<PAGE>

         This AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT dated November
10, 1998, between SILICON VALLEY BANK ("Bank"), whose address is 3003 Tasman
Drive, Santa Clara, California 95054 with a loan production office located at
915 118th Ave. S.E., Ste. 250, Bellevue, Washington 98005 and ROSETTA
INPHARMATICS, INC., formerly known as Rosetta Biosystems, Inc. ("Borrower"),
whose address is 12040 115th Avenue NE, Suite 210, Kirkland, Washington 98034.

                                    RECITALS

         A. Bank and Borrower are parties to that certain Promissory Note,
Business Loan Agreement, and Commercial Security Agreement, each dated February
13, 1997, as amended (collectively, the "Original Agreement").

         B. Borrower and Bank desire in this Agreement to set forth their
agreement with respect to a working capital and term loan and to amend and
restate in its entirety without novation the Original Agreement in accordance
with the provisions herein.

                                    AGREEMENT

         The parties agree as follows:

1        ACCOUNTING AND OTHER TERMS

         Accounting terms not defined in this Agreement will be construed
following GAAP Calculations and determinations must be made following GAAP. The
term "financial statements" includes the notes and schedules. The terms
"including" and "includes" always mean "including (or includes) without
limitation," in this or any Loan Document. This Agreement shall be construed to
impart upon Bank a duty to act reasonably at all times.

2        LOAN AND TERMS OF PAYMENT

2.1      CREDIT EXTENSIONS.

         Borrower will pay Bank the unpaid principal amount of all Credit
Extensions and interest on the unpaid principal amount of the Credit Extensions.

 2.1.1   REVOLVING ADVANCES.

         (a) Bank will make Advances not exceeding (i) the Committed Revolving
Line, minus (ii) the amount of all outstanding Letters of Credit (including
drawn but unreimbursed Letters of Credit). Amounts borrowed under this Section
may be repaid and reborrowed during the term of this Agreement.

         (b) To obtain an Advance, Borrower must notify Bank by facsimile or
telephone by 3:00 p.m. Pacific time on the Business Day the Advance is to be
made. Borrower must promptly confirm the notification by delivering to Bank the
Payment/Advance Form attached as Exhibit B. Bank will credit Advances to
Borrower's deposit account. Bank may make Advances under this Agreement based on
instructions from a Responsible Officer or his or her designee or without
instructions if the Advances are necessary to meet Obligations which have become
due. Bank may rely on any telephone notice given by a person whom Bank believes
is a Responsible Officer or designee. Borrower will indemnify Bank for any loss
Bank suffers due to reliance.


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         (c) The Committed Revolving Line terminates on the Revolving Maturity
Date, when all Advances and other amounts due under this Agreement are
immediately payable.

 2.1.2   LETTERS OF CREDIT.

         Bank will issue or have issued Letters of Credit for Borrower's account
not exceeding (i) the Committed Revolving Line minus (ii) the outstanding
principal balance of the Advances; however, the face amount of outstanding
Letters of Credit (including drawn but unreimbursed Letters of Credit and any
Letter of Credit Reserve) may not exceed $750,000. Each Letter of Credit will
have an expiry date of no later than 180 days after the Revolving Maturity Date,
but Borrower's reimbursement obligation will be secured by cash on terms
acceptable to Bank at any time after the Revolving Maturity Date if the term of
this Agreement is not extended by Bank.

 2.1.3   TERM LOAN.

         (a) Bank will continue to make a Term Loan available to Borrower.

         Borrower will continue to pay 16 equal installments of principal plus
Interest of $7,434.63 (the "Term Loan Payment"). Each Term Loan Payment is
payable on the 13th of each month during the term of the loan. Borrower's final
Term Loan Payment, due on February 13, 2000, includes all outstanding Term Loan
principal and accrued interest?

 2.2     OVERADVANCES.

         If Borrower's Obligations under Section 2.1.1 and 2.1.2 exceed the
Committed Revolving Line, Borrower must immediately pay in cash to Bank the
excess.

 2.3     INTEREST RATE, PAYMENTS.

         (a) Interest Rate. (i) Advances accrue interest on the outstanding
principal balance at a per annum rate of 1 percentage point above the Prime
Rate; and (ii) the Term Loan accrues interest at a per annum rate of 2
percentage points above the Prime Rate. After an Event of Default, Obligations
accrue interest at 5 percent above the rate effective immediately before the
Event of Default. The interest rate increases or decreases when the Prime Rate
changes. Interest is computed on a 360 day year for the actual number of days
elapsed.

         (b) Payments. Interest due on the Committed Revolving Line is payable
on the last day of each month. Bank may debit any of Borrower's deposit accounts
including Account Number 3300044634 for principal and interest payments or any
amounts Borrower owes Bank. Bank will notify Borrower when it debits Borrower's
accounts. These debits are not a set-off. Payments received after 12:00 noon
Pacific time are considered received at the opening of business on the next
Business Day. When a payment is due on a day that is not a Business Day, the
payment is due the next Business Day and additional fees or interest accrue.

 2.4     FEES.

         Borrower will pay:

         (a) Facility Fee. A fully earned, non-refundable Facility Feel of
$2,000 for the Committed Revolving Line due on the Closing Date; and


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         (b) Bank Expenses. All Bank Expenses (including reasonable attorneys'
fees and expenses) incurred through and after the date of this Agreement, are
payable when due.

3        CONDITIONS OF LOANS

3.1      CONDITIONS PRECEDENT TO INITIAL CREDIT EXTENSION.

         Bank's obligation to make the initial Credit Extension is subject to
the condition precedent that it receive the agreements, documents and fees it
requires.

3.2      CONDITIONS PRECEDENT TO ALL CREDIT EXTENSIONS.

         Bank's obligations to make each Credit Extension, including the initial
Credit Extension, is subject to the following:

         (a) timely receipt of any Payment/Advance Form; and

         (b) the representations and warranties in Section 5 must be materially
true on the date of the Payment/Advance Form and on the effective date of each
Credit Extension and no Event of Default may have occurred and be continuing, or
result from the Credit Extension. Each Credit Extension is Borrower's
representation and warranty on that date that the representations and warranties
of Section 5 remain true.

4        CREATION OF SECURITY INTEREST

4.1      GRANT OF SECURITY INTEREST.

         Borrower grants Bank a continuing security interest in all present!y
existing and later acquired Collateral to secure all Obligations and performance
of each of Borrower's duties under the Loan Documents. Except for Permitted
Liens, any security interest will be a first priority security interest in the
Collateral. Bank may place a "hold" on any deposit account pledged as
Collateral.

