<PAGE>
INCORPORATED UNDER THE LAWS OF THE STATE OF CALIFORNIA
NUMBER ___________ ___________ SHARE(S)
SPECIALTY LABORATORIES, INC.
AUTHORIZED CAPITAL STOCK: 110,000,000 SHARES, NO PAR VALUE
100,000,000 SHARES COMMON STOCK 10,000,000 SHARES PREFERRED STOCK
THESE SHARES ARE SUBJECT TO CERTAIN RESTRICTIONS DESCRIBED ON THE REVERSE HEREOF
THIS CERTIFIES THAT ** SPECIMEN ** IS THE REGISTERED HOLDER OF
______________________________________ SHARES TRANSFERABLE ONLY ON THE BOOKS OF
THE CORPORATION BY THE HOLDER HEREOF IN PERSON OR BY ATTORNEY UPON SURRENDER OF
THIS CERTIFICATE PROPERLY ENDORSED.
IN WITHNESS WHEREOF, THE SAID CORPORATION HAS CAUSED THIS CERTIFICATE TO BE
SIGNED BY ITS DULY AUTHORISDED OFFICERS AND ITS CORPORATE SEAL TO BE HEREUNTO
AFFIXED THIS ____________ DAY OF ____________ A.D._______
[SEAL]
-------------------------------- --------------------------------
DEBORAH A. ESTES SECRETARY PAUL F. BEYER PRESIDENT
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FOR VALUE RECEIVED __________________ HEREBY SELL, ASIGN AND TRANSFER UNTO
PLEASE INSERT SOCIAL SECURITY OR OTHER
IDENTIFYING NUMBER OF ASSIGNEE
_______________________________________________________________________________
_______________________________________________________________________________
(NAME AND ADDRESS OF TRANSFEREE SHOULD BE PRINTED OR TYPEWRITTEN)
________________________________________________________________________ SHARES
REPRESENTED BY THE WITHIN CERTIFICATE AND, IF REQUIRED, DO HEREBY IRREVOCABLY
CONSTITUTE AND APPOINT____________________________ ATTORNEY TO TRANSFER THE SAID
SHARES ON THE BOOKS OF THE WITHIN NAMED CORPORATION, WITH FULL POWER OF
SUBSTITUTION IN THE PREMISES.
DATED__________________________
IN PRESENCE OF ________________________ , ________________________
NOTICE: THE SIGNATURE ON 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.
THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED (THE "ACT"). THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR
HYPOTHECATED IN THE ABSENCE OF A REGISTRAITON STATEMENT IN EFFECT WITH RESPECT
TO THE SECURITIES UNDER SUCH ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE
COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED OR UNLESS SOLD PURSUANT TO RULE
144 OF SUCH ACT.
