Press Release

Discovery Partners International, Inc. to Acquire Xenometrix, Inc.

DPII Strengthens its Gene Expression Profiling Capabilities

SAN DIEGO--(BW HealthWire)--Feb. 28, 2001--Discovery Partners International Inc.
(Nasdaq:DPII  - news)  announced  today that it has  entered  into a  definitive
agreement to acquire Xenometrix, Inc. (OTCBB:XENO.OB - news), a company that has
proprietary  gene  profiling   technology.   Xenometrix's   technology  provides
important  efficacy  and  safety  data  with  regard to a  compound's  potential
therapeutic  and toxic  effects,  allowing  scientists  to  streamline  the drug
development process, according to Riccardo Pigliucci, Chief Executive Officer of
Discovery Partners.

Under  the  terms of the  agreement,  Discovery  Partners  will  acquire  all of
Xenometrix's  common stock for $0.59 cash per Xenometrix share.  Xenometrix will
become a wholly owned subsidiary of Discovery Partners.  The transaction,  which
has been  approved by the Boards of Directors of both  companies,  is subject to
approval by Xenometrix  stockholders  and customary  closing  conditions  and is
expected to close in the second quarter of this year.

Xenometrix  holds a strong patent  portfolio for its gene profiling  technology,
which  Discovery  Partners will be able to leverage.  In particular,  Xenometrix
shares  ownership of some patents with Harvard  University  and has an exclusive
worldwide license to Harvard's ownership interests in the intellectual property.
Xenometrix has granted  non-exclusive  licenses to over twenty companies who are
leaders  in  different  aspects  of  genomics  including:   Affymetrix,   Aurora
Biosciences,  Corning, Gene Logic,  GeneTrace,  Genometrix,  Genzyme,  Motorola,
Packard,  Pfizer,  Phase-1,  Rosetta  Inpharmatics  and SmithKline  Beecham.  In
addition  to gene  profiling  technology,  Discovery  Partners  gains  exclusive
licenses  to  the  technology  that  enables  high   throughput   screening  for
genotoxicity from GeneBioMed, Inc. and the University of California, Berkeley.

"The  Xenometrix   acquisition  broadens  and  complements  our  in-vitro  assay
development   and   toxicology   services,"   Pigliucci   said.   "Incorporating
Xenometrix's   capabilities  into  Discovery  Partners'  lead  optimization  and
chemistry  services will allow  scientists to determine  which drug  development
candidates have the best  combination of desirable  characteristics.  Properties
such  as  pharmacological  activity,  potency,   selectivity  and  side  effects
determine economic and commercial  feasibility,  and this technology complements
our services  throughout the drug discovery process.  In addition,  Xenometrix's
assays can be readily  modified into our  automated  high  throughput  screening
process and the information incorporated into our bioinformatics databases."

The  acquisition  of  Xenometrix  strengthens  Discovery  Partners'  offering of
technologies,  products and services in segments of the drug  discovery  process
which  already  include  discovery   chemistry,   medicinal   chemistry,   assay
development,  high throughput screening and informatics. In addition,  Discovery
Partners will hold a founding  patent  position in and will build upon the field
of gene profiling and in-vitro predictive toxicology.

"Xenometrix's   technology  not  only  enhances  Discovery   Partners'  existing
screening and lead optimization  services, but Discovery Partners' commitment to
be the best provider maximizes the potential of gene profiling in all aspects of
drug  discovery  and  development,"  said Dr.  Pauline Gee,  President and Chief
Executive  Officer of  Xenometrix.  "Our assays  permit the  measurement  of the
activity of genes,  biomarkers  or targets,  in human cells  cultured to closely
approximate the physiology of a whole cell,  without losing the  practicality of
high throughput screening. Understanding the patterns of gene activity increases
the probability of bringing better drugs to market faster."

Discovery  Partners  International,  Inc.  is  focused  on  providing  the  best
platforms,  services and  information  available to complement the internal drug
discovery  efforts of  pharmaceutical  and  biopharmaceutical  companies  in the
post-genomic  era. The  Company's  comprehensive  and  integrated  suite of drug
discovery  services  currently  includes  combinatorial  chemistry  products and
technologies,  high output medicinal  chemistry services,  industrialized  ultra
high throughput screening services and informatics. DPII is headquartered in San
Diego, California and has operations in San Diego, South San Francisco,  Tucson,
AZ,  Closter,  NJ and Basel,  Switzerland.  For more  information  on  Discovery
Partners   International,   Inc.,   please  visit  the   company's   website  at
http://www.discoverypartners.com.

Statements  in  this  press  release  that  are  not  strictly   historical  are
"forward-looking"  statements  within  the  meaning  of the  Private  Securities
Litigation Reform Act of 1995 and involve a high degree of risk and uncertainty.
The Company's  actual results may differ  materially from those projected in the
forward  looking  statements  due to risks and  uncertainties  that exist in the
Company's operations,  development efforts and business  environment,  including
integration  of  acquired  businesses,  the trend  toward  consolidation  of the
pharmaceutical industry, quarterly sales variability,  technological advances by
competitors,  and other  risks and  uncertainties  more fully  described  in the
Company's Form S-1 registration statement as declared effective on July 27, 2000
by the Securities and Exchange Commission.

Contact:

Discovery Partners International, Inc.
Riccardo Pigliucci, 858/552-3639
or
Xenometrix, Inc.
Pauline Gee, 303/447-1773
or
Mentus, Inc
Linda Seaton, 858/455-5500 ext.133 (Media)
lcs@mentusonline.com