5        REPRESENTATIONS AND WARRANTIES

         Borrower represents and warrants as follows:

5.1      DUE ORGANIZATION AND AUTHORIZATION.

         Borrower and each Subsidiary is duly existing and in good standing in
its state of formation and qualified and licensed to do business in, and in good
standing in, any state in which the conduct of its business or its ownership of
property requires that it be qualified.

         The execution, delivery and performance of the Loan Documents have been
duly authorized, and do not conflict with Borrower's formation documents, nor
constitute an event of default under any material agreement by which Borrower is
bound. Borrower is not in default under any agreement to which or by which it is
bound in which the default could cause a Material Adverse Change.

5.2      COLLATERAL.

         Borrower has good title to the Collateral, free of Liens except
Permitted Liens. All Inventory is in


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all material respects of good and marketable quality, free from material
defects.

5.3      LITIGATION.

         Except as shown in the Schedule, there are no actions or proceedings
pending or, to Borrower's knowledge, threatened by or against Borrower or any
Subsidiary in which an adverse decision could cause a Material Adverse Change.

5.4      NO MATERIAL ADVERSE CHANGE IN FINANCIAL STATEMENTS.

         All consolidated financial statements for Borrower, and any Subsidiary,
delivered to Bank fairly present in all material respects Borrower's
consolidated financial condition and Borrower's consolidated results of
operations. There has not been any material deterioration in Borrower's
consolidated financial condition since the date of the most recent financial
statements submitted to Bank.

5.5      SOLVENCY.

         The fair salable value of Borrower's assets (including goodwill minus
disposition costs) exceeds the fair value of its liabilities; the Borrower is
not left with unreasonably small capital after the transactions in this
Agreement; and Borrower is able to pay its debts (including trade debts) as they
mature.

5.6      REGULATORY COMPLIANCE.

         Borrower is not an "investment company" or a company "controlled" by an
"investment company' under the Investment Company Act. Borrower is not engaged
as one of its important activities in extending credit for margin stock (under
Regulations G, T and U of the Federal Reserve Board of Governors). Borrower has
complied with the Federal Fair Labor Standards Act. Borrower has not violated
any laws, ordinances or rules, the violation of which could cause a Material
Adverse Change. None of Borrower's or any Subsidiary's propertied' or assets has
been used by Borrower or any Subsidiary or, to the best of Borrower's knowledge,
by previous Persons, in disposing, producing, storing, treating, or transporting
any hazardous substance other than legally. Borrower and each Subsidiary has
timely filed all required tax returns and paid, or made adequate provision to
pay, all taxes, except those being contested in good faith with adequate
reserves under GAAP. Borrower and each Subsidiary has obtained all consents,
approvals and authorizations of, made all declarations or filings with, and
given all notices to, all government authorities that are necessary to continue
its business as currently conducted.

5.7      SUBSIDIARIES.

         Borrower does not own any stock, partnership interest or other equity
securities except for Permitted Investments.

5.8      FULL DISCLOSURE.

         No representation, warranty or other statement of Borrower in any
certificate or written statement given to Bank contains any untrue statement of
a material fact or omits to state a material fact necessary to make the
statements contained in the certificates or statements not misleading.

6        AFFIRMATIVE COVENANTS


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         Borrower will do all of the following:

6.1      GOVERNMENT COMPLIANCE.

         Borrower will maintain its and all Subsidiaries' legal existence and
good standing in its jurisdiction of formation and maintain qualification in
each jurisdiction in which the failure to so qualify could have a material
adverse effect on Borrower's business or operations. Borrower will comply, and
have each Subsidiary comply, with all laws, ordinances and regulations to which
it is subject, noncompliance with which could have a material adverse effect on
Borrower's business or operations or cause a Material Adverse Change.

6.2      FINANCIAL STATEMENTS, REPORTS, CERTIFICATES.

          (a) Borrower will deliver to Bank: (i) as soon as available, but no
later than 30 days after the last day of each month, a company prepared
consolidated balance sheet and income statement covering Borrower's consolidated
operations during the period, in a form and certified by a Responsible Officer
acceptable to Bank; (ii) as soon as available, but no later than 120 days after
the last day of Borrower's fiscal year, audited consolidated financial
statements prepared under GAAP, consistently applied, together with an
unqualified opinion on the financial statements from an independent certified
public accounting firm acceptable to Bank; (iii) a prompt report of any legal
actions pending or threatened against Borrower or any Subsidiary that could
result in damages or costs to Borrower or any Subsidiary of $100,000 or more;
and (iv) budgets, sales projections, operating plans or other financial
information Bank requests.

         (b) Within 30 days after the last day of each month, Borrower will
deliver to Bank with the monthly financial statements a Compliance Certificate
signed by a Responsible Officer in the form of Exhibit C.

         (c) Bank has the right to audit Borrower's Collateral at Borrower's
expense, at such times as an Event of Default has occurred and is continuing.

6.3      INVENTORY; RETURNS.

         Borrower will keep all Inventory in good and marketable condition, free
from material defects. Returns and allowances between Borrower and its account
debtors will follow Borrower's customary practices as they exist at execution of
this Agreement. Borrower must promptly notify Bank of all returns, recoveries,
disputes and claims, that involve more than $50,000.

6.4      TAXES.

         Borrower will make, and cause each Subsidiary to make, timely payment
of all material federal, state, and local taxes or assessments and will deliver
to Bank, on demand, appropriate certificates attesting to the payment.

6.5      INSURANCE.

         Borrower will keep its business and the Collateral insured for risks
and in amounts, as Bank requests. Insurance policies will be in a form, with
companies, and in amounts that are satisfactory to Bank. All property policies
will have a lender's loss payable endorsement showing Bank as an additional loss
payee and all liability policies will show the Bank as an additional insured and
provide that the


                                      -5-
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insurer must give Bank at least 20 days notice before canceling its policy. At
Bank's request, Borrower will deliver certified copies of policies and evidence
of all premium payments. Proceeds payable under any policy will, at Bank's
option, be payable to Bank on account of the Obligations. Statutory notice
regarding insurance:

                                     WARNING

         Unless you provide us with evidence of the insurance coverage as
required by our contract or loan agreement, we may purchase insurance at your
expense to protect our interest. This insurance may, but need not, also protect
your interest. If the collateral becomes damaged, the coverage we purchase may
not pay any claim you make or any claim made against you. You may later cancel
this coverage by providing evidence that you have obtained property coverage
elsewhere.

         You are responsible for the cost of any insurance purchased by us. The
cost of this insurance may be added to your contract or loan balance. If the
cost is added to your contract or loan balance, the interest rate on the
underlying contract or loan will apply to this added amount. The effective date
of coverage may be the date your prior coverage lapsed or the date you failed to
provide proof of coverage.

