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                                                                     Exhibit 4.2

                       MASTER LOAN AND SECURITY AGREEMENT

No.7691                                                      Dated July 21, 1999

LENDER:                                          CUSTOMER:
       OXFORD VENTURE FINANCE, LLC                        CELLOMICS, INC.
       a Virginia limited liability corporation           a Delaware corporation

Address:                                         Address:
         133 North Fairfax Street                         635 William Pitt Way
         Alexandria, Virginia 22314                       Pittsburgh, PA 15238

         In consideration of each Loan Agreement, Customer hereby agrees with
Lender that, whenever Customer shall be at any time or times directly or
contingently indebted, liable or obligated to Lender in any manner whatsoever,
Lender shall have the following rights:

         1. DEFINITIONS. To the extent not otherwise specifically defined in
this Agreement, unless the context otherwise requires, all other terms contained
in this Agreement shall have the meanings assigned or referred to them in the
UCC. The following terms shall have the following meanings:

         "Acceptance Date" with respect to each item of Equipment shall have the
meaning assigned to such term in Section 3 of this Agreement.

         "Affiliate" shall mean, with respect to any person, firm or entity, any
other person, firm or entity controlling, controlled by, or under common control
with such person, firm or entity; for the purposes hereof "control" shall mean
the possession, directly or indirectly, of the power to direct or cause the
direction of the management and policies of any such person, firm or entity,
whether through the legal or beneficial ownership of voting securities, by
contract or otherwise.

         "Agreement" shall mean this Master Loan and Security Agreement, as
amended or modified from time to time.

         "Attorneys' Fees and Expenses" shall mean all reasonable attorneys'
fees and legal costs and expenses (including, without limitation, those fees,
costs and expenses incurred in connection with bankruptcy proceedings, including
Relief from Stay Motions, Cash Collateral Motions and disputes concerning any
proposed disclosure statement and/or bankruptcy plan).

         "Collateral" shall mean all Equipment and any licenses, trademarks or
other tangible or intangible property ancillary to the Equipment and all
products, proceeds, rents and profits therefrom or thereof including proceeds in
the form or goods, accounts, chattel paper, documents, instruments and insurance
proceeds.

         "Default" shall have the meaning ascribed to such term in Section 8 of
this Agreement.

         "Equipment" shall mean one or more items or units of personal property
now owned or hereafter acquired by Customer, as described in each Equipment
Schedule, wherever the same may be located, including all present and future
additions, attachments, accessions and accessories thereto and all replacements,
substitutions and a right to use license for any software related to any of the
foregoing and proceeds thereof, including all proceeds of insurance thereon.

         "Equipment Schedule" shall mean each Equipment Schedule, which
incorporates by reference the terms and conditions of this Agreement and
describes one or more items of Equipment and specific terms and conditions with
respect thereto.

         "Event of Default" shall have the meaning ascribed to such term in
Section 8 of this Agreement.

         "Loan Agreement" shall mean the applicable Equipment Schedule
incorporating the terms and conditions of this Agreement, including all
exhibits, addenda, schedules, certificates, riders and all other documents and
instruments executed and delivered in connection with the applicable Equipment
Schedule or this Master Loan and Security Agreement.

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         "Note" shall mean a promissory note of Customer in favor of Lender
evidencing Customer's obligations to lender with respect to a Loan Agreement.

         "Obligations" shall mean all liabilities, absolute or contingent,
joint, several or independent, of Customer or any Affiliate of Customer now or
hereafter existing, due or to become due to, or held or to be held by, Lender
for its own account or as agent for another or others, whether created directly
or acquired by assignment or otherwise and howsoever evidenced, including,
without limitation, the Loan Agreement, and all interest, taxes, fees, charges,
expenses and Attorneys' Fees and Expenses chargeable to Customer or incurred by
Lender under the Loan Agreement, or any other document or instrument delivered
in connection herewith.

         "Person" shall mean any individual, partnership, joint venture, firm,
corporation, association, trust, or other enterprise or any government or
political subdivision or any agency, department or instrumentality thereof.

         "Security Deposit" with respect to each item of Equipment shall have
the meaning assigned to such term in the Equipment Schedule applicable to such
item of Equipment.

         "UCC" shall mean the Uniform Commercial Code as enacted in the State of
Connecticut.

         2. INDEPENDENT LOAN; CROSS-COLLATERALIZATION; SECURITY INTEREST. Each
Equipment Schedule shall constitute a separate, distinct and independent Loan
Agreement and contractual obligation of Customer. As security for the due and
punctual payment of any and all of the present and future Obligations of
Customer to Lender, Customer hereby (i) grants to Lender with respect to each
Loan Agreement and for the full amount of all Obligations, a security interest
in all of the Collateral and all collateral securing any other lease or security
agreement between Customer and Lender, whether now in existence or hereafter
entered into and (ii) assigns to Lender all of its rights, title and interest in
surplus money to which Customer may be entitled upon the sale of all such
Collateral. The extent to which Lender's security interest in any item of
Collateral shall be entitled to purchase money priority shall be determined by
reference to the unpaid principal balance of any Note evidencing the financing
of the purchase price of such item of Equipment.

         3. ACCEPTANCE OF EQUIPMENT. The Equipment is to be delivered and
installed at the location specified or referred to in the applicable Equipment
Schedule. The Equipment shall be deemed to have been accepted by Customer for
all purposes under this Agreement upon Customer's execution of an Equipment
Schedule (the "Acceptance Date"). Customer shall not be liable or responsible
for any failure or delay in the delivery of the Equipment to Customer for
whatever reason.

         4. TERM; PRINCIPAL AND INTEREST; NO PREPAYMENT; LATE CHARGES. The term
for any Loan Agreement shall be as specified in the applicable Equipment
Schedule. No Loan Agreement is prepayable by Customer, in whole or in part,
without the express written consent of Lender in its sole discretion. Principal
and interest payments shall be in the amounts and shall be due and payable as
set forth in the applicable Equipment Schedule. If any payment of principal or
interest or other amount payable hereunder shall not be paid within 10 days of
the date when due, Customer shall pay as an administrative and late charge an
amount equal to 5% of the amount of any such overdue payment. In addition,
Customer shall pay overdue interest on any delinquent payment or other amounts
due under any Loan Agreement (by reason of acceleration or otherwise) from the
due date until paid at the rate of one and one-half percent (1.5%) per month or
the maximum amount permitted by applicable law, whichever is lower. All payments
to be made to Lender shall be made to Lender in immediately available funds at
the address shown above, or at such other place as Lender shall specify in
writing.

         5. REPRESENTATIONS, WARRANTIES AND COVENANTS. Customer hereby
represents and warrants to and covenants with Lender (provided that if Customer
is an individual or sole proprietorship, the representations, warranties and
covenants relating to corporate status shall not apply) that, as of the date
hereof and for so long as any Obligations shall remain outstanding:

         (a) Customer is duly organized and is existing in good standing under
the laws of its jurisdiction of organization and is duly qualified and in good
standing in those jurisdictions where the conduct of its business or the
ownership of its properties requires qualification;

         (b) Customer has the power and authority to own the Collateral, to
enter into and perform this Agreement and any other document or instrument
delivered in connection herewith and to incur the Obligations;

         (c) Customer's chief executive office is located at the address set
forth above;


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         (d) Customer does not utilize, and has not in the last five years
utilized, any trade names in the conduct of business except as set forth on
Schedule 1 hereto;

         (e) Customer has not changed its name, been the surviving entity in a
merger, acquired any business or changed the location of its chief executive
office within the previous five years, except as set forth on Schedule 2 hereto;

         (f) Neither the execution, delivery or performance by Customer of the
Loan Agreement nor compliance by it with the terms and provisions hereof, nor
the consummation of the transactions contemplated herein, (i) will contravene
any applicable provision of any law, statute, rule or regulation, or any order,
writ, injunction or decree of any court or governmental instrumentality, (ii)
will conflict or be inconsistent with or result in any breach of any of the
terms, covenants, conditions or provisions of, or constitute a default under, or
result in any lien upon any property, pursuant to the terms of any indenture,
mortgage, deed of trust, loan agreement or any other material agreement or
instrument to which Customer is a party or by which it or any of its property or
assets are bound or to which it may be subject or (iii) will violate any
provision of its Certificate of Incorporation or By-Laws, or other governance
documents;

         (g) The Loan Agreement, the Note and any document or instrument
delivered in connection herewith and the transactions contemplated hereby or
thereby are duly authorized, executed and delivered, and the Loan Agreement, the
Note and such other documents and instruments constitute valid and legally
binding obligations of Customer and are enforceable against Customer in
accordance with their respective terms;

