<PAGE>   1
                                                                   EXHIBIT 10.50


December 6, 2000


Mr. Christopher C. Zorn
32 Planting Field Road
Medfield, MA  02052

Dear Chris:

I am pleased to offer you the position of executive vice president of sales for
Bio-Plexus, Inc. Your employment will begin on a mutually agreed upon date. In
this role, you will report directly to me and will be based at our corporate
office in Vernon, Connecticut. The basic terms and conditions of your employment
are summarized below:

Position              Executive Vice President of Sales for Bio-Plexus, Inc

Base Salary           $135,000 annually, payable in accordance with the
                      company's standard payroll practices. You will be eligible
                      for an annual performance review and a standard merit
                      increase if recommended and approved by the Compensation
                      Committee.


Retention Bonuses     Retention and stay bonuses will be paid as follows:

                           -    A retention bonus of $16,000 for year 2001 paid
                                on a monthly basis. This $16,000 bonus will
                                continue through December 31, 2002, assuming
                                your performance is at expected levels.

                           -    A $10,000 stay bonus to be paid on July 1, 2001.

                      Retention and stay bonuses pay will be deducted from any
                      performance bonus payout below.

Performance Bonus     Up to 100% of base salary for achievement of individual
                      and corporate goals. Your individual performance goals and
                      objectives will be in place no later than January 15,
                      2001. A bonus schedule as follows and based on net product
                      sales to budget as established by the Board for Directors:

<TABLE>
<S>                                     <C>
                            88-90%      $20,000
                            91-93%      $25,000
                            94-96%      $30,000
</TABLE>
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Mr. Christopher C. Zorn
December 6, 2000
Page 2

<TABLE>
<S>                                     <C>
                            97-99%      $40,000
                            100%        $67,500
                            101-103%    $72,500
                            104-107%    $80,000
                            108-110%    $90,000
                            111-115%    $105,000
                            116-119%    $120,000
                            120+%       $135,000
</TABLE>


                      -    If budgeted profit goals are achieved, you are
                           eligible for full payment for performance to sales
                           objectives up to 110% of budgeted net product sales.
                           Under a circumstance whereby revenue of net product
                           sales goals are achieved but corporate profitability
                           to budget is not, you will be guaranteed a bonus
                           payout of 80% for achievement of sales targets. For
                           example if sales budget is achieved you would be
                           eligible for a bonus of $67,500; however, if budget
                           profitability goals are not achieved, you will
                           receive 80% or $54,000.

                      -    Payments for net sales above 110% of budget will be
                           paid according to the following:

                           -    Achievement of budgeted profit goals but less
                                than targeted profit goals above budget.

                                    o    Full payment or 100% of the increment
                                         up to 110% and 80% payment of the
                                         increment above 110%. Example: if sales
                                         are 116% of budget, payment would be
                                         $114,000 (i.e. $90,000 plus $24,000
                                         which is 80% of the increment above
                                         $90,000 payment level).

                           -    Achievement of targeted profit goals above
                                budget: full payout or 100% at all levels of
                                performance to budgeted net sales goals.

                      The performance bonus payment will be made - in a gross
                      amount less any applicable taxes and will become payable
                      following the close of the fiscal year on December 31 and
                      within a reasonable time period after determination by the
                      Company's Board of Directors as to relevant performance
                      attainment based on established goals.
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Mr. Christopher C. Zorn
December 6, 2000
Page 3

Stock Options         An option package of 150,000 shares with an exercise price
                      at the grant date will be made within 10 business days
                      from date of hire.. Of these 150,000 share, 100,000 shares
                      will be retention options which will vest over three
                      years. The remaining 50,000 shares will be performance
                      options which will vest under one of two occurrences:

                      1.   The end of seven years.

                      2.   When net product sales revenue for a cumulative,
                           sequential 12-month period totals $15 million.

                      In the event of a Change of Control, as defined in the
                      Bio-Plexus, Inc. Non-Statutory Stock Option Agreement to
                      be signed between you and the Company, and pursuant to
                      Section 9 of that Agreement, you will become fully vested
                      in all retention options.. Performance options will become
                      fully vested and exercisable at the discretion of the
                      Board of Directors. For clarity, "Change of Control" is
                      defined below.