         This coverage we purchased may be considerably more expensive than
insurance you can obtain on your own and may not satisfy any need for property
damage coverage or any mandatory liability insurance requirements imposed by
applicable law.

6.6      PRIMARY ACCOUNTS.

         Borrower will maintain its primary depository and operating accounts
with Bank.

6.7      FINANCIAL COVENANTS.

         Borrower will maintain as of the last day of each month:

                  Either,

                  (i) Minimum Cash Balance. Minimum cash (and cash equivalents)
of $2,000,000.

                  Or

                  (ii) Remaining Months Liquidity. Borrower will maintain, as of
the last day of each month, at least 6 months Remaining Months Liquidity.
Remaining Months Liquidity is cash on hand (and cash equivalents) plus 50% of
Borrower's net accounts receivable, divided by Cash Burn. If cash (and cash
equivalents) increases from the prior period, "Cash Bum" is cash (prior period)
minus cash (current period) plus increases/less decreases in short and long term
borrowings plus increases/less decreases in stock, paid-in capital and
Subordinated Debt. If cash (and cash equivalents) decreases from prior period,
"Cash Burn" is cash (prior period) less (current period) minus increases/plus
decreases in short and long term borrowings minus increases/plus decreases in
stock, paid-in capital and subordinated debt.

6.8      FURTHER ASSURANCES.

         Borrower will execute any further instruments and take further action
as Bank requests to perfect or continue Bank's security interest in the
Collateral or to effect the purposes of this Agreement.


                                      -6-
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7        NEGATIVE COVENANTS

         Borrower will not do any of the following:

7.1      DISPOSITIONS.

         Convey, sell, lease, transfer or otherwise dispose of (collectively
"Transfer"), or permit any of its Subsidiaries to Transfer, all or any part of
its business or property, other than Transfers (i) of inventory in the ordinary
course of business; (ii) of non-exclusive licenses and similar arrangements for
the use of the property of Borrower or its Subsidiaries in the ordinary course
of business; or (iii) of worn-out or obsolete Equipment.

7.2      CHANGES IN BUSINESS, OWNERSHIP, MANAGEMENT OR BUSINESS LOCATIONS.

         Engage in or permit any of its Subsidiaries to engage in any business
other than the businesses currently engaged in by Borrower or have a material
change in its ownership of greater than 25%. Borrower will not, without at least
30 days prior written notice, relocate its chief executive office or add any new
offices or business locations.

7.3      MERGERS OR ACQUISITIONS.

         (i) Merge or consolidate, or permit any of its Subsidiaries to merge or
consolidate, with any other Person, or acquire, or permit any of its
Subsidiaries to acquire, all or substantially all of the capital stock or
property of another Person, except (I) where no Event of Default has occurred
and is continuing or would result from such action during the term of this
Agreement and Tangible Net Worth will not decrease by more than 25%; or (ii)
merge or consolidate a Subsidiary into another Subsidiary or into Borrower.

7.4      INDEBTEDNESS.

         Create, incur, assume, or be liable for any Indebtedness, or permit any
Subsidiary to do so, other than Permitted Indebtedness.

7.5      ENCUMBRANCE.

         Create, incur, or allow any Lien on any of its property, or assign or
convey any right to receive income, including the sale of any Accounts, or
permit any of its Subsidiaries to do so, except for Permitted Liens, or permit
any Collateral not to be subject to the first priority security interest granted
here.

         Directly or indirectly acquire or own any Person, or make any
Investment in any Person, other than Permitted Investments, or permit any of its
Subsidiaries to do so. Pay any dividends or make any distribution or payment or
redeem, retire or purchase any capital stock.

7.7      TRANSACTIONS WITH AFFILIATES.

         Directly or indirectly enter or permit any material transaction with
any Affiliate except transactions that are in the ordinary course of Borrower's
business, on terms less favorable to Borrower than would be obtained in an arm's
length transaction with a non-affiliated Person.


                                      -7-
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7.8      SUBORDINATED DEBT.

         Make or permit any payment on any Subordinated Debt, except under the
terms of the Subordinated Debt, or amend any provision in any document relating
to the Subordinated Debt without Bank's prior written consent.

7.9      COMPLIANCE.

         Become an "investment company' or a company controlled by an
"investment company,' under the Investment Company Act of 1940 or undertake as
one of its important activities extending credit to purchase or carry margin
stock, or use the proceeds of any Credit Extension for that purpose; fail to
meet the minimum funding requirements of ERISA, permit a Reportable Event or
Prohibited Transaction, as defined in ERISA, to occur; fail to comply with the
Federal Fair Labor Standards Act or violate any other law or regulation, if the
violation could have a material adverse effect on Borrower's business or
operations or cause a Material Adverse Change, or permit any of its Subsidiaries
to do so.

8        EVENTS OF DEFAULT

         Any one of the following is an Event of Default:

8.1      PAYMENT DEFAULT.

         If Borrower fails to pay any of the Obligations;

8.2      COVENANT DEFAULT.

         If Borrower does not perform any obligation in Section 6 or violates
any covenant in Section 7 or does not perform or observe any other material
term, condition or covenant in this Agreement, any Loan Documents, or in any
agreement between Borrower and Bank and as to any default under a term,
condition or covenant that can be cured, has not cured the default within 10
days after it occurs, or if the default cannot be cured within 10 days or cannot
be cured after Borrower's attempts within 10 day period, and the default may be
cured within a reasonable time, then Borr6wer has an additional period (of not
more than 30 days) to attempt to cure the default. During the additional time,
the failure to cure the default is not an Event of Default (but no Credit
Extensions will be made during the cure period);

8.3      MATERIAL ADVERSE CHANGE.

         (i) If there occurs a material impairment in the perfection or priority
of the Bank's security interest in the Collateral or in the value of such
Collateral which is not covered by adequate insurance or (ii) if the Bank
determines, based upon information available to it and in its reasonable
judgment, that there is a reasonable likelihood that Borrower will fail to
comply with one or more of the financial covenants in Section 6 during the next
succeeding financial reporting period.

