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                                                                   EXHIBIT 10.14

STATE OF GEORGIA

GWINNETT COUNTY

      This Lease Agreement is made this 22nd day of Dec., 1999, by and between
DUKE-WEEKS REALTY LIMITED PARTNERSHIP, an Indiana limited partnership,
hereinafter referred to as "Landlord", and VISIBLE GENETICS CORP. hereinafter
referred to as "Tenant".

                                 LEASED PREMISES

      1.01 Landlord hereby leases to Tenant, and Tenant hereby leases from
Landlord, the property hereinafter referred to as the LEASED PREMISES, described
as approximately 99,822 rentable square feet of office/warehouse at 100
Crestridge Drive, Suwanee, Georgia, Gwinnett County, in Horizon Park, as shown
on the plan attached hereto as Exhibit "A" and by reference incorporated herein.
The building in which the Leased Premises are located is herein referred to as
the "Building"; and the real property on which the building is situated is
herein referred to as the "Land".

                                      TERM

      2.01 TO HAVE AND TO HOLD said Leased Premises for a term of ten (10) years
one (1) month, commencing on February 15, 2000 as this date may be adjusted as
set forth herein ("Commencement Date"), and continuing until March 15, 2010.

                                     RENTAL

      3.01 As rental for the Leased Premises, Tenant agrees to pay to Landlord,
without offset or abatement (except as otherwise provided herein), the base
rental as set forth below:

21,000 square feet ("Initial Space")

      February 15, 2000 -- March 14, 2000 $7,367.50/month

Entire Leased Premises:

March 15, 2000 -- March 14, 2001    $35,020.89/month    $420,250.68/year
March 15, 2001 -- March 14, 2002    $36,102.29/month    $433,227.48/year
March 15, 2002 -- March 14, 2003    $37,183.70/month    $446,204.40/year
March 15, 2003 -- March 14, 2004    $38,265.10/month    $459,181.20/year
March 15, 2004 -- March 14, 2005    $39,429.69/month    $473,156.28/year
March 15, 2005 -- March 14, 2006    $40,594.28/month    $487,131.36/year
March 15, 2006 -- March 14, 2007    $41,842.06/month    $502,104.72/year
March 15, 2007 -- March 14, 2008    $43,089.83/month    $517,077.96/year
March 15, 2008 -- March 14, 2009    $44,420.79/month    $533,049.48/year
March 15, 2009 -- March 14, 2010    $45,751.75/month    $549,021.00/year


on or before the first day of each calendar month beginning on February 15, 2000
and thereafter for the remainder of the term, together with any other additional
rental as hereinafter set forth. Tenant shall pay interest at a rate of twelve
percent (12%) per annum on all late payments of rent. If the Lease shall
commence on any date other than the first day of a calendar month, or end on any
date, other than the last day of a calendar month, rent for such month shall be
prorated. Tenant has deposited with Landlord, upon delivery of this Lease
Agreement, an amount equal to Two Hundred Forty Five Thousand One Hundred Forty
Six and 14/100 ($245,146.14) Dollars, a portion of which, or Thirty Five
Thousand Twenty and 80/100 ($35,020.80) Dollars, is to be applied as first
month's rental, the remaining portion, or Two Hundred Ten Thousand One

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Hundred Twenty Five and 34/100 ($210,125.34) Dollars, shall be held as a
refundable interest bearing security deposit. At Tenant's option, Landlord shall
obtain a Certificate of Deposit in a federally-insured bank ("CD") with the
Tenant's security deposit, in which event Tenant shall be entitled to receive
all interest as paid unless and until such CD is used to cure a default
hereunder, but with payment to Tenant of any unpaid, accrued or future interest
commencing thereafter again if the security deposit is fully restored by Tenant.
Landlord may apply all or any pan of the security deposit to cure any default by
Tenant hereunder and Tenant shall promptly restore to the security deposit all
amounts so applied upon invoice therefor. If Tenant shall fully perform each
provision of this Lease, any portion of the security deposit which has not been
appropriated by Landlord in accordance with the provisions hereof shall be
returned to Tenant, with interest, within thirty (30) days after the expiration
of the term of this Lease. If at the commencement of the fourth year of the
Lease term there has been no breach of any undertaking by Tenant under the Lease
beyond any applicable notice and grace period and Visible Genetics, Inc.,
("Guarantor") has achieved "tangible net worth" (as hereinafter defined) of
Thirty Million Dollars ($30,000,000.00), then the Landlord agrees to refund
fifty percent (50%) of the security deposit together with accrued interest to
Tenant. Tangible Net Worth for the purpose of this Lease shall mean Tangible Net
Worth as determined by generally accepted accounting principles ("GAAP") which
for purposes hereof shall include cash and account receivables, and as certified
by the Chief Financial Officer of the Tenant.

      In addition, within thirty days of Lease execution, Tenant shall cause
Visible Genetics, Inc., ("Guarantor") to issue to Landlord, or its affiliate, a
warrant to purchase 10,000 shares of common stock of the Guarantor at a strike
price equal to the closing price of the Guarantor's common stock on the date of
Lease execution, said warrant to be in the form attached hereto as Exhibit "H".
For the purposes of this section, the date of Lease execution shall be the day
on which Tenant has executed the Lease.

      3.02 As consideration for Tenant's performance of all obligations to be
performed by Tenant under this Lease, Landlord shall contribute $5.50 per
rentable square foot contained in the Leased Premises, which is the sum of Five
Hundred Forty Nine Thousand Twenty One and 00/100 ($549,021.00) (the
"Allowance") towards the cost of tenant improvements to the Leased Premises on
the basis set forth in the plans and specifications attached, or to be attached,
hereto in Exhibit "B" (`Tenant improvements"). A construction management fee
equal to a $.25 per square foot contained in the Leased Premises shall be
deducted from the Allowance and paid to Landlord. The Allowance shall be used
for the construction of the Tenant improvements, alterations, improvements,
fixtures and equipment which become part of or are attached or affixed to the
Leased Premises, including walls, wall coverings and floor coverings, but
excluding trade fixtures, furniture and furnishings or other personal property.
In the event the cost of the Tenant Improvements exceeds the Allowance, the
excess shall be paid by Tenant. The construction management fee shall not apply
to such excess paid by Tenant.

      Landlord will disburse the Allowance to Tenant (in two equal draws), upon
compliance by Tenant with the following conditions:

      (a) The first draw shall be made when Tenant has approval by Gwinnett
County of all rough in inspections (framing, electrical, plumbing and HVAC) and
all walls have been double-sided.

            (i) Tenant shall submit to Landlord an application and certificate
for payment, showing the amount of the improvements installed or constructed
through the date of the draw request. The form shall be signed by Tenant and its
contractor and shall be accompanied by such documentation as is reasonably
required by Landlord to verify and ensure that the work shown on the draw
request has been completed.

            (ii) Tenant shall submit to Landlord such lien waivers and
affidavits as are necessary, in Landlord's opinion, to ensure that the Leased
Premises, the Building and the Land remain free and clear of all liens and other
encumbrances arising as a result of the installation and construction of the
Improvements. All such lien waivers and affidavits shall be satisfactory in form
and substance to Landlord.


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      (b) The final draw will be paid to Tenant upon satisfaction of the
following conditions:

            (i) Tenant shall provide to Landlord such documentation as is
reasonably required by Landlord to verify and ensure that the Tenant
Improvements have been substantially completed (so called punch list items
excepted);

            (ii) a certificate of occupancy or a temporary certificate of
occupancy for the Leased Premises has been issued by the Gwinnett County and
City of Suwanee, if applicable. (Tenant agrees it will not occupy the Leased
Premises until a certificate of occupancy or a temporary certificate of
occupancy for the Leased Premises has been issued by the appropriate
governmental authority(ies).)

            (iii) Tenant shall submit to Landlord such lien waivers and
affidavits as are necessary, in Landlord's opinion, to ensure that the Leased
Premises, the Building and the Land remain free and clear of all liens and other
encumbrances arising as a result of the installation and construction of the
Tenant Finish Improvements. All such lien waivers and affidavits shall be
satisfactory in form and substance to Landlord.

      3.03 In addition to the base rental, Tenant agrees to pay Landlord as
additional rental, its pro rata share of the amounts described in subparagraphs
(a) and (b) below. Each year during the term hereof, Landlord shall give Tenant
written notice of its estimate of the amount of common area maintenance charges
and common area utility charges (collectively "Charges") for the Leased Premises
for the calendar year. Tenant shall, thereafter, during that calendar year, pay
to Landlord one-twelfth (1/12) of the amount set forth in said statement at such
time as its monthly installments of base rental hereunder are due and payable.
At such time as Landlord is able to determine the actual Charges for such
calendar year, Landlord shall deliver to Tenant a statement thereof and in the
event the estimated Charges differ from the actual Charges, any adjustment
necessary shall be made to additional rental payments next coming due under this
paragraph.

      (a) Landlord agrees to maintain those areas around the Building and in the
Project, including parking areas, planted areas, signs and landscaped areas.
Tenant agrees to pay to Landlord as additional rental its pro rata share of all
ground maintenance charges and other common area charges and expenses for the
Building and the Land ("CAM Charges"), estimated to be $.25 per square foot per
year. The term "grounds maintenance" shall include, without limitation, all
landscaping, planting, lawn and grounds care, irrigation costs, all repairs and
maintenance to the grounds, signs and other common areas around the Building and
in the Project and to all sidewalks, driveways, loading areas and parking areas,
all of which Landlord agrees to perform. CAM Charges shall not include items of
a capital nature.

      (b) Tenant shall pay directly to the utility provider the charges for gas,
water, electricity, fuel, light and heat, garbage collection services and for
all other separately metered utilities and sanitary services rendered to the
Leased Premises and used by Tenant. In the event any utilities furnished to the
Building or the Leased Premises are not separately metered, Tenant shall pay to
Landlord, as additional rental, the charges for all such services rendered to
the Leased Premises used by Tenant, unless Landlord reasonably determines that
Tenant's use of the Leased Premises justifies a disproportionate allocation of
utility costs to Tenant.

      3.04 Tenant agrees to pay as additional rent to Landlord, upon demand, its
pro rata share of any utility surcharges, or any other costs levied, assessed or
imposed by, or at the direction of, or resulting from statutes or regulations,
or interpretations thereof, promulgated by any Federal, State, Municipal or
local governmental authorities in connection with the use or occupancy of the
Leased Premises.

                         DELAY TN DELIVERY OF POSSESSION

      4.01 If Landlord cannot deliver the Initial Space to Tenant in such a
condition that allows the Tenant's contractor to obtain an interior finish
building permit for construction of the Tenant Improvements on or before the day
that Tenant executes the Lease, and the delay is in no way attributable to
Tenant Delays or an event of Force Majeure (as hereinafter defined) this Lease
shall not be void or voidable, however Landlord shall pay Tenant on demand, as
agreed upon


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liquidated damages, the sum of Three Thousand and 00/100 ($3,000.00) Dollars for
each business day thereafter until the Initial Space is delivered to Tenant.
Landlord and Tenant agree the above amount is a reasonable estimate of the
damages Tenant would sustain if the completion of the Initial Space is delayed,
and that it is not and shall not be construed as a penalty. Provided, however,
in the event the Commencement Date is delayed due to Tenant Delays (as
hereinafter defined), than Tenant shall commence payment of rent as set forth
herein on the date that the Commencement Date would have occurred but for the
Tenant Delays.

      4.02 If Landlord cannot deliver the remaining Leased Premises to Tenant in
such a condition that allows the Tenant's contractor to obtain an interior
finish building permit for construction of the Tenant Improvements on January
15, 2000, and the delay is in no way attributable to Tenant Delays or an event
of Force Majeure (as hereinafter defined) this Lease shall not be void or
voidable, however Landlord shall pay Tenant on demand, as agreed upon liquidated
damages, the sum of Three Thousand and 00/100 ($3,000.00) Dollars for each
business day thereafter until the Initial Space is delivered to Tenant. Landlord
and Tenant agree the above amount is a reasonable estimate of the damages Tenant
would sustain if the completion of the Initial Space is delayed, and that it is
not and shall not be construed as a penalty. Provided, however, in the event the
Commencement Date is delayed due to Tenant Delays (as hereinafter defined), than
Tenant shall commence payment of rent as set forth herein on the date that the
Commencement Date would have occurred but for the Tenant Delays.

      4.03 In the event the Initial Space cannot be delivered to Tenant by the
date set forth in Section 4.01 above because of a Force Majeure event, then
notwithstanding any other provision herein Tenant's obligation to pay rent for
the Initial Space shall be abated until sixty (60) days after the date the
Initial Space is delivered to Tenant. In the event the remaining Leased Premises
cannot be delivered to Tenant by the date set forth in Section 4.02 above
because of a Force Majeure event, then notwithstanding any other provision
herein Tenant's obligation to pay rent for the remaining Leased Premises shall
be abated until sixty (60) days after the date the remaining Leased Premises is
delivered to Tenant.

      4.04 "Tenant Delays", as used herein, shall mean and refer to delays
directly or substantially attributable to or caused by Tenant or Tenant's
employees or agents. "Force Majeure", as used herein, shall mean a delay, not
within Landlord's control, in a party s performance hereunder due to act of God,
adverse weather, fire, earthquake, flood, explosion, war, invasion,
insurrection, riot, mob violence, sabotage, vandalism, failure of
transportation, strikes, lockouts, litigation, condemnation, requisition,
governmental restrictions including inability or delay in obtaining governmental
consents or permits, laws or orders of governmental, civil, military or naval
authorities, or any other cause, whether similar or dissimilar to the foregoing,
not within Landlord's control.

                             USE OF LEASED PREMISES

      5.01 The Leased Premises may be used and occupied only for manufacturing,
assembly, testing, warehousing and distribution of medical test and diagnostic
kits, medical diagnostics and screening, molecular biology laboratory, training,
showroom and general office purposes, some of which purposes may involve the
use, handling and storage of Class One, Class Two and Class Three biohazard
materials ("Permitted Biohazards") and for no other purpose or purposes, without
Landlord's prior written consent. Tenant shall promptly comply at its sole
expense with all laws, ordinances, orders, and regulations affecting the Leased
Premises and their cleanliness, safety, occupation and use. Tenant shall not do
or permit anything to be done in or about the Leased Premises that will in any
way increase the fire insurance upon the building. Tenant will not perform any
act or carry on any practices that may injure the building or be a nuisance or
menace to tenants of adjoining premises. Tenant shall not cause, maintain or
permit any outside storage on or about the Leased Premises, including pallets or
other refuse. The rear loading areas of the Tenant's unit must be clean and
unobstructed. On or before the Commencement Date, Tenant shall take possession
of, and, thereafter, continuously occupy the Leased Premises (if delivered as
provided herein) during the term of this Lease, and operate thereon the normal
business operations of Tenant.

