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                                                                   Exhibit 10.24


                                                          Loan No.: 1910185-0001

HELLER FINANCIAL

                               SECURITY AGREEMENT

THIS SECURITY AGREEMENT ("Agreement") is entered into as of the 22nd day of
December, 1998, by and between Microcide Pharmaceuticals, Inc., a Delaware
corporation ("Debtor"), whose business address is 850 Maude Avenue, Mountain
View, California 94043 and Heller Financial Leasing, Inc., a Delaware
corporation ("Secured Party"), whose address is Commercial Equipment Finance
Division, 500 West Monroe Street, Chicago, Illinois 60661.

                                   WITNESSETH:

1. Secure Payment. To secure payment of indebtedness in the principal sum of up
to Four Million and 00/ 100 Dollars ($4,000,000.00), as evidenced by a note or
notes executed and delivered by Debtor to Secured Party (the "Notes") and any
obligations arising under this Agreement, and also to secure any other
indebtedness or liability of Debtor to Secured Party, direct or indirect,
absolute or contingent, due or to become due, now existing or hereafter arising
and no matter how acquired by Secured Party, including all future advances or
loans which may be made at the option of Secured Party (all the foregoing
hereinafter called the "Indebtedness"), Debtor hereby grants and conveys to
Secured Party a first priority continuing lien and security interest in the
personal property described on any schedule(s) now or hereafter attached to or
made a part hereof by reference hereto (the "Schedules"), all products and
proceeds (including insurance proceeds) thereof, if any, and all substitutions,
replacements, attachments, additions, and accessions thereto (all of the
foregoing hereinafter called the "Collateral.") The Schedules may be
supplemented from time to time to evidence the Collateral subject to this
Agreement.

2. Representations, Warranties and Covenants. Except as otherwise provided, each
representation and warranty made by Debtor in this Agreement shall be true,
correct and complete as of the date of this Agreement and as of the date of each
advance of funds under a Note. Debtor hereby represents, warrants and covenants
as follows:

     (a) Perform Obligations. Debtor shall pay as and when due all Indebtedness
secured by this Agreement and perform all of the obligations contained in this
Agreement according to its terms. Debtor shall use the loan proceeds for
business uses and not for personal, family, household, or agricultural uses.

     (b) Perfection. This Agreement and all necessary Uniform Commercial Code
filings together create a valid, perfected and first priority continuing lien
and security interest in the Collateral, securing the payment and performance of
the Indebtedness, and all filings and other actions necessary or desirable to
create, perfect and protect such security interest have been or will be duly
taken.

     (c) Collateral Free and Clear. Except as may be set forth on a Schedule,
the Collateral is and shall remain free and clear of all liens, claims, charges,
encumbrances and other security interests of any kind (other than the security
interest granted hereby). Debtor shall defend the title to the Collateral
against all persons and against all claims and demands whatsoever.
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     (d) Possession and Operating Order of the Collateral. Debtor shall retain
possession of the Collateral at all times and shall not sell, exchange, assign,
loan, deliver, lease, mortgage, or otherwise dispose of the Collateral or any
part thereof without the prior written consent of Secured Party. Debtor shall at
all times keep the Collateral at the location[s] specified on the Schedules
(except for removals thereof in the usual course of business for temporary
periods). At Debtor's sole cost and expense, Debtor shall keep the Collateral in
good repair and condition and shall not misuse, abuse, waste or otherwise allow
it to deteriorate, except for normal wear and tear. Secured Party may verify any
Collateral in any reasonable manner which Secured Party may consider
appropriate, and Debtor shall furnish all reasonable assistance and information
and perform any acts which Secured Party may reasonably request in connection
therewith.