8.4      ATTACHMENT.

         If any material portion of Borrower's assets is attached, seized,
levied on, or comes into possession of a trustee or receiver and the attachment,
seizure or levy is not removed in 10 days, or if Borrower is enjoined,
restrained, or prevented by court order from conducting a material part of its
business or if a judgment or other claim becomes a Lien on a material portion of
Borrower's assets, or if a notice of lien, levy, or assessment is filed against
any of Borrower's assets by any government agency


                                      -8-
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and not paid within 10 days after Borrower receives notice. These are not Events
of Default if stayed or if a bond is posted pending contest by Borrower (but no
Credit Extensions will be made during the cure period);

8.5      INSOLVENCY.

         If Borrower becomes insolvent or if Borrower begins an Insolvency
Proceeding or an Insolvency Proceeding is begun against Borrower and not
dismissed or stayed within 30 days (but no Credit Extensions will be made before
any Insolvency Proceeding is dismissed);

8.6      OTHER AGREEMENTS.

         If there is a default in any agreement between Borrower and a third
party that gives the third party the right to accelerate any Indebtedness
exceeding $100,000 or that could cause a Material Adverse Change;

8.7      JUDGMENTS.

         if a money judgment(s) in the aggregate of at least $50,000 is rendered
against Borrower and is unsatisfied and unstayed for 10 days (but no Credit
Extensions will be made before the judgment is stayed or satisfied); or

8.8      MISREPRESENTATIONS.

         If Borrower or any Person acting for Borrower makes any material
misrepresentation or material misstatement now or later in any warranty or
representation in this Agreement or in any writing delivered to Bank or to
induce Bank to enter this Agreement or any Loan Document.

9        BANK'S RIGHTS AND REMEDIES

9.1      RIGHTS AND REMEDIES.

         When an Event of Default occurs and continues Bank may, without notice
or demand, do any or all of the following:

         (a) Declare all Obligations immediately due and payable (but if an
Event of Default described in Section 8.5 occurs all Obligations are immediately
due and payable with6ut any action by Bank);

         (b) Stop advancing money or extending credit for Borrower's benefit
under this Agreement or under any other agreement between Borrower and Bank;

         (c) Settle or adjust disputes and claims directly with account debtors
for amounts, on terms and in any order that Bank considers advisable;

         (d) Make any payments and do any acts it considers necessary or
reasonable to protect its security interest in the Collateral. Borrower will
assemble the Collateral if Bank requires and make it available as Bank
designates. Bank may enter premises where the Collateral is located, take and
maintain possession of any part of the Collateral, and pay, purchase, contest,
or compromise any Lien which appears to be prior or superior to its security
interest and pay all expenses incurred. Borrower grants Bank a license to enter
and occupy any of its premises, without charge, to exercise any of Bank's rights
or


                                      -9-
<PAGE>

remedies;

         (e) Apply to the Obligations any (i) balances and deposits of Borrower
it holds, or (ii) any amount held by Bank owing to or for the credit or the
account of Borrower;

         (f) Ship, reclaim, recover, store, finish, maintain, repair, prepare
for sale, advertise for sale, and sell the Collateral; and

         (g) Dispose of the Collateral according to the Code.

9.2      POWER OF ATTORNEY.

         Effective only when an Event of Default occurs and continues, Borrower
irrevocably appoints Bank as its lawful attorney to: (i) endorse Borrower's name
on any checks or other forms of payment or security (ii) sign Borrower's name on
any invoice or bill of lading for any Account or drafts against account debtors,
(iii) make, settle, and adjust all claims under Borrower's insurance policies;
(iv) settle and adjust disputes and claims about the Accounts directly with
account debtors, for amounts and on terms Bank determines reasonable; and (v)
transfer the Collateral into the name of Bank or a third party as the Code
permits. Bank may exercise the power of attorney to sign Borrower's name on any
documents necessary to perfect or continue the perfection of any security
interest regardless of whether an Event of Default has occurred. Bank's
appointment as Borrower's attorney in fact, and all of Bank's rights and powers,
coupled with an interest, are irrevocable until all Obligations have been fully
repaid and performed and Bank's obligation to provide Credit Extensions
terminates.

9.3      ACCOUNTS COLLECTION.

         When an Event of Default occurs and continues, Bank may notify any
Person owing Borrower money of Bank's security interest in the funds and verify
the amount of the Account. Borrower must collect all payments in trust for Bank
and, if requested by Bank, immediately deliver the payments to Bank in the form
received from the account debtor, with proper endorsements for deposit.

9.4      BANK EXPENSES.

         If Borrower fails to pay any amount or furnish any required proof of
payment to third persons Bank may make all or part of the payment or obtain
insurance policies required in Section 6.5, and take any action under the
policies Bank deems prudent. Any amounts paid by Bank are Bank Expenses and
immediately due and payable, bearing interest at the then applicable rate and
secured by the Collateral. No payments by Bank are deemed an agreement to make
similar payments in the future or Bank's waiver of any Event of Default.

9.5      BANK'S LIABILITY FOR COLLATERAL.

         If Bank complies with reasonable banking practices it is not hable for:
(a) the safekeeping of the Collateral; (b) any loss or damage to the Collateral;
(c) any diminution in the value of the Collateral; or (d) any act or default of
any carrier, warehouseman, bailee, or other person. Borrower bears all risk of
loss, damage or destruction of the Collateral.

9.6      REMEDIES CUMULATIVE.

         Bank's rights and remedies under this Agreement, the Loan Documents,
and all other agreements


                                      -10-
<PAGE>

are cumulative. Bank has all rights and remedies provided under the Code, by
law, or in equity. Bank's exercise of one right or remedy is not an election,
and Bank's waiver of any Event of Default is not a continuing waiver. Bank's
delay is not a waiver, election, or acquiescence. No waiver is effective unless
signed by Bank and then is only effective for the specific instance and purpose
for which it was given.

9.7      DEMAND WAIVER.

         Borrower waives demand, notice of default or dishonor, notice of
payment and nonpayment, notice of any default, nonpayment at maturity, release,
compromise, settlement, extension, or renewal of accounts, documents,
instruments, chattel paper, and guarantees held by Bank on which Borrower is
liable.

10       NOTICES

         All notices or demands by any party about this Agreement or any other
related agreement must be in writing and be personally delivered or sent by an
overnight delivery service, by certified mail, postage prepaid, return receipt
requested, or by telefacsimile to the addresses set forth at the beginning of
this Agreement. A Party may change its notice address by giving the other Party
written notice.

11       CHOICE OF LAW .VENUE AND JURY TRIAL WAIVER

         Washington law governs the Loan Documents without regard to principles
of conflicts of law. Borrower and Bank each submit to the exclusive jurisdiction
of the State and Federal courts in King County, Washington.

BORROWER AND BANK EACH WAIVE THEIR RIGHT TO A JURY TRIAL OF ANY CLAIM OR CAUSE
OF ACTION ARISING OUT OF ANY OF THE LOAN DOCUMENTS OR ANY CONTEMPLATED
TRANSACTION, INCLUDING CONTRACT, TORT, BREACH OF DUTY AND ALL OTHER CLAIMS. THIS
WAIVER IS A MATERIAL INDUCEMENT FOR BOTH PARTIES TO ENTER INTO THIS AGREEMENT.
EACH PARTY HAS REVIEWED THIS WAIVER WITH ITS COUNSEL.

