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                                                                   Exhibit 10.10

                                LICENSE AGREEMENT

                                     BETWEEN

                          VISIBLE GENETICS, INC.("VGI")

                      AND BIOS LABORATORIES, INC. ("BIOS")

            Agreement made and entered into this 21st day of November, 1996,
(hereinafter referred to as the "Effective Date") by and between BIOS
LABORATORIES, INC., a corporation duly organized and existing under the laws of
the State of Delaware and having its principal office at Five Science Park, New
Haven, State of Connecticut, U.S.A. (hereinafter referred to as "BIOS"), and
VISIBLE GENETICS, INC., a corporation duly organized and existing under the laws
of the Province of Ontario having its principal office at 700 Bay Street,
Toronto, Ontario, Canada M5G 1Z6 (hereinafter referred to as "VGI").

                                   WITNESSETH

            WHEREAS, BIOS, among other things, has heretofore been in the
business of designing, developing, using, selling and licensing others to use
and sell, technology relating to "Coupled Amplification and Sequencing of DNA"
disclosed in U.S. Patent No. 5,427,911(hereinafter "CAS Technology"), and
continues to make improvements therein, has acquired substantial know-how,
substantial goodwill and substantial reputation in the area of CAS Technology,
and has acquired certain rights thereto;

            WHEREAS, BIOS is an exclusive licensee to make, have made, use, sell
and

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practice the invention covered by U.S. Patent No. 5,427,911 by virtue of an
Agreement with Yale University and has the right to sublicense the rights
granted thereunder to third parties subject to rights heretofore granted to the
United States government, Yale University and Amersham Life Science, Inc.
(hereinafter referred to as "Amersham");

            WHEREAS, VGI desires to obtain a FIELD OF USE license under BIOS'
PATENT RIGHTS (as later defined herein) to commercialize CAS Technology in
conjunction with VGI's chemistry kit currently known as "CLIP" and any other
chemistry systems that make use of the CAS Technology upon the terms and
conditions hereinafter set forth; and

            NOW, THEREFORE, in consideration of the mutual undertakings and
covenants contained herein, the parties hereto agree as follows:

                                    ARTICLE 1

                                   DEFINITIONS

            For the purposes of this Agreement, the following words and phrases
shall have the following meanings:

            1.1 PATENT RIGHTS shall include all rights exclusively licensed to
BIOS under U.S. Patent No. 5,427,911 (hereinafter the "'911 patent"), together
with any reissue or reexamination of such patent, and any extensions of such
patent, subject to a royalty-free, non-exclusive license heretofore granted to
the United States government; the rights retained by Yale University in
accordance with the June 9, 1994 license agreement between Yale and BIOS to
make, use and practice the inventions for Yale's own non-commercial purposes;
and the exclusive license granted to Amersham for non-diagnostic research
applications only, including preclinical,


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non-patient-charged research but excluding all patient-charged diagnostic
applications whether or not FDA approval is required; and shall include any and
all rights under the IMPROVEMENTS on the '911 patent.

            1.2 "LICENSED PRODUCT" shall mean VGI's chemistry kits that make use
of the CAS Technology and any chemistry system that makes use of the CAS
Technology. For greater clarity, "LICENSED PRODUCT" shall not include hardware,
software, or non-chemistry components.

            1.3 "NET SALES" shall mean the gross invoice price billed by VGI,
its distributors, agents or sublicensees to END USERS of LICENSED PRODUCTS less
credits or allowances on account of any rejection or returns of LICENSED
PRODUCTS previously billed, and less any import duties, taxes or use taxes which
are included in the gross invoice price, and less any accounts past due over 180
days, except that the amount of any such accounts that are subsequently
collected shall be restored to NET SALES. No deductions shall be made for any
amounts including commissions paid to individuals whether they be with
independent sales agencies or regularly employed by VGI and on its payroll, or
for cost of collections. LICENSED PRODUCTS shall be deemed to have been
"billed", when shipped, delivered or when invoiced, whichever is first. In the
event VGI is unable to account for sales by any distributor, agent or
sublicensee, NET SALES shall be calculated as the price to the distributor or
agent multiplied by 1.5, which factor represents a 33 1/3% margin for the
distributor or agent.