     (e) Insurance. Debtor shall insure the Collateral against loss by fire
(including extended coverage), theft and other hazards, for its full insurable
value including replacement costs, with a deductible not to exceed Fifty
Thousand and 00/100 Dollars ($50,000.00) per occurrence and without
co-insurance. In addition, Debtor shall obtain liability insurance covering
liability for bodily injury, including death and property damage, in an amount
of at least Five Million and 00/100 Dollars ($5,000,000.00) per occurrence or
such greater amount as may comply with general industry standards, or in such
other amounts as Secured Party may otherwise require. All policies of insurance
required hereunder shall be in such form, amounts, and with such companies as
Secured Party may approve; shall provide for at least thirty (30) days prior
written notice to Secured Party prior to any modification or cancellation
thereof; shall name Secured Party as loss payee or additional insured, as
applicable, and shall be payable to Debtor and Secured Party as their interests
may appear; shall waive any claim for premium against Secured Party; and shall
provide that no breach of warranty or representation or act or omission of
Debtor shall terminate, limit or affect the insurers' liability to Secured
Party. Certificates of insurance or policies evidencing the insurance required
hereunder along with satisfactory proof of the payment of the premiums therefor
shall be delivered to Secured Party. Debtor shall give immediate written notice
to Secured Party and to insurers of loss or damage to the Collateral and shall
promptly file proofs of loss with insurers. Debtor hereby irrevocably appoints
Secured Party as Debtor's attorney-in-fact, coupled with an interest, for the
purpose of obtaining, adjusting and canceling any such insurance and endorsing
settlement drafts. Debtor hereby assigns to Secured Party, as additional
security for the Indebtedness, all sums which may become payable under such
insurance.

            In the event Debtor fails to provide Secured Party with evidence of
the insurance coverage required by this Agreement, Secured Party may purchase
insurance at Debtor's expense to protect Secured Party's interests in the
Collateral. This insurance may, but need not, protect Debtor's interests. The
coverage purchased by Secured Party may not pay any claim made by Debtor or any
claim that is made against Debtor in connection with the Collateral. Debtor may
later cancel any insurance purchased by Secured Party, but only after providing
Secured Party with evidence that Debtor has obtained insurance as required by
this Agreement. If Secured Party purchases insurance for the Collateral, Debtor
will be responsible for the costs of that insurance, including interest and
other charges imposed by Secured Party in connection with the placement of the
insurance, until the effective date of the cancellation or expiration of the
insurance. The costs of the insurance may be added to the Indebtedness. The
costs of the insurance may be more than the cost of insurance Debtor is able to
obtain on its own.

     (f) If Collateral Attaches to Real Estate. If the Collateral or any part
thereof has been attached to or is to be attached to real estate, an accurate
description of the real estate and the name and address of the record owner is
set forth on the Schedules.


     (g) Financial Statements. Debtor shall furnish to Secured Party, as soon as
practicable, and in any event within sixty (60) days after the end of each
fiscal quarter of Debtor and each guarantor of all or any part of the
Indebtedness (each, a "Guarantor"), respectively, Debtor's and each Guarantor's
unaudited financial statements including in each instance, balance sheets,
income statements, and

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statements of cash flow, on a consolidated and consolidating basis, as
appropriate, and separate profit and loss statements as of and for the quarterly
period then ended and for the respective person's fiscal year to date, prepared
in accordance with generally accepted accounting principles, consistently
applied ("GAAP"). Debtor shall also furnish to Secured Party, as soon as
practicable, and in any event within one hundred and twenty (120) days after the
end of each fiscal year of Debtor and each Guarantor, respectively, Debtor's and
each Guarantor's annual audited financial statements, including balance sheets,
income statements and statements of cash flow for the fiscal year then ended, on
a consolidated and consolidating basis, as appropriate, which have been prepared
by its independent accountants in accordance with GAAP. Such audited financial
statements shall be accompanied by the independent accountant's opinion, which
opinion shall be in a form generally recognized as "unqualified".

     (h) Authorization. Debtor is now, and will at all times remain, duly
licensed, qualified to do business and in good standing in every jurisdiction
where failure to be so licensed or qualified and in good standing would have a
material adverse effect on its business, properties or assets. The execution and
delivery of this Agreement, the Notes, the commitment executed by the parties,
if any, (to the extent not inconsistent herewith) and any other documents and
instruments executed contemporaneously with or delivered pursuant to this
Agreement and the Notes, all as amended from time to time (collectively the
"Loan Documents"), have been duly authorized by Debtor and constitute the legal,
valid, and binding obligations of Debtor, enforceable against Debtor in
accordance with their respective terms. Debtor shall preserve and maintain its
existence and shall not wind up its affairs or otherwise dissolve. Debtor shall
not, without thirty (30) days prior written notice to Secured Party, (1) change
its name or so change its structure such that any financing statement or other
record notice becomes misleading or (2) change its principal place of business
or chief executive or accounting offices from the address stated herein.