12       GENERAL PROVISIONS

12.1     SUCCESSORS AND ASSIGNS.

         This Agreement binds and is for the benefit of the successors and
permitted assigns of each party. Borrower may not assign this Agreement or any
rights under it without Bank's prior written consent which may be granted or
withheld in Bank's discretion. Bank has the right, without the consent of or
notice to Borrower, to sell, transfer, negotiate, or grant participation in all
or any part of, or any interest in, Bank's obligations, rights and benefits
under this Agreement.

12.2     INDEMNIFICATION.

         Borrower will indemnify, defend and hold harmless Bank and its
officers, employees, and agents against: (a) all obligations, demands, claims,
and liabilities asserted by any other party in connection with the transactions
contemplated by the Loan Documents; and (b) all losses or Bank Expenses
incurred, or paid by Bank from, following, or consequential to transactions
between Bank and Borrower (including reasonable attorneys fees and expenses),
except for losses caused by Bank's gross negligence or willful misconduct.


                                      -11-
<PAGE>

12.3     TIME OF ESSENCE.

         Time is of the essence for the performance of all obligations in this
Agreement.

12.4     SEVERABILITY OF PROVISION.

         Each provision of this Agreement is severable from every other
provision in determining the enforceability of any provision.

12.5     AMENDMENTS IN WRITING, INTEGRATION.

         All amendments to this Agreement must be in writing and signed by
Borrower and Bank. This Agreement represents the entire agreement about this
subject matter, and supersedes prior negotiations or agreements. All prior
agreements, understandings, representations, warranties, and negotiations
between the parties about the subject matter of this Agreement merge into this
Agreement and the Loan Documents. ORAL AGREEMENTS OR ORAL COMMITMENTS TO LOAN
MONEY, EXTEND CREDIT, OR FORBEAR FROM ENFORCING REPAYMENT OF A DEBT ARE NOT
ENFORCEABLE UNDER WASHINGTON LAW. UNDER OREGON OR WASHINGTON LAW, MOST
AGREEMENTS, PROMISES AND COMMITMENTS MADE BY THE BANK AFTER OCTOBER 3, 1989
CONCERNING LOANS AND OTHER CREDIT EXTENSIONS WHICH ARE NOT FOR PERSONAL, FAMILY
OR HOUSEHOLD PURPOSES OR SECURED SOLELY BY THE BORROWER'S RESIDENCE MUST BE IN
WRITING, EXPRESS CONSIDERATION AND BE SIGNED BY US TO BE ENFORCEABLE.

 12.6    COUNTERPARTS.

         This Agreement may be executed in any number of counterparts and by
different parties on separate counterparts, each of which, when executed and
delivered, are an original, and all taken together, constitute one agreement.

 12.7    SURVIVAL.

         All covenants, representations and warranties made in this Agreement
continue in full force while any Obligations remain outstanding. The obligations
of Borrower in Section 12.2 to indemnify Bank will survive until all statutes of
limitations for actions that may be brought against Bank have run.

12.8     CONFIDENTIALITY.

         In handling any confidential information, Bank will exercise the same
degree of care that it exercises for its own proprietary information, but
disclosure of information may be made (i) to Bank's subsidiaries or affiliates
in connection with their business with Borrower, (ii) to prospective transferees
or purchasers of any interest in the Loans, (iii) as required by law,
regulation, subpoena, or other order, (iv) as required in connection with Bank's
examination or audit and (v) as Bank considers appropriate exercising remedies
under this Agreement. Confidential information does not include information that
either: (a) is in the public domain or in Bank's possession when disclosed to
Bank, or becomes part of the public domain after disclosure to Bank; or (b) is
disclosed to Bank by a third party, if Bank does not know that the third party
is prohibited from disclosing the information.

12.9     EFFECT OF AMENDMENT AND RESTATEMENT.


                                      -12-
<PAGE>

         This Agreement is intended to and does completely amend and restate,
without novation, the Original Agreement. All credit extensions or loans
outstanding under the Original Agreement are and shall continue to be
outstanding under this Agreement. All security interests granted under the
Original Agreement are hereby confirmed and ratified and shall continue to
secure all Obligations under this Agreement.

12.10    ATTORNEYS' FEES, COSTS AND EXPENSES.

         In any action or proceeding between Borrower and Bank arising out of
the Loan Documents, the prevailing party will be entitled to recover its
reasonable attorneys' fees and other costs and expenses incurred, in addition to
any other relief to which it may be entitled.

13       DEFINITIONS

13.1     DEFINITIONS.

         In this Agreement:

         "ACCOUNTS" are all existing and later arising accounts, contract
rights, and other obligations owed Borrower in connection with its sale or lease
of goods (including licensing software and other technology) or provision of
services, all credit insurance, guaranties, other security and all merchandise
returned or reclaimed by Borrower and Borrower's Books relating to any of the
foregoing.

         "AFFILIATE" of a Person is a Person that owns or controls directly or
indirectly the Person, any Person that controls or is controlled by or is under
common control with the Person, and each of that Person's senior executive
officers, directors, partners and, for any Person that is a limited liability
company, that Person's managers and members.
         "BANK EXPENSES" are all audit fees and expenses and reasonable costs or
expenses (including reasonable attorneys' fees and expenses) for preparing,
negotiating, administering, defending and enforcing the Loan Documents
(including appeals or Insolvency Proceedings).

         "BORROWER'S BOOKS" are all Borrower's books and records including
ledgers, records regarding Borrower's assets or liabilities, the Collateral,
business operations or financial condition and all computer programs or discs or
any equipment containing the information.

         "BUSINESS DAY" is any day that is not a Saturday, Sunday or a day on
         which the Bank is closed.

         "CASH BURN" is defined in Section 6.7.

         "CLOSING DATE" is the date of this Agreement.

         "CODE" is the Washington Uniform Commercial Code.

         "COLLATERAL" is the property described on EXHIBIT A.

         "COMMITTED REVOLVING LINE" is an Advance of up to $750,000.