         (h) No order, consent, approval, license, authorization, or validation
of, or filing, recording or registration with, or exemption by any governmental
or public body or authority, or any subdivision thereof, is required to
authorize or required in connection with (i) the grant by Customer of the
security interest in connection with the Loan Agreement, (ii) the execution,
delivery and performance of the Loan Agreement, (iii) the legality, validity,
binding effect or enforceability of the Loan Agreement or (iv) the perfection or
maintenance of the aforementioned lien and security interest;

         (i) Customer has filed all federal, state and local tax returns and
other reports it is required to file, has paid or made adequate provision for
payment of all such taxes, assessments and other governmental charges, and shall
pay or deposit promptly when due all sales, use, excise, personal property,
income, withholding, corporate, franchise and other taxes, assessments and
governmental charges upon or relating to the manufacture, purchase, ownership,
maintenance, modification, delivery, installation, possession, condition, use,
acceptance, rejection, operation or return of the Equipment and, upon request by
Lender, Customer will submit to Lender proof satisfactory to Lender that such
payments and/or deposits have been made;

         (j) There are no pending or threatened actions or proceedings before
any court or administrative agency, an unfavorable resolution of which could
have a material adverse effect on Customer's financial condition or operations;

         (k) No representation, warranty or statement by Customer contained in
the Loan Agreement or in any certificate or other document furnished or to be
furnished by Customer pursuant to the Loan Agreement contains or at the time of
delivery shall contain any untrue statement of material fact, or omits, or shall
omit at the time of delivery, to state a material fact necessary to make it not
misleading;

         (l) All financial statements delivered and to be delivered by Customer
to Lender in connection with the execution and delivery of the Loan Agreement
are true and correct in all material respects and have been prepared in
accordance with generally accepted accounting principles, and at all times since
the date of the most recent financial statements, there has been no material
change in Customer's financial affairs or business operations. Customer shall
furnish Lender: (i) within 120 days after the last day of each fiscal year of
Customer, a financial statement including a balance sheet, income statement,
statement of retained earnings and statement of cash flows, each prepared in
accordance with generally accepted accounting principles consistently applied
with a report signed by an independent certified public accountant satisfactory.
to Lender: (ii) upon the request of Lender, within 60 days after the close of
each quarter of each fiscal year of Customer, financial statements similar to
those described in the immediately preceding clause, prepared by Customer and
certified by the chief financial officer of Customer; (iii) promptly upon the
request of Lender, such tax returns or financial statements regarding any
guarantor of the Obligations or any Affiliate of Customer as Lender may
reasonably request from time to time; (iv) promptly upon request of Lender, in
form satisfactory to Lender, such other and additional information as Lender may
reasonably request from time to time, and; (v) promptly inform Lender of any
Defaults (defined below) or any events or changes in the financial condition of
Customer occurring since the date of the last financial statements of Customer
delivered to Lender which, individually or cumulatively, when viewed in light of
prior financial statements, may result in a material adverse change in the
financial condition of Customer;


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         (m) Customer shall permit Lender, through its authorized attorneys,
accountants and representatives, to inspect and examine the Equipment and the
books, accounts, records, ledgers and assets of every kind and description of
Customer with respect thereto at all reasonable times; provided, however, that
the failure of Lender to inspect the Equipment or to inform Customer of any
noncompliance shall not relieve Customer of any of its Obligations hereunder;

         (n) Customer is the owner of the Equipment free and clear of all
rights, title, security interests, encumbrances or liens of any other party,
will defend the Equipment against all claims and demands of all persons at any
time claiming any interest therein and shall deliver to Lender any and all
evidence of ownership of, and certificates of title to, any and all of the
Equipment;

         (o) The Equipment is personal property and not a fixture under the law
of the jurisdiction in which the Equipment is located even though the Equipment
may hereafter become attached or affixed to real property;

         (p) Each site where Equipment is located, if not owned by Customer, is
leased by Customer pursuant to a valid lease or rental agreement which permits
the possession, use and operation of the Equipment at such location;

         (q) Customer shall provide Lender with disclaimers and waivers from
landlords, mortgagees and other persons holding any interest or claim in and to
any premises where Equipment is located, acceptable in all respects to Lender,
which may be necessary or advisable in the sole discretion of Lender to confirm
that the first priority security interest and rights of Lender in the Equipment
are and will remain valid and superior against all other parties;

         (r) The Equipment is in the possession of Customer at the location(s)
specified in the applicable Equipment Schedule, and shall not be removed from
such location without the prior written consent of Lender, which consent shall
in any event be conditioned upon Customer having completed all notifications,
filings, recordings, and other actions in such new location as Lender may
require to protect and perfect Lender's interests in the Collateral;

         (s) Customer shall not, without the prior written consent of Lender,
sell, offer to sell, lease, rent, hire or in any other manner dispose, transfer
or surrender use and possession of any Equipment;

         (t) Customer will not, directly or indirectly, create, incur or permit
to exist any lien, encumbrance, mortgage, pledge, attachment or security
interest on or with respect to the Equipment other than in connection with the
execution and delivery of the Loan Agreement;

         (u) Customer shall permit each item of Equipment to be used only within
the continental United States by qualified personnel solely for business
purposes and the purpose for which it was designed and, at its sole expense,
shall service, repair, overhaul and maintain each item of Equipment in the same
condition as when received, ordinary wear and tear excepted, in good operating
order, consistent with prudent industry practice (but, in no event less than the
same extent to which Customer maintains other similar equipment in the prudent
management of its assets and properties) and in compliance with all applicable
laws, ordinances, regulations, and conditions of all insurance policies required
to be maintained by Customer under the Loan Agreement and all manuals, orders,
recommendations, instructions and other written requirements as to the repair
and maintenance of such item of Equipment issued at any time by the vendor
and/or manufacturer thereof;

         (v) If any item of Equipment does not comply with the requirements of
the Loan Agreement, Customer shall bring such Equipment into compliance with the
provisions hereof; and Customer shall not use any Equipment, nor allow the same
to be used, for any unlawful purpose;

         (w) Customer acknowledges that Lender has not selected, manufactured or
supplied the Equipment to Customer and has acquired any Equipment subject hereto
solely in connection with this Loan Agreement and Customer has received and
approved the terms of any purchase order or agreement with respect to the
Equipment; and

         (x) Customer has all permits, licenses and other authorizations which
are required with respect to its business under Environmental Laws (as defined
below) and is in compliance with all terms and conditions of such permits,
licenses and other authorizations, including all limitations, restrictions,
standards, prohibitions, requirements, obligations, schedules and timetables.
The Customer is not presently in violation of any Environmental Laws.
"Environmental Laws" shall mean any Federal, state or local law relating to
releases or threatened releases of Hazardous Substances; the manufacture,
handling, transport, use, treatment, storage or disposal of Hazardous Substances
or materials containing Hazardous Substances; or otherwise relating to pollution
of the environment or the protection of human health "Hazardous Substances"
shall mean substances or materials which contain substances defined in or
regulated as toxic or hazardous materials, chemicals, substances,


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waste or pollutants under any present or future Federal statutes and their state
counterparts, as well as any implementing regulations as amended from time to
time and as interpreted by administering agencies.

         6. DISCLAIMER OF WARRANTIES; LIMITATION OF REMEDY; LIMITATION OF
LIABILITY. (Customer has selected both the Equipment and the supplier
(identified in the Equipment Schedule, herein ("Supplier") from whom Customer
agrees to purchase the Equipment.) CUSTOMER ACKNOWLEDGES THAT LENDER HAS NO
SPECIAL FAMILIARITY OR EXPERTISE WITH RESPECT TO THE EQUIPMENT. CUSTOMER AGREES
THAT THE EQUIPMENT IS "AS IS" AND IS OF A SIZE, DESIGN AND CAPACITY SELECTED BY
CUSTOMER AND THAT CUSTOMER IS SATISFIED THAT THE SAME IS SUITABLE FOR CUSTOMER'S
PURPOSES, AND THAT EXCEPT AS MAY OTHERWISE BE SPECIFICALLY PROVIDED HEREIN OR IN
THE EQUIPMENT SCHEDULE, LENDER HAS MADE NO REPRESENTATION OR WARRANTY AS TO ANY
MATTER WHATSOEVER. LENDER DISCLAIMS, AND CUSTOMER HEREBY EXPRESSLY WAIVES AS TO
LENDER, ALL WARRANTIES WITH RESPECT TO THE EQUIPMENT INCLUDING BUT NOT LIMITED
TO ALL EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE, QUALITY, CAPACITY, OR WORKMANSHIP, ALL EXPRESS OR IMPLIED
WARRANTIES AGAINST PATENT INFRINGEMENTS OR DEFECTS, WHETHER HIDDEN OR APPARENT,
AND ALL EXPRESS OR IMPLIED WARRANTIES WITH RESPECT TO COMPLIANCE OF THE
EQUIPMENT WITH THE REQUIREMENTS OF ANY LAW, REGULATION, SPECIFICATION OR
CONTRACT RELATIVE THERETO. IN NO EVENT SHALL LENDER BE LIABLE (INCLUDING WITHOUT
LIMITATION, UNDER ANY THEORY IN TORTS) FOR ANY LOSS OF USE, REVENUE, ANTICIPATED
PROFITS OR SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF
OR IN CONNECTION WITH THE LOAN OR THE USE, PERFORMANCE OR MAINTENANCE OF THE
EQUIPMENT. If the Equipment is not properly installed, does not operate as
represented or warranted by the Supplier, manufacturer and/or service company or
is unsatisfactory for any reason, Customer shall make any claim on account
thereof solely against the Supplier, manufacturer and/or service company and
shall, nevertheless, pay Lender all amounts payable under the Loan Agreement and
any such claims shall not act as a defense, counterclaim, deduction, setoff or
otherwise limit Customer's Obligations under the Loan Agreement.