     (i) Litigation. Except as disclosed by Debtor on a Schedule, there are no
judgments outstanding against or affecting Debtor, its officers, directors or
affiliates or any part of the Collateral and there are no actions, charges,
claims, demands, suits, proceedings, or investigations pending or threatened
against Debtor or otherwise affecting any part of the Collateral ("Litigation").
Debtor shall furnish to Secured Party all information regarding any material
Litigation as Secured Party shall reasonably request and in any event shall
promptly notify Secured Party in writing of any Litigation against it which if
decided against it would materially and adversely affect the finances or
operations of Debtor. For the purposes of this subsection 2(i), One Million and
00/100 Dollars ($1,000,000.00) shall be deemed material.

     (j) No Conflicts. Debtor is not in violation of any material term or
provision of its by-laws, or of any material agreement or instrument, decree,
order, or any statute, rule, or governmental regulation applicable to it. The
execution, delivery, and performance of the Loan Documents do not and will not
violate, constitute a default under, or otherwise conflict with any such term or
provision or result in the creation of any security interest, lien, charge, or
encumbrance upon any of the properties or assets of Debtor, except for the
security interest created hereunder.

     (k) Compliance with Laws. Debtor shall use and maintain the Collateral in
accordance with all applicable laws, regulations, ordinances, and codes and
shall otherwise comply in all material respects with all applicable laws, rules,
and regulations and duly observe all valid requirements of all governmental
authorities, and all statutes, rules and regulations relating to its business as
now in effect and which may be imposed in the future.

     (l) Taxes. Debtor has timely filed all tax returns (federal, state, local,
and foreign) required to be filed by it and has paid or established reserves for
all taxes, assessments, fees, and other governmental charges in respect of its
properties, assets, income and franchises. Debtor shall promptly file, pay and
discharge all taxes, assessments, license fees (related to the Collateral) and
other governmental charges prior to the date on which penalties are attached
thereto, establish adequate reserves for the payments of such taxes,
assessments, and other governmental charges and make all required withholding
and other tax deposits, and, upon request, provide Secured Party with receipts
or other proof that any or all of such

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taxes, assessments, license fees or governmental charges have been paid in a
timely fashion; provided, however, that nothing contained herein shall require
the payment of any tax, assessment, or other governmental charge so long as its
validity is being diligently contested in good faith and by appropriate
proceedings diligently conducted and Debtor has established cash reserves
therefor in accordance with GAAP. Should any stamp, excise, or other tax,
including mortgage, conveyance, deed, intangible, or recording taxes become
payable in connection with or respect of any of the Loan Documents, Debtor shall
pay the same (including interest and penalties, if any) and shall hold Secured
Party harmless with respect thereto.

     (m) Environmental Laws Compliance. Except as disclosed by Debtor on a
Schedule, Debtor (1) has not received any claim, summons, complaint, order, or
other notice that it is not in compliance with, or that any public authority is
investigating its compliance with, any federal, state, and local laws, rules,
regulations, orders, and decrees relating to pollution, hazardous substances,
waste, disposal or the protection of human health or safety, plant life or
animal life, natural resources or the environment, all as amended from time to
time (collectively, "Environmental Laws"), (2) has no knowledge of any material
violation of any Environmental Laws on or about its assets or property, and (3)
is not under any current clean up or other remediation program or order. Debtor
has obtained all environmental, health and safety permits necessary for the
operation of Debtor's business. Debtor is and shall remain in compliance, in all
respects, with the terms and conditions of all permits and with all applicable
Environmental Laws. Debtor shall provide Secured Party, promptly following
receipt, copies of any correspondence, notice, complaint, order, or other
document that it receives asserting or alleging a circumstance or condition
which requires or may require a cleanup, removal, remedial action or other
response by or on the part of Debtor under any Environmental Laws, or which
seeks damages or civil, criminal or punitive penalties from Debtor for an
alleged violation of any Environmental Laws. Debtor will promptly notify Secured
Party of any release, spill or material change in the nature or extent of any
hazardous substances or contaminants used, transported or stored by Debtor or
any subsidiary of Debtor, and allow no material change in the use thereof or of
Debtor's operations that would increase in any material amount the risk of
violation of any Environmental Laws without the express prior written approval
of Secured Party.

     (n) Regulations. No proceeds of the loans or any other financial
accommodation hereunder will be used, directly or indirectly, for the purpose of
purchasing or carrying any margin security, as that term is defined in
Regulations G, T, U, X of the Board of Governors of the Federal Reserve System.