         "CONTINGENT OBLIGATION" is, for any Person, any direct or indirect
liability, contingent or not, of that Person for (i) any indebtedness, lease,
dividend, letter of credit or other obligation of another such as


                                      -13-
<PAGE>

an obligation directly or indirectly guaranteed, endorsed, co-made, discounted
or sold with recourse by that Person, or for which that Person is directly or
indirectly liable; (ii) any obligations for undrawn letters of credit for the
account of that Person; and (iii) all obligations from any interest rate,
currency or commodity swap agreement, interest rate cap or collar agreement, or
other agreement or arrangement designated to protect a Person against
fluctuation in interest rates, currency exchange rates or commodity prices; but
"Contingent Obligation' does not include endorsements in the ordinary course of
business. The amount of a Contingent Obligation is the stated or determined
amount of the primary obligation for which the Contingent Obligation is made or,
if not determinable, the maximum reasonably anticipated liability for it
determined by the Person in good faith; but the amount may not exceed the
maximum of the obligations under the guarantee or other support arrangement.

         "CREDIT EXTENSION" is each Advance, Letter of Credit, Term Loan, or any
other extension of credit by Bank for Borrower's benefit.

         "EQUIPMENT" is all present and future machinery, equipment, tenant
improvements, furniture, fixtures, vehicles, tools, parts and attachments in
which Borrower has any interest.

         "ERISA" is the Employment Retirement Income Security Act of 1974, and
its regulations.

         "INDEBTEDNESS" is (a) indebtedness for borrowed money or the deferred
price of property or services, such as reimbursement and other obligations for
surety bonds and letters of credit, (b) obligations evidenced by notes, bonds,
debentures or similar instruments, (c) capital lease obligations and (d)
Contingent Obligations.

         "INSOLVENCY PROCEEDING" are proceedings by or against any Person under
the United States Bankruptcy Code, or any other bankruptcy or insolvency law,
including assignments for the benefit of creditors, compositions, extensions
generally with its creditors, or proceedings seeking reorganization,
arrangement, or other relief.

         "INVENTORY" is present and future inventory in which Borrower has any
interest, including merchandise, raw materials, parts, supplies, packing and
shipping materials, work in process and finished products intended for sale or
lease or to be furnished under a contract of service, of every kind and
description now or later owned by or in the custody or possession, actual or
constructive, of Borrower, including inventory temporarily out of its custody or
possession or in transit and including returns on any accounts or other proceeds
(including insurance proceeds) from the sale or disposition of any of the
foregoing and any documents of title.

         "INVESTMENT" is any beneficial ownership of (including stock,
partnership interest or other securities) any Person, or any loan, advance or
capital contribution to any Person.

         "LETTER OF CREDIT" is defined in Section 2.

         "LIEN" is a mortgage, lien, deed of trust, charge, pledge, security
interest or other encumbrance.

         "LOAN DOCUMENTS" are, collectively, this Agreement, any note, or notes
or guaranties executed by Borrower or Guarantor, and any other present or future
agreement between Borrower and/or for the benefit of Bank in connection with
this Agreement, all as amended, extended or restated.

         "MATERIAL ADVERSE CHANGE" is defined in Section 8.3.


                                      -14-
<PAGE>

         "OBLIGATIONS" are debts, principal, interest, Bank Expenses and other
amounts Borrower owes Bank now or later, including letters of credit and
Exchange Contracts and including interest accruing after Insolvency Proceedings
begin and debts, liabilities, or obligations of Borrower assigned to Bank.

         "ORIGINAL AGREEMENT" has the meaning set forth in recital paragraph A.

         "PERMITTED INDEBTEDNESS" is:

         (a) Borrower's indebtedness to Bank under this Agreement or any other
Loan Document;

         (b) Indebtedness existing on the Closing Date and shown on the
Schedule;

         (c) Subordinated Debt;

         (d) Indebtedness to trade creditors incurred in the ordinary course of
business; and

         (e) Indebtedness secured by Permitted Liens. "Permitted Investments"
are:

         "PERMITTED INVESTMENTS: ARE:

         a)   Investments shown on the Schedule and existing on the Closing
Date; and

         (b) (i) marketable direct obligations issued or unconditionally
guaranteed by the United States or its agency or any State maturing within 1
year from its acquisition, (ii) commercial paper maturing no more than 1 year
after its creation and having the highest rating from either Standard & Poor's
Corporation or Moody's Investors Service, Inc., and (iii) Bank's certificates of
deposit issued maturing no more than I year after issue.

         "PERMITTED LIENS" are:

         (a) Liens existing on the Closing Date and shown on the Schedule or
arising under this Agreement or other Loan Documents;

         (b) Liens for taxes, fees, assessments or other government charges or
levies, either not delinquent or being contested in good faith and for which
Borrower maintains adequate reserves on its Books, if they have no priority over
any of Bank's security interests;

         (c) Purchase money Liens (i) oh Equipment acquired or held by Borrower
or its Subsidiaries incurred for financing the acquisition of the Equipment, or
(ii) existing on equipment when acquired, jf the Lien is confined to the
property and improvements and the proceeds of the equipment;

         (d) Leases or subleases and licenses or sublicenses granted in the
ordinary course of Borrower's business and any interest or title of a lessor,
licensor or under any lease or license, If the leases, subleases, licenses and
sublicenses permit granting Bank a security interest;

         (e) Liens incurred in the extension, renewal or refinancing of the
indebtedness secured by Liens described in (a) through (c), BUT any extension,
renewal or replacement Lien must be limited to the property encumbered by the
existing Lien and the principal amount of the indebtedness may not increase.

         "PERSON" is any individual, sole proprietorship, partnership, limited
liability company, joint


                                      -15-
<PAGE>

venture, company association, trust, unincorporated organization, association,
corporation, institution, public benefit corporation, firm, joint stock company,
estate, entity or government agency.

         "PRIME RATE" is Bank's most recently announced "prime rate," even if it
is not Bank's lowest rate.

         "REMAINING MONTHS LIQUIDITY" is defined in Section 6.7.

         "RESPONSIBLE OFFICER" is each of the Chief Executive Officer, the
President, the Chief Financial Officer and the Controller of Borrower.

         "REVOLVING MATURITY DATE" is June 30, 1999.

         `SCHEDULE" is any attached schedule of exceptions.

         "SUBORDINATED DEBT" is debt incurred by Borrower subordinated to.
Borrower's debt to Bank (and identified as subordinated by Borrower and Bank).

         "SUBSIDIARY" is for any Person, or any other business entity of which
more than 50% of the voting stock or other equity interests is owned or
controlled, directly or indirectly, by the Person or one or more Affiliates of
the Person.

         "TERM LOAN" a loan of $117,396.87.

         "TERM LOAN MATURITY DATE" is February 13, 2000.


                                      -16-
<PAGE>

BORROWER:

Rosetta lnpharmatics, Inc.