            1.4 "END USER" shall mean any entity billed for LICENSED PRODUCTS
who is not a reseller.


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            1.5 "FIELD OF USE" shall mean diagnostic applications only,
including but not limited to human and veterinary purposes.

            1.6 "PARTY" shall mean BIOS or VGI; the term "PARTIES" shall mean
BIOS and VGI.

            1.7 "VGI" shall mean and include any subsidiary, affiliated or
related firm, association, corporation, or entity owned or controlled by VGI and
for the purposes of Articles 1.3 and 1.4 above shall include any transferee of
LICENSED PRODUCTS.

            1.8 "QUARTER YEAR" shall mean the three month periods ending March
31, June 30, September 30 and December 31 of each calendar year.

            1.9 "IMPROVEMENTS" shall mean any and all improvements to the CAS
Technology conceived or invented by BIOS during the term of this Agreement,
including, without limitation, all patents and patent applications related
thereto, whether in existence as of the date of this Agreement or coming into
existence hereafter.

                                    ARTICLE 2

                                      GRANT

            2.1 BIOS hereby grants to VGI, subject to the terms and conditions
contained herein, a worldwide exclusive license within the FIELD OF USE under
the PATENT RIGHTS to make, have made, use, and sell LICENSED PRODUCTS, until the
termination of the PATENT RIGHTS.


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<PAGE>

*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION. ASTERISKS DENOTE SUCH OMISSIONS.


            2.2 VGI shall have the right to grant sublicenses hereunder anywhere
in the world only during the term of this Agreement. VGI shall pay to BIOS a
sublicense issue fee of $100,000 immediately upon the grant of each sublicense
permitted hereunder (which fee shall not be considered a prepayment of
Royalties), and VGI shall pay to BIOS Running Royalties of ***************** on
NET SALES of LICENSED PRODUCTS sold by VGI's sublicensees in the United States,
in the manner set forth in Paragraph 4.2a.

            2.3 All sublicenses granted by VGI shall provide that the
obligations to BIOS within Articles 1, 2, 4 through 12, and 15 of this Agreement
shall be binding on the sublicensee as if it were a party to this Agreement. All
sublicenses granted hereunder shall be coterminable with this Agreement, subject
to Paragraph 12.4 hereof.

            2.4 VGI shall forward to BIOS a copy of the executed original of any
and all sublicense agreements, promptly after execution. The copy may be
redacted to delete any proprietary and confidential information contained in the
sublicense agreement.

            2.5 VGI and any sublicensee thereof shall comply with the relevant
provisions of 37 C.F.R. Part 401, a copy of which is attached hereto and
incorporated herein by reference.

            2.6 The term of this Agreement shall commence upon the Effective
Date and shall continue for the life of the last to expire patent within the
PATENT RIGHTS.

            2.7 BIOS reserves to itself the right to practice under the PATENT
RIGHTS within the FIELD OF USE only for BIOS' own non-commercial research use,
except that the


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research may be part of a grant or a contract research agreement for which a fee
is paid.

            2.8 In the event VGI enters into any agreement or license with
Amersham regarding VGI's CLIP technology or the CAS Technology, VGI shall use
its best efforts to ensure that any such agreement or license shall not
adversely affect or shall enhance BIOS' income or payments under the license
herein granted to VGI or its license of the CAS Technology to Amersham.

            2.9 The license granted hereunder shall not be construed to confer
any rights upon either party by implication, estoppel or otherwise as to any
technology not specifically identified herein.

