<PAGE>
                                                                    EXHIBIT 10.1


                     AMENDMENT NO. 1 TO EMPLOYMENT AGREEMENT


         THIS AMENDMENT NO. 1 TO EMPLOYMENT AGREEMENT ("Amendment") is entered
into as of the ___ day of ________, 2004, by and between LANCE FORS ("Employee"
or "Executive") and THIRD WAVE TECHNOLOGIES, INC., a Delaware corporation (the
"Company").

         WHEREAS, the Company currently employs Employee as its Chairman and
Chief Executive Officer pursuant to an Employment Agreement dated as of October
16, 2003 (the "Agreement"); and

         WHEREAS, the Company and the Employee wish to amend the Agreement on
the terms and provisions set forth herein.

         NOW, THEREFORE, in consideration of the mutual covenants and conditions
hereinafter set forth, and other good and valuable consideration, receipt of
which is hereby acknowledged, the parties agree as follows:

         1. Section 1 - Employment. The first two sentences of Section 1 are
deleted in their entirety and the following are substituted therefore:

         The Company hereby agrees to employ Employee as its Chairman and Chief
         Executive Officer, and Employee hereby agrees to serve the Company in
         such positions, all subject to the terms and provisions of this
         Agreement; provided, however, subject to the authorization by the Board
         of Directors of the Company, as of June 15, 2004 (the "Change Date"),
         Employee shall be employed solely as the Executive Chairman of the
         Company. Employee agrees (a) to devote his full-time professional
         efforts, attention and energies to the business of the Company, and (b)
         to perform such reasonable responsibilities and duties customarily
         attendant to the positions of Chairman and CEO, provided; however, at
         such time as Employee is employed solely as Executive Chairman,
         Executive's time commitment to the Company shall be part-time and
         flexible. Executive shall be allowed to determine those hours needed to
         fulfill the Board approved role described on Schedule C to this
         Agreement, subject to the oversight of the Board. Any change in the
         Executive Chairman's role, responsibilities and duties shall be agreed
         by the Employee and the Company's Board of Directors. When Employee is
         employed solely as Executive Chairman after June 15, 2004, he will be
         allowed to work on non-Company matters, subject to the provisions of
         the Noncompetition and Nonsolicitation Agreement entered into by the
         Employee.

         2. Section 2 - Term of Employment. Section 2 is deleted in its entirety
and the following is substituted therefore:

         Subject to an earlier termination as provided in Section 6, Employee
         shall be employed hereunder through June 30, 2007. The Agreement shall
         automatically expire on June 30, 2007, unless the Company and Employee
         agree in writing at least six months prior to the

<PAGE>

         expiration of the term to renew the Agreement for an extended term of
         one year. The parties may thereafter extend the Agreement for
         additional one year terms by agreeing in writing to such extensions at
         least six months prior to the expiration of each successive term.

         3. Section 3.1 - Base Salary. Section 3.1 is deleted in its entirety
and the following substituted therefore:

         Employee's base salary is $400,000 per annum through the Change Date
         ("Base Salary"). After the Change Date, Employee's Base Salary remains
         at $400,000 per annum, but will be treated as comprised of $133,000 per
         year for services to be performed as Executive Chairman ("Base
         Compensation") and $267,000 per year as a severance obligation
         associated with transition by Employee from the position of Chairman
         and Chief Executive Officer to Executive Chairman ("Severance
         Compensation"). All Base Salary shall be payable in accordance with the
         normal payroll practices of the Company.

         4. Section 3.3 - Equity Incentives. The fourth and fifth sentences of
Section 3.3 are deleted in their entirety and the following is substituted for
the fourth sentence:

         In the event Employee resigns for Good Reason pursuant to Section
         6.1(c), or is terminated by the Company for other than Cause pursuant
         to Section 6.2(c), or upon Non-Renewal as defined in and pursuant to
         Section 6.2(d), the stock options granted to Employee shall fully vest
         and be exercisable in accordance with Section 7.8.

         5. Section 4.1 - General Benefits. Section 4.1 is deleted in its
entirety and the following is substituted therefore:

         Employee will be entitled to participate in the sick leave, insurance
         (including medical, life and long-term disability), profit-sharing,
         retirement, and other benefit programs that are generally provided to
         executive employees of the Company, including any stock option plans,
         long term incentive plans or deferred compensation plans, all in
         accordance with the rules and policies of the Company as to such
         matters and the plans established therefore.

