BEDFORD, MA
September 14, 2005

Sionex Corporation, a high technology company focused on commercializing breakthrough chemical and biological sensor chips and systems based on its proprietary microDMxTM detection technology, today announced that it is participating in a consortium which has been awarded a $25 Million grant from the National Institute of Allergy and Infectious Diseases (NIAID) through the National Institutes of Health (NIH).

The consortium, headed by Columbia University Medical Center, has been awarded a major grant to develop new technologies to rapidly screen large numbers of people for radiation exposure in the event of a terrorist attack on a nuclear facility or detonation of a radiological “dirty bomb”.

"We are delighted that our proposed technologies have been selected for this grant to help provide rapid, targeted triage following a radiation event," said David J. Brenner, Ph.D., D.Sc., professor of radiation oncology and public health, Center for Radiological Research, Columbia University College of Physicians and Surgeons. Dr. Brenner is the principal investigator of the consortium.

Over the next five years, the team will develop new devices that can assess, rapidly following a potentially catastrophic radiological incident, the radiation doses received by hundreds of thousands of individuals.

“The role of Sionex in this consortium is to lead the development and commercialization of a handheld device for non-invasive screening for radiation exposure,” said Anthony D. Bashall, VP of Marketing & Business Development at Sionex Corporation. “The device will analyze sweat, urine or saliva samples to detect and identify metabolites which are indicative of radiation exposure. Our proprietary technology is currently being used to detect chemical & biological warfare agents, explosives, toxic compounds and narcotics with low cost handheld or highly portable devices.”

The eight participants involved in the research consortium are: Columbia University Medical Center (lead institution); Harvard University School of Public Health; Arizona State University's Biodesign Institute; the National Cancer Institute; University of Sionex Corporation is a high technology company focused on commercializing breakthrough chemical and biological sensor chips and systems based on its proprietary microDMxTM detection technology.

Pittsburgh Medical Center; Translational Genomics Research Institute; Sionex
Corporation; and the City of New York Department of Health and Mental Hygiene.

About Sionex Corporation
Sionex maintains its worldwide headquarters and laboratories in Bedford, Massachusetts, close to Boston with its commercial, technology and communications infrastructure. The Company is privately held and was founded in 2001 with patented technology exclusively licensed from The Charles Stark Draper Laboratory. Additional information about Sionex Corporation is available at www.sionex.com or by calling 781-457-5400 or fax to 781-457-5399.

Forward-looking Statement
Some statements in this announcement constitute forward-looking statements. Forward- looking statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Sionex Corporation to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. There can be no assurance that the forward-looking statements included in this announcement will prove to be accurate. In light of the significant uncertainties inherent in the forward-looking statements included herein, the inclusion of this information should not be regarded as a representation by the Company or any other person that the objectives and plans of the Company will be achieved.

microDMxTM is a trademark of Sionex Corporation.