       5.02 Tenant shall, at Tenant's sole cost and expense, comply fully with
all environmental laws and regulations, and all other legal requirements,
applicable to Tenant's operations at, on or


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within, or to Tenant's use and occupancy of, the Leased Premises. Tenant shall
not (either with or without negligence) cause or permit the escape, disposal or
release of any biologically or chemically active or other hazardous substances,
or materials. Tenant shall not allow the storage or use of such substances or
materials in any manner not sanctioned by law or by the typical standards
prevailing in the industry for the storage and use of such substances or
materials, nor allow to be brought into the Project any such materials or
substances except to use in the ordinary course of Tenant's business, and then
only after written notice is given to Landlord of the identity of such
substances or materials. Notwithstanding the above, Landlord understands and
agrees that Tenant's ordinary course of business may involve and require the use
of the Permitted Biohazards, and that Tenant may bring to, store on and use the
Leased Premises for its purposes such Permitted Biohazards without the further
consent of Landlord being required. Without limitation, hazardous substances and
materials shall include those described in the Comprehensive Environmental
Response, Compensation and Liability Act of 1980, as amended, 42 U.S.C. Section
9601 et seq., the Resource Conservation and Recovery Act, as amended, 42 U.S.C.
Section 6901 et seq., any applicable state or local laws and the regulations
adopted under these acts. If any lender or governmental agency shall ever
require testing to ascertain whether or not there has been any release of
hazardous materials, then the reasonable costs thereof shall be reimbursed by
Tenant to Landlord upon demand as additional charges if such requirement applies
to the Leased Premises. In addition, Tenant shall execute affidavits,
representations and the like from time to time at Landlord's request concerning
Tenant's best knowledge and belief regarding the presence of hazardous
substances or materials on the Leased Premises. In all events, Tenant shall
indemnify Landlord in the manner elsewhere provided in this lease from any
release of hazardous materials on the Leased Premises occurring while Tenant is
in possession, or elsewhere if caused by Tenant or persons acting under Tenant.
The within covenants shall survive the expiration or earlier termination of the
lease term.

      5.03 Landlord represents and warrants that on the Commencement Date, the
Leased Premises shall either be in compliance with all governmental codes,
ordinances, rules and regulations, including environmental laws, or if required
at such time, shall be brought into such compliance. Landlord hereby agrees to
indemnify, defend and hold Tenant harmless from and against any claim, action,
damage or liability incurred by, or filed or asserted against, Tenant, and
arising out of the presence of hazardous materials in, on, about or underneath
the Leased Premises and resulting from the actions or omissions of (i) any
parties in possession of the Leased Premises prior to Tenant's possession, or
(ii) Landlord or its servants, employees, agents, representatives, contractors
or invitees. Landlord shall hold harmless and indemnify Tenant for, from and
against any clean-up costs, remedial costs, preventative costs, and or
governmental fees, costs, expenses, charges or the like arising from any
presence or alleged presence of any hazardous or toxic substances (as those
terms are defined in any state or federal statute or regulation) on, in or under
the Leased Premises which were present on the Leased Premises prior to the
commencement of the term of the Lease or which were released by Landlord or any
third parties unrelated to Tenant at the property containing the Leased
Premises. Notwithstanding anything in the foregoing to the contrary, Tenant
shall have no liability to Landlord or to any other party with respect to the
presence of hazardous materials in, on, about or underneath the Leased Premises
unless directly caused by the acts or omissions of Tenant, its servants,
employees, agents, representatives, contractors, or invitees. Nothing in this
paragraph shall be interpreted as imposing any liability on Landlord for any
other costs or expenses incurred by Tenant including any consequential damages
or lost sales or profits of Tenant resulting from any such presence or alleged
presence.

                                    UTILITIES

      6.01 Landlord shall not be liable in the event of any interruption in the
supply of any utilities. Tenant agrees that it will not install any equipment
which will exceed or overload the capacity of any utility facilities and that if
any equipment installed by Tenant shall require additional utility facilities,
the same shall be installed by Tenant at Tenant's expense in accordance with
plans and specifications approved in writing by Landlord. Tenant shall be solely
responsible for and shall pay all charges for use or consumption of sanitary
sewer, water, gas, electricity and any other utility services. In the event
Landlord determines that it is advisable to separately meter any utility
services provided to the Leased Premises, Landlord shall have the right to
install a sub-meter and bill Tenant for the actual cost thereof, which shall be
paid to Landlord within fifteen days (15) following billing.


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                          ACCEPTANCE OF LEASED PREMISES

      7.01 Upon delivery of possession of the Leased Premises to Tenant, Tenant
agrees to execute and deliver to Landlord a Tenant's Acceptance of Premises, in
the form attached hereto as Exhibit "C", acknowledging that it has examined the
Leased Premises and accepts the same as being in the condition called for by
this Lease, and as suited for the uses intended by Tenant.

      7.02 A. Once the base building structure of the Initial Space is completed
and thereafter once the base building structure is completed as to the remaining
portion of the Leased Premises, the base building requirements are described in
Exhibit "G" attached hereto Tenant may enter upon the Initial Space or the
remaining portion of the Leased Premises for purposes of completing the Tenant
Improvements and for installing trade fixtures and telephones, erecting
temporary or permanent signs and doing such other work as may be appropriate or
desirable without being deemed thereby to have taken possession or obligated
itself to pay rent but Tenant agrees that: (a) Landlord shall have no liability
to Tenant for injury to any person or damage to any property of Tenant stored on
the Leased Premises except for damages caused by or resulting from the willful
acts, omissions or negligence of Landlord or its employees or agents, (b) Tenant
shall not interfere with Landlord's construction work on the Leased Premises,
(c) Tenant shall indemnify, protect and hold harmless Landlord from and against
any and all claims, demands, damages, losses, costs, expenses, liabilities and
actions at law or in equity based upon any occurrence or condition arising out
of or attributable to Tenant's acts, omissions, or negligence of Tenant or its
employees, contractors, agents or invitees exercise of such right, and (d)
Tenant shall be solely responsible for the permitting of any such work it
performs.

      B. Tenant and it's contractor, or contractors, shall be responsible for
the design, installation and construction of the Tenant Improvements to the
Leased Premises as shown on the plans and specifications (herein referred to as
the "Plans") set forth on Exhibit "B" attached hereto or as subsequently
attached hereto. Prior to the Tenant's commencing construction of the Tenant
Improvements, the Tenant must obtain the Landlord's approval of the Plans.
Landlord shall have three (3) business days after Tenant has submitted the
Plans, to review and approve the same. Landlord will notify Tenant in writing at
the time it approves the Plans which specific improvement, alteration, addition
or installation must be removed at the expiration or termination of this Lease,
provided that Landlord agrees that the Tenant Improvements identified on Exhibit
"B", or as they may be changed or added to prior to occupancy of the Leased
Premises by Tenant, need not be removed at the end of the term or any renewal or
extension thereof. Tenant shall have the right to make changes to the Plans with
Landlord's approval; however, changes to the Plans which increase the time for
completion of the Tenant Improvements, shall not delay commencement of payment
of rent under this Lease.

      C. All construction work done ,by Tenant in the Leased Premises shall be:
(i) completed by contractors previously approved by Landlord, Landlord
acknowledges that it approves of S&E Contractors, (ii) pursued diligently to
completion, and (iii) performed in a good and workmanlike manner, and in
compliance with all governmental regulations including, but not limited to, all
OSHA requirements. Tenant covenants and agrees that all contractors,
subcontractors and other persons or entities performing work for Tenant at the
Leased Premises will carry (i) liability insurance in the amount of
$1,000,000.00, and (ii) worker's compensation insurance in the amounts required
by law. In addition, Tenant and Landlord each shall use reasonable measures to
ensure that their contractors abide by the terms and conditions contained within
the Exhibit F attached hereto.

      D. Tenant covenants and agrees that all contractors, subcontractors and
other persons or entities performing work for Tenant at the Leased Premises
shall:

            (i) acknowledge Landlord as the general contractor on the shell and,
as such, Landlord shall be entitled to the final decision in all aspects of
Tenant's work which might impact the structural aspects of the Building;

            (ii) cooperate with Landlord in coordinating all work which might
interfere with that of the other;


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             (iii) take all precautions to protect the work of Landlord and its
subcontractors; and

            (iv) adhere to Landlord's safety requirements as detailed on the
attached Exhibit F.

      E. Tenant covenants and agrees that the contractor shall be required to
clean up and haul away all debris and trash generated in the construction of the
Tenant Improvements and to maintain a clean jobsite. Should Tenant's contractor
not remove trash and debris within three (3) days of written notice to comply,
Landlord shall have the right to perform this work and charge all costs to
Tenant.

      F. Landlord will cooperate with Tenant and its contractors in a timely
manner, including requesting that the architect and engineers be available as
reasonably needed to facilitate completion of the Tenant Improvements by Tenant
in a timely manner.

      G. Tenant hereby indemnifies Landlord against, and shall keep all portions
of the Leased Premises, the Building and the Land free from liens for any work
performed, material furnished or obligations incurred by Tenant. Should any
liens or claims be filed against all or any portion of the Leased Premises, the
Building or the Land by reason of Tenant's acts, omissions or work performed by
any person or entity, Tenant shall cause same to be discharged by bond or
otherwise within sixty (60) days following notice thereof. If Tenant fails to
cause any such lien or claim to be so discharged within the required time,
Landlord may cause same to be discharged and may make any payment that Landlord,
in its reasonable judgment, considers necessary, desirable or proper in order to
do so. All amounts paid by Landlord shall bear interest at the lower of (i)
twelve percent (12%) per annum, or (ii) the highest rate permitted under
applicable law, from the date of payment by Landlord and shall be payable by
Tenant to Landlord upon written demand.

                          ALTERATIONS, MECHANICS' LIENS

      8.01 Alterations may not be made to the Leased Premises without prior
written consent of Landlord, and any alterations of the Leased Premises
excepting movable furniture and trade fixtures, manufacturing, assembly, test,
laboratory and similar equipment shall at Landlord's option become part of the
realty and belong to Landlord.

      8.02 Should Tenant desire to alter the Leased Premises and Landlord gives
written consent to such alterations, at Landlord's option, Tenant shall contract
with a contractor approved by Landlord for the construction of such alterations.
Upon completion of the work, Tenant shall provide lien waivers from the
subcontractors or a final affidavit of lien waiver from the general contractor.
(Lien waivers and the Affidavit of Lien Waiver shall be in a form acceptable to
Landlord.)

      8.03 Notwithstanding anything in paragraph 8.02 above, Tenant may, upon
written consent of Landlord, install trade fixtures, machinery or other trade
equipment in conformance with all applicable laws, statutes, ordinances, rules,
regulations, and the same may be removed upon the termination of this Lease
provided Tenant shall not be in default under any of the terms and conditions of
this Lease, and the Leased Premises are not damaged by such removal. Tenant
shall return the Leased Premises on the termination of this Lease in the same
condition as when rented to Tenant, reasonable wear and tear and fire and
casualty only excepted. Tenant shall keep the Leased Premises, the building and
property in which the Leased Premises are situated free from any liens arising
out of any work performed for, materials furnished to, or obligations incurred
by Tenant. All such work provided for above, shall be done at such times and in
such manner as Landlord may from time to time designate. Tenant shall give
Landlord written notice five (5) days prior to employing any laborer or
contractor to perform work resulting in an alteration of the Leased Premises so
that Landlord may post a notice of non-responsibility. Tenant will pay or cause
to be paid all costs and charges for work done by Tenant or caused to be done by
Tenant in or to the Leased Premises or any property in which Landlord may hold
any interest, and for all materials furnished for or in connection with such
work. Tenant will indemnify Landlord against, and hold harmless Landlord against
the liens and claims of lien and all other liabilities, liens, claims and
demands on account of such work by or on behalf of Tenant. If any such lien at
any time is filed against the Leased Premises or any part of the Building,
Tenant shall immediately cause such lien to be discharged of record, or at its
discretion bond off the lien pursuant to O.C.G.A. Sec. 44-14-364. Nothing
herein will be deemed the consent or agreement of Landlord to subject Landlord's
interest in the Leased Premises or Building to liability under any mechanics or
other lien law. In the event that Tenant fails to cause a lien which has been
filed to be discharged, or shall fail to bond off said lien as herein provided,
within ten (10) days of notice of said lien, in addition to all other rights and
remedies it may have under the Lease or at law, Landlord may, at its option, pay
such charge and related costs and interests and said amount and expenses,
including reasonable attorneys' fees shall be immediately due from Tenant to
Landlord as additional rent.

                          QUIET CONDUCT/QUIET ENJOYMENT

      9.01 Tenant shall not commit, or suffer any waste upon the Leased
Premises, or any nuisance, or other act or thing which may disturb the quiet
enjoyment of any other tenant in the Building or any building in the project in
which the Leased Premises are located.

      9.02 So long as Tenant is not in default in the payment of rent, or other
charges or in the performance of any of the other terms, covenants, or
conditions of the Lease, Tenant shall not be disturbed by Landlord or anyone
claiming by, through or under Landlord in Tenant's possession, enjoyment, use
and occupancy of the Leased Premises during the original or any renewal term of
the Lease or any extension or modification thereof

                             FIRE INSURANCE, HAZARDS

      10.01 No use shall be made or permitted to be made of the Leased Premises,
nor acts done which might increase the existing rate of insurance upon the
building or cause the cancellation of any insurance policy covering the
building, or any part thereof, nor shall Tenant sell, or permit to be kept, used
or sold, in or about the Leased Premises, any article which may be prohibited by
the Standard form of fire insurance policies. Tenant shall, at its sole cost and
expense, comply with any and all requirements pertaining to the Leased Premises,
of any insurance organization or company, necessary for the maintenance of
reasonable fire and public liability insurance, covering the Leased Premises,
building and appurtenances. Tenant's permitted uses as described elsewhere
herein shall be deemed not to be in violation of this Section but if there are
increased insurance premium costs resulting therefrom Tenant shall be
responsible for paying such costs.

       10.O2 Tenant shall maintain in full force and effect on all of its Tenant
Improvements, inventory, fixtures and equipment in the Leased Premises a policy
or policies of fire and extended coverage insurance with standard coverage
endorsement to the extent of at least eighty percent (80%) of their insurable
value.. Landlord will not carry insurance on Tenant's possessions. Tenant shall
furnish Landlord with a certificate of such policy within thirty (30) days of
the commencement of this Lease, and whenever required, shall satisfy Landlord
that such policy is in full force and effect.

                                 INDEMNIFICATION

      11.01 Except to the extent of claims arising from the negligence,
omissions or willful misconduct of Landlord or its agents, contractors or
employees Tenant shall indemnify and hold harmless Landlord against and from any
and all claims arising from Tenant's use of the Leased Premises, or the conduct
of its business or from any activity, work, or thing done, permitted or suffered
by the Tenant in or about the Leased Premises, and shall further indemnify and
hold harmless Landlord against and from any and all claims arising from any
breach or default in the performance of any obligation on Tenant's part to be
performed under the terms of this Lease, or arising from any act, neglect, fault
or omission of the Tenant, or of its agents or employees, and from and against
all costs, attorney's fees, expenses and liabilities incurred in or about such
claim or any action or proceeding brought relative thereto and in case any
action or proceeding be brought against Landlord by reason of any such claim,
Tenant upon notice from Landlord shall defend the same at Tenant's expense by
counsel, chosen by Tenant and who is reasonably acceptable to Landlord. Tenant,
as a material part of the consideration to Landlord, hereby assumes all risk of
damage to property or injury to persons in or about the Leased Premises from any
cause whatsoever except that which is caused by the failure of Landlord to
observe any of the terms and conditions of this Lease where such failure has
persisted for an unreasonable period of time after written notice of such
failure, and Tenant hereby waives all claims in respect thereof against
Landlord. B


                                       8
<PAGE>

      11.02 Landlord shall indemnify Tenant and hold Tenant harmless against and
from all claims arising from the negligence, omissions or willful misconduct of
Landlord, its agents, employees or contractors, with respect to the Leased
Premises.