     (o) Books and Records. Debtor shall maintain, at all times, true and
complete books and records in accordance with GAAP and consistent with those
applied in the preparation of Debtor's financial statements. At all reasonable
times, upon reasonable notice, and during normal business hours, Debtor shall
permit Secured Party or its agents to audit, examine and make extracts from or
copies of any of its books, ledgers, reports, correspondence, and other records
relating to the Collateral.

     (p) Set off. Without limiting any other right of Secured Party, whenever
Secured Party has the right to declare any Indebtedness to be immediately due
and payable (whether or not it has so declared), Secured Party is hereby
authorized at any time and from time to time to the fullest extent permitted by
law, but shall not be obligated to, set off and apply against any and all
Indebtedness, any and all monies then or thereafter owed to Debtor by Secured
Party, whether or not the obligation to pay such monies owed by Secured Party is
then due. An election by Secured Party to exercise its right of set off shall be
effective immediately upon such election even though any charge therefor is made
or entered on Secured Party's records subsequent thereto.

     (q) Standard of Care; Notice of Claims. Debtor acknowledges and agrees that
Secured Party shall not be liable for any acts or omissions nor for any error of
judgment or mistake of fact or law other than as a sole and direct result of
Secured Party's gross negligence or willful misconduct. Debtor shall give
Secured Party written notice of any action or inaction by Secured Party or any
agent or attorney of

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Secured Party that may give rise to a claim against Secured Party or any agent
or attorney of Secured Party or that may be a defense to payment of the
Indebtedness or performance hereunder for any reason, including commission of a
tort (subject, in any event, to the first sentence of this paragraph) or
violation of any contractual duty or duty implied by law. Debtor agrees that
unless such notice is fully given as promptly as possible (and in any event
within thirty (30) days) after Debtor has knowledge, or with the exercise of
reasonable diligence should have had knowledge, of any such action or inaction,
Debtor shall not assert, and Debtor shall be deemed to have waived, any claim or
defense arising therefrom.

     (r) Indemnity. Debtor shall indemnify, defend and hold Secured Party, its
parent, affiliates, officers, directors, agents, employees, consultants, persons
engaged by Secured Party to evaluate or monitor the Collateral, auditors and
attorneys harmless from and against any loss, cost, expense (including
reasonable attorneys' fees and costs and any consultants' or other experts' fees
and expenses), damage, penalty, fine, claim, lien, suit, judgment or liability
of every kind and nature arising directly or indirectly out of (i) any Loan
Document, (ii) the ownership, possession, lease, operation, use, condition,
sale, return, or other disposition of the Collateral, except to the extent the
loss, expense, damage or liability arises solely and directly from Secured
Party's gross negligence or willful misconduct, (iii) any Environmental Laws,
and (iv) the enforcement by Secured Party of its rights or remedies hereunder.
Any payments required to be made hereunder shall be due and payable on demand.

     (s) Payments Set Aside. If any payment is made to Secured Party or Secured
Party enforces its security interest or exercises its right of set off, and such
payment or part, or any proceeds of such enforcement or set off are subsequently
invalidated, declared to be fraudulent or preferential, set aside and/or
required to be repaid to a trustee, receiver or any other party under any
bankruptcy law, state or federal law, common law or equitable cause, then to the
extent of such recovery, the Indebtedness or part thereof originally intended to
be satisfied, and all liens, security interests, rights and remedies therefor,
shall be revived and continued in full force and effect as if such payment had
not been made or such enforcement or set off had not occurred.

     (t) Expenses and Attorneys' Fees. Debtor shall be liable for all charges,
costs, expenses and attorneys' fees incurred by Secured Party (including
allocated costs of internal counsel): (i) in perfecting, defending, protecting
or terminating its security interest in the Collateral, or any part thereof,
(ii) in the negotiation, execution, delivery, administration, amendment or
enforcement of the Loan Documents or the collection of any amounts due under any
Note or other Loan Document; (iii) in any lawsuit or other legal proceeding in
any way connected with any of the Loan Documents, including any contract or tort
or other actions, any arbitration or other alternative dispute resolution
proceeding, all appeals and judgment enforcement actions and any bankruptcy
proceeding (including any relief from stay and/or adequate protection motions,
cash collateral disputes, assumption/rejection motions and disputes or
objections to any proposed disclosure statement or reorganization plan).