         7. RISK OF LOSS AND DAMAGE; INSURANCE. Customer assumes all risk of
loss, damage or destruction to the Equipment from whatever cause and for
whatever reason. If all or a portion of an item of Equipment shall become lost,
stolen, destroyed, damaged beyond repair or rendered permanently unfit for use
for any reason, or in the event of any condemnation, confiscation, theft or
seizure or requisition of title to or use of such item of Equipment, Customer
shall immediately pay to Lender an amount equal to the outstanding principal
balance of and accrued and unpaid interest on any Note with respect to such
Equipment, less the net amount of the recovery, if any, received by Lender from
insurance on the Equipment. For so long as any Obligations shall remain
outstanding, Customer shall procure and maintain insurance in such amounts and
with such coverages, and upon such terms and with such companies, as Lender may
approve, at Customer's expense; provided, however, that in no event shall such
insurance be less than the following coverages and amounts: (a) Worker's
Compensation and Employer's Liability Insurance, in the full statutory amounts
provided by law; (b) Comprehensive General Liability Insurance including
product/completed operations and contractual liability coverage, with minimum
limits on a per occurrence basis, as reasonably required by Lender, and Combined
Single Limit Bodily Injury and Property Damage on an aggregate basis, as
reasonably required by Lender or, in either case, as otherwise specified in any
Equipment Schedule hereto; and (c) All Risk Physical Damage Insurance, excluding
earthquake and flood, on each item of Equipment, in an amount not less than the
greater of (i) the outstanding principal balance owing under any Note with
respect to such Equipment; or (ii) its full replacement value. Customer shall
cause Lender to be included as an additional insured on each such Comprehensive
General Liability Insurance policy. On each such All Risk Physical Damage
Insurance policy Lender shall be named as loss payee. Such policies shall be
endorsed to provide that the coverage afforded to Lender shall not be rescinded,
impaired or invalidated by any act or neglect of Customer. Customer agrees to
waive Customer's rights and its insurance carrier's rights of subrogation
against Lender for any and all loss or damage. In addition to the foregoing
minimum insurance coverage, Customer shall procure and maintain such other
insurance coverage as Lender may require. All policies shall be endorsed or
contain a clause requiring the insurer to furnish Lender with at least 30 days
prior written notice of any material change, cancellation or non-renewal of
coverage. Upon execution of this Agreement, and thereafter, 30 days prior to the
expiration of each insurance policy required hereunder, Customer shall furnish
Lender with a certificate of insurance or other evidence satisfactory to Lender
that the insurance coverages required under such policy are and will continue in
effect, provided, however, that Lender shall be under no duty either to
ascertain the existence of or to examine such insurance coverage or to advise
Customer in the event such insurance coverage should not comply with the
requirements hereof. If Customer shall at any time or times hereafter fail to
obtain and/or maintain any of the policies of insurance required herein, or fail
to pay any premium in whole or in part relating to any such policies, Lender
may, but shall not be obligated to, obtain and/or cause to be maintained
insurance coverage with respect to the Collateral, including, at Lender's
option, the coverage provided by all or any of the policies of Customer and pay
all or any part of the premium therefor, without waiving any Event of Default by
Customer, and any sums so disbursed by Lender shall be additional Obligations of
Customer to Lender payable


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on demand. Lender shall have the right to settle and compromise any and all
claims under any of the All Risk Physical damage policies required to be
maintained by Customer hereunder and Customer hereby appoints Lender as its
attorney-in-fact, with power to demand, receive and receipt for all monies
payable thereunder, to execute in the name of Customer or Lender or both any
proof of loss, notice, draft or other instruments in connection with such
policies or any loss thereunder and generally to do and perform any and all acts
as Customer, but for this appointment, might or could perform.

         8. EVENTS OF DEFAULT. An "Event of Default" under this Agreement shall
be deemed to have occurred upon the occurrence or existence of any one or more
of the following events or conditions (each a "Default") and after the giving of
any required notice or the passage of any required period of time (or both)
specified below with respect to such Default: (a) Customer shall fail to make
any payment due under any Note or as required under the Loan Agreement within 10
days of its due date; or (b) Customer shall fail to obtain or maintain any of
the insurance required under the Loan Agreement; or (c) Customer shall remove,
sell, transfer, encumber, or part with possession of any Equipment; (d) Customer
shall fail to perform or observe any other covenant, condition or agreement
under the Loan Agreement, and such failure shall continue for 20 days after
notice thereof to Customer; or (e) Customer or any of its Affiliates shall
default in the payment or performance of any Obligation owing to Lender, and
such default shall continue for 20 days after notice thereof to Customer; or (f)
any representation or warranty made by Customer herein or in any certificate,
agreement, statement or document heretofore or hereafter furnished Lender,
including without limitation any financial information, except projections,
disclosed to Lender, shall prove to be false or incorrect in any material
respect; or (g) death or judicial declaration of incompetence of Customer, if an
individual; or (h) the commencement of any bankruptcy, insolvency, arrangement,
reorganization, receivership, liquidation or other similar proceeding by or
against Customer or any of its properties or businesses, or the appointment of a
trustee, receiver, liquidator or custodian for Customer or any of its properties
or businesses, or if Customer suffers the entry of an order for relief under
Title 11 of the United States Code; or (i) the making by Customer of a general
assignment or deed of trust for the benefit of creditors; or (j) Customer shall
default in any payment or other material obligation to any other lender and such
lender has accelerated the debt in accordance with its terms; or (k) Customer
shall merge with or consolidate into any other entity or sell all or
substantially all of its assets or in any manner terminate its existence; or (l)
if Customer is a privately held corporation, more than 50% of Customer's voting
capital stock, or effective control of Customer's voting capital stock, issued
and outstanding from time to time, is not retained by the holders of such stock
on the date the Loan Agreement is executed; or (m) if Customer is a publicly
held corporation, there shall be a change in the ownership of Customer's stock
such that Customer is no longer subject to the reporting requirements of the
Securities Exchange Act of 1934 or no longer has a class of equity securities
registered under Section 12 of the Securities Act of 1933; or (n) Lender shall
determine that there has been a material adverse change in the financial
condition or business operations of Customer since the date of the execution of
the Loan Agreement, or that Customer's ability to perform its obligations is
materially impaired; or (o) if Customer leases the premises where any Equipment
is located, a breach by Customer of any such lease and the commencement of an
action by the landlord to evict Customer or to repossess the premises; or (p)
any event or condition set forth in subsections (e) through (o) of this Section
8 shall occur with respect to any guarantor or other person liable or
responsible, in whole or in part, for payment or performance of any Obligations;
or (q) any event or condition set forth in subsections (e) through (o) shall
occur with respect to any Affiliate of Customer. Customer shall promptly notify
Lender of the occurrence of any Event of Default or the occurrence or existence
of any event or condition which, upon the giving of notice or lapse of time, or
both, would constitute an Event of Default.