      11.03 The obligations of Landlord and Tenant under this paragraph arising
by reason of any occurrence taking place during the term of this Lease shall
survive the termination or expiration of this Lease.

                                 WAIVER OF CLAIMS

      12.01 Notwithstanding any indemnity granted herein, and notwithstanding
any other term or provision of the Lease to the contrary, Landlord and Tenant
hereby both release the other and their respective employees, agents and
invitees from and waive any claims either may have against the other and their
employees, agents, servants or invitees for any loss or damage to the Building,
Leased Premises, Land, Project, improvements on or to the Building, Leased
Premises, Land, Project, or the contents of the foregoing, and any personal
property stored or placed thereon by either of them caused by any of the perils
insurable against under fire and extended coverage insurance policies with "all
risks" endorsement, whether such damage or loss was caused by the negligence of
either of them or their respective employees, agents, servants or invitees. The
foregoing mutual release and waiver of subrogation shall apply whether or not
such insurance on the Building, Leased Premises, Land, Project improvements,
contents, and/or personal property was in force at the time of the loss of
damage. Moreover, each party agrees to take all actions necessary to make the
foregoing release effective and binding upon their respective insurance carriers
so that such carriers specifically waive any right of subrogation that such
carriers might otherwise have against the other party and/or their respective
employees, agents, servants or invitees.

                                     REPAIRS

      13.01 Tenant shall, at its sole cost, keep and maintain the Leased
Premises and appurtenances and every part thereof (excepting foundations,
exterior walls, exterior glass and frames (to extent installed by Landlord) and
structural elements including roofs which Landlord agrees to repair) including
by way of illustration and not by way of limitation all windows, doors, any
store front and the interior of the Leased Premises, including all plumbing,
heating, air conditioning, sewer, electrical systems and all fixtures and all
other similar equipment serving the Leased Premises in good and sanitary order,
condition, and repair, reasonable wear and tear and fire and casualty excepted.
Tenant shall be responsible for all pest control within the Leased Premises,
including, but not limited to the eradication of any ants or termites should
infestation be observed during the term of the Lease. Tenant shall, at its sole
cost, keep and maintain all utilities, fixtures and mechanical equipment used by
Tenant in good order, condition, and repair, reasonable wear and tear and fire
and casualty excepted. All windows shall be washed and cleaned as often as
necessary to keep them clean and free from smudges and stains. In the event
Tenant fails to maintain the Leased Premises as required herein or fails to
commence repairs (requested by Landlord in writing) within thirty (30) days
after such request, or fails diligently to proceed thereafter to complete such
repairs, Landlord shall have the right in order to preserve the Leased Premises
or portion thereof, and/or the appearance thereof, to make such repairs or have
a contractor make such repairs and charge Tenant for the cost thereof as
additional rent, together with interest at the rate of twelve percent (12%) per
annum from the date of making such payments.

      13.02 Landlord agrees to keep in good repair the foundations, exterior
walls, exterior glass and frames (to extent installed by Landlord) and
structural elements including roof of the Leased Premises except repairs
rendered necessary by the negligence of Tenant, its agents, employees or
invitees. Landlord gives to Tenant exclusive control of Leased Premises and
shall be under no obligations to inspect said Leased Premises. Tenant shall
promptly report in writing to Landlord any defective condition known to it which
Landlord is required to repair, and Landlord shall move with reasonable
diligence to repair such item. Failure to report such defects shall make Tenant
responsible to Landlord for any additional liability incurred by Landlord by
reason of Tenant's failure to report such defects.


                                        9
<PAGE>

      13.03 Tenant shall obtain upon occupancy and keep current during the lease
term a service maintenance contract on the heating, ventilation and air
conditioning (HVAC) equipment serving the Leased Premises. The contract shall
be between Tenant and a dealer-authorized company acceptable to Landlord, and
shall at a minimum provide for an equipment check and tune-up service each
spring and fall, and filter and lubrication service every three months. A copy
of said contract shall be provided to Landlord, as well as any modification,
extension, renewal or replacement thereof.

      13.04 Landlord shall assign to Tenant all warranties which are legally
assignable, and if not assignable, shall cooperate with Tenant to enforce such
warranties. Landlord agrees to assign any and all manufacturers' warranties
directly to the Tenant, which warranties shall include, but not be limited to,
warranties for heating, ventilating and air conditioning systems, which shall be
the standard warranties available from the manufacturers.

                               SIGNS, LANDSCAPING

      14.01 Landlord shall have the right to control landscaping and Tenant
shall make no alterations or additions to the landscaping. Tenant shall have the
right, at their sole cost and expense, to construct a monument sign for the
Building comparable to other monument signs in the Project provided, Landlord
shall have the right to approve the placing of such signs and the size and
quality of the same. So long as Tenant occupies at least sixty percent (60%) of
the Building, Tenant shall be able to have exclusive use of any monument size
installed by Tenant. Tenant shall place no exterior signs on the Leased Premises
without the prior written consent of Landlord. Any signs not in conformity with
the Lease may be immediately removed by Landlord. Tenant shall have the right to
install a fence around the perimeter of the Building, provided however, Landlord
shall have the right to approve the size, materials, installation and appearance
of said fence, which approval shall not be unreasonably withheld, conditioned or
delayed. The Landlord agrees to pay for fifty percent (50%) of the fence up to a
maximum amount of Two Thousand Five Hundred Dollars ($2,500.00). Upon the
expiration of this Lease, if Landlord requests, Tenant shall promptly remove
said fence and correct any damage to the Property in any manner whatsoever
caused by the same.

                                ENTRY BY LANDLORD

      15.01 Tenant shall permit Landlord and Landlord's agents to enter the
Leased Premises at all reasonable times for the purpose of inspecting the same
or for the purpose of maintaining the building, or for the purpose of making
repairs, alterations, or additions to any portion of the building, including the
erection and maintenance of such scaffolding, canopies, fences and props as may
be required, or for the purpose of posting notices of non-responsibility for
alterations, additions, or repairs, or for the purpose of showing the Leased
Premises to prospective tenants, or placing upon the building any usual or
ordinary "for sale" signs, without any rebate of rent and without any liability
to Tenant for any loss of Occupation or quiet enjoyment of the Leased Premises
thereby occasioned; and shall permit Landlord at any time within six (6) months
prior to the expiration of this Lease, to place upon the Leased Premises any
usual or ordinary "to let" or "to lease" signs. Any entry by Landlord shall be
made during regular business hours or as otherwise acceptable to Tenant and
shall be made with not less than 24 hours. Written notice to Tenant (other than
in an emergency). In an emergency, Landlord shall have the right to enter the
Leased Premises for any proper purpose. Tenant shall have the right to install
an electronic or other security system, provided however it is previously
approved by Landlord and, Landlord shall at all times have and retain a key or
mechanism for the security system for the ability to unlock all of the exterior
doors about the Leased Premises. Notwithstanding the foregoing, Landlord shall
only have access to areas of the Leased Premises that contain the Permitted
Biohazards when accompanied by an employee or an agent of the Tenant that is
trained in the proper handling of such materials. Tenant shall have quiet
enjoyment and possession of the Leased Premises throughout the term of this
Lease, subject, however, to the terms and conditions hereof.

                                      TAXES

      16.01(a) Tenant shall, without notice or demand, as additional rent, pay
and discharge, on or before the last day on which the same may be paid without
penalty, "all taxes", (as hereinafter defined) which shall or may during the
term be levied, assessed or imposed on or become a lien


                                       10
<PAGE>

upon or grow due or payable out of or for or by reason of the Leased Premises
or any part thereof, or the Landlord's interest in the real property described
on Exhibit "A" hereto. For the purposes hereof "taxes" means all taxes at any
time imposed by the United States of America or by any state, city, county or
other political or taxing subdivision thereof upon or against this Lease, the
Leased Premises, the use or occupancy thereof, the buildings, improvements or
personality thereon, and all assessments imposed subsequent to the execution and
delivery of this lease by both Landlord and Tenant (including assessments for
benefits from public works or improvements, whether commenced or completed prior
to the commencement of the term hereof and whether or not to be completed within
said term), levies, license fees, permit fees, water rents and charges, sewer
rents, excises, franchises, imposts, interest, costs, penalties and charges,
general and special, ordinary and extraordinary, of whatever name, nature and
kind, and whether or not within the contemplation of the parties hereto, which
are now or may hereafter be levied, assessed, charged or imposed upon or against
this Lease, the Leased Premises, the use or occupancy thereof, or the building,
improvements or personal property thereon or which are or may become a lien on
any thereof. Notwithstanding anything hereinabove to the contrary, "taxes" shall
not include any penalties or interest imposed or incurred because of Landlord's
dilatory payment, unless the delay in payment is due to Tenant's breach of its
obligations under this Section 16.

      (b) All assessments imposed upon the Leased Premises during the term of
this Lease for public improvements which shall benefit the Leased Premises after
the expiration of this Lease shall be equitably pro rated, so that only the
portion of such assessments properly allocable to the term of this Lease shall
be included in determining Tenant's share of "taxes" in accordance with Section
16.01 (a) above.

      16.02 Tenant shall pay as additional rent the amount of all taxes, other
than income taxes, upon or measured by the rent payable hereunder, whether as a
sales tax, transaction privilege tax, excise tax, or otherwise, which additional
rent shall be due and payable at the same time as each installment of basic
rent.

      16.03 Joint Assessment. If the Leased Premises are not separately
assessed, Tenant's liability shall be an equitable proportion of the real
property taxes for all of the land and improvements included with the tax parcel
assessed, such proportion to be determined by Landlord from the respective
valuations assigned in the assessor's work sheets or such other information as
may be reasonably available. Landlord's reasonable determination thereof, in
good faith, shall be conclusive.

      16.04 Personal Property Taxes. Tenant shall pay prior to delinquency all
taxes assessed against and levied upon trade fixtures, furnishings, equipment
and all other personal property of Tenant contained in the Leased Premises or
elsewhere.

                                    INSURANCE

      17.01 Liability Insurance. Tenant, at its own expense, shall provide and
keep in force with companies acceptable to Landlord public liability insurance
for the benefit of Tenant against liability for bodily injury and property
damage in the amount of not less than One Million Dollars ($1,000,000.00)
combined single limit in respect to injuries to or death of more than one person
in any one occurrence, and Two Million Dollars ($2,000,000.00 in the aggregate,
Tenant shall also maintain an umbrella policy in the amount of One Million
Dollars ($1,000,000.00), such limits to be for any greater amounts as may be
reasonably indicated by circumstances from time to time existing. Tenant shall
furnish Landlord with a certificate of such policy within thirty (30) days of
the commencement date of this Lease and whenever required shall satisfy Landlord
that such policy is in full force and effect. Such policy shall name Landlord as
an additional insured with respect to liabilities arising out of the use of the
Leased Premises by Tenant and shall be primary and noncontributing with any
insurance carried by Landlord. The policy shall further provide that it shall
not be cancelled or altered without twenty (20) days prior written notice to
Landlord. The limits of said insurance shall not, however, limit the liability
of Tenant hereunder. if Tenant shall fail to procure and maintain said insurance
Landlord may, but shall not be required to procure and maintain the same but at
the expense of Tenant.


                                       11
<PAGE>

      17.02 Property Insurance. (a) Tenant shall maintain in full force and
effect on all of its Tenant Improvements, fixtures and equipment in the Leased
Premises a policy or policies of fire and extended coverage insurance with
standard coverage endorsement to the extent of at least eighty percent (80%) of
their insurable value. Landlord will not carry insurance on Tenant's
possessions. Tenant shall furnish Landlord with a certificate of such policy
within thirty (30) days of the commencement of this Lease, and whenever
required, shall satisfy Landlord that such policy is in full force and effect.

      (b) At Tenant's cost, Landlord shall obtain and keep in force during the
term of this Lease a policy or policies of insurance covering loss or damage to
the Leased Premises and Building, in the amount of the full replacement value
thereof, as the same may exist from time to time, but in no event less than the
total amount of promissory notes secured by liens on the Leased Premises against
all perils included within the classification of fire, extended coverage,
vandalism, malicious mischief, special extended perils (all risk) and sprinkler
leakage. Said insurance shall provide for payment of loss thereunder to Landlord
or to the holders of mortgages or deeds of trust on the Leased Premises.
Landlord shall, in addition, obtain at Tenant's expense and keep in force during
the term of this Lease a policy of rental income insurance covering a period of
one (1) year, which insurance shall also cover all real estate taxes and
insurance costs for said period.

      (c) if the Leased Premises are part of a larger building, or if the Leased
Premises are part of a group of buildings owned by Landlord, which are adjacent
to the Leased Premises, then Tenant shall pay for any increase in the property
insurance of such other building or buildings if said increase is caused by
Tenant's acts, omissions, use or occupancy of the Leased Premises.

      (d) All policies of property insurance insuring Landlord or Tenant's
property shall provide that the insurers waive any right of subrogation against
Landlord or Tenant and that any such waiver shall not adversely affect said
policies or prejudice the rights of the insured to recovery thereunder.

                                   ABANDONMENT

      18.01 Tenant shall not vacate nor abandon the Leased Premises at any time
during the term of this Lease; and if Tenant shall abandon, vacate or surrender
the Leased Premises, or be dispossessed by process of law, or otherwise, any
personal property belonging to Tenant and left on the Leased Premises shall, at
the option of the Landlord, be deemed abandoned and be and become the property
of Landlord.

                                   DESTRUCTION

      19.01 If the Building or Leased Premises or any portion thereof are
destroyed by storm, fire, lightning, earthquake or other casualty, Tenant shall
immediately notify Landlord. In the event the Building or the Leased Premises
cannot, in Landlord's reasonable judgment, be restored within one hundred eighty
(180) days of the date of such damage or destruction, this Lease shall terminate
as of the date of such destruction, and all rent and other sums payable by
Tenant hereunder shall be accounted for as between Landlord and Tenant as of
that date. Landlord shall notify Tenant within thirty (30) days of the date of
the damage or destruction whether the Building and the Leased Premises can be
restored within one hundred eighty (180) days. If this Lease is not terminated
as provided in this Paragraph, Landlord shall, to the extent insurance proceeds
payable on account of such damage or destruction are available to Landlord (with
the excess proceeds belonging to Landlord), using reasonable diligence, repair,
restore, rebuild, reconstruct or replace the damaged or destroyed portion of the
Leased Premises to a condition substantially similar to the condition which
existed prior to the damage or destruction. Provided, however, Landlord shall
only be required to repair, restore, rebuild, reconstruct and replace the base
building as shown on Exhibit "B" and detailed in Exhibit "G" ("Landlord's
Work"). Tenant shall, at its sole cost and expense, upon completion of the
Landlord's Work, repair, restore, rebuild, reconstruct and replace, as required,
any and all Tenant Improvements installed in the Leased Premises by Tenant and
all trade fixtures, personal property, inventory, signs and other contents in
the Leased Premises, and all other repairs not specifically required of Landlord
hereunder, in a manner and to at least the condition substantially similar to
that existing prior to the damage, provided however, if the destruction has
occurred in the lab or the


12

<PAGE>

manufacturing area, the Tenant shall have the option to either restore such
areas to the condition that existed prior to the damage or restore the damaged
area to be standard office space similar to the existing office space within the
Leased Premises, the plans and specifications for such office space would
require Landlord's prior review and approval. Tenant's obligation to pay Base
Rent and additional rent shall abate until the earlier of Tenant's occupancy or
sixty (60) days after Landlord has repaired, restored, rebuilt, reconstructed or
replaced the Leased Premises, as required herein, in proportion to the part of
the Leased Premises which are unusable by Tenant. In the event of any dispute
between Landlord and Tenant relative to the provisions of this paragraph, they
may each select an arbitrator, the two arbitrators so selected shall select a
third arbitrator and the three arbitrators so selected shall hear and determine
the controversy and their decision thereon shall be final and binding on both
Landlord and Tenant who shall bear the cost of such arbitration equally between
them. Landlord shall not be required to repair any property installed in the
Leased Premises by Tenant. Tenant waives any right under applicable laws
inconsistent with the terms of this paragraph. Notwithstanding the provisions of
this paragraph, if any such damage or destruction occurs within the final two
(2) years of the term hereof, and such damage affects a material portion of the
Leased Premises or Tenant's use thereof then Landlord or Tenant may, without
regard to the aforesaid 180-day period, terminate this Lease by written notice
to the other party.