     (u) Complete Information. No representation or warranty made by Debtor in
any Loan Document and no other document or statement now or hereafter furnished
to Secured Party by or on behalf of Debtor contains or will contain any
misstatement of a material fact or omit to state any material fact which would
make the statements contained therein misleading. Except as expressly set forth
in the Schedules, there is no fact known to Debtor that has or could have a
materially adverse affect on the business, operation, condition (financial or
otherwise), performance, properties or prospects of Debtor or Debtor's ability
to timely pay all of the Indebtedness and perform all of its other obligations
contained in or secured by this Agreement.

     (v) Collateral Documentation. Debtor shall deliver to Secured Party prior
to any advance, satisfactory documentation regarding the Collateral to be
financed, including such invoices, canceled checks evidencing payments, or other
documentation as may be reasonably requested by Secured Party. Additionally,
Debtor shall satisfy Secured Party that Debtor's business and financial
information is as

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has been represented and there has been no material change in Debtor's business,
financial condition, or operations.

     (w) Year 2000 Compliance. Debtor has made an assessment of the microchip
and computer-based systems and the software used in its business and based upon
such assessment believes that it will be "Year 2000 Compliant" by January 1,
2000. For purposes of this paragraph, "Year 2000 Compliant" means that all
software, embedded microchips and other processing capabilities utilized by, and
material to the business operations or financial condition of, Debtor are able
to interpret, store, transmit, receive and manipulate data on and involving all
calendar dates correctly and without causing any abnormal ending scenarios in
relation to dates in and after the Year 2000. From time to time, at the request
of Secured Party, Debtor shall provide to Secured Party such updated information
as is requested regarding the status of its efforts to become Year 2000
Compliant.

3. Prepayment. Upon forty-five (45) days prior written notice to Secured Party,
Debtor may prepay in whole, but not in part, the then entire unpaid principal
balance of any Note, together with all accrued and unpaid interest thereon to
the date of such prepayment, provided that in addition to such prepayment,
Debtor shall pay any and all other sums then due under any of the Loan
Documents.

4. Events of Default. If any one of the following events (each of which is
herein called an "Event of Default") shall occur: (a) Debtor fails to pay any
part of the Indebtedness within ten (10) calendar days of its due date, or (b)
any warranty or representation of Debtor in any Loan Document is materially
untrue, misleading or inaccurate, or (c) Debtor or any Guarantor breaches or
defaults in the performance of any other agreement or covenant under any Loan
Document, or (d) Debtor or any Guarantor breaches or defaults in the payment or
performance of any debt or other obligation owed by it to Secured Party or any
affiliate of Secured Party, and Secured Party has (without being obligated to do
so) declared such event, an Event of Default hereunder, or (e) Debtor breaches
or defaults in the payment or performance of any debt or other obligation,
whether now or hereafter existing, with an outstanding principal balance in
excess of One Million and 00/100 Dollars ($1,000,000.00), and the same is
subsequently accelerated, or (f) there shall be a change in the beneficial
ownership and control, directly or indirectly, of the majority of the
outstanding voting securities or other interests entitled (without regard to the
occurrence of any contingency) to elect or appoint members of the board of
directors or other managing body of Debtor or any Guarantor (a "change of
control"), or there is any merger, consolidation, dissolution, liquidation,
winding up or sale or other transfer of all or substantially all of the assets
of Debtor or any Guarantor pursuant to which there is a change of control or
cessation of Debtor or the Guarantor or the business of either, provided,
however, that a change of control shall not constitute an Event of Default if
immediately following the change of control, the financial condition and
business prospects of Debtor are, in the reasonable discretion of Secured Party,
at least as favorable as the financial condition and business prospects of
Debtor immediately before the change of control, or (g) any money judgment is
entered or filed against Debtor or any Guarantor in excess of One Million and
00/100 Dollars ($1,000,000.00), or (h) Debtor or any Guarantor shall file a
voluntary petition in bankruptcy, shall apply for or permit the appointment by
consent or acquiescence of a receiver, conservator, administrator, custodian or
trustee for itself or all or a substantial part of its property, shall make an
assignment for the benefit of creditors or shall be unable, fail or admit in
writing its inability to pay its debts generally as such debts become due, or
(i) there shall have been filed against Debtor or any Guarantor an involuntary
petition in bankruptcy or Debtor or any Guarantor shall suffer or permit the
involuntary appointment of a receiver, conservator, administrator, custodian or
trustee for all or a substantial part of its property or the issuance of a
warrant of attachment, diligence, execution or similar process against all or
any substantial part of its property; unless, in each case, such petition,
appointment or process is fully bonded against, vacated or dismissed within
forty-five (45) days from its effective date, but no later than ten (10) days
prior to any proposed disposition of any assets pursuant to any such proceeding,
then, and in any such event, Secured Party shall have the right to exercise any
one or more of the remedies hereinafter provided.