         9. RIGHTS AND REMEDIES; ACCELERATION. (a) Upon the occurrence of an
Event of Default, Lender shall have all of the rights and remedies enumerated
herein (all of which are cumulative and not exclusive of any other right or
remedy available to Lender) and Lender may, at its sole option and discretion,
exercise one or more of the following remedies with respect to any or all of the
Collateral: (i) by written notice to Customer, terminate any or all Loan
Agreements as such notice shall specify, and, with respect to such terminated
Loan Agreements, declare immediately due and payable and recover from Customer,
as liquidated damages for loss of Lender's bargain and not as a penalty, an
amount equal to the aggregate of all unpaid periodic installment payments and
other sums due under Loan Agreements to the date of default plus the charges set
forth in Section 4 hereof, if any, plus an amount equal to the outstanding
principal balances of and accrued and unpaid interest on any of the Notes with
respect to the Loan Agreements, (ii) Lender may declare, at its option, all or
any part of the Obligations immediately due and payable, without demand, notice
of intention to accelerate, notice of acceleration, notice of nonpayment,
presentment, protest, notice of dishonor, or any other notice whatsoever, all of
which are hereby waived by Customer and any endorser, guarantor, surety or other
party liable in any capacity for any of the Obligations; (iii) cause Customer to
promptly ship, with insurance and freight prepaid by Customer, any or all
Equipment to such location as Lender may designate, or Lender, at its option,
may enter upon the premises where the Equipment is located and take immediate
possession of and remove the same by summary proceedings or otherwise, all
without liability to Lender for or by reason of damage to property or such entry
or taking possession except for Lender's gross negligence or willful misconduct;
(iv) sell any or all Collateral at public or private sale or otherwise dispose
of, hold, use, operate, lease to others or keep idle the Equipment, all as
Lender in its sole discretion may determine and all free and clear of any rights
of Customer; (v) remedy such default, including making repairs or modifications
to the Equipment, for the account and expense of Customer, and Customer agrees
to


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reimburse Lender for all of Lender's costs and expenses; (vi) apply any Security
Deposit or other cash collateral or sale or remarketing proceeds of the
Equipment at any time to reduce any amounts due to Lender, or (vii) exercise any
other right or remedy which may be available to Lender under applicable law, or
proceed by appropriate court action to enforce the terms hereof or to recover
damages for the breach hereof; including Attorneys' Fees and Expenses. Any
notice required to be given by Lender of a sale or other disposition or other
intended action which is made in accordance with the terms of the Loan Agreement
at least seven (7) days prior to such proposed action, shall constitute fair and
reasonable notice to Customer of any such action. Lender shall be liable to
Customer only for its gross negligence or willful misconduct in failing to
comply with any applicable law imposing duties upon Lender; Lender's liability
for any such failure shall be limited to the actual loss suffered by Customer
directly resulting from such failure; and in no event shall Lender have any
liability to Customer for incidental, consequential, punitive or exemplary
damages. No remedy referred to in this Section 9 shall be exclusive, but each
shall be cumulative and in addition to any other remedy referred to above or
otherwise available to Lender at law or in equity.

         (b) The exercise or pursuit by Lender of any one or more of such
remedies shall not preclude the simultaneous or later exercise or pursuit by
Lender of any or all such other remedies, and all remedies hereunder shall
survive termination of the Loan Agreement. In the event Lender takes possession
and disposes of the Collateral, the proceeds of any such disposition shall be
applied in the following order: (l) to all of Lender's costs, charges and
expenses incurred in taking, removing, holding, repairing and selling or leasing
the Equipment; (2) to pay the Lender the remaining amount of any Obligations
owed to Lender and (3) the balance, if any, to Customer. A termination shall
occur only upon written notice by Lender and only with respect to such Equipment
as Lender shall specify in such notice. Termination under this Section 9 shall
not affect Customer's duty to perform Customer's Obligations under the Loan
Agreement in full. Customer agrees to reimburse Lender on demand for any and all
costs and expenses incurred by Lender in enforcing its rights and remedies
hereunder following the occurrence of an Event of Default, including, without
limitation, Attorneys' Fees and Expenses, and the costs of repossession,
storage, insuring, reletting, selling and disposing of any and all Equipment.

         10. INDEMNITY. (a) Customer agrees to indemnify, reimburse and hold
Lender and its successors, Affiliates, assigns, officers, directors, employees,
agents and servants (hereinafter in this Section 10 referred to individually as
"Indemnitee", and collectively as "Indemnitees") harmless from any and all
liabilities, obligations, damages, injuries, penalties, claims, demands,
actions, suits, judgments and any and all costs, expenses or disbursements,
including Attorneys' Fees and Expenses of whatsoever kind and nature imposed on,
asserted against or incurred by any of the Indemnitees in any way relating to or
arising out of the Loan Agreement or any other document executed in connection
herewith or therewith or in any other way connected with the administration of
the transactions contemplated hereby or thereby or the enforcement of any of the
terms of, or the preservation of any rights under any thereof, or in any way
relating to or arising out of the manufacture, ownership, ordering, purchase,
delivery, control, acceptance, lease, financing, possession, operation,
condition, sale, return or other disposition, or use of the Equipment
(including, without limitation, latent or other defects, whether or not
discoverable), the violation of the laws of any country, state or other
governmental body or unit, any tort (including, without limitation, claims
arising or imposed under the doctrine of strict liability, or for or on account
of injury to or the death of any Person (including any Indemnitee), or property
damage), or contract claim, or any claim based on patent, trademark or copyright
infringement or any obligation or liability to the manufacturer or supplier of
the Equipment under any Supply Contracts (referenced in the Equipment Schedule),
including purchase orders issued by Customer or Lender or assigned to Lender;
provided, however, that no Indemnitee shall be indemnified pursuant to this
Section 10 for losses, damages or liabilities to the extent caused solely by the
gross negligence or willful misconduct of such Indemnitee. Customer agrees that
upon written notice by any Indemnitee of the assertion of such a liability,
obligation, damage, injury, penalty, claim, demand, action, suit or judgment,
Customer shall assume full responsibility for the defense thereof. Each
Indemnitee agrees to use its best efforts to promptly notify Customer of any
such assertion of which such Indemnitee has knowledge.

         (b) Without limiting the application of Section 10(a) hereof, Customer
agrees to pay, or reimburse Lender for any and all reasonable fees, costs and
expenses (including Attorneys' Fees and Expenses) of whatever kind or nature
incurred in connection with the creation, preservation or protection of Lender's
liens on, and security interest in, the Collateral, including, without
limitation, all fees and taxes in connection with the recording or filing of
instruments and documents in public offices, payment or discharge of any taxes
or liens upon or in respect of the Collateral, premiums for insurance with
respect to the Collateral and all other fees, costs and expenses in connection
with protecting, maintaining or preserving the Collateral and Lender's interest
therein, whether through judicial proceedings or otherwise, or in defending or
prosecuting any actions, suits or proceedings arising out of or relating to the
Collateral.

         (c) Customer shall, at its sole cost and expense, protect, defend,
indemnify, release and hold harmless the Indemnitees from and against any and
all Losses imposed upon or incurred by or asserted against any Indemnitees, and
arising out of or in any way relating to any one or more of the following,
unless caused solely by the gross negligence or willful misconduct of any
Indemnitee: (i) any presence of any Hazardous Substances in, on, above or under
Customer's leased or owned real property (the "Property"); (ii) any past,
present or threatened Release of Hazardous Substances


                                     Page 7

<PAGE>   8

in, on, above, under or from the Property; or (iii) any past or present
violation of any Environmental Laws. The term "Release" of any Hazardous
Substance includes, but is not limited to, any release, deposit, discharge,
emission, leaking, spilling, seeping, migrating, injecting, pumping, pouring,
emptying, escaping, dumping, disposing or other movement of Hazardous
Substances. The term "Losses" includes any and all claims, suits, liabilities
(including, without limitation, strict liabilities), actions, proceedings,
obligations, debts, damages, losses, costs, expenses, diminutions in value,
fines, penalties, charges, fees, expenses, judgments, awards, amounts paid in
settlement, costs of remediating a Hazardous Substance (whether or not performed
voluntarily), engineers' fees, environmental consultants' fees, and costs of
investigation (including, but not limited to sampling, testing and analysis of
soil, water, air, building materials and other materials and substances whether
solid, liquid or gas) or punitive damages, of whatever kind or nature
(including, but not limited to Attorneys' Fees and Expenses).

         (d) Without limiting the application of Section 10(a) or (b), or (c)
hereof, Customer agrees to pay, indemnify and hold each Indemnitee harmless from
and against any loss, costs, damages and expenses (including Attorneys Fees and
Expenses) which such Indemnitee may suffer, expend or incur in consequence of or
growing out of any misrepresentation or omission of a material fact by Customer
in the Loan Agreement or in any writing contemplated by or made or delivered
pursuant to or in connection with the Loan Agreement.

         (e) If and to the extent that the obligations of Customer under this
Section 10 are unenforceable for any reason, Customer hereby agrees to make the
maximum contribution to the payment and satisfaction of such obligations which
is permissible under applicable law.