                            ASSIGNMENT AND SUBLETTING

      20.01 Landlord shall have the right to transfer and assign, in whole or in
part its rights and obligations in the building and property that are the
subject of this Lease. Tenant shall not assign this Lease or sublet all or any
part of the Leased Premises without the prior written consent of the Landlord,
which shall not be unreasonably withheld or delayed. In the event of any
assignment or subletting, Tenant shall nevertheless at all times, remain fully
responsible and liable for the payment of the rent and for compliance with all
of its other obligations under the terms, provisions and covenants of this
Lease. If all or any part of the Leased Premises are then assigned or sublet,
Landlord, in addition to any other remedies provided by this Lease or provided
by law, may at its option, collect directly from the assignee or subtenant all
rents becoming due to Tenant by reason of the assignment or sublease. Any
collection directly by Landlord from the assignee or subtenant shall not be
construed to constitute a novation or a release of Tenant from the further
performance of its obligations under this Lease. In the event that Tenant
sublets the Leased Premises or any part thereof, or assigns this Lease and at
any time receives rent and/or other consideration which exceeds that which
Tenant would at that time be obligated to pay to Landlord, Tenant shall pay to
Landlord 100% of the gross excess in such rent as such rent is received by
Tenant and 100% of any other consideration received by Tenant from such
subtenant in connection with such sublease or, in the case of any assignment of
this Lease by Tenant, Landlord shall receive 100% of any consideration paid to
Tenant by such assignee in connection with such assignment; notwithstanding the
foregoing, Tenant shall be entitled to the excess profit earned from a sublease
or an assignment above a rental rate of $6.00 per square foot for the space that
is the subject of any such sublease or assignment. In addition, should Landlord
agree to an assignment or sublease agreement, Tenant will pay to Landlord on
demand the sum of $500.00 to partially reimburse Landlord for its costs,
including reasonable attorneys' fees, incurred in connection with processing
such assignment or subletting request.

                              INSOLVENCY OF TENANT

      21.01 Either (a) the appointment of a trustee in a Chapter 7 bankruptcy
proceeding to take possession of all or substantially all of the assets of
Tenant, or (b) a general assignment by Tenant for the benefit of creditors, or
(c) any action taken or suffered by Tenant under Chapter 7 of the bankruptcy act
shall, if any such appointments, assignments or action continues for a period of
sixty (60) days, constitute a breach of this Lease by Tenant, and Landlord may
at its election upon fifteen (15) days notice, terminate this Lease and in that
event be entitled to immediate possession of the Leased Premises and damages as
provided below.

                                BREACH BY TENANT

      22.01 In the event that (i) Tenant shall not make payment of any
installment of rent or other sum herein specified and such failure shall
continue for five business days after written notice


                                       13
<PAGE>

thereof from Landlord, but if a failure to pay Base Rent shall occur more than
twice in any twelve month period then no notice shall be required for any
subsequent failure to pay Base Rent when due, or (ii) Tenant shall fail to
observe or perform any other of Tenant's obligations hereunder and such failure
shall not be corrected within thirty days after written notice thereof from
Landlord (or such longer period if reasonably required and Tenant is proceeding
diligently to correct such failure), then this shall be considered a default
hereunder. In the event of a default, Landlord in addition to any and all other
rights or remedies that it may have hereunder, at law or in equity shall have
the right to either terminate this Lease or from time to time, without
terminating this Lease relet the Leased Premises or any part thereof for the
account and in the name of Tenant or otherwise, for any such term or terms and
conditions as Landlord in its sole discretion may deem advisable with the right
to make reasonable alterations and repairs to the Leased Premises. Tenant shall
pay to Landlord, as soon as ascertained, the costs and expenses reasonably
incurred by Landlord in such reletting or in making such reasonable alterations
and repairs. Should such rentals received from time to time from such reletting
during any month be less than that agreed to be paid during that month by Tenant
hereunder, the Tenant shall pay such deficiency to Landlord. Such deficiency
shall be calculated and paid monthly.

      22.02 No such reletting of the Leased Premises by Landlord shall be
construed as an election on its part to terminate this Lease unless a notice of
such intention be given to Tenant or unless the termination thereof be decreed
by a court of competent jurisdiction. Notwithstanding any such reletting without
termination, Landlord may immediately or at any time thereafter terminate this
Lease, and this Lease shall be deemed to have been terminated upon receipt by
Tenant of notice of such termination; upon such termination Landlord shall
recover from Tenant all damages that Landlord may suffer by reason of such
termination including, without limitation, all arrearages in rentals, costs,
charges, additional rentals, and reimbursements, the cost (including court costs
and attorneys' fees actually incurred) of recovering possession of the Leased
Premises, the actual or estimated (as reasonably estimated by Landlord) cost of
any alteration of or repair to the Leased Premises which is necessary or proper
to prepare the same for reletting and, in addition thereto, Landlord shall have
and recover from Tenant the difference between the present value (discounted at
a rate per annum equal to the discount rate of the Federal Reserve Bank of
Atlanta at the time the Event of Default occurs) of the rental to be paid by
Tenant for the remainder of the lease term, and the present value (discounted at
the same rate) of the rental for the Leased Premises for the remainder of the
lease term, taking into account the cost, time and other factors necessary to
relet the Leased Premises; provided, however that such payment shall not
constitute a penalty or forfeiture, but shall constitute full liquidated damages
due to Landlord as a result of Tenant's default. Landlord and Tenant
acknowledge that Landlord's actual damages in the event of a default by Tenant
under this Lease will be difficult to ascertain, and that the liquidated damages
provided above represent the parties' best estimate of such damages. The parties
expressly acknowledge that the foregoing liquidated damages are intended not as
a penalty, but as full liquidated damages, as permitted by Section 13-6-7 of the
Official Code of Ga. Annotated.

      22.03 Landlord agrees that the payment by the Guarantor of any rent or
other amount due Landlord hereunder, or the performance by Guarantor of any
obligation of Tenant hereunder, shall be deemed to be the making of a payment by
Tenant or the performance of the obligation by the Tenant.

                                 ATTORNEY'S FEES

      23.01 If Landlord and Tenant litigate or arbitrate any provision of this
Lease or the subject matter of this Lease, each party will pay its own legal
costs and expenses. If, without fault, either Landlord or Tenant is made a party
to any litigation instituted by or against the other, the other will indemnify
the faultless one against all loss, liability, and expense, including reasonable
attorneys' fees and court costs, incurred by it in connection with such
litigation.

                                  CONDEMNATION

      24.01 If, at any time during the term of this Lease, title to the entire
Leased Premises should become vested in a public or quasi-public authority by
virtue of the exercise of expropriation, appropriation, condemnation or other
power in the nature of eminent domain, or by voluntary transfer from the owner
of the Leased Premises under threat of such a taking then this Lease shall


                                       14
<PAGE>

terminate as of the time of such vesting of title, after which neither party
shall be further obligated to the other except for occurrence antedating such
taking. The same results shall follow if less than the entire Leased Premises be
thus taken, or transferred in lieu of such a taking, but to such extent that it
would be legally and commercially impractical for Tenant to occupy the portion
of the Leased Premises remaining, and impractical for Tenant to reasonably
conduct his trade or business therein.

      24.02 Should there be such a partial taking or transfer in lieu thereof,
but not to such an extent as to make such continued occupancy and operation by
Tenant an impracticality, then this Lease shall continue on all of its same
terms and conditions subject only to an equitable reduction in rent and other
expenses proportionate to such taking.

      24.03 In the event of any such taking or transfer, whether of the entire
Leased Premises, or a portion thereof, it is expressly agreed and understood
that all sums awarded, allowed or received in connection therewith shall belong
to Landlord, and any rights otherwise vested in Tenant are hereby assigned to
Landlord, and Tenant shall have no interest in or claim to any such sums or any
portion thereof, whether the same be for the taking of the property or for
damages, or otherwise. Nothing herein shall be construed, however, to preclude
Tenant from prosecuting any claim directly against the condemning authority for
loss of business, moving expenses, damage to, and cost of, trade fixtures,
furniture and other personal property belonging to Tenant; provided, however,
that Tenant shall make no claim which shall diminish or adversely affect any
award claimed or received by Landlord.

                                     NOTICES

      25.01 All notices, statements, demands, requests, consents, approvals,
authorization, offers, agreements, appointments, or designations under this
Lease by either party to the other shall be in writing and shall be sufficiently
given and served upon the other party, (i) by depositing same in the United
States mail, addressed to the party to be notified, postage prepaid and
registered or certified with return receipt requested; (ii) by recognized
overnight, third party prepaid courier service (such as Federal Express),
requiring signed receipt; (iii) by delivering the same in person to such party;
or (iv) by telecopy with delivery of an original copy of any such notice
delivered pursuant to (ii) or (iii) above to be received no later than the next
business day. Notice personally delivered or sent by courier service, or
telecopy shall be effective upon receipt. Any notice mailed in the foregoing
manner shall be effective three (3) business days after its deposit in the
United States mail. Either party may change its address for notices by giving
notice to the other as provided above. For purposes of notice, the addresses of
the parties shall be as follows:

      (a)   To Tenant at the Leased Premises; addressed to the attention of the
            Chief Operating Officer; with a copy to Visible~Genetics, Inc., 700
            Bay Street, Suite 1000, Toronto, Ontario, Canada M5G1Z6, Attention
            Chief Executive

      (b)   To Landlord, addressed to Landlord at 4497 Park Drive, Norcross,
            Georgia 30093, with a copy to such other place as Landlord may from
            time to time designate by notice to Tenant.

                                     WAIVER

      26.01 The waiver by either party of any breach of any term, covenant, or
condition herein contained shall not be deemed to be a waiver of such term,
covenant, or condition or any subsequent breach of the same or any other term,
covenant, or condition herein contained. The subsequent acceptance of rent
hereunder by Landlord shall not be deemed to be a waiver of any preceding breach
by Tenant of any term, covenant, or condition of this Lease, other than the
failure of Tenant to pay the particular rental so accepted, regardless of
Landlord's knowledge of such preceding breach at the time of acceptance of such
rent.

                             EFFECT OF HOLDING OVER

      27.01 If Tenant should remain in possession of the Leased Premises after
the expiration of the lease term and without executing a new lease, then such
holding over shall be construed as a tenancy from month to month, subject to all
the conditions, provisions, and obligations of this


                                       15

<PAGE>

Lease insofar as the same are applicable to a month to month tenancy, except
that the rent payable pursuant to subparagraph 3.01 hereof shall be 150% of the
rent payable pursuant to subparagraph 3.01.

                                  SUBORDINATION

      28.01 This Lease, at Landlord's option, shall be subordinate to any ground
lease, first priority mortgage, first priority deed of trust, or first priority
security deed now or hereafter placed upon the real property of which the Leased
Premises are a part and to any and all advances made on the security thereof and
to all renewals, modifications, consolidations, replacements and extensions
thereof.

      28.02 Tenant agrees to execute any documents reasonably required to
effectuate such subordination or to make this Lease prior to the lien of any
such ground lease, mortgage, deed of trust, or security deed, as the case may
be, including specifically a subordination, non-disturbance and attornment
agreement in the form hereto attached as Exhibit "D", and failing to do so
within ten (10) days after written demand, does hereby make, constitute and
irrevocably appoint Landlord as Tenant's attorney in fact and in Tenant's name,
place and stead, to do so. if requested to do so, Tenant agrees to attorn to any
person or other entity that acquires title to the real property encompassing the
Leased Premises, whether through judicial foreclosure, sale under power, or
otherwise, and to any assignee of such person or other entity.

                              ESTOPPEL CERTIFICATE

      29.01 Upon ten (10) days notice from Landlord to Tenant, Tenant shall
deliver a certificate dated as of the first day of the calendar month in which
such notice is received, executed by an appropriate officer, partner or
individual, in the form as Landlord may reasonably require and stating but not
limited to the following: (i) the commencement date of this Lease; (ii) the
space occupied by Tenant hereunder; (iii) the expiration date hereof; (iv) a
description of any renewal or expansion options; (v) the amount of rental
currently and actually paid by Tenant under this Lease; (vi) the nature of any
default or claimed default hereunder by Landlord and (vii) that Tenant is not in
default hereunder nor has any event occurred which with the passage of time or
the giving of notice would become a default by Tenant hereunder.

                                     PARKING

      30.01 Tenant shall have exclusive use of the parking areas designated as
parking areas on the site plan attached hereto as Exhibit "A". Tenant agrees to
park all Tenant's trucks in the parking spaces provided at the rear of the
building. "Parking" as used herein means the use by Tenant's employees, its
visitors, invitees, contractors and customers for the parking of motor vehicles
for such periods of time as are reasonably necessary in connection with use of
and/or visits to the Leased Premises. No vehicle may be repaired or serviced in
the parking area and any vehicle deemed abandoned by Landlord will be towed from
the project and all costs therein shall be borne by the Tenant. No area outside
of the Leased Premises shall be used by Tenant for storage without Landlord's
prior written permission. There shall be no parking permitted on any of the
streets or roadways located in Horizon.

                              MORTGAGEE PROTECTION

      31.01 In the event of any default on the part of Landlord, Tenant will
give notice by registered or certified mail to any beneficiary of a deed or
trust or holder of a security deed or mortgage covering the Leased Premises
whose name and address shall have been furnished to Tenant by Landlord in
writing prior to the default, and shall offer such beneficiary or holder a
reasonable opportunity to cure the default, including time to obtain possession
of the Leased Premises by power of sale or a judicial foreclosure, if such
should prove necessary to effect a cure.

                              PROTECTIVE COVENANTS

      32.01 This Lease is subject to the Protective Covenants of Horizon, and to
such rules and regulations as may hereafter be adopted and promulgated. In
addition, Tenant shall comply with all


16

<PAGE>

covenants, restrictions and other matters of record in the deed records of the
county in which the Leased Premises are located which affect or encumber the
Leased Premises, the Building or the Land.

                                   RELOCATION

      33.01 Intentionally deleted.

                              BROKERAGE COMMISSIONS

      34.01 Tenant's Agent and Landlord's Agent (collectively, "Agent") shall
each be entitled to receive a commission in the amounts, and upon the terms and
conditions, contained in a separate commission agreement between Landlord and
such parties.

      34.02 Tenant warrants and represents to Landlord that, other than Agent,
no other party is entitled, as a result of the actions of Tenant, to a
commission or other fee resulting from the execution of this Lease. Landlord
warrants and represents to Tenant that, except as set forth above, no other
party is entitled, as a result of the actions of Landlord, to a commission or
other fee resulting from the execution of this Lease. Landlord and Tenant agree
to indemnify and hold each other harmless from any loss, cost, damage or expense
(including reasonable attorneys' fees) incurred by the nonindemnifying party as
a result of the untruth or incorrectness of the foregoing warranty and
representation, or failure to comply with the provisions of this subparagraph.