By: /s/ John J. King
    -----------------------------

Title: Sr. Vice President
       --------------------------


BANK:

SILICON VALLEY BANK

By: /s/
    -----------------------------

Title: Vice President
       --------------------------


                                      -17-
<PAGE>

                                    EXHIBIT A

         The Collateral consists of all of Borrower's right, title and interest
in and to the following:

         All goods and equipment now owned or hereafter acquired, including,
without limitation, all machinery, fixtures, vehicles (including motor vehicles
and trailers), and any interest in any of the foregoing; and all attachments,
accessories, accessions, replacements, substitutions, additions, and
improvements to any of the foregoing, wherever located;

         All inventory, now owned or hereafter acquired, including, without
limitation, all merchandise, raw materials, parts, supplies, packing and
shipping materials, work in process and finished products including such
inventory as is temporarily out of Borrower's custody or possession or in
transit and including any returns upon any accounts or other proceeds, including
insurance proceeds, resulting from the sale or disposition of any of the
foregoing and any documents of title representing any of the above;

         All contract rights and general intangibles now owned or hereafter
acquired, including, without limitation, goodwill, trademarks, servicemarks,
trade styles, trade names, patents, patent applications, leases, license
agreements, franchise agreements, blueprints, drawings, purchase orders,
customer lists, route lists, infringements, claims, computer programs, computer
discs, computer tapes, literature, reports, catalogs, design rights, income tax
refunds, payments of insurance and rights to payment of any kind;

         All now existing and hereafter arising accounts, contract rights,
royalties, license rights and all other forms of obligations owing to Borrower
arising out of the sale or lease of goods, the licensing of technology or the
rendering of services by Borrower, whether or not earned by performance, and any
and all credit insurance, guaranties, and other security therefor, as well as
all merchandise returned to or reclaimed by Borrower;

         All documents, cash, deposit accounts, securities, securities
entitlements, securities accounts, investment property, financial assets,
letters of credit, certificates of deposit, instruments and chattel paper now
owned or hereafter acquired and Borrower's Books relating to the foregoing;

         All copyright rights, copyright applications, copyright registrations
and like protections in each work of authorship and derivative work thereof,
whether published or unpublished, now owned or hereafter acquired; all trade
secret rights, including all rights to unpatented inventions, know-how,
operating manuals, license rights and agreements and confidential information,
now owned or hereafter acquired; all mask work or similar rights available for
the protection of semiconductor chips, now owned or hereafter acquired; all
claims for damages by way of any past, present and future infringement of any of
the foregoing; and

All Borrower's Books relating to the foregoing and any and all claims, rights
and interests in any of the above and all substitutions for, additions and
accessions to and proceeds thereof.


<PAGE>

                                    EXHIBIT B

                   LOAN PAYMENT/ADVANCE TELEPHONE REQUEST FORM

              DEADLINE FOR SAME DAY PROCESSING IS 3:00 P.M., P.S.T.

TO: CENTRAL CLIENT SERVICE DIVISION                        DATE:
                                                                ---------------
FAX#: (408) 496-2426                                       TIME:
                                                                ---------------
-------------------------------------------------------------------------------
FROM: Rosetta Inpharmatics, Inc.
      -------------------------------------------------------------------------
                             CLIENT-NAME (BORROWER)
REQUESTED BY:
             ------------------------------------------------------------------
                            AUTHORIZED SIGNER'S NAME
PHONE NUMBER:
             ------------------------------------------------------------------
FROM ACCOUNT #                     TO ACCOUNT #
             ---------------------             --------------------------------

<TABLE>
<CAPTION>
REQUESTED TRANSACTION TYPE                   REQUESTED DOLLAR AMOUNT
--------------------------                   -----------------------
<S>                                          <C>
PRINCIPAL INCREASE (ADVANCE)                 $
                                              ---------------------------------
PRINCIPAL PAYMENT (ONLY)                     $
                                              ---------------------------------
INTEREST PAYMENT (ONLY)                      $
                                              ---------------------------------
PRINCIPAL AND INTEREST (PAYMENT)             $
                                              ---------------------------------
</TABLE>

OTHER INSTRUCTIONS:
                   ------------------------------------------------------------

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

All borrower's representations and warranties in the Amended and Restated Loan
and Security Agreement are true, correct and complete in all material respects
on the date of the telephone request for and Advance confirmed by this Borrowing
Certificate; but those representations and warranties expressly referring to
another date shall be true, correct and complete in all material respects as of
that date.

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

                                  BANK USE ONLY
TELEPHONE REQUEST:
The following person is authorized to request the loan payment transfer/loan
advance on the advance designated account and is known to me.

-----------------------------------               ----------------------
        Authorized Requester                              Phone #

-----------------------------------               ----------------------
        Received By (Bank)                                Phone #

                     --------------------------------------
                           Authorized Signature (Bank)
-------------------------------------------------------------------------------


<PAGE>

                                    EXHIBIT C
                             COMPLIANCE CERTIFICATE

TO:      SILICON VALLEY BANK
         3003 Tasman Drive
         Santa Clara, CA 95054

FROM:    ROSETTA INPHARMATICS, INC.

         The undersigned authorized officer of Rosetta Inpharmatics, Inc.
("Borrower") certifies that under the terms and conditions of the Amended and
Restated Loan and Security Agreement between Borrower and Bank (the
"Agreement"), (i) Borrower is in complete compliance for the period ending
___________ with all required covenants except as noted below and (ii) all
representations and warranties in the Agreement are true and correct in all
material respects on this date.

  PLEASE INDICATE COMPLIANCE STATUS BY CIRCLING YES/NO UNDER "COMPLIES" COLUMN.

<TABLE>
<CAPTION>
REPORTING COVENANT                               REQUIRED                                   COMPLIES
------------------                               --------                                   --------
<S>                                              <C>                                        <C>            <C>
Monthly financial statements                     Monthly within 30 days                     Yes            No

Annual (Audited)                                 FYE within 120 days                        Yes            No
</TABLE>

<TABLE>
<CAPTION>
FINANCIAL COVENANT                               REQUIRED               ACTUAL              COMPLIES
------------------                               --------               ------              --------
<S>                                              <C>                    <C>                 <C>              <C>
Maintain on a Monthly Basis:
Either,
     Minimum Cash                                $2,000,000             $                   Yes              No
                                                                         -----------
No
Or
     Remaining Months Liquidity                  6 Months               ___ Months          Yes              No
</TABLE>

COMMENTS REGARDING EXCEPTIONS: See attached.