Vacation              Three weeks annually

Employee Health       You will be able to participate in the company's medical
and Other Benefits    and dental programs and all  other benefit programs that
                      will be developed over time.

Severance             You will be entitled to receive six months of salary,
                      medical benefits continuation and bonus compensation that
                      was earned but not paid upon your termination by the
                      company for any reason other than for cause. If your
                      employment is terminated by the company for reasons other
                      than cause or performance your bonus for the current year
                      will vest on a pro rata basis and will be paid at the end
                      of the fiscal year as though you were currently employed.<
                      In addition, any retention stock options not completely
                      vested will immediately vest on a pro rata basis
                      (reference Attachment 1). Only the following shall
                      constitute "cause" for such termination: (i) material
                      failure to perform a substantial portion of your duties
                      and responsibilities hereunder, which failure continues
                      after written notice given to you by the President of the
                      Company; (ii) conduct by you that is dishonest, fraudulent
                      or unlawful relative to your employment by the Company;
                      (iii) conduct that constitutes gross negligence or willful
                      misconduct by you with respect to the Company; or (iv)
                      your conviction or admission of guilt of a felony and/or
                      crime
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Mr. Christopher C. Zorn
December 6, 2000
Page 4

                      involving moral turpitude, deceit, dishonesty or fraud.

Contingencies         This offer is contingent upon approval by the board
                      compensation committee for Bio-Plexus, your passing of a
                      drug test providing documentation that you have the right
                      to live and work in the United States, execution of other
                      standard employee documents and agreements, and after
                      successful completion of references to the satisfaction of
                      Bio-Plexus.

Indemnity             The Company agrees to indemnify you as provided under
                      Connecticut law and consistent with the terms of the
                      Certificate of Incorporation.


You should understand that all employees are employed at the will of the Company
for an indefinite period. Employees may resign from the Company at any time, for
any reason and may be terminated by the Company at any time, for any reason,
with or without notice.

Definition:

         "Change in Control" means any (i) consolidation or merger involving the
Company, if the shareholders of the Company immediately before such merger or
consolidation do not own, directly or indirectly, immediately following such
merger or consolidation, more than fifty percent (50%) of the combined voting
power of the outstanding voting securities of the corporation or other entity
resulting from such merger or consolidation in substantially the same proportion
as their ownership of the shares of Common Stock immediately before such merger
or consolidation; (ii) sale, lease, license, exchange or other transfer (in one
transaction or a series of related transactions) of all, or substantially all,
of the business and/or assets of the Company or assets representing over 50% of
the operating revenue of the Company; or any (iii) person (as such term is used
in Sections 13(d) and 14(d) of the Securities Exchange Act of 1934, as amended
(the "Exchange Act")), other than Appaloosa Management, L.P. and its affiliates
and/or related funds, who is not, as of September 28, 2000, a controlling person
(as defined in Rule 405 under the Securities Act of 1933, as amended) (a
"Controlling Person") of the Company becomes (x) the beneficial owner (within
the meaning of Rule 13d-3 under the Exchange Act) of over 50% of the Company's
outstanding Common Stock or the combined voting power of the Company's then
outstanding voting securities entitled to vote generally or (y) a Controlling
Person of the Company.


Upon acceptance of this offer, please immediately return this signed letter in
the enclosed pre-addressed envelope. A copy will be provided to you upon
request. This offer of employment will be valid for one week from the date of
this letter.
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Mr. Christopher C. Zorn
December 6, 2000
Page 5

We look forward to you joining us at Bio-Plexus. We believe you will bring
significant contributions to the firm and also be a valuable member of the
executive management team.

Sincerely,



John Metz
Chief Executive Officer


I have read and accepted the above offer:

-----------------------------               ------------------------
Christopher C. Zorn                                  Date
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Mr. Christopher C. Zorn
December 6, 2000
Page 6


                                  ATTACHMENT 1



Pro rata Share Example:

<TABLE>
<S>               <C>               <C>
Options:          100m

Vesting           Year 1             33,333
                  Year 2             66,667
                  Year 3            100,000
</TABLE>

Termination without cause or for performance reasons after 17 months of complete
employment: pro rata shares that vest will be 17/36 = 47.2% of total,
approximately 47,200 shares, 33,333 of which have already vested. The additional
shares that vest and become exercisable are 13,867.