                                    ARTICLE 3

                                  DUE DILIGENCE

            3.1 VGI shall, with all reasonable due diligence and good faith, use
its best efforts to bring one or more LICENSED PRODUCTS to market through a
thorough, vigorous and diligent program for the exploitation of the PATENT
RIGHTS within two (2) years following the Effective Date of this Agreement. VGI
will provide to BIOS technical and commercial reports for each QUARTER YEAR and
shall at BIOS' request have quarterly research and sales meetings with BIOS.

            3.2 In the event VGI fails to bring one or more LICENSED PRODUCTS to
market within two (2) years following the Effective Date of this Agreement, BIOS
shall have the sole right to convert the exclusive license granted hereunder to
a non-exclusive license upon notice to VGI, whereupon BIOS shall have the right
to grant non-exclusive licenses and to


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*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION. ASTERISKS DENOTE SUCH OMISSIONS.

practice without limitation under the PATENT RIGHTS and to make, have made, use,
sell, distribute and import the LICENSED PRODUCTS for all purposes within the
FIELD OF USE. If BIOS shall exercise its right to convert the exclusive license
granted hereunder to a non-exclusive license, BIOS shall promptly deliver back
to VGI ************************************* of the common shares of the capital
stock of VGI which BIOS has received on the Effective Date of this Agreement.

                                    ARTICLE 4

                          ROYALTIES AND OTHER PAYMENTS

            As consideration for the rights, privileges and license granted
hereunder, VGI shall make the following payments to BIOS.

            4.1 Upon execution of this Agreement, VGI shall pay or deliver to
BIOS the following:

                  a.    ************************************** Dollars by cash
                        or certified check, of which Fifty Thousand (U.S.
                        $50,000) Dollars has already been paid.

                  b.    ***************************** common shares of the
                        capital stock of VGI, which BIOS agrees to hold for a
                        period of two (2) years from the Effective Date of this
                        Agreement; provided, however, that BIOS shall have the
                        right to pledge or assign the shares to any third party
                        who agrees to hold the shares for the same two-year
                        period from the Effective Date of this Agreement. The
                        certificate for ************************************* of
                        such shares shall be held in escrow by Robinson & Cole
                        to ensure the return of such shares to VGI in the event
                        BIOS exercises its right pursuant to Paragraph 3.2 of
                        this


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*CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION. ASTERISKS DENOTE SUCH OMISSIONS.

                        Agreement.

                  c.    The payment and the delivery of shares under this
                        Paragraph 4.1 shall not be considered prepayments of the
                        Royalties under Paragraph 4.2 of this Agreement.

            4.2 VGI shall pay to BIOS royalties in the manner hereinafter
provided until termination of the PATENTS RIGHTS or until this Agreement is
terminated:

                  a.    Running Royalties in an amount equal to ************
                        **** of NET SALES of LICENSED PRODUCTS sold in the
                        United States, to be paid by VGI within sixty (60) days
                        after each QUARTER YEAR.

                  b.    Running Royalties in an amount equal to ***********
                        *********************** of all NET SALES of LICENSED
                        PRODUCTS sold throughout the world except the United
                        States to be paid by VGI within sixty (60) days after
                        each QUARTER YEAR.

No minimum Royalties shall be required hereunder.

            4.3 All Royalties and other payments under this Agreement shall be
paid to BIOS in United States dollars, in full, in New Haven, Connecticut.
Royalties earned from foreign sales will be converted into United States dollars
at the exchange rates in effect at the end of the applicable QUARTER YEAR.


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            4.4 VGI hereby grants to BIOS a worldwide non-exclusive royalty-free
license of the CLIP technology, including the technology that is the subject of
applications for patents filed by VGI which are currently pending, only for
BIOS' own non-commercial research use during the term of this Agreement, except
that the research may be part of a grant or a contract research agreement for
which a fee is paid.

