CombiMatrix Announces First Commercially Available Microarray for ``Bird Flu'' Influenza A Virus.

Business Editors/Health/Medical Writers

BIOWIRE2K

NEWPORT BEACH, Calif.--(BUSINESS WIRE)--Jan. 29, 2004

Acacia Research Corporation (Nasdaq:CBMX) (Nasdaq:ACTG) announced today that its CombiMatrix group has made commercially available the first microarray designed for the H5N1 "Bird Flu" influenza A virus.

The World Health Organization (WHO) appealed Tuesday, Jan. 27th for technical assistance and expert advice to help stop the threat to humans and agriculture posed by this virus. CombiMatrix utilized its proprietary probe-design software and ability to rapidly synthesize novel DNA microarrays to respond within two days.

CombiMatrix's microarray allows for the identification of the H5N1 virus, and importantly, also allows the tracking of mutations that can occur in its genetic makeup as it goes through patterns of bird and human infection.

Bird Flu is a member of the influenza A virus family, the same family responsible for the 1918 influenza pandemic, which killed 20-40 million people. According to Dr. Amit Kumar, President and CEO of CombiMatrix, "Mutations in the genetic makeup of this family of influenza viruses have in the past greatly affected infectiousness and lethality of individual strains. Our microarray, with its ability to help track such mutations, may be of assistance in dealing with this virus and its impact upon public health. Similar to our efforts with the SARS virus, this new array demonstrates our ability to rapidly respond to emerging diseases."

ABOUT ACACIA RESEARCH CORPORATION

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 active biochips, which are semiconductor-based tools for use in identifying and determining the roles of genes, gene mutations and proteins. CombiMatrix's technology has a wide range of applications including DNA synthesis/diagnostics, siRNA synthesis, drug discovery, and immunochemical detection. CombiMatrix provides DNA arrays to researchers under the CustomArray(TM) brand.

CombiMatrix's Express Track(sm) drug discovery program is a systems biology approach, using its technology, to target common viral diseases with siRNA compounds. The initial focus of Express Track(sm) includes the following viral diseases:

Virus                                 Collaborator
-----                                 ------------
SARS                                  NIAID/USAMRIID
HIV type 1                            irsiCaixa-Dr. Bonaventura Clotet

HIV type 2                            To Be Announced
West Nile virus                       To Be Announced
Human Papillomavirus type 16          To Be Announced
Human Herpes 8 (Kaposi's sarcoma)     To Be Announced
Smallpox (Variola)                    To Be Announced
Influenza virus A                     To Be Announced
Influenza virus B                     To Be Announced
Hepatitis C                           To Be Announced

CombiMatrix is also establishing applications of its arrays through
other partnerships as follows:

Project                          Collaborator
-------                          ------------
Cancer Diagnosis  (Lymphoma)     University of Washington/
                                 Rational Diagnostics
RNA Drug Targets                 Professor Gregory L. Verdine,
                                 Harvard University

Parasite
--------
Leishmania                       Seattle Biomedical Research Institute
Trypasonoma                      Seattle Biomedical Research Institute

The Acacia Technologies group licenses its Digital Media Transmission (DMT) technology to media and electronics companies. The DMT technology covers the transmission and receipt of digital audio and digital video content, commonly known as audio on-demand, video on-demand, and audio/video streaming, and is supported by 5 U.S. and 31 foreign patents.

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 Acacia Research Corporation and the Acacia Technologies group is available at www.acaciaresearch.com. Information about the CombiMatrix group is available at www.combimatrix.com.

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 recent 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.