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5. Remedies. Upon the occurrence of an Event of Default (and, if the Event of
Default is as specified in Section 4(a), upon at least five (5) days prior
written notice thereof to Debtor from Secured Party), in addition to all rights
and remedies of a secured party under the Uniform Commercial Code, Secured Party
may, at its option, at any time (a) declare the Indebtedness to be immediately
due and payable; (b) without demand or legal process, enter the premises where
the Collateral may be found and take possession of and remove the Collateral,
all without charge to or liability on the part of Secured Party; or (c) require
Debtor to assemble the Collateral, render it unusable, and crate, pack, ship,
and deliver the Collateral to Secured Party in such manner and at such place in
the State of California as Secured Party may require, all at Debtor's sole cost
and expense. DEBTOR HEREBY EXPRESSLY WAIVES ITS RIGHTS, IF ANY, TO (1) PRIOR
NOTICE OF REPOSSESSION AND (2) A JUDICIAL OR ADMINISTRATIVE HEARING PRIOR TO
SUCH REPOSSESSION. Secured Party may, at its option, ship, store and repair the
Collateral so removed and sell any or all of the Collateral at a public or
private sale or sales, which such sale or sales may be held on the premises
where the Collateral is located. Unless the Collateral is perishable or
threatens to decline speedily in value or is of a type customarily sold on a
recognized market, Secured Party will give Debtor reasonable notice of the time
and place of any public sale thereof or of the time after which any private sale
or any other intended disposition thereof is to be made, it being understood and
agreed that Secured Party may be a buyer at any such sale and Debtor may not,
either directly or indirectly, be a buyer at any such sale. The requirements, if
any, for reasonable notice will be met if such notice is mailed postage prepaid
to Debtor at its address shown above, at least five (5) days before the time of
sale or disposition. After any such sale or disposition, Debtor shall be liable
for any deficiency of the Indebtedness remaining unpaid, with interest thereon
at the rate set forth in the related Notes.

6. Cumulative Remedies/Marshaling. All remedies of Secured Party hereunder are
cumulative, are in addition to any other remedies provided for by law or in
equity, or under any other provision of any of the Loan Documents, or under the
provisions of any other document, instrument or other writing executed by Debtor
or any third party in favor of Secured Party, all of which may, to the extent
permitted by law, be exercised concurrently or separately, and the exercise of
any one remedy shall not be deemed an election of such remedy or to preclude the
exercise of any other remedy. No failure on the part of Secured Party to
exercise, and no delay in exercising any right or remedy, shall operate as a
waiver thereof or in any way modify or be deemed to modify the terms of this
Agreement or any other Loan Document or the Indebtedness, nor shall any single
or partial exercise by Secured Party of any right or remedy preclude any other
or further exercise of the same or any other right or remedy. Secured Party
shall not be under any obligation to marshal any assets in favor of Debtor, any
Guarantor or any other person or against or in payment of any or all of the
Indebtedness.

7. Assignment. Secured Party may transfer or assign all or any part of the
Indebtedness and the Loan Documents without releasing Debtor or the Collateral,
and upon such transfer or assignment the assignee or holder shall be entitled to
all the rights, powers, privileges and remedies of Secured Party to the extent
assigned or transferred. The obligations of Debtor shall not be subject, as
against any such assignee or transferee, to any defense, set off, or
counter-claim available to Debtor against Secured Party and any such defense,
set-off, or counter-claim may be asserted only against Secured Party.

8. Time is of the Essence. Time and manner of performance by Debtor of its
duties and obligations under the Loan Documents is of the essence. If Debtor
shall fail to comply with any material provision of any of the Loan Documents,
Secured Party shall have the right, but shall not be obligated, to take action
to address such non-compliance, in whole or in part, and all moneys spent and
expenses and obligations incurred or assumed by Secured Party shall be paid by
Debtor upon demand and shall be added to the Indebtedness. Any such action by
Secured Party shall not constitute a waiver of Debtor's default.

