In the U.S., schizophrenia affects more than 2 million people each year, and more than 20 million people suffer from depression. Although many therapeutic options are available for patients suffering from these conditions, for some patients the side effects of drug therapy can range from unpleasant to life-threatening. Determining optimal drug regimens and dosing strategies are challenges that are currently addressed by trial-and-error prescribing practices. Side effects may be caused by a variety of factors, including variations in genes that are targets of the drugs or are involved in drug response. In addition to the negative effect on an individual's health, significant direct and indirect costs are associated with these adverse drug responses.

"We are optimistic that Nanogen's partnership with Pathway Diagnostics will result in exciting products that will contribute to more personalized medical treatments," said Howard C. Birndorf, Nanogen's chairman of the board and CEO. "Because our NanoChip(R) platform can simultaneously analyze multiple genetic markers, we have the capability to develop a diagnostic panel to detect these newly licensed genetic variations, along with genes in the cytochrome P450 family that are related to drug metabolism, in order to allow the physician to prescribe the right drug at the right dosage."

"We are committed to developing novel biomarkers that will improve the quality of health care," said Sanford S. Zweifach, CEO of Pathway Diagnostics. "This agreement with Nanogen represents an important milestone for our company as we work with commercial partners to convert our proprietary assays into diagnostic products."

About Nanogen, Inc.

Nanogen's advanced diagnostics provide physicians and patients worldwide with sophisticated information to predict, diagnose and treat disease. Research and clinical reference labs use the highly accurate and reliable NanoChip(R) Molecular Biology Workstation, NanoChip(R) Electronic Microarray and broad suite of analyte specific reagents to develop tests to detect infectious diseases, drug toxicity and mutations associated with cancer, cardiovascular and genetic diseases. The next generation instrument system, the NanoChip(R) 400, is expected to be available in 2005. Nanogen's subsidiary SynX offers a line of point-of-care diagnostic tests and is building expertise in cardiac related health conditions. Nanogen's ten years of pioneering research involving nanotechnology may also have future applications in medical diagnostics, biowarfare and other industries. For additional information please visit Nanogen's website at www.nanogen.com.

About Pathway Diagnostics

Pathway Diagnostics develops and commercializes novel, proprietary biological markers. The company in-licenses proprietary biomarkers, develops them into validated assays, offers the assays as part of its clinical trials testing service, and commercializes them as diagnostic tests in partnerships with leading diagnostics manufacturers and national laboratories. More information is available at www.pathwaydx.com.

SOURCE Nanogen, Inc.

Robert Saltmarsh, Chief Financial Officer of Nanogen, Inc., +1-858-410-4600; or Bart
Thielen, Chief Financial Officer of Pathway Diagnostics Corporation, +1-310-774-3560