         11. MAINTENANCE; INSPECTION. During the term of the Loan Agreement,
Customer shall, unless Lender shall otherwise consent in writing: (a) maintain
conspicuously on any Equipment such labels, plates, decals or other markings as
Lender may reasonably require, stating that Lender has a security interest in
such Equipment; (b) furnish to Lender such information concerning the condition,
location, use and operation of the Equipment as Lender may request; (c) permit
any person designated by Lender to visit and inspect any Equipment and any
records maintained in connection therewith, provided, however, that the failure
of Lender to inspect the Equipment or to inform Customer of any noncompliance
shall not relieve Customer of any of its obligations hereunder; and (d) make no
additions, alterations, modifications or improvements (collectively,
"Improvements") to any item of Equipment that are not readily removable without
causing material damage to such item of Equipment or which will cause the value,
utility or useful life of such item of Equipment to materially decline. If any
such Improvement is made and cannot be removed without causing material damage
or decline in value, utility or useful life (a "Non-Severable Improvement"),
then Customer warrants that such Non-Severable Improvement shall immediately
become subject to Lender's security interest upon being installed and shall be
free and clear of all liens and encumbrances and shall become Equipment subject
to all of the terms and conditions of the Loan Agreement.

         12. FURTHER ASSURANCES. Customer shall promptly execute and deliver to
Lender such further documents and take such further action as Lender may require
in order to more effectively carry out the intent and purpose of the Loan
Agreement. Customer shall execute and deliver to Lender upon Lender's request
any and all schedules, forms and other reports and information as Lender may
deem necessary or appropriate to respond to requirements or regulations imposed
by any governmental authorities or to comply with the provisions of the law of
any jurisdiction in which Customer may then be conducting business or in which
any of the Equipment may be located. Customer shall execute and deliver to
Lender upon Lender's request such further and additional documents, instruments
and assurances as Lender deems necessary to acknowledge and confirm, for the
benefit of Lender or any assignee or transferee of any of Lender's rights, title
and interests hereunder in accordance with Section 13 hereof (an "Assignee"),
all of the terms and conditions of all or any part of the Loan Agreement and
Lender's or Assignee's rights with respect thereto, and Customer's compliance
with all of the terms and provisions thereof.

         13. ASSIGNMENT. The provisions of the Loan Agreement shall be binding
upon and shall inure to the benefit of the heirs, administrators, successors and
assigns of Lender and Customer, provided, however, Customer may not assign any
of its rights, transfer any interest in the Equipment or delegate any of its
obligations under the Loan Agreement without the prior written consent of Lender
in its sole discretion. Lender may, from time to time, absolutely or as
security, without notice to Customer, sell, assign, transfer, participate,
pledge or otherwise dispose of all or any part of a Loan Agreement, the
Obligations and/or the Collateral therefor, subject to the rights of Customer
under the Loan Agreement for the use and possession of the Equipment. In such
event, each and every immediate and successive Assignee shall have the right to
enforce the Loan Agreement with respect to those Obligations and/or Collateral
transferred to the Assignee, by legal action or otherwise, for its own benefit
as fully as if such Assignee were herein by name specifically given such rights.
Customer agrees that the rights of any such Assignee hereunder or with respect
to the related Obligations, shall not be subject to any defense, set off or
counterclaim that Customer may assert or claim against Lender, and that any such
Assignee shall have all of Lender's rights hereunder but none of Lender's
obligations. Lender shall have an unimpaired right to enforce the Loan Agreement
for its


                                     Page 8

<PAGE>   9

benefit with respect to that portion of any Loan Agreement, Obligations and/or
Collateral that Lender has not sold, assigned, edged or otherwise transferred.

         14. GOVERNING LAW; MEDIATION OF THE LOAN AGREEMENT. THE LOAN AGREEMENT
AND THE LEGAL RELATIONS OF THE PARTIES HERETO SHALL IN ALL RESPECTS BE GOVERNED
BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF CONNECTICUT,
WITHOUT REGARD TO PRINCIPLES REGARDING THE CHOICE OF LAW. CUSTOMER HEREBY
CONSENTS AND SUBMITS TO THE NON-EXCLUSIVE JURISDICTION OF THE COURTS OF THE
STATE OF CONNECTICUT AND THE FEDERAL DISTRICT COURT FOR THE DISTRICT OF
CONNECTICUT FOR THE PURPOSES OF ANY SUIT, ACTION OR OTHER PROCEEDING ARISING OUT
OF ITS OBLIGATIONS UNDER THE LOAN AGREEMENT, AND EXPRESSLY WAIVES ANY OBJECTIONS
THAT IT MAY HAVE TO THE VENUE OF SUCH COURTS. CUSTOMER HEREBY EXPRESSLY WAIVES
ANY RIGHT TO TRIAL BY JURY IN ANY ACTION BROUGHT ON OR WITH RESPECT TO THE LOAN
AGREEMENT. Any action by Customer against Lender for any cause of action under
the Loan Agreement shall be brought within one year after any such cause of
action first arises. If requested by Lender, Customer agrees that prior to the
commencement of any litigation regarding the terms and conditions of the Loan
Agreement, the parties hereto shall subject themselves to non-binding mediation
with a qualified mediator mutually satisfactory to both parties.

         15. NOTICES. Any demand or notice required or permitted to be given
hereunder shall be deemed effective (a) when deposited in the United States
mail, and sent by certified mail, return receipt requested, postage prepaid,
addressed to Lender or to Customer at the addresses set forth herein, or to such
other address as may be hereafter provided by the party to be notified by
written notice complying with the provisions hereof or (b) when transmitted to
Lender or Customer by facsimile at the respective numbers provided for such
purpose; provided, that such facsimile notice is promptly followed by notice
given in accordance with the immediately preceding subsection (a).

         16. SECURITY DEPOSIT. Lender may, at its option, apply the Security
Deposit, if any is indicated in an Equipment Schedule, to cure any default of
Customer, whereupon Customer shall promptly restore such Security Deposit to its
original amount. Lender shall return to Customer any unapplied Security Deposit,
without interest, upon full payment and performance of Customer's Obligations
under the Loan Agreement.

         17. MISCELLANEOUS; GENERAL PROVISIONS. The Loan Agreement will not be
binding on Lender until accepted and executed by Lender at its executive office
in South Norwalk, Connecticut. All options, powers and rights granted to Lender
hereunder or under any promissory note, guaranty, letter of credit agreement,
depository agreement, instrument, document or other writing delivered to Lender
shall be cumulative and shall be in addition to any other options, powers or
rights which Lender may now or hereafter have under any applicable law or
otherwise. Time is of the essence in the payment and performance of all of
Customer's obligations under the Loan Agreement. The captions in the Loan
Agreement are for convenience only and shall not define or limit any of the
terms thereof.

         Any provisions of the Loan Agreement which are unenforceable in any
jurisdiction shall, as to such jurisdiction, be ineffective to the extent of
such unenforceability without invalidating the remaining provisions hereof, and
any such unenforceability in any jurisdiction shall not render unenforceable
such provisions in any other jurisdiction. To the extent permitted by applicable
law, Customer hereby waives any provisions of law which render any provision of
the Loan Agreement unenforceable in any respect.

         CUSTOMER ACKNOWLEDGES THAT THE TRANSACTION OF WHICH THIS LOAN AGREEMENT
IS A PART IS A COMMERCIAL TRANSACTION AND EXCEPT AS OTHERWISE PROVIDED IN THE
LOAN AGREEMENT CUSTOMER HEREBY WAIVES, TO THE EXTENT PERMITTED BY APPLICABLE
LAW, NOTICE AND JUDICIAL HEARING IN CONNECTION WITH LENDER'S TAKING POSSESSION
OR LENDER'S DISPOSITION OF ANY OF THE COLLATERAL, INCLUDING, WITHOUT LIMITATION,
ANY AND ALL PRIOR NOTICE AND HEARING FOR ANY PREJUDGMENT REMEDY OR REMEDIES AND
ANY SUCH RIGHT WHICH CUSTOMER WOULD OTHERWISE HAVE UNDER THE CONSTITUTION OR ANY
STATUTE OF THE UNITED STATES OR OF ANY STATE, INCLUDING, WITHOUT LIMITATION, ITS
RIGHTS TO NOTICE AND HEARING UNDER CHAPTER 903A OF THE CONNECTICUT GENERAL
STATUTES.

