<PAGE>
COUNTERSIGNED AND REGISTERED:
CHASEMELLON SHAREHOLDER SERVICES, L.L.C.
BY TRANSFER AGENT AND REGISTRAR
AUTHORIZED SIGNATURE
NUMBER SHARES
AGN [LOGO] AEROGEN
AEROGEN, INC
INCORPORATED UNDER THE LAWS
OF THE STATE OF DELAWARE SEE REVERSE FOR CERTAIN
DEFINITIONS
CUSIP 007779 10 1
This Certifies that
is the record holder of
FULLY PAID AND NONASSESSABLE SHARES OF COMMON STOCK, $0.001 PAR VALUE, OF
---------------------------------- -------------------------------
---------------------------------- AEROGEN, INC. -------------------------------
---------------------------------- -------------------------------
transferable on the books of the Corporation by the holder hereof in person
or by duly authorized attorney upon surrender of this certificate properly
endorsed. This certificate is not valid until countersigned by the Transfer
Agent and registered by the Registrar.
WITNESS the facsimile seal of the Corporation and the facsimile
signatures of its duly authorized officers.
Dated:
/s/ Carol Gamble [SEAL] /s/ Jane E. Shaw
Secretary Chairman and Chief Executive Officer
<PAGE>
The Corporation shall furnish without charge to each stockholder who so
requests a statement of the powers, designations, preferences and relative,
participating, optional, or other special rights of each class of stock of
the Corporation or series thereof and the qualifications, limitations or
restrictions of such preferences and/or rights. Such requests shall be made
to the Corporation's Secretary at the principal office of the Corporation.
The following abbreviations, when used in the inscription on the face of
this certificate, shall be construed as through they were written out in full
according to applicable laws or regulations:
<TABLE>
<S> <C>
TEN COM - as tenants in common UNIF GIFT MIN ACT-..................Custodian...............
TEN ENT - as tenants by the entireties (Cust) (Minor)
JT TEN - as joint tenants with right of Under................Uniform Gifts to Minors Act
survivorship and not as tenants (State)
in common
</TABLE>
Additional abbreviations may also be used though not in the above list.
For Value Received, _____________________________ hereby sell(s), assign(s)
and transfer(s) unto
PLEASE INSERT SOCIAL SECURITY OR OTHER
IDENTIFYING NUMBER OF ASSIGNEE
---------------------------------------
---------------------------------------
------------------------------------------------------------------------------
(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)
------------------------------------------------------------------------------
------------------------------------------------------------------------------
----------------------------------------------------------------------- Shares
of the common stock represented by the within certificate, and do hereby
irrevocably constitute and appoint
---------------------------------------------------------------------- Attorney
to transfer the said stock on the books of the within named Corporation with
full power of substitution in the premises.
Dated ___________________
X _____________________________________
X _____________________________________
NOTICE: THE SIGNATURE TO THIS ASSIGNMENT
MUST CORRESPOND WITH THE NAME AS
WRITTEN UPON THE FACE OF THE
CERTIFICATE IN EVERY PARTICULAR,
WITHOUT ALTERATION OR ENLARGEMENT OR
ANY CHANGE WHATEVER.
Signature(s) Guaranteed
By__________________________________________
THE SIGNATURE(S) MUST BE GUARANTEED BY AN
ELIGIBLE GUARANTOR INSTITUTION (BANKS,
STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS
AND CREDIT UNIONS WITH MEMBERSHIP IN AN
APPROVED SIGNATURE GUARANTEE MEDALLION
PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15.