         6. Section 4.2 - Paid Time Off (PTO). The following sentence is added
to the end of Section 4.2:

         Employee will no longer be eligible for PTO once Employee is employed
         solely as the Executive Chairman of the Company because his position
         will be part time. The Company will pay to Employee within 15 days
         after the Change Date a prorated amount of Base Salary equal to the
         number of PTO days the Employee had accrued but unused as of the Change
         Date.

         7. Section 6.1(d) - Good Reason. Section 6.1(d)(iii) is deleted in its
entirety and the following is substituted therefore:


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<PAGE>

         (iii) While employed as Chairman and Chief Executive Officer, Employee
         is assigned duties materially inconsistent with the duties of a chief
         executive officer of similarly situated companies; and while employed
         solely as Executive Chairman, Employee is assigned duties materially
         inconsistent with duties of a chairman of similarly situated companies,
         unless any inconsistent duties have been agreed to by the Employee and
         the Company's Board of Directors.

         8. Section 6.1(d) - Good Reason. The following is added to the
Agreement as Section 6.1(d)(v):

         (v) A resignation by Employee following the occurrence of a Change in
         Control (as defined in Schedule D to the Agreement as attached
         hereto), but not earlier than six months after the occurrence of the
         Change in Control; provided, that if the Executive is terminated
         without Cause during such six month period, the benefits of 7.1 shall
         apply; provided, that notwithstanding anything to the contrary herein,
         during such 6 month period the Employee shall be entitled to resign
         for Good Reason under the other provisions of Section 6.1(c).

         9. Section 6.2(d) - Notice of Non-Renewal. Section 6.2(d) is deleted in
it entirety and the following is substituted therefore: -

         (d) Notice of Renewal. Subject to Section 7.1, the Company and Employee
         may, pursuant to Section 2 hereof, renew Employee's term of employment
         for one-year terms by agreement in writing entered into at least six
         months prior to the expiration of the term. If the Company fails to
         provide to Employee a notice of its desire to renew this Agreement in
         accordance with its terms at least six months prior to the expiration
         of the term, Employee's employment shall expire at the conclusion of
         the applicable term (a "Non-Renewal"). Upon Non-Renewal by the Company
         under this Section 6.2(d), the Company may, in its sole discretion and
         for any or all of the six-month period prior to the expiration of the
         term, suspend Employee's duties, as long as the Company continues to
         pay compensation to Employee, including benefits, through such period.
         Employee shall not take any vacations during such notice period without
         the prior consent of the Company.

         10. Section 7.1 - Termination of Agreement Pursuant to Section 6.1(c)
or 6.2(c). The first sentence of Section 7.1 is deleted in its entirety and the
following is substituted therefore:

         If the Employee terminates his employment for Good Reason pursuant to
         Section 6.1(c), or the Company terminates Employee's employment without
         Cause pursuant to Section 6.2(c), subject to the conditions described
         in Section 7.3 below, the Company will pay to Employee the following
         severance: (i) the greater of (A) an amount equal to all Base
         Compensation to which Employee would have been entitled through June
         30, 2007 had he not been terminated without Cause or resigned for Good
         Reason, or (B) twenty-four (24) months of Employee's Base Compensation
         at the date of termination, 6/24ths of


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<PAGE>

         which amount shall be paid in a lump sum within 3 business days of the
         termination date, with the balance to be paid in 18 equal monthly
         installments (the first installment due on the first day of the
         calendar month following the month in which termination occurs); (ii)
         any portion of Severance Compensation to which the Employee would have
         been entitled through June 30, 2007 had Employee not been terminated,
         which portion remains unpaid at termination, payable as follows: (A)
         if 18 months or less of Severance Compensation remains due hereunder,
         then Severance Compensation shall be paid in the amounts and at the
         times at which Severance Compensation would otherwise have been due
         hereunder, or (B) if more than 18 months of Severance Compensation
         remains due hereunder, then 6/24ths of such aggregate amount shall be
         paid in a lump sum within 3 business days of the termination date,
         with the balance to be paid in 18 equal monthly installments (the
         first installment due on the first day of the calendar month following
         the month in which termination occurs); (iii) a pro-rata portion of
         Employee's target annual incentive compensation award in or around
         March of the year following Employee's termination based upon the
         number of months (rounded to the next highest number for a partial
         month) of the year elapsed prior to Executive's termination and any
         other amounts earned, accrued or owing to Executive under the plans
         and programs of the Company, including any earned bonus for any
         completed fiscal year; (iv) an amount equal to 1/12th of 7.6% of
         Employee's Base Salary payable each month (the first installment due
         on the first day of the calendar month following the month in which
         termination occurs) in twelve (12) monthly installments, or a monthly
         amount equal to 1/12th of such greater percentage as may be in effect
         for senior employees of the Company immediately prior to Employee's
         termination; which amount is intended, but not required, to be used by
         Employee to acquire such medical, dental, hospitalization, accident,
         disability, life insurance and any other benefits as the Employee may
         determine; and (v) the purchase of an outplacement consulting package
         for Employee, up to a maximum value of Fifteen Thousand Dollars
         ($15,000), which shall be selected at the discretion of the Employee.