            4.5 In accordance with Paragraph 2 of the Letter of Understanding
between the PARTIES dated July 24, 1996 VGI shall enter into a Research
Agreement with BIOS to design a commercial D-Loop mitochondrial kit that makes
use of the CAS Technology (The "Research Agreement"), for six (6) months
effective as of October 1, 1996, providing for five (5) monthly payments of
$20,000, with the first such payment to be made upon the execution of this
Agreement, which five (5) payments shall be in addition to an initial payment of
$20,000 which has been made prior to the date of this Agreement. VGI shall also
provide to BIOS free of charge a full OpenGene Sequencing System as soon as
possible, but not later than December 1, 1996, which shall immediately become
the property of BIOS.

                                    ARTICLE 5

                               REPORTS AND RECORDS

            5.1 VGI shall keep full, true and accurate records, books of account
containing all particulars in sufficient detail and form so as to enable
verification of the amounts payable to BIOS hereunder. Said records shall be
kept at VGI's principal place of business or the principal place of business of
the appropriate division or affiliate of VGI to which this Agreement relates.
Said records and the supporting data shall be maintained and kept open at all
reasonable times for no less than three (3) years following the end of the
calendar year to which they pertain, to the inspection of BIOS or its agents for
BIOS to verify the amount of royalties payable by VGI under


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this Agreement. Such examination shall be at BIOS' expense not more than once in
any calendar year, during normal business hours, and upon ten (10) days prior
written notice to VGI unless such inspection should lead to the discovery of a
greater than ten percent (10%) discrepancy in reporting to BIOS' detriment, in
which event VGI agrees to pay the full cost of such inspection. Any inspection
hereunder shall be subject to the parties entering into a mutually acceptable
confidentiality agreement.

            5.2 Within sixty (60) days after each QUARTER YEAR, VGI shall
deliver to BIOS a written report providing at least the following:

                  a.    number of LICENSED PRODUCTS made, used, and sold by VGI,
                        its distributors, agents, sublicensees and transferees;

                  b.    total billings for LICENSED PRODUCTS by VGI, its
                        distributors, agents, sublicensees, and transferees;

                  c.    credits or allowances, if any, on account of rejection
                        or returns on LICENSED PRODUCTS previously sold, and
                        import duties, taxes and use taxes;

                  d.    accounting of royalties paid or due BIOS and other
                        payments received pursuant to Article 4; and

                  e.    total royalties due and owed to BIOS.

            5.3 With each such report submitted, VGI shall pay to BIOS the
royalties and other payments due and payable under this Agreement. If no
royalties or other payments shall be due, VGI shall so report.

            5.4 The payments set forth in this Agreement and amounts due to BIOS
under Article 4 shall, if overdue, bear interest until payment at a per annum
rate two percent (2%) above


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the prime rate in effect as published in the Wall Street Journal on the due
date. The payment of such interest shall not foreclose BIOS from exercising any
other rights it may have as a consequence of the lateness of any payment.

                                    ARTICLE 6

                               PATENT OBLIGATIONS

            6.1 BIOS shall maintain at its own cost during the term of this
Agreement the PATENT RIGHTS.

            6.2 VGI hereby grants BIOS a worldwide non-exclusive royalty-free
perpetual license to exploit any improvements in relation to CAS Technology
conceived or invented by VGI during the term of this Agreement, for BIOS' own
non-commercial research use (except that the research may be part of a grant or
contract research agreement for which a fee is paid), including, without
limitation, all patents and patent applications related thereto, whether in
existence as of the date of the Agreement or coming into existence hereafter.

            6.3 VGI shall mark and shall require its distributors, agents,
sublicensees, transferees, and importers to mark LICENSED PRODUCTS, made, used
or sold in the United States with all applicable United States patent numbers
and notices required by U.S. law.

                                    ARTICLE 7

                                  INFRINGEMENT

            7.1 Each party shall promptly notify the other in writing of any
alleged infringement of the PATENT RIGHTS by a third party and of any available
evidence thereof.


