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                                                         Contacts:  Rob Stewart
                                                             Investor Relations
FOR RELEASE                                                 Tel (949) 480-8300
- -----------                                                 Fax (949) 480-8301
March 20, 2002

            ACACIA RESEARCH ANNOUNCES PLAN TO CREATE SEPARATE NASDAQ
                  LISTED PUBLIC SHARES FOR ITS COMBIMATRIX AND
                         ACACIA TECHNOLOGIES BUSINESSES

NEWPORT  BEACH,  Calif.  - (BUSINESS  WIRE) - March 20,  2002 - Acacia  Research
Corporation  (NASDAQ:ACRI)  announced  today  that its  Board of  Directors  has
approved  a plan  to  divide  its  common  stock  into  two  new  classes  - new
"CombiMatrix"  stock,  that would  reflect  the  performance  of its  subsidiary
CombiMatrix Corporation, and new "Acacia Technologies" stock, that would reflect
the  performance  of  Acacia's  media  technology  businesses.  The plan will be
submitted to the Company's stockholders for approval.

If the plan is approved,  Acacia Research  stockholders  would receive shares of
both of the new classes of stock in exchange  for the shares they now hold,  and
the new shares would be separately traded NASDAQ listed public securities.

Paul R.  Ryan,  Chairman  and CEO of  Acacia  Research,  said  "We  believe  the
separately  traded shares would increase market awareness of the performance and
value  of our two  distinct  businesses,  increase  investor  interest,  attract
industry-specific   investors   and  better   enable  us  to  pursue   strategic
opportunities.  This is an important step toward realizing the full market value
of our separate businesses."

Acacia also  announced  that its Board of Directors and  CombiMatrix's  Board of
Directors  have  approved  an  Agreement  for  Acacia to  acquire  the  minority
stockholder   interest  in  CombiMatrix.   The  proposed  acquisition  would  be
accomplished through a merger in which the minority  stockholders of CombiMatrix
would  receive  shares of the new  "CombiMatrix"  stock,  in exchange  for their
existing shares. The proposed  transaction will be submitted to the stockholders
of both Companies for approval.

"CombiMatrix  minority  stockholders and Acacia Research stockholders would both
benefit  by  receiving   publicly   traded  NASDAQ  listed  shares  of  the  new
"CombiMatrix"  stock," commented Dr. Amit Kumar, CEO & President of CombiMatrix.
"Both groups of  stockholders  would benefit from the liquidity  provided by the
new "CombiMatrix" stock if the proposals are approved," concluded Dr. Kumar.

A.G. Edwards and Gerard Klauer Mattison are investment  advisors for CombiMatrix
in the merger and William Blair & Co. will advise Acacia Research.

Commenting on this new  structure,  Mr. Ryan stated,  "To maximize the potential
value of our  distinct  businesses,  we are pursuing a financial  and  operating
structure  that will allow our two  businesses  to grow as quickly as  possible.
After reviewing various  alternative  operating  structures,  our Board believes
this targeted approach is optimal for our situation."

Acacia Research's Board of Directors believes the new stock structure can unlock
numerous   benefits  for   stockholders,   achieving  the  following   important
objectives:

     1.   Facilitate  autonomy.  The structure  allows each business to optimize
          its own identity, business strategy and financial model.

     2.   Accommodate investor interests. The structure is designed to serve the
          interests of investors by providing separate  investment  vehicles for
          Acacia's  different  businesses,  particularly  to  the  extent  those
          businesses  operate in different  industry  sectors and have different
          characteristics and goals with respect to timing,  growth,  risks, and
          financial requirements.

     3.   Attract  institutional  research.  The  separate  stocks  would enable
          research coverage by industry specific analysts.

     4.   Targeted stock  ownership.  The structure would enable Acacia Research
          stockholders to have targeted ownership of both "Acacia  Technologies"
          stock and "CombiMatrix" stock.

     5.   Acquisition  currencies.  The Company would have two different  equity
          securities for issuance in connection with any potential acquisitions.

The  proposed  recapitalization  and  merger are  subject  to several  important
conditions,  including  receipt  of  stockholder  approval  for both  companies,
receipt of satisfactory  tax and accounting  opinions,  approval of the proposed
merger by a special committee of the CombiMatrix Board of Directors,  receipt of
a fairness opinion regarding the merger, approval for listing of both of the new
shares on NASDAQ and other customary conditions.

Prior  to the  completion  of the  proposed  transaction,  Acacia  Research  and
CombiMatrix  anticipate  that Acacia  would  convey its  majority  ownership  of
Advanced Material Sciences to CombiMatrix in exchange for CombiMatrix stock.

Acacia Research is preparing to file a preliminary proxy statement with the U.S.
Securities  and  Exchange  Commission,  and the  proposals  are  expected  to be
presented to  stockholders  for approval at a special  meeting.  Proxy materials
will be mailed to stockholders following a registration statement being declared
effective.

This press  release  does not  constitute  an offer of any  security for sale or
solicitation of an offer to buy. Any sale of the securities will be made only by
means of the prospectus included within the registration statement.



ABOUT ACACIA RESEARCH CORPORATION

Acacia Research  develops,  licenses and provides  products for the life science
and  media  technology  sectors.   Acacia  licenses  its  V-chip  technology  to
television  manufacturers  and owns pioneering  technology for digital streaming
and video-on-demand.  Acacia's  CombiMatrix  subsidiary is developing a bio-chip
technology for the life science market.  Acacia Research's website is located at
www.acaciaresearch.com.


ABOUT COMBIMATRIX

CombiMatrix  is  developing  a  platform  technology  that  has a wide  range of
applications,  from DNA  synthesis/diagnostics to immunochemical  detection. The
platform allows the company 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.  The company is  designing  its
products   principally  to  be  responsive  to  the  needs  of   pharmaceutical,
biotechnology,  and academic  researchers  in analyzing  raw genomic data in the
discovery and development of pharmaceutical products.  CombiMatrix's Web site is
located 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 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.