EXHIBIT 99.1

ACACIA
RESEARCH
CORPORATION

                                                        Contacts:  Bret L. Undem
                                                                 Media Relations
                                                             Tel. (425) 493-2293
                                                             Fax. (425) 493-2010
FOR RELEASE
- -----------
September 16, 2005

                 COMBIMATRIX GROUP TO RECEIVE $10.5 MILLION FROM
                   ACACIA RESEARCH REGISTERED DIRECT OFFERING


         Newport Beach, Calif. - (BUSINESS WIRE) - September 16, 2005 - Acacia
Research Corporation (Nasdaq: CBMX:ACTG) today announced that it has obtained
commitments to purchase approximately $10.5 million of its Acacia
Research-CombiMatrix common stock in a registered direct offering. Under the
terms of the transaction, Acacia will sell approximately 6.4 million shares of
its Acacia Research-CombiMatrix common stock at $1.65 per share to a select
group of accredited investors and grant to such investors five year warrants for
the purchase of an aggregate of approximately 1.6 million shares of common stock
at an exercise price of $2.40 per share. Piper Jaffray & Co. acted as exclusive
placement agent for the transaction.

         This press release shall not constitute an offer to sell or the
solicitation of an offer to buy nor shall there be any sale of these securities
in any state or jurisdiction in which such offer, solicitation or sale would be
unlawful prior to registration or qualification under the securities laws of any
such state or jurisdiction. The shares of common stock may only be offered by
means of a prospectus. Copies of the prospectus supplement and accompanying base
prospectus can be obtained from Piper Jaffray & Co. at 405 Lexington Avenue,
58th Floor, New York, New York 10174-5899, fax (212) 284.9579.


ABOUT ACACIA RESEARCH COPORATION

Acacia Research Corporation comprises two operating groups: Acacia Technologies
Group and CombiMatrix Group. The CombiMatrix group is developing a platform
technology to rapidly produce customizable arrays, which are semiconductor-based
tools for use in identifying and determining the roles of genes, gene mutations
and proteins. The CombiMatrix's group's technology has a wide range of potential
applications in the areas of genomics, proteomics, biosensors, drug discovery,
drug development, diagnostics, combinatorial chemistry, material sciences and
nanotechnology.

The Acacia Technologies group develops, acquires, and licenses patented
technologies. Acacia controls 33 patent portfolios, which include over 120 U.S.
patents, and certain foreign counterparts, covering technologies used in a wide
variety of industries including audio/video enhancement & synchronization,
broadcast data retrieval, computer memory cache coherency, credit card fraud
protection, database management, data encryption & product activation, digital
media transmission (DMT(R)), digital video production, dynamic manufacturing
modeling, enhanced Internet navigation, high resolution optics, image resolution
enhancement, interactive data sharing, interactive television, hearing aid ECS,
interstitial Internet advertising, laptop docking station connectivity,
microprocessor enhancement, multi-dimensional bar codes, network data storage,
resource scheduling, rotational video imaging and spreadsheet automation.




Acacia Research-Acacia Technologies (NASDAQ: ACTG) and Acacia
Research-CombiMatrix (NASDAQ: CBMX) are both classes of common stock issued by
Acacia Research Corporation and are intended to reflect the performance of the
respective operating groups and are not issued by the operating groups.

Information about the Acacia Technologies Group and the CombiMatrix Group is
available at www.acaciaresearch.com.
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SAFE HARBOR STATEMENT UNDER THE PRIVATE SECURITIES LITIGATION REFORM ACT OF
1995:

THIS NEWS RELEASE CONTAINS FORWARD-LOOKING STATEMENTS WITHIN THE MEANING OF THE
"SAFE HARBOR" PROVISIONS OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF
1995. THESE STATEMENTS ARE BASED UPON OUR CURRENT EXPECTATIONS AND SPEAK ONLY AS
OF THE DATE HEREOF. OUR ACTUAL RESULTS MAY DIFFER MATERIALLY AND ADVERSELY FROM
THOSE EXPRESSED IN ANY FORWARD-LOOKING STATEMENTS AS A RESULT OF VARIOUS FACTORS
AND UNCERTAINTIES, INCLUDING THE ECONOMIC SLOWDOWN AFFECTING TECHNOLOGY
COMPANIES, OUR ABILITY TO SUCCESSFULLY DEVELOP PRODUCTS, RAPID TECHNOLOGICAL
CHANGE IN OUR MARKETS, CHANGES IN DEMAND FOR OUR FUTURE PRODUCTS, LEGISLATIVE,
REGULATORY AND COMPETITIVE DEVELOPMENTS AND GENERAL ECONOMIC CONDITIONS. OUR
ANNUAL REPORT ON FORM 10-K, RECENT AND FORTHCOMING QUARTERLY REPORTS ON FORM
10-Q, RECENT CURRENT REPORTS ON FORMS 8-K AND 8-K/A, AND OTHER SEC FILINGS
DISCUSS SOME OF THE IMPORTANT RISK FACTORS THAT MAY AFFECT OUR BUSINESS, RESULTS
OF OPERATIONS AND FINANCIAL CONDITION. WE UNDERTAKE NO OBLIGATION TO REVISE OR
UPDATE PUBLICLY ANY FORWARD-LOOKING STATEMENTS FOR ANY REASON.