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            7.2 During the term of this Agreement, BIOS shall have the right,
but shall not be obligated, to bring any legal action for infringement or for
defending any counterclaim of invalidity or action of a third party for
declaratory judgment of non-infringement or interference relating to such PATENT
RIGHTS. In furtherance of such right, VGI hereby agrees that BIOS may include
VGI as a party plaintiff in any such suit, and VGI agrees to fully cooperate
with BIOS in the prosecution of such infringements. If BIOS decides not to
exercise such rights to bring legal action within three (3) months of VGI giving
notice thereof to BIOS, VGI shall be entitled to do so in its own right if
legally permissible, provided, however, that BIOS through counsel of its own
selection, shall oversee such legal action and be provided the opportunity to
approve all actions which are case dispositive. All fees, costs and expenses of
any such infringement action shall be borne by the party bringing the action and
such party shall obtain any recovery or damages, if any, whether by judgment,
award, decree or settlement, including interest for past infringement. The
excess of such recoveries, damages and interest over VGI's out of pocket
expenses in connection with the prosecution or defense of such actions shall be
included in VGI's NET SALES under this Agreement for the benefit of BIOS. VGI
may settle any such actions solely at its own expense and through counsel of its
own selection; provided, however, that BIOS shall be entitled in each instance
to participate through counsel of its selection and at its own expense in any
such settlement and to approve the terms of such settlement, such approval not
to be unreasonably withheld.

            7.3 In the event that BIOS is involved with the enforcement and/or
defense of the PATENT RIGHTS by litigation, VGI may not withhold any payments
otherwise deemed earned and due to BIOS under Article 4 hereunder.


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            7.4 In any patent infringement suit that BIOS may institute to
enforce the PATENT RIGHTS pursuant to this Agreement, VGI shall, at the request
of BIOS, cooperate in all reasonable respects and, to the extent reasonably
possible, have its employees testify when requested and make available relevant
records, papers, information, samples, specimens, and the like during the term
of this Agreement.

                                    ARTICLE 8

                                PRODUCT LIABILITY

            8.1 VGI shall at all times during the term of this Agreement and
thereafter, indemnify, defend and hold, BIOS's trustees, directors, officers,
employees, affiliates and agents harmless against all claims, proceedings,
demands and liabilities, including legal expenses and reasonable attorneys'
fees, arising out of the death of or injury to any person or persons or out of
damage to property resulting from the production, manufacture, sales, use,
lease, importation, distribution, consumption, advertisement or other
disposition of the LICENSED PRODUCT(s) and arising from any breach of any
obligation hereof or negligence of VGI and/or its distributors, importers,
agents, transferees and sublicensees hereunder except to the extent that any
such claims, proceedings, demands or liabilities arise out of or were caused by
the negligence or default of BIOS.

            8.2 VGI shall obtain and carry in full force and effect commercial
and product liability insurance of an amount and scope which VGI shall deem
appropriate and BIOS shall be entitled to a certificate of coverage on request
on reasonable notice.


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            8.3 Except as otherwise expressly set forth in this Agreement, BIOS,
its trustees, directors, officers, employees, affiliates and agents make no
representations and extend no warranties of any kind, either express or implied,
including, but not limited to, warranties of merchantability, fitness for a
particular purpose, validity or patentability of any of the subject matter
covered under PATENT RIGHTS, and the absence of latent or other defects, whether
or not discoverable. Nothing in this Agreement shall be construed as a
representation made or warranty given by BIOS that the practice by VGI of the
license granted hereunder does not infringe the patent or other rights of any
third party. In no event shall BIOS, its trustees, directors, officers,
employees, affiliates and agents be liable for incidental or consequential
damages of any kind, including economic damage or injury to property and lost
profits, regardless of whether BIOS shall be advised, shall have other reason to
know, or in fact shall know of the possibility of such damages. VGI shall make
no statements, representations or warranties whatsoever to any third parties
which are inconsistent with such disclaimer given by BIOS.

            8.4 BIOS warrants that it is legally entitled to grant the existing
rights granted by this Agreement and that the PATENT RIGHTS for the '911 patent
are currently existing.