         11. Section 7.2 Expiration of Agreement Pursuant to Section 6.2(d). The
following is added to the end of Section 7.2:

         (iii) an amount equal to 1/12th of 7.6% of Employee's Base Salary
         payable each month (the first installment due on the first day of the
         calendar month following the month in which termination occurs) in
         twelve (12) monthly installments, or a monthly amount equal to 1/12th
         of such greater percentage as may be in effect for senior employees of
         the Company immediately prior to Employee's termination; which amount
         is intended, but not required, to be used by Employee to acquire such
         medical, dental, hospitalization, accident, disability, life insurance
         and any other benefits as the Employee may determine.

         12. Section 7.3 - Conditions Precedent to Payment of Severance. Section
7.3 is deleted in its entirety and the following substituted therefore:

                  7.3 Conditions Precedent to Payment of Severance. The
         Company's obligations to Employee described in Section 7.1 and 7.2 are
         contingent on Employee's delivery to the Company of the form of
         agreement attached hereto as Schedule E pursuant to which

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<PAGE>

         Employee (A) affirms his agreement not to compete with the Company for
         a period of one year following the termination of Employee's
         employment and (B) waives and releases any other claims which Employee
         may have against the Company.

         13. Section 7.8 - Acceleration of Stock Options The following is added
to the Agreement as Section 7.8:

                  7.8 Acceleration of Stock Options. In the event Executive is
         terminated by the Company other than for Cause, or should the Executive
         resign his employment for Good Reason, or in the event of Non-Renewal,
         all stock options granted to Executive shall be immediately accelerated
         and shall be considered fully vested upon such termination, resignation
         or Non-Renewal. Executive's vested Non-Qualified Stock Options (whether
         vested by their original terms or by acceleration upon termination
         other than for Cause or resignation for Good Reason or Non-Renewal)
         shall be open for exercise until the latest date on which those options
         would expire or are eligible to be exercised under the Option Grant
         Agreements, determined without regard to such termination or
         resignation or non-renewal. Executive and the Company acknowledge and
         agree that such extended exercise period shall not apply to any
         Incentive Stock Options, the exercise periods for which shall continue
         be governed by the terms of the Option Grant Agreements. Executive
         understands and agrees that any extended exercise period granted to
         Incentive Stock Options issued to the Executive on or prior to October
         16, 2003 converted those Incentive Stock Options into Non-Qualified
         Stock Options.

         14. Section 11 - General Provisions. The following is added as
subparagraph (f) to Section 11:

         (f) Board Authority. To the extent that the Company shall be required
         or permitted to take or omit to take any action pursuant to this
         Agreement, such authority shall be derived from the Board of Directors
         of the Company who shall provide direction to the Company with respect
         to such matters.

         15. Counterparts. This Amendment may be executed in one or more
counterparts, each of which shall be deemed an original but all of which
together shall constitute one and the same instrument.

         16. Full Force and Effect. Except as amended hereby, the Agreement
remains in full force and effect and is hereby ratified, confirmed and approved.

                     (SIGNATURES CONTINUE ON THE NEXT PAGE)



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<PAGE>


         The parties hereto have executed this Amendment No. 1 to Employment
  Agreement as of the date first written above.


                                         ---------------------------------------
                                         LANCE FORS

                                         THIRD WAVE TECHNOLOGIES, INC.


                                         By:
                                              ----------------------------------
                                              Lance Fors,
                                              Chief Executive Officer

                                         Confirmed and Agreed:



                                         ---------------------------------------
                                         John Neis
                                         Chairman, Third Wave Technologies, Inc.
                                         Compensation Committee of the Board
                                         of Directors





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<PAGE>



                                   SCHEDULE C

                    EXECUTIVE CHAIRMAN'S ROLE AND TRANSITION


EXECUTIVE CHAIRMAN'S GOAL:

To manage BOD activities, assist with long-term strategic issues and to identify
incremental technology opportunities for TWT.

