "Convertible Note Purchase
Agreement"),

          (d) Subsection 6.4 of the Note is amended by deleting the
reference to "February 28, 2000" and substituting in lieu therefor "April
30, 2000".

          (e) (i) Subsection 7.1 of the Note is amended by adding the
following definition:
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               "Note" shall mean this Note, as amended from time to time.

               (ii) Subsection 7.1 of the Note is further amended by
deleting the definitions of "Maturity Date," "Proxy Statement" and
"Transaction Documents" in their entirety and substituting in lieu therefor
the following:

               "Maturity Date" shall mean the earlier of April 30, 2000 and
               the Rollover Date.

               "Proxy Statement" shall mean the proxy statement in a
               definitive form relating to the Company Meeting and any
               amendments, supplements or other solicitation materials
               relating thereto.

               "Transaction Documents" shall mean, the 7.5% Note, this
               Note, the 15% Secured Note, in the initial aggregate
               principal amount of $2,200,000, issued by the Company to the
               Holder on the date hereof (as such 15% Secured Note may be
               amended from time to time), the side letter, dated December
               30, 1999, between the Company and the Holder (as such side
               letter may be amended and restated from time to time), the
               Security Agreement, the Registration Rights Agreement, the
               warrants to be issued to Affiliates of the Holder pursuant
               to section (c) of the aforesaid side letter, the Warrants
               and the side letter, dated April 3, 2000, between the
               Company and the Holder (as such side letter may be amended
               and restated from time to time).

          3. Representations and Warranties. The Company hereby confirms,
reaffirms and restates the representations and warranties set forth in
Section 3 of the Note. The Company represents and warrants that as of the
date hereof and, after giving effect to this First Amendment and the
transactions contemplated hereby, no Default or Event of Default has
occurred and is continuing.

          4. Effectiveness. The First Amendment shall become effective as
of the date upon which the Holder receives the counterpart of this First
Amendment duly executed by the Company and a duly executed copy of the side
letter, dated the date hereof, between the Company and the Holder.

          5. Continuing Effect of the Transaction Documents. This First
Amendment shall not constitute an amendment of any other provisions of the
Note or any other Transaction Documents not expressly referred to herein
and shall not be construed as a waiver or consent to any further or future
action on the part of the Company that would require a waiver or consent of
the Holder. Except as expressly amended hereby, the provisions of the
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Note and the other Transaction Documents are and shall remain in full force and
effect.

          6. Counterparts. This First Amendment may be executed by the
parties hereto in any number of separate counterparts, each of which shall
be deemed to be an original, and all of which taken together shall be
deemed to constitute one and the same instrument.

          7. GOVERNING LAW. THIS FIRST AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW
YORK.

          IN WITNESS WHEREOF, the parties hereto have caused this First
Amendment to be duly executed and delivered by their respective proper and
duly authorized officers as of the day and year first above written.



                                        BIO-PLEXUS, INC.


                                        By: /s/ Carl R. Sahi
                                           --------------------------------
                                           Name:  Carl R. Sahi
                                           Title: President and Chief
                                                  Executive Officer


                                        APPALOOSA INVESTMENT LIMITED
                                          PARTNERSHIP I

                                        By:  Appaloosa Management L.P., its
                                               General Partner
                                        By:  Appaloosa Partners Inc., its
                                               General Partner


                                        By: /s/ James E. Bolin
                                           --------------------------------
                                           Name:   James E. Bolin
                                           Title:  Vice President