                                    ARTICLE 9

                                 EXPORT CONTROLS

            VGI, its distributors, agents, transferees and sublicensees shall
make all reasonable efforts, if not contrary to Canadian law, to comply with all
foreign and United States federal, state, and local laws, regulations, rules and
orders applicable to the testing, production, transportation, packaging,
labeling, export, import, sale and use of the LICENSED PRODUCTS. In particular,
VGI, its distributors, agents, transferees and sublicensees shall be responsible
for assuring compliance with all U.S. export and import laws and regulations
applicable to this license


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and their activities hereunder.

                                   ARTICLE 10

                         NON-USE OF NAMES; ANNOUNCEMENTS

            10.1 (a) VGI, its distributors, agents, transferees and sublicensees
shall not use the names or trademarks of BIOS nor any adaptation thereof, nor
the names of any of its employees, in any advertising, promotional or sales
literature without prior written consent obtained from BIOS, which consent shall
not be unreasonably withheld or delayed, or from said employee, in each case,
except that they may state that it is licensed by BIOS under the PATENT RIGHTS.

                  (b) BIOS, its distributors, agents, transferees and
sublicensees shall not use the names or trademarks of VGI nor any adaptation
thereof, nor the names of any of its employees, in any advertising, promotional
or sales literature without prior written consent obtained from VGI, which
consent shall not be unreasonably withheld or delayed, or from said employee, in
each case, except that they may say that BIOS has granted a license to VGI under
the PATENT RIGHTS.

            10.2 Each party agrees that, prior to any announcement by them
concerning this Agreement, its subsequent operation or performance or any
subsequent material connected with it, except as may be required by law, none
shall disclose the existence, substance or details of this Agreement without the
prior written consent of the others, such consent not to be unreasonably
withheld or delayed; provided that each PARTY may disclose information
concerning this Agreement to its lenders, and its stockholders, and to the
investment and business public as it may deem necessary or appropriate to
fulfill its obligations of disclosure to them. Furthermore, nothing herein shall
prevent any party from disclosing such information as is reasonably necessary


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<PAGE>

to its distributors, agents, transferees or sublicensees; provided however, each
party shall take such steps as necessary to ensure that such distributors,
agents, transferees and sublicensees conduct themselves as if they were bound by
the provisions of this paragraph. In cases in which disclosure may be required
by law, the disclosing party, prior to such disclosure, shall so far as is
practicable, notify the non-disclosing parties of the contents of the proposed
disclosure. Consistent with applicable law, and stock exchange requirements, the
non-disclosing parties shall have the right to make reasonable changes to the
disclosure to protect their interests. The disclosing party shall not
unreasonably refuse to include such changes in its disclosure. Once a joint
announcement of the parties has been made, no party shall have any obligation of
non-disclosure with respect to information contained in the joint announcement,
provided however the parties agree that all other information with respect to
this Agreement shall remain subject to the non-disclosure obligation.

                                   ARTICLE 11

                               DISPUTE RESOLUTION

            11.1 In the event of any controversy, dispute, disagreement or claim
arising out of or in connection with or relating to any provision of this
Agreement or the breach thereof, the parties shall try to settle such conflicts
amicably between themselves. Subject to the limitation stated in the final
sentence of this section, any party hereto who is unable to satisfy by mutual
agreement any claim or demand arising directly or indirectly out of or in
connection with this Agreement, the interpretation hereof, the performance or
non-performance and/or the rights, obligations or liabilities of the parties
hereunder, shall cause such claim or demand to be determined by submission
thereof to arbitration before the American Arbitration Association pursuant to
the Connecticut Arbitration Law and the rules then applicable of the American
Arbitration Association. A submission to arbitration shall be filed within
ninety (90) days after


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<PAGE>

written notice of failure to agree has been given, and in no event after the
date upon which institution of legal proceedings based on such controversy or
claim would be barred by the applicable statute of limitation.