         THE LOAN AGREEMENT AND ANY OTHER WRITTEN AGREEMENT(S) BETWEEN THE
PARTIES EXECUTED SIMULTANEOUSLY HEREWITH, REPRESENT THE FINAL AGREEMENT BETWEEN
THE PARTIES CONCERNING THE SUBJECT MATTER HEREOF, AND SUPERSEDE AND MAY NOT BE
CONTRADICTED BY ANY PRIOR WRITTEN AGREEMENTS BETWEEN THE PARTIES, INCLUDING,
WITHOUT LIMITATION, PROPOSALS, LETTERS, COMMITMENT LETTERS OR BY ANY PRIOR,
CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS BETWEEN THE PARTIES. CUSTOMER
ACKNOWLEDGES AND CERTIFIES


                                     Page 9

<PAGE>   10

THAT NO SUCH ORAL AGREEMENTS EXIST. THE LOAN AGREEMENT MAY NOT BE AMENDED, NOR
MAY ANY RIGHTS UNDER THE LOAN AGREEMENT BE WAIVED, EXCEPT BY AN INSTRUMENT IN
WRITING SIGNED BY THE PARTY AGAINST WHOM SUCH AGREEMENT OR WAIVER IS ASSERTED.
The failure of Lender at any time or times hereafter to require strict
performance by Customer of any of the provisions, warranties, terms and
conditions contained in the Loan Agreement or in any other agreement, guaranty,
note, depository agreement, letter of credit, instrument or document now or at
any time or times hereafter executed by Customer or an Affiliate of Customer and
delivered to Lender shall not waive, affect or diminish any right of Lender at
any time or times hereafter to demand strict performance thereof. The Loan
Agreement may be executed in any number of counterparts, each of which shall be
deemed to be an original, but all of which together shall constitute but one and
the same instrument. Each reference herein to "Lender" shall be deemed to
include its successors and assigns, and each reference to "Customer" and any
pronouns referring thereto as used herein shall be construed in the masculine,
feminine, neuter, singular or plural, as the context may require, and shall be
deemed to include the legal representatives, successors and assigns of Customer,
all of whom shall be bound by the provisions hereof. EACH REFERENCE HEREIN TO
"CUSTOMER" SHALL MEAN AND INCLUDE ANY AND ALL CUSTOMERS WHO SIGN BELOW, EACH OF
WHOM SHALL BE JOINTLY AND SEVERALLY LIABLE UNDER THIS LOAN AGREEMENT.

         The Loan Agreement and all related documents, including (a) amendments,
addenda, consents, waivers and modifications which may be executed
contemporaneously or subsequently herewith, (b) documents received by Lender
from the Customer, and (c) financial statements, certificates and other
information previously or subsequently furnished to Lender, may be reproduced by
Lender by any photographic, photostatic, microfilm, micro-card, miniature
photographic, compact disk reproduction or other similar process and Lender may
destroy any original document so reproduced. Customer agrees, herein waives all
right to object to the admissibility of such reproduction and stipulates that
any such reproduction shall, to the extent permitted by law, be admissible in
evidence as the original itself in any judicial or administrative proceeding
(whether or not the original itself is in existence and whether or not the
reproduction was made by Lender in the regular course of business) and that any
enlargement, facsimile or further reproduction of the reproduction shall
likewise be admissible in evidence.

         18. SURVIVAL. Sections 6, 7, 9, 10, 11, 13, 15, 16 and 17 shall survive
and continue in full force and effect without regard to the payment in full of
all Obligations under the Loan Agreement.

         Executed and delivered by duly authorized representatives of the
parties hereto as of the date set forth below.


LENDER:                                          CUSTOMER:
OXFORD VENTURE FINANCE, LLC                      CELLOMICS, INC.

By:    /s/ J. Alden Philbrick, IV                By:    /s/ D. Lansing Taylor
   ------------------------------                   -------------------------
Name:  J. Alden Philbrick, IV                    Name:  D. Lansing Taylor
     ----------------------------                     -----------------------
Title: President                                 Title: CEO
      ---------------------------                      ----------------------
Date:  7-21-99                                   Date:  8/16/99
     ----------------------------                     -----------------------


                                     Page 10

<PAGE>   11

                                   SCHEDULE I


TRADE NAMES


                                     Page 11

<PAGE>   12

                                   SCHEDULE 2


NAME CHANGES; CHANGES IN CHIEF EXECUTIVE OFFICE

BioDx, Inc.
Biological Detection, Inc.


                                     Page 12

<PAGE>   13

NEITHER THIS WARRANT NOR THE SECURITIES ISSUABLE UPON EXERCISE OF THIS WARRANT
HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. NO SALE OR
DISPOSITION MAY BE EFFECTED EXCEPT IN COMPLIANCE WITH RULE 144 UNDER SAID ACT OR
WITHOUT AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO OR AN OPINION OF
COUNSEL FOR THE HOLDER, SATISFACTORY TO THE COMPANY, THAT SUCH REGISTRATION IS
NOT REQUIRED UNDER THE ACT OR RECEIPT OF A NO-ACTION LETTER FROM THE SECURITIES
AND EXCHANGE COMMISSION.


                 WARRANT TO PURCHASE 429 SHARES OF COMMON STOCK


                                                                 August 30, 1999

THIS CERTIFIES THAT, for value received, Phoenixcor, Inc., ("Holder") is
entitled to subscribe for and purchase Four Hundred Twenty-nine (429) shares of
the fully paid and nonassessable Common Stock ("the Shares") of Cellomics, Inc.,
a Delaware corporation (the "Company"), at the Warrant Price (as hereinafter
defined), subject to the provisions and upon the terms and conditions
hereinafter set forth. As used herein, the term "Common Stock" shall mean the
Company's presently authorized Common Stock, and any stock into which such
Common Stock may hereafter be exchanged.

1. Warrant Price. The Warrant Price shall initially be six and 60/100 dollars
($6.60) per share, subject to adjustment as provided in Section 7 below.

2. Conditions to Exercise. The purchase right represented by this Warrant may be
exercised at any time, or from time to time, in whole or in part during the term
commencing on the date hereof and ending on the earlier of:

         (a)      5:00 P.M. Eastern Standard time on the fifth annual
                  anniversary of this Warrant Agreement; or

         (b)      the closing of the initial public offering of the Company's
                  Common Stock pursuant to a registration statement under the
                  Securities Act of 1933, as amended (the "Initial Public
                  Offering"). The Company shall provide notice of the Initial
                  Public Offering to the Holder at least 30 days prior to the
                  closing thereof; or

         (c)      the effective date of the merger of the Company with or into,
                  the consolidation of the Company with, or the sale by the
                  Company of all or substantially all of its assets or all or
                  substantially all of its shares to another corporation or
                  other entity (other than such a transaction wherein the
                  shareholders of the Company retain or obtain a majority of the
                  voting capital stock of the surviving, resulting, or
                  purchasing corporation); provided that the Company shall
                  notify the registered Holder of this Warrant of the proposed
                  effective date of the merger, consolidation, or sale at least
                  30 days prior to the effectiveness thereof.

In the event that, although the Company shall have given notice of a transaction
pursuant to subparagraph (b) or subparagraph (c) hereof, the transaction does
not close within 60 days of the day specified by the Company, unless otherwise
elected by the Holder any exercise of the Warrant subsequent to the giving of
such notice shall be rescinded and the Warrant shall again be exercisable until
terminated in accordance with this Paragraph 2.

3. Method of Exercise; Payment; Issuance of Shares; Issuance of New Warrant.

(a) Cash Exercise. Subject to Section 2 hereof, the purchase right represented
by this Warrant may be exercised by the Holder hereof, in whole or in part, by
the surrender of this Warrant (with a duly executed Notice of Exercise in the
form attached hereto) at the principal office of the Company (as set forth in
Section 18 below) and by payment to the Company, by check, of an amount equal to
the then applicable Warrant Price per share multiplied by the number of shares
then being purchased. In the event of any exercise of the rights represented by
this Warrant, certificates for the shares of stock so purchased shall be in the
name of, and delivered to, the Holder hereof, or as such Holder may direct
(subject to the terms of transfer contained herein and upon payment by such
Holder hereof of any applicable transfer taxes). Such delivery shall be made
within 10 days after exercise of the Warrant and at the Company's expense and,
unless this Warrant has been fully exercised or expired, a new Warrant having
terms and conditions


                                     Page 1

<PAGE>   14

substantially identical to this Warrant and representing the portion of the
Shares, if any, with respect to which this Warrant shall not have been
exercised, shall also be issued to the Holder hereof within 10 days after
exercise of the Warrant.

(b) Net Issue Exercise. In lieu of exercising this Warrant pursuant to Section
3(a), Holder may elect to receive shares equal to the value of this Warrant (or
of any portion thereof remaining unexercised) by surrender of this Warrant at
the principal office of the Company together with notice of such election, in
which event the Company shall issue to Holder the number of shares of the
Company's Common Stock computed using the following formula:

         X = Y (A-B)
            --------
                A

         Where X = the number of shares of Common Stock to be issued to Holder.

