[ABS letterhead]



Scientific Contact:                          Media and Investor
Contact:
Emer Leahy, Ph.D.                            Jeffrey Davis
Senior Vice President, Business Development  StartUp Solutions LLC
(516) 789-2600                              (212) 554-4158  
Fax: (516) 789-1661                         Fax: (212) 554-4058
eleahy@mabxa.com                             JBDx1@aol.com


AMERICAN BIOGENETIC SCIENCES, INC. ACQUIRES STELLAR BIO SYSTEMS, INC.,
        A MANUFACTURER OF IMMUNODIAGNOSTIC KITS AND REAGENTS

Copiague, New York - April 27, 1998 - American Biogenetic
Sciences, Inc. (ABS)(NASDAQ:MABXA)  today announced that it has
acquired Stellar Bio Systems, Inc. (Stellar) for an initial
payment of $700,000 in stock and $120,000 in cash.  ABS will make
additional payments of up to $650,000 in stock over the next
three years, should Stellar achieve its aggressive sales
projections. Stellar, based in Columbia, Maryland, is a
manufacturer of immunodiagnostic kits and reagents.  For
the year ended December 31, 1997, Stellar was profitable on
revenues of $1.4 million.

The acquisition brings a number of major benefits that will help
ABS expand its diagnostic business. Stellar provides
immunodiagnostic tests and access to potential new distribution
channels and customers for ABS' Thrombus Precursor Protein (TpP )
and Functional Intact Fibrinogen (FiF ) diagnostic products. 
Stellar also provides contract services in the development,
process scale-up, production and purification of monoclonal and
polyclonal antibodies in an FDA registered 16,000 sq. ft.
facility. In addition Stellar's contract services could be
greatly enhanced with ABS' Antigen Free technology which has the
capability to generate monoclonal antibodies unattainable by
conventional means.

Under the terms of the Agreement, the upfront payments consist of
$700,000 shares of common stock and $120,000 in cash.  Additional
milestone payments of up to $650,000 will be made in stock over
the next three years should Stellar achieve its sales targets
while maintaining profitability.  The number of shares to be
issued in milestone payments will be determined by the price per
share on the respective anniversary date.

Commenting on the acquisition, Alfred J. Roach, Chairman and CEO
of ABS said, "The acquisition of Stellar is an important move for
ABS as we strategically position the Company to become a leader
in high affinity monoclonal antibody production with a growing
diagnostic business.  There are numerous operational and
technical synergies between our two companies which will enable
us to develop and expand our business.  Most importantly, the
acquisition  significantly increases ABS' marketing and
distribution capability through the addition of leading
distributors in several countries."

John Brewer, President and CEO of Stellar said, "We at Stellar
are very pleased to be a part of a larger growing company.  ABS
provides unique proprietary diagnostic products and Antigen Free
technology with the capability of generating high affinity
monoclonal antibodies.  Stellar provides menus of
immunodiagnostic tests and reagents, a modern FDA registered
manufacturing and research facility and an international
distribution network.  Together our growth potential is
significantly enhanced."

American Biogenetic Sciences, Inc., has a fully integrated
diagnostic business to develop and commercialize proprietary
diagnostic tests; and a neurobiology initiative to develop
therapeutic compounds for the treatment of serious neurological
conditions.  ABS also conducts research and development
throughout its Global Scientific Network  in the U.S., Europe,
Israel and Russia.  

Statements in this release that are not strictly historical are
"forward-looking" statements within the meaning of Private
Securities Litigation Reform Act of 1995, and should be
considered as subject to various risks and uncertainties that
could cause actual results to differ materially from those
anticipated.  Specifically, the ability of each business to
synergistically enhance the other may not materialize and the
acquired business may not maintain profitability going forward
due to increased costs and/or decreased market revenues due to
reduced market penetration or the emergence of increasing
competition.  For further details and a discussion of these risks
and uncertainties, see the Company's Securities and Exchange
Commission filings, including the Company's Annual Report or Form
10-K. 

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