                                        ---------------------------------------
                                                      BANK USE ONLY

Sincerely,                              Received by:
                                                    ---------------------------
                                                    AUTHORIZED SIGNER
Rosetta Inpharmatics, Inc.
                                        Date:
                                             ----------------------------------
------------------------------------
SIGNATURE                               Verified:
                                                 ------------------------------
                                                    AUTHORIZED SIGNER
------------------------------------
TITLE                                   Date:

                                        Compliance Status:           Yes     No
------------------------------------
DATE
                                        ---------------------------------------

<PAGE>

                               SILICON VALLEY BANK

                       PRO FORMA INVOICE FOR LOAN CHARGES

BORROWER:                  ROSETTA INPHARMATICS, INC.

LOAN OFFICER:              PETER PALSSON

DATE:                      NOVEMBER 10, 1998

<TABLE>
<S>                                                              <C>
                           REVOLVING LOAN FEE                    $2,000.00
                           CREDIT REPORT                             35.00
                           DOCUMENTATION FEE                        750.00

                           TOTAL FEE DUE                         $2,785.00
                           -------------                         ---------
                                                                 ---------
</TABLE>

PLEASE INDICATE THE METHOD OF PAYMENT:

         {  }   A CHECK FOR THE TOTAL AMOUNT IS ATTACHED.

         {  }   DEBIT DDA #_______________ FOR THE TOTAL AMOUNT.

         {  }   LOAN PROCEEDS

BORROWER:

BY: /s/
    -------------------------------------
            (AUTHORIZED SIGNER)


-----------------------------------------
SILICON VALLEY BANK                 DATE
ACCOUNT OFFICER'S SIGNATURE


<PAGE>

<TABLE>
<S><C>
This UCC-3 CHANGE STATEMENT is presented for filing pursuant to the WASHINGTON
UNIFORM COMMERCIAL CODE, chapter 62A.9 RCW; Crop Lien filings, chapter 60.11 and
Processor and Preparer Liens chapter 60.13 RCW. PLEASE TYPE FORM
------------------------------------------------------------------------- ----------------------------------------------------------
1.  DEBTOR(S) (see instruction #2)                        Debtor 1        2.  FOR OFFICE USE ONLY - DO NOT WRITE IN THIS BOX
/ /      PERSONAL (last, first, middle name and address)  SSN:
                                                              -----------
/ /      BUSINESS (legal business name and address)       FEIN:
                                                              -----------
                                                          Debtor 2
                                                          SSN:
                                                              -----------
                                                          FEIN:
                                                              -----------
ROSETTA INPHARMATICS, INC.
12040 115th Avenue N.E., Suite 210
Kirkland, WA 98034


TRADE NAME, DBA, AKA:
------------------------------------------------------------------------- ----------------------------------------------------------
3.  SECURED PARTY(IES) (name and address)                                 4.   ASSIGNEE(S) of SECURED PARTY(IES) if applicable
                                                                               (name and address)
SILICON VALLEY BANK
3003 Tasman Drive
Santa Clara, CA 95054

                                                                 Jos/152
------------------------------------------------------------------------------------------------------------------------------------
5.   This change statement affects the original filing statement recorded with the Department of Licensing.  List one number and
     date only.    WASHINGTON
     Original filing number 970510087                                             Date 2/20/97
                            ----------------------------------------------------       ---------------------------------------------

------------------------------------------------------------------------------------------------------------------------------------
6.   FEES: A $12.00 filing fee is required for each action checked in box 7,
     except termination which requires no fee. Secured party contact person:                             Phone:
                                                                            ----------------------------       -----------------

------------------------------------------------------------------------------------------------------------------------------------
7. Please check one or more of the following actions:
/ /           CONTINUATION. The original financing statement between the
              Debtor(s) and Secured Party(ies), bearing file number shown in box
              5, is still effective.
/ /           FULL ASSIGNMENT. All of the Secured Party's rights under the
              financing statement bearing file number shown in box 5 have been
              assigned to the Assignee(s) whose name(s) and address(es) appear
              in box 4.
/ /           PARTIAL ASSIGNMENT. The Secured Party's rights under the financing
              statement bearing file number shown in box 5, to the property
              described in box 8, have been assigned to the Assignee(s) whose
              name(s) and address(es) appear in box 4.
/ /           AMENDMENT.  Financing statement bearing file number shown in box
              5 is amended as set forth in box 8.
/ /           PARTIAL RELEASE.  Secured Party releases the collateral described
              in box 8 from the financing statement bearing file number shown
              in box 5.
/ /           TERMINATION. Secured Party(ies) no longer claims a security
              interest under the financing statement bearing file number shown
              in box 5.

------------------------------------------------------------------------------------------------------------------------------------
8.   DESCRIPTION of partial assignment, amendment or partial release: (Attach additional 8.5" 3 11" sheet(s) if needed.)

     THE COLLATERAL STATED ON THE ORIGINAL FINANCING STATEMENT IS HEREBY AMENDED
     TO INCLUDE THE COLLATERAL LISTED ON EXHIBIT "A" ATTACHED HERETO AND MADE A
     PART HEREOF.


------------------------------------------------------------------------------------------------------------------------------------
9.   DEBTOR NAME(S) AND SIGNATURE(S):                                 10.  SECURED PARTY NAME(S) AND SIGNATURE(S)
     ROSETTA INPHARMATICS, INC.                                            SILICON VALLEY BANK


     -------------------------------------------------                     ---------------------------------------------------------
     TYPE NAME(S) OF DEBTOR(S) AS IT APPEARS IN BOX 1.                     TYPE NAME(S) OF SECURED PARTY(IES) AS IT APPEARS IN BOX 3
                                                                            OR 4.

     -------------------------------------------------                     ---------------------------------------------------------
     SIGNATURE(S) OF DEBTOR(S)                                             SIGNATURE(S) OF SECURED PARTY(IES)

     -------------------------------------------------                     ---------------------------------------------------------
     SIGNATURE(S) OF DEBTOR(S)                                             SIGNATURE(S) OF SECURED PARTY(IES)

------------------------------------------------------------------------------------------- ----------------------------------------
11.  RETURN ACKNOWLEDGEMENT COPY TO:                                                        12.  FILE WITH:
                                                                                                 UNIFORM COMMERCIAL CODE
     Data File Services, Inc.                                                                    DEPARTMENT OF LICENSING
     P.O. Box 275                                                                                P.O. BOX 9660
     Van Nuys, CA 91408-2750                                                                     OLYMPIA, WA 98507-9660
                                                                                                 (206) 753-2523
     800-331-3282                                                                             MAKE CHECKS PAYABLE TO THE DEPARTMENT
     818-909-4717                                                                             OF LICENSING
(1)  FILING OFFICER -INDEX                                                                  13.  FOR OFFICE USE ONLY
                                                                                                           IMAGES TO
                                                                                                           BE FILMED
</TABLE>