            11.2 All arbitration proceedings shall be heard and decided by a
single arbitrator mutually acceptable to VGI and BIOS. In the event that VGI and
BIOS are unable to agree on the selection of a single arbitrator, then the
proceedings shall be heard by a panel of three arbitrators, one of whom is
chosen by VGI, one of whom is chosen by BIOS, and the third of whom is appointed
by the American Arbitration Association from its panel of arbitrators. Such
arbitration shall be held in New Haven, Connecticut. The award through
arbitration shall be final and binding. Either party may enter any such award in
a court having jurisdiction or may make application to such court for judicial
acceptance of the award and an order of enforcement, as the case may be.
Notwithstanding the foregoing, either party may, without recourse to
arbitration, assert against the other party a third-party claim or cross-claim
in any action brought by a third party to which the subject matter of this
Agreement may be relevant.

            11.3 Notwithstanding the foregoing, nothing in this Article shall be
construed to waive any rights or timely performance of any obligations existing
under this Agreement.

                                   ARTICLE 12

                                   TERMINATION

            12.1 If either party shall cease to carry on its business, it shall
promptly communicate such action to the other within thirty (30) days and this
Agreement shall be terminable upon written notice by the other. Failure to give
notice of termination or take any step or action in the case of any violation or
breach of the terms of this Agreement shall not be deemed


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<PAGE>

a waiver of any rights, remedies or causes of action, nor prejudice any rights
with respect to such violation or breach.

            12.2 Should VGI fail to make any payment whatsoever due and payable
to BIOS hereunder, unless the failure to make such payment is the result of a
bona fide dispute as to whether the amount in issue is in fact due and payable
hereunder, BIOS shall have the right to terminate this Agreement effective on
thirty (30) days' written notice, unless VGI shall make all such payments to
BIOS within said thirty (30) day period. Upon the expiration of the thirty (30)
day period, if VGI shall not have made all such payments to BIOS, the rights,
privileges and license granted hereunder shall automatically terminate.

            12.3 Upon any material breach or default of this Agreement by either
party other than those occurrences set out in paragraphs 12.1 and 12.2
hereinabove, which shall always take precedence in that order over any material
breach or default referred to in this paragraph, the other party shall have the
right to terminate this Agreement (including in the case of BIOS the rights,
privileges and license granted hereunder) effective on sixty (60) days' written
notice. Such termination shall become automatically effective unless the
defaulting party shall have cured any such material breach or default prior to
the expiration of the sixty (60) day period.

            12.4 Upon termination of this Agreement for any reason, nothing
herein shall be construed to release either party from any obligation that
matured prior to the effective date of such termination; and Articles 1, 4, 5,
6, 7, 8, 9, 10, 11, 12, 13, and 15 shall survive any such termination of this
Agreement. VGI, its distributors, agents, transferees, sublicensees and
importers may, however, after the effective date of such termination, sell all
LICENSED PRODUCTS, and complete LICENSED PRODUCTS in the process of manufacture
at the time


                                      -18-
<PAGE>

of such termination and sell the same within one (1) year of the effective date
of the termination of this Agreement, provided that they shall make the payments
to BIOS as required by Article 4 of this Agreement and shall submit the reports
required by Article 5 hereof.

            12.5 Upon termination of this Agreement for any reason, any
sublicensee not then in default may seek a license directly from BIOS and BIOS
shall give serious consideration to the grant of such a license.

            12.6 Waiver by either party of a single default or breach of a
succession of defaults or breaches shall not deprive such party of any right to
terminate this Agreement pursuant to the terms hereof upon the occasion of any
subsequent default or breach.

                                   ARTICLE 13

                                PAYMENTS, NOTICES
                            AND OTHER COMMUNICATIONS

            Any payment, notice or other communication pursuant to this
Agreement shall be sufficiently made or given on the date of mailing if sent to
such party by certified or registered mail, return receipt requested, postage
prepaid, addressed to it at its address below or as it shall designate by
written notice given to the other party:

            In the case of BIOS:

                  Chief Financial Officer
                  BIOS Laboratories, Inc.
                  Five Science Park
                  New Haven, Connecticut
                  U.S.A. 06511


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<PAGE>

            In the case of VGI:

                  Attention: The President
                  Visible Genetics, Inc.
                  Suite 1000, 700 Bay Street
                  Toronto, Ontario
                  Canada M5G 1Z6

and shall be deemed received four (4) working days thereafter (excluding public
holidays).