         Y = the number of shares of Common Stock purchasable under this Warrant
         (at the date of such calculation).

         A = the Fair Market Value of one share of the Company's Common Stock
         (at the date of such calculation).

         B = Warrant Price (as adjusted to the date of such calculation).

(c) Fair Market Value. For purposes of this Section 3, Fair Market Value of one
share of the Company's Common Stock shall mean:

         (i) In the event of an exercise in connection with an Initial Public
         Offering, the per share Fair Market Value for the Common Stock shall be
         the Offering Price at which the underwriters initially sell Common
         Stock to the public; or

         (ii) The average of the closing bid and asked prices of the Common
         Stock quoted in the Over-The-Counter Market Summary, or the average
         of, the last reported sale price of the Common Stock or the closing
         price quoted on the Nasdaq National Market System ("NMS") or on any
         exchange on which the Common Stock is listed, whichever is applicable,
         as published in The Wall Street Journal over the ten (10) trading days
         prior to the date of determination of fair market value; or

         (iii) In the event of an exercise in connection with a merger,
         acquisition or other consolidation in which the Company is not the
         surviving entity, as described in Section 2(c), the per share Fair
         Market Value for the Common Stock shall be the value to be received per
         share of Common Stock by all holders of the Common Stock in such
         transaction as determined by the Board of Directors; or

         (iv) If the Common Stock is not publicly traded, the per share fair
         market value of the Common Stock shall be as determined in good faith
         by the Company's Board of Directors unless Holder elects to have such
         fair market value determined by an appraiser, which election must be
         made by Holder within ten (10) business days of the date the Company
         notifies Holder of the fair market value as determined by its Board of
         Directors. In the event of such an appraisal, the cost thereof shall be
         borne by the Holder unless such appraisal results in a fair market
         value in excess of 115% of that determined by the Company's Board of
         Directors, in which event the Company shall bear the cost of such
         appraisal.

In the event of 3(c)(iii) or 3(c)(iv), above, the Company's Board of Directors
shall prepare a certificate, to be signed by an authorized Officer of the
Company, setting forth in reasonable detail the basis for and method of
determination of the per share Fair Market Value of the Common Stock. The Board
will also certify to the Holder that this per share Fair Market Value will be
applicable to all holders of the Company's Common Stock. Such certification must
be made to Holder at least thirty (30) business days prior to the proposed
effective date of the merger, consolidation, sale, or other triggering event as
defined in 3(c)(iii) and 3(c)(iv).


                                     Page 2

<PAGE>   15

(d) Automatic Exercise. To the extent this Warrant is not previously exercised,
it shall be automatically exercised in accordance with Sections 3(b) and 3(c)
hereof (even if not surrendered) immediately before: (i) its expiration, or (ii)
the consummation of any consolidation or merger of the Company, or any sale or
transfer of a majority of the Company's assets or stock pursuant to Section
2(b).

4. Representations and Warranties of Holder and Restrictions on Transfer Imposed
by the Securities Act of 1933.

(a) Representations and Warranties by Holder. The Holder represents and warrants
to the Company with respect to this purchase as follows:

         (i) The Holder has substantial experience in evaluating and investing
         in private placement transactions of securities of companies similar to
         the Company so that the Holder is capable of evaluating the merits and
         risks of its investment in the Company and has the capacity to protect
         its interests.

         (ii) The Holder is acquiring the Warrant and the Shares of Common Stock
         issuable upon exercise of the Warrant (collectively the "Securities")
         for investment for its own account and not with a view to, or for
         resale in connection with, any distribution thereof. The Holder
         understands that the Securities have not been registered under the
         Securities Act of 1933, as amended (the "Act") by reason of a specific
         exemption from the registration provisions of the Act which depends
         upon, among other things, the bona fide nature of the investment intent
         as expressed herein. In this connection, the Holder understands that,
         in the view of the Securities and Exchange Commission (the "SEC"), the
         statutory basis for such exemption may be unavailable if this
         representation was predicated solely upon a present intention to hold
         the Securities for the minimum capital gains period specified under tax
         statutes, for a deferred sale, for or until an increase or decrease in
         the market price of the Securities or for a period of one year or any
         other fixed period in the future.

         (iii) The Holder acknowledges that the Securities must be held
         indefinitely unless subsequently registered under the Act or an
         exemption from such registration is available. The Holder is aware of
         the provisions of Rule 144 promulgated under the Act ("Rule 144") which
         permits limited resale of securities purchased in a private placement
         subject to the satisfaction of certain conditions, including, in case
         the securities have been held for more than one but less than two
         years, the existence of a public market for the shares, the
         availability of certain public information about the Company, the
         resale occurring not less than one years after a party has purchased
         and paid for the security to be sold, the sale being through a
         "broker's transaction" or in a transaction directly with a "market
         maker" (as provided by Rule 144(f)) and the number of shares or other
         securities being sold during any three-month period not exceeding
         specified limitations.

         (iv) The Holder further understands that at the time the Holder wishes
         to sell the Securities there may be no public market upon which such a
         sale may be effected, and that even if such a public market exists, the
         Company may not be satisfying the current public information
         requirements of Rule 144, and that in such event, the Holder may be
         precluded from selling the Securities under Rule 144 unless a) a
         one-year minimum holding period has been satisfied and b) the Holder
         was not at the time of the sale nor at any time during the three-month
         period prior to such sale an affiliate of the Company.

         (v) The Holder has had an opportunity to discuss the Company's
         business, management and financial affairs with its management and an
         opportunity to review the Company's facilities. The Holder understands
         that such discussions, as well as the written information issued by the
         Company, were intended to describe the aspects of the Company's
         business and prospects which it believes to be material but were not
         necessarily a thorough or exhaustive description.

(b) Legends. Each certificate representing the Securities shall be endorsed with
the following legend:

         THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
         1933 AND MAY NOT BE TRANSFERRED UNLESS COVERED BY AN EFFECTIVE
         REGISTRATION STATEMENT UNDER SAID ACT, A "NO ACTION" LETTER FROM THE
         SECURITIES AND EXCHANGE COMMISSION WITH RESPECT TO SUCH TRANSFER, A
         TRANSFER MEETING THE REQUIREMENTS OF RULE 144


                                     Page 3

<PAGE>   16
         OF THE SECURITIES AND EXCHANGE COMMISSION, OR (IF REASONABLY REQUIRED
         BY THE COMPANY) AN OPINION OF COUNSEL SATISFACTORY TO THE ISSUER TO THE
         EFFECT THAT ANY SUCH TRANSFER IS EXEMPT FROM SUCH REGISTRATION.

The Company need not enter into its stock register a transfer of Securities
unless the conditions specified in the foregoing legend are satisfied. The
Company may also instruct its transfer agent not to register the transfer of any
of the Shares unless the conditions specified in the foregoing legend are
satisfied.

(c) Removal of Legend and Transfer Restrictions. The legend relating to the Act
endorsed on a certificate pursuant to paragraph 4(b) of this Warrant and the
stop transfer instructions with respect to the Securities represented by such
certificate shall be removed and the Company shall issue a certificate without
such legend to the Holder of the Securities if (i) the Securities are registered
under the Act and a prospectus meeting the requirements of Section 10 of the Act
is available or (ii) the Holder provides to the Company an opinion of counsel
for the Holder reasonably satisfactory to the Company, or a no-action letter or
interpretive opinion of the staff of the SEC reasonably satisfactory to the
Company, to the effect that public sale, transfer or assignment of the
Securities may be, to the effect that public sale, transfer or assignment of the
Securities may be made without registration and without compliance with any
restriction such as Rule 144.

5. Condition of Transfer or Exercise of Warrant. It shall be a condition to any
transfer or exercise of this Warrant that at the time of such transfer or
exercise, the Holder shall provide the Company with a representation in writing
that the Holder or transferee is acquiring this Warrant and the shares of Common
Stock to be issued upon exercise, for investment purposes only and not with a
view to any sale or distribution, or will provide the Company with a statement
of pertinent facts covering any proposed distribution. As a further condition to
any transfer of this Warrant or any or all of the shares of Common Stock
issuable upon exercise of this Warrant, other than a transfer registered under
the Act, the Company must have received a legal opinion, in form and substance
satisfactory to the Company and its counsel, reciting the pertinent
circumstances surrounding the proposed transfer and stating that such transfer
is exempt from the registration and prospectus delivery requirements of the Act.
Each certificate evidencing the shares issued upon exercise of the Warrant or
upon any transfer of the shares (other than a transfer registered under the Act
or any subsequent transfer of shares so registered) shall, at the Company's
option, contain a legend in form and substance satisfactory to the Company and
its counsel, restricting the transfer of the shares to sales or other
dispositions exempt from the requirements of the Act.