      34.03 Tenant's Agent is representing Tenant in connection with this Lease,
and is not representing Landlord. Landlord's Agent, or employees of Landlord or
its affiliates, are representing Landlord and are not representing Tenant.

      34.04 The parties acknowledge that certain officers, directors,
shareholders, or partners of Landlord or its general partner(s), are licensed
real estate brokers and/or salesmen under the laws of the State of Georgia.
Tenant consents to such parties acting in such dual capacities.

                            MISCELLANEOUS PROVISIONS

      A. Whenever the singular number is used in this Lease and when required by
the context, the same shall include the plural, and the masculine gender shall
include the feminine and neuter genders, and the word "person" shall include
corporation, firm or association. If there be more than one tenant, the
obligations imposed upon Tenant under this Lease shall be joint and several.

      B. The headings or titles to paragraphs of this Lease are for convenience
only and shall have no effect upon the construction or interpretation of any
part of this Lease.

      C. This instrument contains all of the agreements and conditions made
between the parties to this Lease and may not be modified orally or in any other
manner than by agreement in writing signed by all parties to this Lease.

      D. Where the consent of a party is required, such consent will not be
unreasonably withheld or delayed.

      E. This Lease shall create the relationship of Landlord and Tenant between
Landlord and Tenant; no estate shall pass out of Landlord; Tenant has only a
usufruct, not subject to levy and/or sale and not assignable by Tenant except as
provided in paragraph 20.01 hereof.

      F. Except as otherwise expressly stated, each payment required to be made
by Tenant shall be in addition to and not in substitution for other payments to
be made by Tenant.

      G. All covenants and agreements to be performed by Tenant under any of the
terms of this Lease shall be performed by Tenant at Tenant's sole cost and
expense and without any abatement of rent.


17
<PAGE>

      H. No payment by Tenant or receipt by Landlord of a lesser amount than any
installment or payment of rent due shall be deemed to be other than on account
of the amount due, and no endorsement or statement on any check or payment of
rent shall be deemed an accord and satisfaction. Landlord may accept such check
or payment without prejudice to Landlord's right to recover the balance of such
installment or payment of rent, or pursue any other remedies available to
Landlord.

      I. Subject to paragraph 20, the terms and provisions of this Lease shall
be binding upon and inure to the benefit of the heirs, executors,
administrators, successors, and assigns of Landlord and Tenant. In the event of
any conveyance by Landlord of its interest in and to the Leased Premises, the
Building or the Land, all obligations under this Lease of the conveying party
shall cease and Tenant shall thereafter look solely to the party to whom the
Leased Premises were conveyed for performance of all of Landlord's duties and
obligations under this Lease.

      J. Tenant acknowledges and agrees that Landlord shall not provide guards
or other security protection for the Leased Premises and that any and all
security protection shall be the sole responsibility of Tenant.

      K. This Lease shall be governed by Georgia law.

      L. Time is of the essence of each term and provision of this Lease.

      M. Tenant shall not record this Lease or a memorandum thereof without the
written consent of Landlord. Upon the request of Landlord, Tenant shall join in
the execution of a memorandum or so-called "short form" of this Lease for the
purpose of recordation. Said memorandum or short form of this Lease shall
describe the parties, the Leased Premises and the lease term, and shall
incorporate this Lease by reference.

      N. Landlord's liability for performance of its obligations under the terms
of this Lease shall be limited to its interest in the Leased Premises.

      0. It is a condition to Landlord's obligations under this Lease that
Tenant, and Tenant agrees to, obtain and deliver to Landlord a fully executed
guaranty in the form attached to this Lease as Exhibit "I".

                    (SIGNATURES CONTAINED ON FOLLOWING PAGE)

                                       18


<PAGE>

      IN WITNESS WHEREOF, the parties hereto who are individuals have set their
hands and seals, and the parties who are corporations have caused this
instrument to be duly executed by its proper officers and its corporate seal to
be affixed, as of the day and year first above written.


Signed, sealed and delivered                LANDLORD:
as to Landlord, in the
presence of:                                DUKE-WEEKS REALTY LIMITED
                                            PARTNERSHIP,
                                            an Indiana limited partnership
----------------------------
Unofficial Witness                          By: Duke-Weeks Realty Corporation
                                                an Indiana corporation,
                                                its sole general partner
----------------------------
Notary Public                               By:
                                               -----------------------------
                                            Name:
                                                 ---------------------------
                                            Its:
                                                ----------------------------


Signed, sealed and delivered                TENANT:
as to Tenant, in the presence
of                                          VISIBLE GENETICS CORP.
         [ILLEGIBLE]
----------------------------                By:        [ILLEGIBLE]
Unofficial Witness                             -----------------------------
                                            Name:      [ILLEGIBLE]
         [ILLEGIBLE]                             ---------------------------
----------------------------                Its:       [ILLEGIBLE]
Notary Public                                   ----------------------------


                                            ATTEST:

                                             By:        [ILLEGIBLE]
                                                -----------------------------
                                             Name:      [ILLEGIBLE]
                                                  ---------------------------
                                             Its:       [ILLEGIBLE]
                                                 ----------------------------

                                                     (Corporate Seal)


                                       19
<PAGE>

                                  EXHIBIT "A"
                                    SITE PLAN

[GRAPHIC OMITTED]

                        Horizon Business Distribution III
                     100 Crestridge Drive, Lawrenceville, GA

Building Specifications

o 99,822 square feet on 9.66 acres

o 40' x 40' column spacing; 200' depth

o Brick and block construction

o 22 dock-high doors with 7 knock-outs

o 24' minimum clear height

o Ballasted EPDM roof

o 128 parking spaces

o Class IV sprinkler system

 For more information, please call Duke-Weeks Realty Corporation
                             Mal Hill 770-717-3215
                                                              www. dukerelt.com


<PAGE>
                                   EXHIBIT "B"

                                   FLOOR PLAN

As shown on plans and specifications dated 12/17/99 and prepared for Tenant by
KG Architects.


<PAGE>

                                   EXHIBIT "C"

                             ACCEPTANCE OF PREMISES

Lessee:_______________________________________

Lessor:_______________________________________

Date Lease Signed:____________________________

Term of Lease:________________________________

Address of Leased Premises: Suite ____ containing approximately ____ square
feet, located at

      ________________________________________

      ________________________________________


Commencement Date:____________________________

Expiration Date:______________________________

The above described premises are accepted by Lessee as suitable for the purpose
for which they were let. The above described lease term commences and expires on
the dates set forth above. Lessee acknowledges that it has been received from
Lessor _________ number of keys to the leased premises. It is understood that
there is a punch list which will be completed after move-in and will be an
exhibit to the Tenant Estoppel.

LESSEE

________________________
 (Type Name of Lessee)
                                       WITNESS

By:_____________________           ______________________
      (Signature)                       (Signature)

________________________           ______________________
 (Type Name and Title)                   (Company)


                                       2
<PAGE>
                                   EXHIBIT "D"

             SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT

      THIS AGREEMENT, made as of the _ day of____ , 1995, between _____________
with offices at _____________________________ ("Tenant") and
______________________ (herein, together with its successors, transferees and
assigns, the "Mortgagee");

                                   WITNESSETH:

      WHEREAS, Mortgagee is about to or has heretofore granted to
_____________,a Georgia limited partnership (the "owner") a first mortgage loan,
which loan is secured by a security deed (herein "Mortgage") dated as of
_______, 199_ and duly recorded on _______, 199_ in the land records of Gwinnett
County, Georgia; and

      WHEREAS, the Mortgage is to be a first and prior lien upon the Owner's fee
estate in the real property described in Exhibit "A" annexed hereto ("Mortgaged
Premises"); and

      WHEREAS, Tenant is occupying a portion of the Mortgaged Premises under a
lease dated as of ____________, 199_. in which Owner is Landlord (the "Lease")
covering that portion of the Mortgaged Premises therein more particularly
described (the "Leased Premises"); and

      WHEREAS, Tenant desires to be assured of its continued and undisturbed
occupancy of the Leased Premises should the Mortgage be foreclosed or the
Mortgaged Premises sold pursuant to any power of sale contained therein and
Mortgagee is agreeable thereto.

      NOW, THEREFORE, in consideration of the mutual covenants contained in this
Agreement and in further consideration of the sum of ONE DOLLAR ($1.00) each to
the other in hand paid, the receipt whereof is hereby acknowledged, Tenant and
Mortgagee mutually covenant and agree as follows:

      FIRST: The Lease and all of Tenant's rights, interest and estate therein
and thereunder are hereby made subject and subordinate to the lien of the
Mortgage and to any extensions, renewals, replacements, modifications, additions
or consolidations thereof and to all rights, title and interest of Mortgagee and
its successors and assigns therein and thereunder.

      SECOND: In the event, however, proceedings shall ever be instituted by
Mortgagee to foreclose or liquidate the Mortgage, the Tenant's possession of its
leased portion of the Mortgaged Premises shall not be disturbed by the
foreclosure proceedings and the Mortgaged Premises shall be sold at any
foreclosure sale subject to Tenant's possession on condition that:

      (a)   there shall be, at the time of commencement of foreclosure
            proceedings, as well as all subsequent times, no default by Tenant
            in the due and timely observance and performance of any covenant and
            agreement in the Lease to be observed and performed by Tenant; and

      (b)   the Tenant shall not have entered into any agreement modifying any
            term, condition or agreement of the Mortgagee-approved Lease without
            the prior written consent of Mortgagee.

       THIRD: Tenant shall attorn to Mortgagee while Mortgagee is in possession
of the Mortgaged Premises, or to a Receiver appointed in any action or
proceeding to foreclose the Mortgage. In the event of the completion of
foreclosure proceedings and sale of the Mortgaged Premises or in the event the
Mortgagee should otherwise acquire possession of the Mortgaged Premises, the
Tenant will promptly upon demand attorn to the purchaser at the foreclosure sale
or to the Mortgagee, as the case may be, and will recognize such purchaser or
the Mortgagee as the Tenant's landlord. The Tenant agrees to execute and
deliver, at any time and from time to time, upon the request of the Mortgagee or
the purchaser at the foreclosure sale, as the case may be, any


<PAGE>

instrument which may be necessary or appropriate to such successor landlord to
evidence such attornment. The Tenant shall, upon demand of the Mortgagee or any
Receiver or purchaser at the foreclosure sale, pay to the Mortgagee or to such
Receiver or purchaser, as the case may be, all rental monies then due or as they
thereafter become due.

       FOURTH: Upon the attornment provided for in preceding Paragraph THIRD the
Tenant's occupancy shall thereafter be in full force and effect as under a
direct Lease between Mortgagee, the Receiver or the purchaser at the foreclosure
sale, as the case may be, and Tenant. It is specifically understood and agreed
that Mortgagee or any such Receiver or purchaser shall not be:

      (a)   liable for any act, omission, negligence or default of any prior
            landlord, or

      (b)   subject to any offsets, claims or defenses which Tenant might have
            against any prior landlord; or

      (c)   bound by any rent or additional rent which Tenant might have paid
            for more than one month in advance to any prior landlord; or

      (d)   bound by any amendment or modification of the Lease made without
            the prior written consent of the Mortgagee.

      FIFTH: On and after the date Tenant in good standing attorns to Mortgagee
or any Receiver or subsequent owner in pursuance of its agreement herein set
forth, Mortgagee, the Receiver or such subsequent owner will undertake and
perform all subsequent obligations of the Landlord as set forth in the Lease for
the benefit of and undisturbed occupancy of Tenant under the Lease.

      SIXTH: Tenant agrees it will not amend, modify nor abridge the Lease in
any way, nor cancel or surrender the same without prior written approval of the
Mortgagee other than by reason of a continued uncured material default of the
landlord under the Lease, nor will the Lease ever merge into the fee in the
event that Mortgagee acquires fee title to the Mortgaged Premises.

      SEVENTH: Any notices or other communication to be given hereunder by
either party shall be in writing and shall be deemed to have been sufficiently
given or served for all purposes if sent by registered or certified mail with
return receipt requested to the other party hereto at its address above stated
or such other address of which written notification has been timely given to the
other party.

      EIGHTH: Mortgagee has and shall have the continuing right to execute and
record in the Land Records of Gwinnett County, Georgia at any time, in its
unilateral discretion, a Declaration of Subordination for the purpose of thereby
subordinating its rights, title and interest in and under the Mortgage to the
rights, title and interest of Tenant under the Lease. Such Declaration of
Subordination shall, at Mortgagee's election, operate, function and be in full
force and effect for whatever period of time Mortgagee declares therein that it
shall be in force not exceeding the term of the Lease and any extensions thereof
and the said Declaration may be voided unilaterally by Mortgagee when it so
elects.

      NINTH: Tenant waives any and all rights it may have to execute and record
after the date hereof any document purporting to again or further subordinate
its right, title or interest under the Lease to the lien of either the Mortgage
or any other mortgage or deed of trust or any ground lease or any agreement
modifying or amending the Mortgage except with the written consent of Mortgagee.

      TENTH: This Agreement cannot be changed orally but only in writing signed
by both parties hereto.

      ELEVENTH: This Agreement may be recorded by either party at its own
expense in the Land Records of Gwinnett County, Georgia whenever, in its sole
discretion, either party elects so to do.


                                       2
<PAGE>

      TWELFTH: All of the terms, covenants and conditions hereof shall run with
the Mortgaged Premises and shall be binding upon and inure to the benefit of the
parties hereto and their respective successors and assigns.

      IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed, acknowledged and delivered the day and year first above written.

SIGNED, SEALED AND DELIVERED              TENANT:
in the presence of:

_____________________________

_____________________________              BY:_____________________________

                                           MORTGAGEE:

_____________________________              BY:_____________________________

_____________________________


       The undersigned Owner of the leased and mortgaged premises hereby
consents to the foregoing Agreement and agrees to be bound by and subject to the
terms thereof.

                                           BY:_____________________________


                                        3
<PAGE>

                                   EXHIBIT "E"

                              SPECIAL STIPULATIONS

                                      NONE


<PAGE>

                                   EXHIBIT "F"

                            CONSTRUCTION REQUIREMENTS

INSURANCE: Contractor/Subcontractor shall maintain at least the following
insurance coverages in addition to any other coverages or any greater limits
required by the Contract Documents. The policies shall also provide that it
shall not be canceled or altered without twenty (20) days prior written notice
to Tenant.

1.    Type of Insurance - Worker's Compensation and Employer's Liability.
      Minimum Limits of Liability - In accordance with the laws of the state or
      states in which the work is performed, but with employers' liability
      limits of at least $100,000.00 per occurrence.

2.    Type of Insurance - Comprehensive General Liability. Minimum Limits of
      Liability - Bodily Injury (and death): $1,000,000.00 each occurrence;
      $1,000.000.00 aggregate.* Property Damage; $1,000,000.00 each occurrence;
      $1,000,000.00 aggregate.* Or Bodily Injury and Property Damage combined:
      $1,000,000.0O.

3.    Type of Insurance - Comprehensive Automobile Liability. Minimum Limits of
      Liability-Bodily Injury (and Death): $500,000.00 each person; $500.000.00
      each occurrence. Property Damage: $100,000.00 each occurrence. Or, Bodily
      Injury and Property Damage combined: $500,000.00.