                                   ARTICLE 14

                                   ASSIGNMENT

            VGI shall have the right to assign this Agreement to any person,
firm or corporation upon the condition precedent that (a) any such assignee
shall be approved by BIOS (whose approval shall not be unreasonably withheld or
delayed) and (b) any such assignee shall, by a writing approved by BIOS (whose
approval shall not be unreasonably withheld or delayed) as sufficient in form
and content, agree to assume and to perform all of the obligations on VGI's part
to be performed hereunder. A copy of the fully executed original of said
assignment and assumption agreement shall be delivered to BIOS before the
assignment shall become operative. VGI covenants that after such permitted
assignment, it will not directly or indirectly participate in, contribute,
cause, suffer or permit, when within its power to permit, any breach or
violation of or failure to perform any of the covenants or provisions of this
Agreement by or on the part of its assignee.

                                   ARTICLE 15

                            MISCELLANEOUS PROVISIONS

            15.1 This Agreement shall be construed, governed, interpreted and
applied in accordance with the laws of the State of New York, U.S.A., except
where the federal laws of the


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<PAGE>

United States are applicable and have precedence.

            15.2 The PARTIES acknowledge that the Research Agreement and
Paragraphs 2 and 3 of the Letter of Understanding between the PARTIES dated July
24, 1996 survive this Agreement, and all other prior agreements,
representations, undertakings, understandings, affirmations and promises
relating to the subject matter hereof are merged and superseded hereby. Neither
of the PARTIES has entered into this Agreement in reliance upon any
representation, warranty or undertaking by or on behalf of another party which
is not expressly set out or referenced herein.

            15.3 This Agreement shall not be subject to any change or
modification except by the execution of a written instrument subscribed to by
the PARTIES.

            15.4 This Agreement shall be binding upon, and inure in favor of,
the PARTIES and their respective heirs, personal representatives, successors and
assigns.

            15.5 The provisions of this Agreement are deemed separable, and in
the event that any provision of this Agreement shall be determined to be void,
invalid or unenforceable by a judgment or a decree of a court of final
jurisdiction or by a lower court whose judgment or decree becomes final by
reason of or failure to appeal therefrom, such invalidity or unenforceability
shall not in any way affect the validity or enforceability of any other
provision or provisions hereof, but shall be confined in its operation to the
provisions adjudged invalid and unenforceable.

            15.6 Any delays in or failure by either PARTY in performance of any
obligations hereunder shall be excused if and to the extent caused by such
occurrences beyond such party's


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<PAGE>

reasonable control, including but not limited to such occurrences as acts of
God, strikes or other labor disturbances, fire, earthquake, sabotage, war and
other causes which cannot reasonably be controlled by the party who failed to
perform. Either PARTY may terminate this Agreement by written notice if such
occurrences extend for a period of not less than six (6) months.

            15.7 This Agreement may be executed in two or more counterparts, any
one of which need not contain the signatures of more than one party, but all
such counterparts taken together will constitute one and the same Agreement.

            IN WITNESS WHEREOF, the PARTIES have caused this Agreement to be
duly executed in duplicate originals by their duly authorized representatives on
the day and year set forth below.

BIOS LABORATORIES, INC.                    VISIBLE GENETICS, INC.


By /s/ Gualberto Ruano                     By /s/ John Stevens
   ------------------------------             ------------------------------

Name GUALBERTO RUANO                       Name John Stevens
     ----------------------------               ----------------------------

Title Chief Executive Officer              Title CEO
      ---------------------------                ---------------------------

Date 21 November 1996                      Date 21 Nov 1996
     ----------------------------               ----------------------------


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