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                                                                     EXHIBIT 4.2

VLG

INCORPORATED UNDER THE LAWS
OF THE STATE OF DELAWARE

SEE REVERSE FOR CERTAIN DEFINITIONS

This Certifies that

is the record holder of

FULLY PAID AND NONASSESSABLE SHARES OF COMMON STOCK, $.001 PAR VALUE, OF
VIROLOGIC, 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

CORPORATE SECRETARY

CHIEF EXECUTIVE OFFICER



COUNTERSIGNED AND REGISTERED:
AMERICAN STOCK TRANSFER & TRUST COMPANY
TRANSFER AGENT
AND REGISTRAR,

BY



AUTHORIZED OFFICER
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The Corporation will 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 though they were written out in full
according to applicable laws or regulations:

- as tenants in common

- as tenants by the entireties

- as joint tenants with right of survivorship and not as tenants in common

UNIF GIFT MIN ACT_..........................Custodian...........................
                                                                (Cust)

(Minor)
                                            under Uniform Gifts to Minors
                                            Act.................................
 .......................
(State)

UNIF TRF MIN ACT_...........................Custodian (until age.............)
                                                         (Cust)

                                            .......................under Uniform
Transfers
                                                              (Minor)

                                 to Minors

Act.........................................

(State)

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

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.