If checked, the above insurance policies shall provide coverage against the
following risks:

COMPREHENSIVE GENERAL LIABILITY:
-------------------------------
[X]    a.    Broad Form Property Damage.
[X]    b.    Independent Contractors
[X]    c.    XCU Hazards (explosions, collapse and underground damage)
[X]    d.    Contractual liability (arising from indemnity agreement in
             Subcontract).
[X]    e.    Completed Operations (for 24 months following completion of Work).

COMPREHENSIVE AUTOMOBILE LIABILITY:
----------------------------------
[X]    a.    All owned vehicles
[X]    b.    Non-ownership Liability
[X]    c.    Hired vehicles

Evidence of insurance coverages shall be furnished in duplicate on a Standard
ACORD Form, Certificate of Insurance, or on the attached Certificate of
Insurance form, naming Contractor as "Addressee", unless a different form is
required by Contract Documents.


<PAGE>

Contractor's/Subcontractor's Certificate of Insurance This certificate is
issued as a matter of information only and confers no rights upon the
certificate holder. This certificate does not amend, extend or alter the
coverage afforded by the policies listed below

--------------------------------------------------------------------------------
NAME & ADDRESS OF AGENCY         COMPANIES AFFORDING COVERAGE
--------------------------------------------------------------------------------
___________________________      COMPANY
___________________________      LETTER      A
PHONE NO, (_______)              COMPANY
                                 LETTER      B
--------------------------------------------------------------------------------
NAME & ADDRESS OF INSURED        COMPANY
                                 LETTER      C
--------------------------------------------------------------------------------
___________________________      COMPANY
                                 LETTER      D
___________________________      COMPANY
                                 COMPANY
                                 LETTER      E
PHONE NO. (______)
--------------------------------------------------------------------------------

       THIS IS TO CERTIFY THAT POLICIES OF INSURAJCE USTED BELOW HAVE BEEN
ISSUED TO THE INSURED NAMED ABOVE FOR THE POLICY period INDICATED, NOT
WITHSTANDING ALLY REQUIREMENT, TERMOR CONDITIONS OP ANY CONtRACT OR OTHER
DOCIMENT WITH RESPECT TO WHICH THIS CERTIFICATE MAY BE ISSUED OP MAY PERTAIN:
THE INSURanCE AFFORdED BY THE POLICES DESCRIBED HEREIN IS SUBJECT TO ALL TILE
TERMS,

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------------
                                           POLICY          POLICY         LIMITS OF LIABILITY
CO.       TYPE OF INSURANCE    POLICY   EFFECTIVE DATE   EXPERATION          IN THOUSANDS
LTR.                           NUMBER                       DATE             (000 OMITTED)
---------------------------------------------------------------------------------------------------------------------------
      <S>                                                             <C>                                       <C>
      General Liability                                               General Aggregate-BVPD                    $1,000
      Commercial General Liability                                    Personal & Advertising Injury             $1,000
                                                                      Each Occurrence                           $1,000
      [_] Occurrence (required)                                       Fire Damage (My One Fire)                 $   50
        Any exclusion to the basic form to                            Medical Expense (My One Person)           $
        be noted below:
        _______________                                               The above are REOUIBED limits for
        _______________                                               each project.
        _______________
---------------------------------------------------------------------------------------------------------------------------
      Automobile Liability                                            Bodily Injury
      o Any Auto                                                      and Property
      0 All Owned Autos                                               Damage                 $ 500
      o Scheduled Autos                                               Combined              (REQUIRED)
      0 Hired Autos
      0 Non-Owned Autos                                               Bodily Injury
                                                                      Each Person)          $
                                                                      Bodily Injury
                                                                      (Each                 $
                                                                      Occurrence)
---------------------------------------------------------------------------------------------------------------------------
      Excess Liability                                                Property Damage       $
      [_] Umbrella Form
      [_] Other Than Umbrella
          Form
---------------------------------------------------------------------------------------------------------------------------
      Workers Compensation                                            Bodily Injury and     Ea. Occurrence      Aggregate
      AND                                                             Properly Damage
      Employers Liability                                             Combined              $                   $
---------------------------------------------------------------------------------------------------------------------------
      OTHER                                                                               STATUTORY
                                                                                 $100 (Required) Each Accident
                                                                                 $500 (Required) Disease/Polic Limit
                                                                                 $100 (Required) Disease/Each Employee
---------------------------------------------------------------------------------------------------------------------------
Description of operations, locations, vehicles, restrictions,         Amount sufficient to cover difference in limits when
special items to which this certiticate applies:                      compared to minimum coverage required.
Type of work to be performed by insured:                              Certificate Holder:  DUKE-WEEKS REALTY CORPORATION
                                                                      4497 Park Drive / Norcross GA 30093
---------------------------------------------------------------------------------------------------------------------------
CANCELLATION: The above poiloes have been endorsed to provide rwenty (20) days when notice of carcellation to the
certificate holder designated herein.
             [                                    ]
MAIL
TO  >        [                                    [       Date Issued:______________________________________

                                                          Authorized Representative:________________________
</TABLE>


<PAGE>
                                                              Project: "Project"

                  CONTRACTOR/SUBCONTRACTOR SAFETY REQUIREMENTS

CONTRACTOR/SUBCONTRACTOR:

All Contractors'/Subcontractors' personnel shall conform to the following safety
requirements while working on a Duke-Weeks Project. The following are not all
the rules required, but consists of those Duke-Weeks considers most important.
These requirements do not, in any way, relieve you of responsibility to carry
out Federal, State and Local safety rules and regulations which might be
required of you while performing your work on a Weeks construction project.

The Contractor/Subcontractor shall provide a written safety program to the
Duke-Weeks Project Manager prior to commencement of any work on the Subcontract.
This program shall address the safety orders applicable to the subcontracted
work.

The Duke-Weeks Project Managers and Superintendents may issue a "safety
violation notice for repeated or serious violations. The
Contractor/subcontractor shall correct the violation by the abatement date and
furnish Duke-Weeks, In writing, the results of his actions. If the
Contractor/Subcontractor has not corrected the violation by the abatement date,
Duke-Weeks may suspend that portion of work until such correction is made.

Any questions or comments you have regarding Duke-Week's policies and procedures
relative to safety should be directed to the Vice President, Philip W. Cobb.

The Contractor/Subcontractor shall be responsible for all citations issued by
Federal, State, and Local authorities or any outside inspection agencies.

1)    The Contractor/Subcontractor is responsible for requiring and providing
      the use of personal protective equipment for their employees.

2)    Approved hard hats shall be worn at all times while on the construction
      site. Hard hats shall be worn properly with the bill forward, unless the
      wearing of eye protection prevents this; as in the case of welders. The
      bill forward is designed for facial and eye protection from falling
      objects, dust, etc.

3)    Long hair shall be contained under hard hat or net if working where it may
      get tangled.

4)    Full length pants without excessive length or flare bottoms will be
      required. Shirts must cover the entire mid-section and the sleeves must
      cover the entire shoulder. Sleeveless shirts, tank-tops, net shirts,
      halter tops, etc. shall not be worn on the construction site.

5)    Serviceable pair of work shoes or boots, made of leather or similar
      material, shall be worn. Tennis shoes, sandals, and other similar shoes
      are not permitted.

6)    Gambling, fighting and/or horseplay shall not be tolerated.

7)    No employee shall possess, use, or be under the influence of drugs or
      alcohol while on the project.

8)    No firearms are to be brought on the construction site or Duke-Weeks
      property.

9)    Trash shall be disposed of properly in designated containers. Good
      housekeeping shall be maintained in all work areas.

10)   Glass containers (jars, soda bottles, etc.) shall not be brought on the
      site.

11)   The speed limit on the site is 10 mph. This speed limit shall not be
      exceeded. Drive slower on rough terrain and in congested areas,

12)   Safety meetings shall be held on a regular basis, Documentation of topic
      and atendees shall be maintained. Minutes of the meeting shall be
      forwarded to the job site office or project manager.

13)   Any employees exposed to hazardous conditions must be protected in
      accordance with OSHA regulations.

14)   No scaffold forms shall be erected, moved, dismantled, or altered except
      under the supervision of competent persons.

15)   All electrical tools, cords, appliances, etc., must comply with applicable
      OSHA and the National Electrical Code Standards.

16)   All equipment with an obstructed view to the rear must be equipped with an
      audible reverse signal alarm. Equipment must be maintained in safe
      operation condition.

17)   Fire prevention must Conform to OSHA and NFPA Standards. Approved safety
      cans shall be used for flammable and combustible liquids. "NO SMOKING NEAR
      OPEN FLAME" signs and fire extinguishers shall be provided where required.

18)   Hearing protection shall be worn where required.


<PAGE>

"Project"
CONTRACTOR/SUBCONTRACTOR SAFETY REQUIREMENTS
(continued)
Page 2

19)   Respiratory protection shall be established and implemented by
      Contractor/Subcontractors as required.

20)   All open holes, excavations, floor openings, etc., shall be properly
      covered or barricaded. It shall be the responsibility of the
      Contractor/Subcontractor to reinstall any barricade or open cover that
      must be removed to perform their work.

21)   Compressed gas cylinders shall be secured in an upright position at all
      times valve caps shall be in place when not in use, Cylinders shall be
      transported and stored in accordance with Federal and State Standards.

22)   Only vehicles approved by the Project Superintendent or Project Manager
      will be allowed on site.

23)   All ladders must be inspected prior to use. Defective ladders must be
      removed from service immediately. All ladders shall have firm footing, be
      made secure at the top and extend 36 inches above landing.

24)   No material shall be dropped outside the exterior wall of the building
      where the drop distance Is more that 20 feet high, unless contained in a
      chute enclosed on all sides. If the drop distance is more than 20 feet
      high, the landing area must be barricaded. Material may be dropped through
      openings in the building, but the opening must be protected with
      barricades at least 42 inches high and back 6 feet or more from the edge
      of each opening.

25)   All tools and equipment used by Contractor/Subcontractor shall comply with
      OSHA Standards while being used on Weeks sites.

26)   Any Contractor's/Subcontractors employees who are found to be in violation
      of these safety rules, or other company policies or procedures, are
      subject to being removed from the job site.

27)   The Contractor/Subcontractor is responsible for providing safe access to
      all of its work locations and maintaining a safe work area for its
      employees.

28)   It is the policy of Duke-Weeks to maintain a safe and secure place to work
      which requires the cooperation of all Contractors/Subcontractors'
      employees.

I acknowledge that I have read the above and agree to comply with the Duke-Weeks
Safety and Security policies and procedures.

                                                 Contractor/Subcontractor

                                               By:_____________________________


                                              Title____________________________

                                              Date:____________________________


<PAGE>

                                                              PROJECT:"Project"

                      Duke-Weeks Realty Limited Partnership

                           DISCIPLINARY ACTION PROGRAM

The purpose of this program is to establish a procedure for documented warnings
to persons employed on Duke-weeks Realty Limited Partnership projects.
Reprimands will be Issued to persons who are found to be in violation of
prescribed federal, state and Duke- Weeks Realty Limited Partnership safety
standards as well as any specific job site rules and regulations.

The limits of this procedure shall include any person who is employed by
Duke-weeks Realty Limited Partnership, Contractor/subcontractor personnel,
Manufacturers representatives, vendor representatives and visitors, if deemed
necessary by the Project Superintendent or Project Manager.

A reprimand may be issued to an individual when noncompliance with safety
standards and/or regulations is detected and is to be issued at the direction of
the Project Superintendent, Project Manager or other Management Personnel.

Safety violations are categorized into two classifications:

      1.    UNSAFE ACT. The act of performing in a manner that is in violation
            of the safety standards or regulations which could result in a
            serious injury or property damage.

      2.    UNSAFE CONDITIONS. The act of performing when subjected to a
            condition that is in violation of the safety standards or
            regulations which could result in a serious injury or property
            damage.

A reprimand may also be issued to an employee for failure to report an accident
or Injury in a timely manner.

If a reprimand Is issued to an employee or a Contractor/Subcontractor, a copy
shall be given to supervisory personnel within that company.

The following steps shall be taken when an individual is detected violating a
safety standard or regulation by Project Superintendent, Project Manager or
other Management Personnel.

      1.    Inform the individual at the time that a safety violation is evident
            the details of the violation and request immediate corrective action
            be taken to prevent recurrence.

      2.    Inform the individual that a safety reprimand may be issued.

      3.    If a reprimand is issued, inform the individual to come by the
            issuer's office and the issuer shall explain the reprimand in
            detail.

      4.    Request the violating individual to sign the reprimand and that they
            may write their comments on the reprimand if they so desire, If the
            person refuses to comment or sign the reprimand, the issuer shall
            note their refusal on the reprimand.

CONSTRUCTION DEPARTMENT

Vice President, Phil Cobb shall receive and maintain a log of all reprimands
related to safety.

JOB SITE

Shall maintain a copy of all reprimands in personnel or subcontract files.

                ACTION TAKEN AS RESULT OF REPRIMAND BEING ISSUED

1.    One (1) reprimand issued to an individual within a 12-month period will be
      considered a warning. However, one (1) may be sufficient for dismissal
      depending upon the seriousness of the violation and evaluation by the
      Project Superintendent, Project Manager and the vice President of
      Construction.

2.    Two (2) reprimands issued to an individual within a 12-month period will
      warrant a three (31 day lay off without pay. The second reprimand may also
      be sufficient for dismissal depending upon the seriousness of the
      violation and evaluation by the Project Superintendent, Project Manager
      and the vice President of Construction.

3.    Three (3) reprimands Issued to an individual within a 12-month period will
      result in termination for the violating individual. All safety related
      reprimands resulting in termination will be evaluated by the Project
      Superintendent, Project Manager and the Vice President of Construction.

This Disciplinary Action Program is very important to our Safety Program. All
employees must be made aware they are required to work in a safe manner at all
times while on a Duke-Weeks Realty Limited Partnership job site.

       CONTRACTOR/SUBCONTRACTOR


BY_________________________________________

TITLE______________________________________

Date:______________________________________


<PAGE>

                                   EXHIBIT "G"

                           Base Building Requirements

       As shown on the plans and specifications prepared by Randall Paulson
Architects, last revised August 6, 1999.


<PAGE>

                                   EXHIBIT "H"

                                  Warrant form

      Neither this Warrant nor the securities issuable upon exercise hereof have
been registered under the Securities Act of 1933, as amended (the "Securities
Act"), the securities laws of any state, or the securities laws of Canada or any
province thereof. Such securities may not be sold or otherwise disposed of
unless pursuant to a registered offering or by transfer exempt from registration
under the Securities Act and applicable state, Canadian and provincial
securities laws.

                              VISIBLE GENETICS INC.

                          Common Share Purchase Warrant

No. W-1

      This certifies that, for value received, _______________________ or its
registered assigns (the "holder"), upon due exercise of this Warrant, is
entitled to purchase from Visible Genetics Inc., a corporation organized under
the laws of the province of Ontario, Canada (the "Company"), at any time on or
after the third anniversary of the date hereof (the "Initial Exercise Date") and
before the close of business on the ninth anniversary of the date hereof (the
"Expiration Date"), all or any part of 10,000 fully paid and nonassessable
Common Shares, no par value, of the Company (the "Common Shares"), at a purchase
price of U.S. $___ per share (the "Initial Purchase Price"), the number of
Common Shares issuable upon exercise of this Warrant being subject to possible
adjustment as provided below.

