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                                                                   EXHIBIT 10.38

                                Bio-Plexus, Inc.
                               129 Reservoir Road
                                Vernon, CT 06066

                                                               December 30, 1999

Appaloosa Investment Limited
  Partnership I
26 Main Street, 1st Floor
Chatham, New Jersey 07928
Attention:  Mr. James Bolin

Dear Mr. Bolin:

          Reference is made to the 7.5% Secured Note, dated October 21,
1999, issued by Bio-Plexus, Inc. (the "Company") to Appaloosa Investment
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Limited Partnership I ("Appaloosa") (as such 7.5% Secured Note may be amended
from time to time, the "7.5% Note"). The purpose of this letter is to set forth
the understanding of the Company and Appaloosa with respect to the matters set
forth herein:

          (a)  on the date hereof, the Company and Appaloosa will enter into
an amendment to the 7.5% Note in the form attached hereto as Exhibit A;

          (b)  no later than January 6, 2000, if no Default (as defined in
the 7.5% Note) shall have occurred and be continuing under the 7.5% Note,
Appaloosa will make additional loans to the Company and, in exchange
therefor, the Company shall execute and deliver a 15% Secured Note (the
"15% Note") in the form attached hereto as Exhibit B (subject to the
satisfaction or waiver of the conditions to such loans specified therein);

          (c)  in connection with the 15% Note, on the Maturity Date (as
defined in the 7.5% Note), regardless of whether the Rollover Transactions
(as defined in the 7.5% Note) are consummated, the Company will sell to one
or more affiliates of Appaloosa, and one or more affiliates of Appaloosa
will purchase from the Company, as part of an investment unit with the 15%
Note, warrants to purchase in the aggregate 200,000 shares of common stock,
no par value, of the Company (the "Common Stock"), with an exercise price
of $3.00 per share in the form attached hereto as Exhibit C (the
"Additional Warrants");

          (d)  on the Maturity Date:

               (i) if either (X) all the conditions to the Purchasers' (as
               defined in the 7.5% Note) obligations to consummate the
               Rollover Transactions, as specified in the 7.5% Note, have
               not been satisfied or waived and the Rollover Transactions
               are not consummated, or (Y) if all the conditions to the
               Company's and the Purchasers' obligations to consummate the
               Rollover Transactions, as specified in the 7.5% Note, have
               been satisfied or waived but the Company fails to consummate
               the Rollover Transactions, the $3 Warrants (as defined in
               the 7.5% Note) will remain in full force and effect and the
               terms and conditions thereof will remain unchanged;

               (ii) if the Rollover Transactions are consummated, the $3
               Warrants will be cancelled and be of no further force and
               effect and, simultaneously therewith, the Company will issue
               to one or more affiliates of Appaloosa replacement warrants
               to purchase 1,000,000 shares of Common Stock with an
               exercise price of $4 per share; and
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               (iii) if all the conditions to the Company's and the
               Purchasers' obligations to consummate the Rollover
               Transactions, as specified in the 7.5% Note, have been
               satisfied or waived but the Purchasers fail to consummate
               the Rollover Transactions, the $3 Warrants will be cancelled
               and be of no further force and effect and, simultaneously
               therewith, the Company will issue to one or more affiliates
               of Appaloosa replacement warrants to purchase 1,000,000
               shares of Common Stock with an exercise price of $5 per
               share.

The warrants to be issued by the Company pursuant to (ii) or (iii) above
(as the case may be, the "Replacement Warrants"; the "Replacement
Warrants", together with the Additional Warrants, the "Warrants") will be
in the form attached hereto as Exhibit D.

          The Company represents that (i) the execution and delivery of
this letter by the Company and the performance by it of the transactions
contemplated hereby (including, without limitation, the issuance of the
Warrants and issuance of shares of Common Stock upon exercise of the
Warrants) and compliance by the Company with all the provisions of the
Warrants (as applicable) have been duly authorized by all requisite
corporate proceedings on the part of the Company and (ii) the shares of
Common Stock issuable upon exercise of the Warrants have been validly
reserved for issuance, and upon issuance, will be validly issued and
outstanding, fully paid and nonassessable.

          The Company cannot assign its rights and obligations under this
letter without the written consent of Appaloosa.

          If any term, provision, covenant or restriction of this letter or
any exhibit hereto is held by a court of competent jurisdiction to be
invalid, void or unenforceable, the remainder of the terms, provisions,
covenants and restrictions of this letter and such exhibits shall remain in
full force and effect and shall in no way be affected, impaired or
invalidated. It is hereby stipulated and declared to be the intention of
the parties that they would have executed the remaining terms, provisions,
covenants and restrictions without including any of such which may be
hereafter declared invalid, void or unenforceable.

          Appaloosa, on the one hand, and the Company, on the other,
acknowledge and agree that irreparable damage would occur in the event that
any of the provisions of this letter were not performed in accordance with
their specific terms or were otherwise breached. It is accordingly agreed
that Appaloosa shall be entitled to an injunction to prevent breaches of
the provisions of this letter and to enforce specifically the terms and
provisions hereof in any court of the United States or any state thereof
having jurisdiction, this being in addition to any other remedy to which
they may be entitled at Law (as defined in the 7.5% Note) or equity.

          Neither the Company nor Appaloosa shall make any public
statements, including, without limitation, any press releases, with respect
to this letter and the transactions contemplated hereby without the
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prior written consent of the other party (which consent shall not be
unreasonably withheld) except as may be required by Law. If a public statement
is required to be made by Law, the parties shall consult with each other in
advance as to the contents and timing thereof.

          THIS LETTER SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH,
AND THE RIGHTS OF THE PARTIES SHALL BE GOVERNED BY, THE LAW OF THE STATE OF
NEW YORK EXCLUDING CHOICE-OF-LAW PRINCIPLES OF THE LAW OF SUCH STATE THAT
WOULD REQUIRE THE APPLICATION OF THE LAWS OF A JURISDICTION OTHER THAN SUCH
STATE.

          If any Litigation (as defined in the 7.5% Note) shall be brought
by Appaloosa in order to enforce any right or remedy under this letter, the
Company hereby consents and will submit to the jurisdiction of any state or
federal court of competent jurisdiction sitting within the area comprising
the Southern District of New York on the date of this letter. The Company
hereby irrevocably waives any objection, including, but not limited to, any
objection to the laying of venue or based on the grounds of forum non
conveniens, which it may now or hereafter have to the bringing of any such
Litigation in such jurisdiction.

          THE COMPANY HEREBY WAIVES ANY RIGHT IT MAY HAVE TO A TRIAL BY
JURY IN RESPECT OF ANY ACTION, PROCEEDING OR LITIGATION DIRECTLY OR
INDIRECTLY ARISING OUT OF, UNDER OR IN CONNECTION WITH, THIS LETTER.

          Please confirm that the foregoing is in accordance with your
understanding by signing and returning to me this letter, whereupon this
letter shall be deemed accepted and binding.

                                          Very truly yours,

                                          BIO-PLEXUS, INC.


                                          By: /s/ Carl Sahi
                                             ---------------------------
                                             Name:  Carl Sahi
                                             Title:



ACCEPTED AND AGREED
THIS 30TH DAY OF DECEMBER, 1999

APPALOOSA INVESTMENT LIMITED
   PARTNERSHIP I

By: Appaloosa Management L.P., its
      General Partner
By: Appaloosa Partners Inc., its
      General Partner
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By: /s/ James E. Bolin
   -------------------------------
   Name:  James E. Bolin
   Title: Vice President