EXECUTIVE CHAIRMAN'S ROLE:

1.   Manage relationships, communications and meetings with BOD.

2.   Communicate and discuss long-term strategic issues with CEO.

3.   Identify, assess and evaluate incremental technology opportunities.

4.   Develop network of technology thought leaderships to assist in
     identification, assessment and evaluation of opportunities to leverage TWT
     into new technology areas (Technology Advisory Board).

5.   Prepare science and technology plan which includes ways to leverage board
     members with R&D backgrounds such as Sam Eletr, Gordon Brunner and Lloyd
     Smith via BOD Technology Advisory Group, Thought Leaders and Technology
     Advisory Board, and present plan at October 2004 board meeting.

As part of this role, Executive Chairman will assess technology opportunities
(e.g. directly, via consultants, Technology Advisory Board, and select BOD
members, etc.) and develop a technology opportunity plan (e.g. opportunity,
potential value, costs, partners, milestones, etc). This plan will be presented
to the BOD at the October board meeting.

EXECUTIVE CHAIRMAN RESOURCES:

1.   On-site Office and Executive Assistant(s).

2.   Access to TWT employees subject to agreement by CEO concerning which
     employees and their availability.

3.   Discretionary resources for technology landscape assessment and evaluation,
     and development of technology opportunity plan for October board meeting.

TRANSITION TIMING:

Announce in April, 2004
Implement by June 15, 2004


<PAGE>


                                   SCHEDULE D

"Change in Control" shall mean, and shall be deemed to have occurred if, on or
after the date of this Agreement, (i) any "person" (as such term is used in
Sections 13(d) and 14(d) of the Securities Exchange Act of 1934, as amended) or
group acting in concert, other than a trustee or other fiduciary holding
securities under an employee benefit plan of the Company acting in such capacity
or a corporation owned directly or indirectly by the stockholders of the Company
in substantially the same proportions as their ownership of stock of the
Company, becomes the "beneficial owner" (as defined in Rule 13d-3 under said
Act), directly or indirectly, or securities of the Company representing more
than 50% of the total voting power represented by the Company's then outstanding
Voting Securities, (ii) during any period of two consecutive years, individuals
who at the beginning of such period constitute the Board of Directors of the
Company and any new director whose election by the Board of Directors or
nomination for election by the Company's stockholders was approved by a vote of
at least two thirds (2/3) of the directors then still in office who either were
directors at the beginning of the period or whose election or nomination for
election was previously so approved, cease for any reason to constitute a
majority thereof, (iii) the stockholders of the Company approve a merger or
consolidation of the Company with any other corporation other than a merger or
consolidation which would result in the Voting Securities of the Company
outstanding immediately prior thereto continuing to represent (either by
remaining outstanding or by being converted into Voting Securities of the
surviving entity) at least 80% of the total voting power represented by the
Voting Securities of the Company or such surviving entity outstanding
immediately after such merger or consolidation, or (iv) the stockholders of the
Company approve a plan of complete liquidation of the Company or an agreement
for the sale or disposition by the Company of (in one transaction or a series of
related transactions) all or substantially all of the Company's assets.

<PAGE>


                                   SCHEDULE E

                              TERMINATION AGREEMENT

         This Termination Agreement confirms the termination of Lance Fors (the
"Executive") from employment with Third Wave Technologies, Inc. (the "Company")
effective _____________, 200___. The Company shall provide Executive with the
severance payments and other benefits (the "Severance") described in Executive's
Employment Agreement dated as of October 16, 2003, as amended from time to time
thereafter (the "Employment Agreement"), and in consideration therefore,
Executive agrees to the terms set forth in this Termination Agreement. The terms
are as follows:

         1. Executive hereby confirms his agreement not to enter into
competition with the Company for a period of one year following the termination
of Executive's employment in accordance with the terms and conditions set forth
in the Noncompetition and Nonsolicitation Agreement dated as of October 16, 2003
by and between the Executive and the Company, as amended.