9. Enforcement. This Agreement shall be governed by and construed in accordance
with the internal laws and decisions of the State of Illinois, without regard to
principles of conflicts of law. At Secured Party's

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election and without limiting Secured Party's right to commence an action in any
other jurisdiction, Debtor hereby submits to the exclusive jurisdiction and
venue of any court (federal, state or local) having situs within the State of
Illinois, expressly waives personal service of process and consents to service
by certified mail, postage prepaid, directed to the last known address of
Debtor, which service shall be deemed completed within ten (10) days after the
date of mailing thereof.

10. Further Assurance; Notice. Debtor shall, at its expense, execute and deliver
such documents and do such further acts as Secured Party may from time to time
reasonably require to assure and confirm the rights created or intended to be
created hereunder, to carry out the intention or facilitate the performance of
the terms of the Loan Documents or to assure the validity, perfection, priority
or enforceability of any security interest created hereunder. Debtor agrees to
execute any instrument or instruments necessary or expedient for filing,
recording, perfecting, notifying, foreclosing, and/or liquidating of Secured
Party's interest in the Collateral upon request of, and as determined by,
Secured Party, and Debtor hereby specifically authorizes Secured Party to
prepare and file Uniform Commercial Code financing statements and other
documents and to execute same for and on behalf of Debtor as Debtor's
attorney-in-fact, irrevocably and coupled with an interest, for such purposes.
All notices required or otherwise given by either party shall be in writing and
shall be delivered by hand, by registered or certified first class United States
mail, return receipt requested, or by overnight courier to the other party at
its address stated herein or at such other address as the other party may from
time to time designate by written notice. All notices shall be deemed given when
received, when delivery is refused or when returned for failure to be called
for. Each provision of this Agreement shall remain in full force and effect
until all of the Indebtedness is fully, finally and indefensibly satisfied and,
notwithstanding anything in this Agreement or implied by law to the contrary,
the agreements of Debtor and Secured Party set forth in Sections 2(p), 2(r),
2(s), 2(t), 9 and 12 shall survive the full, final and indefeasible satisfaction
of the Indebtedness.

11. Joint and Several Obligation. If this Agreement is executed by more than one
person as Debtor, each such Debtor hereby acknowledges it is jointly and
severally liable for and unconditionally guarantees the prompt and full payment
and performance of all obligations of each other Debtor hereunder and under the
other Loan Documents.

12. Waiver of Jury Trial. Debtor and Secured Party hereby waive their respective
rights to a jury trial of any claim or cause of action based upon or arising in
connection with any of the Loan Documents. Debtor and Secured Party acknowledge
that this waiver is a material inducement to enter into a business relationship,
that each has already relied on the waiver in entering into the Loan Documents,
and that each will continue to rely on the waiver in their related future
dealings. Debtor and Secured Party further warrant and represent that each has
reviewed this waiver with its legal counsel and that each knowingly and
voluntarily waives its jury trial rights following consultation with legal
counsel.

13. Complete Agreement. The Loan Documents embody the entire agreement among the
parties hereto superseding all prior commitments, agreements, representations,
and understandings, whether written or oral relating to the subject matter
hereof, and may not be contradicted or varied by evidence of prior,
contemporaneous, or subsequent oral agreements or discussions of the parties
hereto. The Loan Documents may not be altered, modified or terminated in any
manner except by a writing duly signed by the parties thereto. Debtor and
Secured Party intend the Loan Documents to be valid and binding and no
provisions hereof and thereof which may be deemed unenforceable shall in any way
invalidate any other provisions of the Loan Documents, all of which shall remain
in full force and effect. The Loan Documents shall be binding upon the
respective successors, legal representatives, and assigns of the parties. The
Schedules are incorporated herein by this reference and made a part hereof.

IN WITNESS WHEREOF, Secured Party and Debtor have each signed this Agreement as
of the day and year first above written.

HELLER FINANCIAL LEASING, INC.                MICROCIDE PHARMACEUTICALS INC.

A Delaware Corporation                        A Delaware Corporation

By:    /S/ Clifford A. Lehman                 By:    /S/ Matthew J. Hogan
       -----------------------------                 ---------------------------
Title: Senior Vice President                  Title: Chief Financial Officer