      This Warrant is hereinafter called the "Warrant." The holder hereof and
all subsequent holders of this Warrant, shall be entitled to all rights and
benefits provided to the holder or holders hereof pursuant to the terms of this
Warrant.

      Section 1. Exercise of Warrant. The holder of this Warrant may, at any
time on or after the Initial Exercise Date and on or before the Expiration Date,
exercise this Warrant in whole at any time or in part from time to time for the
purchase of the Common Shares or other securities which such holder is then
entitled to purchase hereunder ("Warrant Securities") at the Purchase Price (as
hereinafter defined). In order to exercise this Warrant in whole or in part, the
holder hereof shall deliver to the Company (i) a written notice of such holder's
election to exercise this Warrant, which notice shall specify the number of
Common Shares to be purchased, (ii) payment of the aggregate purchase price of
the Common Shares being purchased by certified or bank cashier's check, and
(iii) this Warrant, provided that, if such Common Shares or other Warrant
Securities have not then been registered under the Securities Act of 1933, as
amended, or, if applicable, Canadian securities laws, the Company may require
that such holder furnish to the Company a written statement that such holder is
purchasing such Common Shares or other Warrant Securities for such holder's own
account for investment and not with a view to the distribution thereof, that
none of such shares will be offered or sold in violation of the provisions of
the Securities Act and applicable Canadian securities laws and as to such other
matters relating to the holder as the Company may reasonably request to permit
the issuance of such Common Shares or other Warrant Securities without
registration under the Securities Act and applicable Canadian securities laws.
Upon receipt thereof, the Company shall, as promptly as practicable, execute or
cause to be executed and deliver to such holder a certificate or certificates
representing the aggregate number of Common Shares (or if applicable, other
Warrant Securities) specified in said notice. The stock certificate or
certificates so delivered shall be registered in the name of such holder.

      No fractional Common Shares are to be issued upon the exercise of this
Warrant, but the Company shall pay a cash adjustment in respect of any fraction
of a share which would otherwise be issuable in an amount equal to the same
fraction of the market price per share of the Common Shares on the day of
exercise, as reasonably determined by the Company. If this Warrant shall


<PAGE>

have been exercised only in part, the Company shall, at the time of delivery of
said certificate or certificates, deliver to such holder a new Warrant
evidencing the rights of such holder to purchase the remaining Common Shares
called for by this Warrant, which new Warrant shall in all other respects be
identical with this Warrant, or, at the request of such holder, appropriate
notation may be made on this Warrant and same returned to such holder. The
Company shall pay all expenses, taxes and other charges payable in connection
with the preparation, execution and delivery of share certificates under this
Section, except that, if such share certificates are requested to be registered
in a name or names other than the name of the holder of this Warrant, funds
sufficient to pay all stock transfer taxes which shall be payable upon the
execution and delivery of such share certificates shall be paid by the holder
hereof at the time of delivering the notice of exercise mentioned above.

      The Company represents, warrants and agrees that all Common Shares
issuable upon any exercise of this Warrant in accordance with all of the terms
of this Warrant shall be validly authorized and issued, fully paid and
nonassessable.

      This Warrant shall not entitle the holder hereof to any of the rights of a
shareholder of the Company prior to exercise in the manner herein provided.

      Section 2. Transfer, Division and Combination. The Company shall keep at
its principal executive office a register for the registration and registration
of transfers of Warrants. The name and address of each holder of one or more
Warrants and each permitted transferee thereof shall be registered in such
register. Prior to due presentment for registration of transfer, the person in
whose name any Warrants shall be registered shall be deemed and treated as the
owner and holder thereof for all purposes hereof, and the Company shall not be
affected by any notice or knowledge to the contrary.

      Subject to the provisions of Section 3, upon surrender of any Warrant at
the principal executive office of the Company for registration of transfer or
exchange (and in the case of a surrender for registration of a permitted
transfer, duly endorsed or accompanied by a written instrument of transfer duly
executed by the registered holder of such Warrant or his attorney duly
authorized in writing and accompanied by the address for notices of each
transferee of such Warrant or part thereof), the Company shall execute and
deliver, at the Company's expense, one or more new Warrants (as requested by the
holder thereof) in exchange therefor, exercisable for an aggregate number of
Common Shares equal to the number of shares for which the surrendered Warrant is
exercisable and issued to such person or persons as such holder may request,
which Warrant or Warrants shall in all other respects be identical with this
Warrant.

      Upon receipt by the Company of evidence reasonably satisfactory to it of
the ownership of and the loss, theft, destruction or mutilation of any Warrant,
and (a) in the case of loss, theft or destruction, of indemnity reasonably
satisfactory to it, or (b) in the case of mutilation, upon surrender and
cancellation thereof, the Company shall execute and deliver, in lieu thereof, a
new Warrant identical in all respects to such lost, stolen, destroyed or
mutilated Warrant.

      Section 3. Compliance with Securities Act; Restrictions on Transfer. Each
Warrant issued in exchange for this Warrant and each certificate for Common
Shares (or other Warrant Securities) initially issued upon the exercise of this
Warrant and each certificate for Common Shares (or other Warrant Securities)
issued to subsequent transferees of any such certificate shall be stamped or
otherwise imprinted with legend in substantially the following form:

          THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT
          BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
          AMENDED (THE "SECURITIES ACT"), THE SECURITIES LAWS OF
          ANY STATE, OR THE SECURITIES LAWS OF CANADA OR ANY
          PROVINCE THEREOF. SUCH SECURITIES MAY NOT BE SOLD OR
          OTHERWISE DISPOSED OF UNLESS PURSUANT TO A REGISTERED
          OFFERING OR BY TRANSFER EXEMPT FROM REGISTRATION UNDER
          THE SECURITIES ACT AND APPLICABLE STATE, CANADIAN AND
          PROVINCIAL SECURITIES LAWS."

      Section 4. Anti-Dilution. As used herein:


<PAGE>

            (i)"Purchase Price" at any time shall mean the price per share of
      Common Shares of the Company at which this Warrant shall then be
      exercisable (including the Initial Purchase Price) in accordance with the
      provisions hereof.

            (ii) "Shares" means, collectively, Common Shares (A) issued or
      issuable upon exercise of the Warrants and (B) exchanged for, or
      distributed, issued or issuable with respect to, the shares included in
      clause (A) of this definition. In case by reason of the operation of this
      Section 4 this Warrant shall be exercisable for any other shares of stock
      or other securities or property of the Company or of any other
      corporation, any reference herein to the exercise of this Warrant shall be
      deemed to refer to and include the exercise of this Warrant for such other
      shares of stock or other securities or property.

      The Purchase Price and the number of Common Shares and the number or
amount of any other securities and property as hereinafter provided for which
this Warrant may be exercisable shall be subject to adjustment from time to time
effective upon each occurrence of any of the following events.

      (a) If the Company shall declare or pay any dividend with respect to its
Common Shares payable in Common Shares, subdivide the outstanding Common Shares
into a greater number of Common Shares, or reduce the number of Common Shares
outstanding (by stock split, reverse stock split, reclassification or otherwise
than by repurchase of its Common Shares) (any of such events being hereinafter
called a "Stock Split"), the Purchase Price and number of Common Shares issuable
upon exercise of this Warrant shall be appropriately adjusted so as to entitle
the holder hereof to receive upon exercise of this Warrant, for the same
aggregate consideration provided herein, the same number of Common Shares (plus
cash in lieu of fractional shares) as the holder would have received as a result
of such Stock Split had such holder exercised this Warrant in full immediately
prior to such Stock Split.

      (b) If the Company shall merge or consolidate with or into one or more
corporations partnerships and the Company is the sole surviving corporation, or
the Company shall adopt a plan of recapitalization or reorganization in which
Common Shares are exchanged for or changed into another class of stock or other
security or property of the Company, the holder of this Warrant shall, for the
same aggregate consideration provided herein, be entitled upon exercise of this
Warrant to receive in lieu of the number of Common Shares as to which this
Warrant would otherwise be exercisable, the number of Common Shares or other
securities (plus cash in lieu of fractional shares) or property to which such
holder would have been entitled pursuant to the terms of the agreement or plan
of merger, consolidation, recapitalization or reorganization had such holder
exercised this Warrant in full immediately prior to such merger, consolidation,
recapitalization or reorganization.

      (c) If the Company is merged or consolidated with or into one or more
corporations or other entities under circumstances in which the Company is not
the sole surviving corporation, or if the Company sells or otherwise disposes of
substantially all its assets, and in connection with any such merger,
consolidation or sale the holders of Common Shares receive stock or other
securities convertible into equity of the surviving or acquiring corporations or
entities, or other securities or property after the effective date of such
merger, consolidation or sale, as the case may be, the holder of this Warrant
shall, for the same aggregate consideration provided herein, be entitled upon
exercise of this Warrant to receive, in lieu of Common Shares as to which this
Warrant would otherwise be exercisable, shares of such stock or other securities
(plus cash in lieu of fractional shares) or property as the holder of this
Warrant would have received pursuant to the terms of the merger, consolidation
or sale had such holder exercised this Warrant in full immediately prior to such
merger, consolidation or sale. In the event of any consolidation, merger or sale
as described in this Section 4(d), provision shall be made in connection
therewith for the surviving or acquiring corporations or other entities to
assume all obligations and duties of the Company hereunder or to issue
substitute warrants in lieu of this Warrant with all such changes and
adjustments in the number or kind of shares of stock or securities or property
thereafter subject to this Warrant or in the Purchase Price as shall be required
in connection with this Section 4(c).

      (d) If the Company shall declare or pay any dividend, or make any
distribution, with respect to its Common Shares that is payable in preferred
stock or other securities, assets (other


<PAGE>

than cash) or rights to subscribe for or purchase any security of the Company
other than Common Shares, or that is payable in debt securities of the Company
convertible into Common Shares, preferred stock or other equity securities of
the Company, the holder hereof shall, for the same aggregate consideration
provided herein, be entitled to receive upon exercise of this Warrant in lieu of
the Common Shares as to which this Warrant would otherwise be exercisable, the
same amount of Common Shares, preferred stock and other securities, assets or
rights to subscribe for or purchase any security (plus cash in lieu of
fractional shares) as the holder would have received had the holder exercised
this Warrant in full immediately prior to any such dividend or distribution;
provided that no such adjustment shall be made pursuant to this Section 4(d) if
this Warrant is exercisable by the holder on or prior to the record date for
such dividend or distribution.

      (e) If the Company (other than in connection with a sale described in
Section 4(d)) proposes to liquidate and dissolve, the Company shall give notice
thereof as provided in Section 5(b) hereof and shall permit the holder of this
Warrant to exercise any unexercised portion hereof at any time within the 10 day
period following delivery of such notice, if such holder should elect to do so,
and participate as a stockholder of the Company in connection with such
dissolution.

      (f) Whenever any adjustment is made as provided in any provision of this
Section 4:

            (i) the Company shall compute the adjustments in accordance with
            this Section 4 and shall prepare a certificate signed by an officer
            of the Company setting forth the adjusted number of shares or other
            securities or property, as applicable, and showing in reasonable
            detail the facts upon which such adjustment is based, and such
            certificate shall forthwith be filed with the Company or its
            designee; and

            (ii) a notice setting forth the adjusted number of shares or other
            securities or property, as applicable, shall forthwith be required,
            and as soon as practicable after it is prepared, such notice shall
            be delivered by the Company to the holder of record of each Warrant.

      (g) If at any time, as a result of any adjustment made pursuant to this
Section 4, the holder of this Warrant shall become entitled, upon exercise
hereof, to receive any shares other than Common Shares or to receive any other
securities, the number of such other shares or securities so receivable upon
exercise of this Warrant shall be subject to adjustment from time to time in a
manner and on terms as nearly equivalent as practicable to the provisions
contained in this Section 4 with respect to the Common Shares.

      Section 5. Notices. Any notice or other document required or permitted to
be given or delivered to holders of Warrants and holders of Common Shares (or
other Warrant Securities) shall be in writing and sent (a) by telecopy if the
sender on the same day sends a confirming copy of such notice by a recognized
overnight delivery service (charges prepaid), or (b) by registered or certified
mail with return receipt requested (postage prepaid) or (c) by a recognized
overnight delivery service (with charges prepaid).

            (i) if to the Company, at 700 Bay Street, Toronto, Ontario MSG 1Z6,
      Attention: Chief Financial Officer, Telecopy No.: (416) 813-3250, or such
      other address as it shall have specified to the holders of Warrants in
      writing; or

            (ii) to a holder, at its address set forth below, or such other
      address as it shall have specified to the Company in writing.

Notices given under this Section 5 shall be deemed given only when actually
received.

      Section 6. Limitation of Liability. No provision hereof, in the absence of
affirmative action by the holder to purchase Common Shares, and no mere
enumeration herein of the rights or privileges of the holder hereof, shall give
rise to any liability of such holder for the Purchase Price or as a shareholder
of the Company, whether such liability is asserted by the Company or by
creditors of the Company.


<PAGE>

       Section 7. Amendment. This Warrant may not be amended, modified or
otherwise altered in any respect except by the written consent of the registered
holder of this Warrant and the Company.

       Section 8. Successors and Assigns. This Warrant shall be binding upon and
inure to the benefit of the Company and the holder of this Warrant and their
respective successors and permitted assigns.

       Section 9. Governing Law. This Warrant shall be governed by and construed
in accordance with the laws of the State of New York, without reference to the
conflicts of law principles thereof. The holder irrevocably submits to the
jurisdiction of any court of the State of New York or the United State District
Court for the Southern District of the State of New York for the purpose of any
suit, action, or other proceeding arising out of this Warrant. The holder
irrevocably and unconditionally waives and agrees not to plead, to the fullest
extent permitted by law, any objection that it may now or hereafter have to the
laying of venue or the convenience of the forum of any action or proceeding with
respect to this Warrant in any such courts.

       IN WITNESS WHEREOF, the Company has caused this Warrant to be signed in
its name by its duly authorized officers and accepted by the holder of this
Warrant this -- day of December, 1999.

Attest:                                  VISIBLE GENETICS INC.


By: ___________________________          By:_________________________________
Name:__________________________          Name:_______________________________
Title: Secretary                         Title: _____________________________

Holder:
Address for Notices:

_______________________________

_______________________________

_______________________________


<PAGE>

                                   ASSIGNMENT

                  TO BE EXECUTED BY THE REGISTERED HOLDER IF IT
                         DESIRES TO TRANSFER THE WARRANT

            FOR VALUE RECEIVED, _____________ hereby sells, assigns and
transfers unto __________________________________ the right to purchase
_________________ shares of stock ________ , evidenced by the within Warrant,
and does hereby irrevocably constitute and appoint _________ Attorney to
transfer the said Warrant on the books of the Company, with full power and
substitution.

                                    ____________________________________________
                                    Signature


                                    ____________________________________________

                                    ____________________________________________

                                     Address
Dated:_____________, 19___
In the presence of:

__________________________


                                     NOTICE

            The signature of the foregoing Assignment must correspond to the
name as written upon the face of the within Warrant in every particular, without
alteration or enlargement or any change whatsoever.


<PAGE>

                                SUBSCRIPTION FORM

                      TO BE EXECUTED BY THE REGISTERED HOLDER IF IT
                         DESIRES TO EXERCISE THE WARRANT

             The undersigned hereby exercises the right to purchase
_________shares of stock covered by this Warrant according to the conditions
thereof and herewith makes payment of the Purchase Price of such shares in full.