As further condition to each transfer, the Holder shall surrender this Warrant
to the Company and the transferee shall receive and accept a Warrant, of like
tenor and date, executed by the Company.

6. Stock Fully Paid: Reservation of Shares. All Shares which may be issued upon
the exercise of the rights represented by this Warrant will, upon issuance, be
fully paid and nonassessable, and free from all taxes, liens, and charges with
respect to the issue thereof. During the period within which the rights
represented by this Warrant may be exercised, the Company will at all times have
authorized, and reserved for issuance upon exercise of the purchase rights
evidenced by this Warrant, a sufficient number of shares of its Common Stock to
provide for the exercise of the rights represented by this Warrant.

7. Adjustment for Certain Events. In the event of changes in the outstanding
Common Stock by reason of stock dividends (other than previously established
dividends payable in association with the Preferred Series A annual coupon rate
compensation), split-ups, recapitalizations, reclassifications, mergers,
consolidations, combinations or exchanges of shares, separations,
reorganizations, liquidations, or the like, the number and class of shares
available under the Warrant in the aggregate and the Warrant Price shall be
correspondingly adjusted, as appropriate, by the Board of Directors of the
Company. The adjustment shall be such as will give the Holder of this Warrant
upon exercise for the same aggregate Warrant Price the total number, class and
kind of shares as he would have owned had the Warrant been exercised prior to
the event and had he continued to hold such shares until after the event
requiring adjustment.

8. Notice of Adjustments. Whenever any Warrant Price shall be adjusted pursuant
to Section 7 hereof, the Company shall prepare a certificate signed by an
officer of the Company's chief financial officer setting forth, in reasonable
detail, the event requiring the adjustment, the amount of the adjustment, the
method by which such adjustment was calculated, and the Warrant Price and number
of shares issuable upon exercise of the Warrant after giving effect to such
adjustment, and shall cause copies of such certificate to


                                     Page 4

<PAGE>   17

be mailed (by certified or registered mail, return receipt required, postage
prepaid) within thirty (30) days of such adjustment to the Holder of this
Warrant as set forth in Section 18 hereof.

9. "Market Stand-Off" Agreement. Holder hereby agrees that for a period of up to
180 days following the effective date of the first registration statement of the
Company covering common stock (or other securities) to be sold on its behalf of
the Company in an underwritten public offering, it will not, to the extent
requested by the Company and any underwriter, sell or otherwise transfer or
dispose of (other than to donees or transferees who agree to be similarly
bound) any of the Shares at any time during such period except common stock
included in such registration; provided, however, that all officers and
directors of the Company who hold securities of the Company or options to
acquire securities of the Company and all other persons with registration rights
enter into similar agreements.

10. Transferability of Warrant. This Warrant is transferable on the books of the
Company at its principal office by the registered Holder hereof upon surrender
of this Warrant properly endorsed, subject to compliance with Section 5 and
applicable federal and state securities laws. The Company shall issue and
deliver to the transferee a new Warrant representing the Warrant so transferred.
Upon any partial transfer, the Company will issue and deliver to Holder a new
Warrant with respect to the Warrant not so transferred. Holder shall not have
any right to transfer any portion of this Warrant to any direct competitor of
the Company.

11. No Fractional Shares. No fractional share of Common Stock will be issued in
connection with any exercise hereunder, but in lieu of such fractional share the
Company shall make a cash payment therefor upon the basis of the Warrant Price
then in effect.

12. Charges, Taxes and Expenses. Issuance of certificates for shares of Common
Stock upon the exercise of this Warrant shall be made without charge to the
Holder for any United States or state of the United States documentary stamp tax
or other incidental expense within respect to of the issuance of such
certificate, all of which taxes and expenses shall be paid by the Company, and
such certificates shall he issued in the name of the Holder.

13. No Shareholder Rights Until Exercise. This Warrant does not entitle the
Holder hereof to any voting rights or other rights as a shareholder of the
Company prior to the exercise hereof.

14. Registry of Warrant. The Company shall maintain a registry showing the name
and address of the registered Holder of this Warrant. This Warrant may be
surrendered for exchange or exercise, in accordance with its terms, at such
office or agency of the Company, and the Company and Holder shall be entitled to
rely in all respects, prior to written notice to the contrary, upon such
registry.

15. Loss, Theft, Destruction or Mutilation of Warrant. Upon receipt by the
Company of evidence reasonably satisfactory to it of the loss, theft,
destruction or mutilation of this Warrant, and, in the case of loss, theft, or
destruction, of indemnity reasonably satisfactory to it, and, if mutilated, upon
surrender and cancellation of this Warrant, the Company will execute and deliver
a new Warrant, having terms and conditions substantially identical to this
Warrant, in lieu hereof.

16. Miscellaneous.

         (a) Issue Date. The provisions of this Warrant shall be construed and
         shall be given effect in all respect as if it had been issued and
         delivered by the Company on the date hereof.

         (b) Successors. This Warrant shall be binding upon any successors or
         assigns of the Company.

         (c) Governing Law. This Warrant shall be governed by and construed in
         accordance with the laws of the State of Connecticut.

         (d) Headings. The headings used in this Warrant are used for
         convenience only and are not to be considered in construing or
         interpreting this Warrant.

         (e) Saturdays, Sundays, Holidays. If the last or appointed day for the
         taking of any action or the expiration of any right required or granted
         herein shall be a Saturday or a Sunday or shall be a


                                     Page 5

<PAGE>   18

         legal holiday in the State of Connecticut, then such action may be
         taken or such right may be exercised on the next succeeding day not a
         legal holiday.

17. No Impairment. The Company will not, by amendment of its Articles of
Incorporation or any other voluntary action, avoid or seek to avoid the
observance or performance of any of the terms of this Warrant, but will at all
times in good faith assist in the carrying out of all such terms and in the
taking of all such action as may be necessary or appropriate in order to protect
the rights of the Holder hereof against impairment.

18. Addresses. Any notice required or permitted hereunder shall be in writing
and shall be mailed by overnight courier, registered or certified mail, return
receipt required, and postage pre-paid, or otherwise delivered by hand or by
messenger, addressed as set forth below, or at such other address as the Company
or the Holder hereof shall have furnished to the other party.

         If to the Company:         CELLOMICS, INC.
                                    635 WILLIAM PITT WAY
                                    PITTSBURGH, PA 15238
                                    Attn: MR. JEFFREY KOMATZ

         If to the Holder:          Phoenixcor, Inc.
                                    65 Water Street
                                    South Norwalk, CT 06854
                                    Attn: Ms. Joan Kossoff

IN WITNESS WHEREOF, CELLOMICS, INC, has caused this Warrant to be executed by
its officers thereunto duly authorized.


Dated as of August 30, 1999.


By: /s/ Lee Robert Johnston, Jr.
   ------------------------------

Name: Lee Robert Johnston, Jr.
     ----------------------------

Title:
      ---------------------------


                                     Page 6

<PAGE>   19

                               NOTICE OF EXERCISE



TO:      CELLOMICS, INC.
         635 WILLIAM PITT WAY
         PITTSBURGH, PA 15238


l. The undersigned, Phoenixcor, Inc. ("Holder") elects to acquire shares of
the Common Stock of CELLOMICS, INC. (the "Company"), pursuant to the terms of
the Stock Purchase Warrant dated August 30, 1999, (the "Warrant").

2. The Holder exercises its rights under the Warrant as set forth below:

         ( )      The Holder elects to purchase 429 shares of Common Stock as
                  provided in Section 3(a), (c) and tenders herewith a check in
                  the amount of $2,831.40 as payment of the purchase price.

         ( )      The Holder elects to convert the purchase rights into shares
                  of Common Stock as provided in Section 3(b), (c) of the
                  Warrant.

3. The Holder surrenders the Warrant with this Notice of Exercise.

4. The Holder represents that it is acquiring the aforesaid shares of Common
Stock for investment and not with a view to, or for resale in connection with,
distribution and that the Holder has no present intention of distributing or
reselling the shares.

5. Please issue a certificate representing the shares of Common Stock in the
name of the Holder or in such other name as is specified below:

Name:
        -------------------------
Address:
        -------------------------

        -------------------------



Taxpayer I.D.:
              -------------------



     ----------------------------
     (Holder)

     By:
        -------------------------

     Name:
          -----------------------

     Title:
           ----------------------

     Date:
          -----------------------


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