         2. In consideration for the Severance and the covenants of the Company
set forth in the Employment Agreement, Executive, for and on behalf of himself
and his heirs, successors, executors and assigns hereby absolutely and
unconditionally releases, waives and forever discharges the Company, its parent
and affiliated entities, its predecessors, successors and assigns, and their
respective officers, members, partners, shareholders, directors, employees,
representatives, agents and other affiliates, from any and all claims or
liabilities of any nature whatsoever, whether known or unknown, in connection
with his affiliation with the Company, the termination of his affiliation with
the Company and any additional wages, vacation pay or other paid time off, other
compensation and payments (whether in contract, tort or otherwise) (the
"Release"), including but not limited to: (i) for wrongful termination or breach
of the covenant of good faith and fair dealing; (ii) under Title VII of the
Civil Rights Act of 1964, as amended; (iii) under the Civil Rights Act of 1991,
as amended; (iv) under any Collective Bargaining Agreement; (v) the Wage Payment
Act, Chap. 109 Wis. Stats.; as amended; (vi) the California Fair Employment and
Housing Act, as amended; (vii) the California Labor Code, as amended; (viii)
under the Americans with Disabilities Act of 1990, as amended; (ix) under any
Wisconsin or California law prohibiting discrimination; (x) under any other
Federal, and state and local laws, orders or regulations in any way relating to
the employment relationship, termination or discrimination; (xi) under common
law; and (xii) the Age Discrimination Employment Act ("ADEA"), and the Older
Worker Benefit Protection Act, as amended. Excluded from this Termination
Agreement are the Severance, any claims or administrative charges that cannot be
waived by law and claims relating to health insurance continuation rights under
the terms of COBRA, rights to vested retirement benefits, if any, and rights
pursuant to Option Grant Agreements.

         3. Executive will not sue the Company for any matter for which the
Release has been given (except to enforce rights granted under paragraph 1,
above).

<PAGE>

         4. Executive will immediately return to the Company all Company
property, including but not limited to, all reports, memoranda, records,
computerized information, keys, credit cards, computers, manuals and other
property which Executive prepared or received in connection with his affiliation
with the Company. Executive agrees not to retain any copies, duplicates or
portions of such information.

         5. The Company agrees not to contest any claim for unemployment filed
after ______________, 200__.

         6. This Termination Agreement shall be construed, interpreted and
applied in accordance with the laws of the State of Wisconsin, without regard to
its conflicts of laws rules. In the event the Company takes any action to
enforce any term or provision hereof or defend any matter released, Executive
will be liable to the Company for all of its costs, expenses and reasonable
attorneys' fees.

         7. If any portion of this Termination Agreement is held invalid by
operation of law or otherwise, the remaining terms of this Termination Agreement
shall not be effected.

         8. Executive agrees that he has been provided with twenty-one days from
the date he received this Agreement within which to consider its terms.
Executive acknowledges that he has consulted with an attorney of his choice, and
has negotiated the terms of this Agreement and Executive has also had the
opportunity to consult with other professional persons unrelated to the Company
regarding the terms of this Agreement. Executive's signature below indicates
that he is entering into this Agreement freely, knowingly and voluntarily with a
full understanding of its terms. Further, the terms of this Agreement cannot
become effective or enforceable until seven (7) days following the date of its
execution, during which time Executive may revoke the Agreement by notifying the
Company in writing. Executive understands that any rights or claims he may have
under the ADEA that arise after the date of this Agreement is executed are not
waived by him.

         9. All rights, privileges and remedies afforded the Company are
cumulative and not exclusive; the exercise of any one shall not be deemed a
waiver of any other right, privilege or remedy.

         10. Executive represents and warrants that he has read and understands
all terms of this Agreement, executes it knowingly and voluntarily with full
knowledge of its significance and with the intent to be bound by it. Executive
represents and warrants that he has been or had the opportunity to be
represented by legal counsel of his choice in connection with this Agreement who
has explained it and advised that it is a legally binding contract. This
document contains the entire agreement between Executive and the Company and the
terms hereof cannot be modified except in writing signed by both Executive and
the Company.

         11. The parties hereto agree that signatures transmitted by facsimile
shall be legally binding.

                       (Signatures continue on next page.)

                                       2

<PAGE>


         IN WITNESS WHEREOF, the parties hereto have entered into this
Termination Agreement as of the date and year set forth below.

                                                 Third Wave Technologies, Inc.

                                                 By:
                                                    ----------------------------
                                                 Its:
                                                     ---------------------------
                                                 Date:
                                                       -------------------------


AGREED TO AND ACCEPTED:



-----------------------------     --------------------
Lance Fors                        Date



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