                                    ____________________________________________
                                    Signature

                                    ____________________________________________
                                    Name
                                    ____________________________________________

                                    ____________________________________________

Dated:____________, 19___.


<PAGE>

                                   EXHIBIT "I"

                         UNCONDITIONAL GUARANTY OF LEASE

      This Unconditional Guaranty of Lease is entered into as of the _____ day
of ,1999, by the undersigned, VISIBLE GENETICS, INC., ("Guarantor").

                                    RECITALS

      WHEREAS, VISIBLE GENETICS CORP., a(n) Pennsylvania corporation ("Tenant")
desires to enter into a certain Lease with DUKE-WEEKS REALTY LIMITED
PARTNERSHIP, a(n) Indiana limited partnership ("Landlord"), for certain space
described therein and more commonly known as 100 Crestridge Drive, Suwanee,
Georgia, (the "Lease"); and

      WHEREAS, Landlord is willing to enter into the Lease only if it receives a
guaranty of obligations thereunder from the undersigned upon the terms and
conditions set forth below; and

      WHEREAS, in order to induce Landlord to enter into the Lease, Guarantor is
willing and agrees to enter into this Unconditional Guaranty of Lease upon the
following terms and conditions; and

      WHEREAS, Guarantor is a shareholder of Tenant and will be benefited by the
Lease;

      NOW, THEREFORE, in consideration of the foregoing recitals and other good
and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, Guarantor agrees as follows:

      1. Within thirty days of Lease execution Guarantor agrees to issue to
Landlord, or its affiliate, a warrant to purchase 10,000 shares of common stock
of the Guarantor at a strike price equal to the closing price of the Guarantor's
common stock on the date of Lease execution, said warrant to be in the form
attached to the Lease as Exhibit "H". For the purposes of this section, the date
of Lease execution shall be the day on which Tenant has executed the Lease.

      2. Guarantor hereby becomes surety for and unconditionally guarantees (i)
the prompt payment of all rents, additional rents and other sums to be paid by
Tenant under the terms of the Lease; and (ii) the performance by Tenant of the
covenants, conditions and terms of the Lease (such payment and performance to be
referred to collectively as "Obligations"). In the event Tenant defaults in the
performance of the Obligations during the term of the Lease, Guarantor hereby
promises and agrees to pay to Landlord all rents and any arrearages thereof and
any other amounts that may be or become due and to fully satisfy all conditions
and covenants of the Lease to be kept and performed by Tenant.

      3. As conditions of liability pursuant to this Guaranty, Guarantor hereby
unconditionally waives (a) any notice of default by Tenant in the payment of
rent or any other amount or any other term, covenant or condition of the Lease;
(b) any requirement that Landlord exercise or exhaust its rights and remedies
against Tenant or against any person, firm or corporation prior to enforcing its
rights against Guarantor, and (c) any and all rights of reimbursement,
indemnity, subrogation or otherwise which, upon payment under this Guaranty,
Guarantor may have against Tenant.

      4. Landlord may, without notice to Guarantor, and Guarantor hereby
consents thereto, (a) modify or otherwise change or alter the terms and
conditions of the Lease; and (b) waive any of its rights under the Lease or
forbear to take steps to enforce the payment of rent or any other term or
condition of the Lease against Tenant.


<PAGE>

      5. Guarantor hereby agrees, upon the request of Landlord, to execute,
acknowledge and deliver to Landlord a statement in writing certifying, if this
be the fact, that this Guaranty of the referenced Lease is unmodified, in full
force and effect, and there are no defenses or offsets thereto; certifying that
the referenced Lease is unmodified, in full force and effect, and there are no
defenses or offsets to such Lease (or if modified, that the Lease is in full
force and effect as modified and that this Guaranty extends to and fully covers
such Lease, as modified); and certifying the dates to which Minimum Annual Rent,
Annual Rental Adjustment, if any, and any other additional rentals have been
paid.

      6. In the event Tenant fails during the term of this Lease to pay any
rent, additional rent or other payments when due or fails to comply with any
other term, covenant or condition of the Lease, Guarantor, upon demand of
Landlord, shall make such payments and perform such covenants as if they
constituted the direct and primary obligations of Guarantor; and such
obligations of Guarantor shall be due with attorneys' fees and all costs of
litigation and without relief from valuation or appraisement laws.

      7. The rights and obligations created by this Guaranty shall inure to the
benefit of and be binding upon the successors, assigns and legal representatives
of Guarantor and Landlord.

      8. Anything herein or in the Lease to the contrary notwithstanding,
Guarantor hereby acknowledges and agrees that any security deposit or other
credit in favor of the Tenant may be applied to cure any Tenant default or
offset any damages incurred by Landlord under the Lease, as Landlord determines
in its sole and absolute discretion, and Landlord shall not be obligated to
apply any such deposit or credit to any such default or damages before bringing
any action or pursuing any remedy available to Landlord against Guarantor.
Guarantor further acknowledges that its liability under this Guaranty shall not
be affected in any manner by such deposit or credit, or Landlord's application
thereof.

      IN WITNESS WHEREOF, Guarantor has executed this Unconditional Guaranty of
Lease as of the date set forth above.

                                      "GUARANTOR"

                                       VISIBLE GENETICS, INC.

                                       By:______________________________
                                       Name:____________________________
                                       Title:___________________________

                                                 (Corporate Seal)

                                       Address:_________________________
                                       _________________________________

                                       Tax Identification Number
                                       _____-_____-_____


<PAGE>

STATE OF_________ )
                  )SS:
COUNTY OF________ )

      Before me, a Notary Public in and for said County and State, personally
appeared _______ , by me known to be the ___________________ of Guarantor, a(n)
_________________________, who acknowledged the execution of the foregoing on
behalf of said ______________________

      WITNESS my hand and Notarial Seal this ______ day of _______________,
1999.

                                         __________________________________
                                         Notary Public

                                         __________________________________
                                         (Printed)

My County of Residence: _________________________

My Commission Expires: __________________________


<PAGE>

                                   COVER PAGE
       The capitalized terms in this Lease shall have the meanings ascribed to
them below, and each reference to such term in the Lease shall incorporate such
meaning therein as if fully set forth therein.

LANDLORD: DUKE-WEEKS REALTY LIMITED PARTNERSHIP, an Indiana limited partnership,
          with an office located at 4497 Park Drive, Norcross, Georgia 30093


TENANT: VISIBLE GENETICS CORP., a corporation duly organized and existing under
        the laws of the State of Pennsylvania.


LEASED
PREMISES    (a)   Address: 100 Crestridge Drive, Suwanee, Georgia

            (b)   Suite: N/A

            (c)   Rentable Area: 99,822 square feet

            (d)   Project: Horizon

TERM: Ten (10) years

COMMENCEMENT DATE:       February 15, 2000

TERMINATION DATE:        February 14, 2010

BASE RENT (FIRST YEAR):  $420,250.62

SECURITY DEPOSIT:        $210,125.34

GUARANTOR:               Visible Genetics, Inc.

TENANT'S AGENT:          Ben Bittan Realty


<PAGE>

                             VISIBLE GENETICS CORP.
                                 LEASE AGREEMENT
                                TABLE OF CONTENTS
SECTION                                                                     PAGE
-------                                                                     ----

 1 LEASED PREMISES ........................................................    1

 2 TERM ...................................................................    1

 3 RENTAL .................................................................    1

 4 DELAY IN DELIVERY ......................................................    2

 5 USE OF LEASED PREMISES .................................................    3

 6 UTILITIES ..............................................................    3

 7 ACCEPTANCE OF PREMISES .................................................    4

 8 ALTERATIONS, MECHANICS' LIENS ..........................................    4

 9 QUIET CONDUCT/QUIET ENJOYMENT ..........................................    4

10 FIRE INSURANCE, HAZARDS ................................................    4

11 INDEMNIFICATION

12 WAIVER OF CLAIMS .......................................................    5

13 REPAIRS ................................................................    6

14 SIGNS, LANDSCAPING .....................................................    6

15 ENTRY BY LANDLORD ......................................................    6

16 TAXES ..................................................................    7

17 INSURANCE ..............................................................    8

18 ABANDONMENT

19 DESTRUCTION ............................................................    9

20 ASSIGNMENT AND SUBLETTING ..............................................   10

21 INSOLVENCY OF TENANT ...................................................   10

22 BREACH BY TENANT .......................................................   10

23 ATTORNEYS' FEES/COLLECTION CHARGES .....................................   11


                                        3

<PAGE>

24 CONDEMNATION ...........................................................   11

25 NOTICES ................................................................   12

26 WAIVER .................................................................   12

27 EFFECT OF HOLDING OVER .................................................   12

28 SUBORDINATION ..........................................................   12

29 ESTOPPEL CERTIFICATE ...................................................   13

30 PARKING ................................................................   13

31 MORTGAGEE PROTECTION ...................................................   13

32 PROTECTIVE COVENANTS ...................................................   13

33 RELOCATION .............................................................   14

34 BROKERAGE COMMISSIONS ..................................................   14

MISCELLANEOUS PROVISIONS ..................................................   14

EXHIBITS:

EXHIBIT "A":       Site Plan
EXHIBIT "B":       Floor Plan of the Leased Premises
EXHIBIT "C":       Tenant's Acceptance of Premises
EXHIBIT "D":       Subordination, Non-disturbance and
                   Attoment Agreement
EXHIBIT "E":       Special Stipulations
EXHIBIT "F":       Construction Requirements
EXHIBIT "G":       Base Building Requirements
EXHIBIT "H":       Warrant form
EXHIBIT "I":       Guaranty


                                        4
<PAGE>



                         UNCONDITIONAL GUARANTY OF LEASE

      This Unconditional; Guaranty of Lease is entered into as of the 22nd day
of December, 1999, by the undersigned, VISIBLE GENETICS, INC., ("Guarantor").

                                    RECITALS

      WHEREAS, VISIBLE GENETICS CORP., a(n) Pennsylvania corporation ("Tenant")
desires to enter into a certain Lease with DUKE-WEEKS REALTY LIMITED
PARTNERSHIP, a(n) Indiana limited partnership ("Landlord"), for certain space
described therein and more commonly known as 100 Crestridge Drive, Suwanee,
Georgia, (the "Lease"); and

      WHEREAS, Landlord is willing to enter into the Lease only if it receives a
guaranty of obligations thereunder from the undersigned upon the terms and
conditions set forth below; and

      WHEREAS, in order to induce Landlord to enter into the Lease, Guarantor is
willing and agrees to enter into this Unconditional Guaranty of Lease upon the
following terms and conditions; and

      WHEREAS, Guarantor is a shareholder of Tenant and will be benefited by the
Lease;

      NOW, THEREFORE, in consideration of the foregoing recitals and other good
and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, Guarantor agrees as follows:

      1. Within thirty days of Lease execution Guarantor agrees to issue to
Landlord, or its affiliate, a warrant to purchase 10,000 shares of common stock
of the Guarantor at a strike price equal to the closing price of the Guarantor's
common stock on the date of Lease execution, said warrant to be in the form
attached to the Lease as Exhibit "H". For the purposes of this section, the date
of Lease execution shall be the day on which Tenant has executed the Lease.

      2. Guarantor hereby becomes surety for and unconditionally guarantees (i)
the prompt payment of all rents, additional rents and other sums to be paid by
Tenant under the terms of the Lease; and (ii) the performance by Tenant of the
covenants, conditions and terms of the Lease (such payment and performance to be
referred to collectively as "Obligations"). In the event Tenant defaults in the
performance of the Obligations during the term of the Lease, Guarantor hereby
promises and agrees to pay to Landlord all rents and any arrearages thereof and
any other amounts that may be or become due and to fully satisfy all conditions
and covenants of the Lease to be kept and performed by Tenant.

      3. As conditions of liability pursuant to this Guaranty, Guarantor hereby
unconditionally waives (a) any notice of default by Tenant in the payment of
rent or any other amount or any other term, covenant or condition of the Lease;
(b) any requirement that Landlord exercise or exhaust its rights and remedies
against Tenant or against any person, firm or corporation prior to enforcing its
rights against Guarantor, and (c) any and all rights of reimbursement,
indemnity, subrogation or otherwise which, upon payment under this Guaranty,
Guarantor may have against Tenant.

      4. Landlord may, without notice to Guarantor, and Guarantor hereby
consents thereto, (a) modify or otherwise change or alter the terms and
conditions of the Lease; and (b) waive any of its rights under the Lease or
forbear to take steps to enforce the payment of rent or any other term or
condition of the Lease against Tenant.

      5. Guarantor hereby agrees, upon the request of Landlord, to execute,
acknowledge and deliver to Landlord a statement in writing certifying, if this
be the fact, that this Guaranty of the referenced Lease is unmodified, in full
force and effect, and there are no defenses or offsets thereto; certifying that
the referenced Lease is unmodified, in full force and


<PAGE>

effect, and there are no defenses or offsets to such Lease (or if modified, that
the Lease is in full force and effect as modified and that this Guaranty extends
to and fully covers such Lease, as modified); and certifying the dates to which
Minimum Annual Rent, Annual Rental Adjustment, if any, and any other additional
rentals have been paid.

        6. In the event Tenant fails during the term of this Lease to pay any
rent, additional rent or other payments when due or fails to comply with any
other term, covenant or condition of the Lease, Guarantor, upon demand of
Landlord, shall make such payments and perform such covenants as if they
constituted the direct and primary obligations of Guarantor; and such
obligations of Guarantor shall be due with attorneys' fees and all costs of
litigation and without relief from valuation or appraisement laws.

        7. The rights and obligations created by this Guaranty shall inure to
the benefit of and be binding upon the successors, assigns and legal
representatives of Guarantor and Landlord.

        8. Anything herein or in the Lease to the contrary notwithstanding,
Guarantor hereby acknowledges and agrees that any security deposit or other
credit in favor of the Tenant may be applied to cure any Tenant default or
offset any damages incurred by Landlord under the Lease, as Landlord determines
in its sole and absolute discretion, and Landlord shall not be obligated to
apply any such deposit or credit to any such default or damages before bringing
any action or pursuing any remedy available to Landlord against Guarantor.
Guarantor further acknowledges that its liability under this Guaranty shall not
be affected in any manner by such deposit or credit, or Landlord's application
thereof.

       IN WITNESS WHEREOF, Guarantor has executed this Unconditional Guaranty of
Lease as of the date set forth above.

                                       "GUARANTOR"

                                       VISIBLE GENETICS, INC.

                                       By: /s/ Thomas J. Clarke
                                           -------------------------------------
                                       Name: Thomas J. Clarke
                                             -----------------------------------
                                       Title: Chief Financial Officer
                                              ----------------------------------
                                                 (Corporate Seal)

                                        Address:___700 Bay St._______________
                                                _Suite 1000, Toronto_________
                                                Ontario, Canada

                                       Tax Identification Number

                                       _____-_____-_____


<PAGE>


PROVINCE OF_ONTARIO____}
                       }SS.
COUNTY OF __YORK_______}


      Before me, a Notary Public in and for said County and Province of Ontario
personally appeared __Thomas J. Clark__, by me known to be the __C.F.O.__ of
Guarantor, a(n) __Company__, who acknowledged the execution of the foregoing on
 behalf of said __Company__.

WITNESS my hand and Notarial Seal this _22nd_ day of _December_, 1999.

                                                     /s/ M. Jason August
                                                     ---------------------------
                                                     Notary Public
                                                     M. Jason August
                                                     ---------------------------
                                                      (Printed)

My County of Residence:__York , Province of Ontario__

My Commission Expires:__no expiry__