Negative Covenant Pledge Agreement

LEASE MANAGEMENT SERVICES, INC. EXHIBIT 10.29


NEGATIVE COVENANT PLEDGE AGREEMENT


Agreement made and entered into as of this 29 day of September 1997, by and between Aurora Biosciences Corporation, a Delaware Corporation, with its principal place of business at 1149 N. Torrey Pines Road, La Jolla, CA 92037 ("Pledgor") and LEASE MANAGEMENT SERVICES, INC., a California Corporation, with its principal place of business at 2500 Sand Hill Road, Suite #101, Menlo Park, CA 94025 ("Pledgee").


In consideration of, and as an inducement for Pledgee to enter into Master Lease Agreement Number 10494, Schedules 07 and subsequent, and Equipment Financing Agreement Number 10794, Schedules 14 and subsequent, (referred to hereinafter as the "Agreements") with Pledgor, and to secure the payment and performance of all Pledgor's obligations under the Agreements, Pledgor and Pledgee agree as follows:


1) If at any point in time from the date of this Agreement, Pledgor's
Unrestricted Cash (as defined below) falls below the greater of
$8,000,000 or 9 months' cash needs (defined as the cash burn for the 3
months just completed, multiplied by a factor of 3.3), or Pledgor is in
default of the Agreements, Pledgor will provide to Pledgee within ten
(10) days of such occurrence a cash security deposit in an amount equal
to fifteen percent (15%) of the total aggregate Equipment cost
(including any soft costs) which are financed under the Agreements
("Collateral Pledge"), but in no event to exceed the remaining gross
receivable.


Unrestricted Cash shall be defined as cash on hand, including
investments in marketable securities with maturities of less than one
(1) year, less all long-term debt which is not subordinated to Pledgee.


The failure to timely provide the Collateral Pledge to Pledgee shall
constitute an event of default under the Agreements.


2) Pledgor agrees to provide quarterly financial statements, including a
balance sheet, statement of operations, and cash flow statement, to
Pledgee within 45 days of each quarter end and an audited annual
statement within 120 days of Pledgor's fiscal year end. All such
statements are to be prepared using generally accepted accounting
principles and are to be in compliance with SEC requirements. Failure to
provide these statements as specified herein will constitute an event of
default under the Agreements.


Additionally, at any time that Pledgor's Unrestricted Cash is several
months from falling below the benchmark above, Pledgor's Chief Financial
Officer or other senior officer will, at Pledgee's request, provide
Pledgee with the monthly closing cash balance by not later than the 10th
business day following each month-end.


3) Pledgor agrees to keep all Unrestricted Cash within the following
financial institutions:


Financial Instit ...