Molecular Devices Corp. has developed a new biosensor systemthat allows scientists to measure physiological responses inliving cells.

Because the system can measure interactions between virtuallyany compound and its cellular receptor, company scientists saidit will lead to a better understanding of cell metabolism and tomore rapid drug development.

Molecular Devices plans to introduce the instrument, called aSilicon Microphysiometer, later this year, said Kim Mulcahy,project manager.

"The philosophy behind the Microphysiometer is that if youpluck a cell's biochemical steady-state, you will see a ripplingeffect," said company scientist Dr. John Owicki. "This means thatwith the proper signal-to-noise ratio and time resolution youshould be able to see any physiological change."

The Microphysiometer uses the company's silicon-based LAP(light-addressable potentiometer) sensor technology to detect achange in the acidity of the media surrounding the cells understudy. Only about 1,000 cells are needed to detect a signal.

This single method can be used to rapidly detect any functionalchanges in a cell's environment, said Owicki.

The company has used the instrument to study neurologicaland immunological cell responses with great success, saidOwicki. The researchers, working with Stanford Universityscientists, have detected short- and long-term effects ofcompounds on nerves deprived of oxygen, such as might occurafter a stroke or heart attack.

The assays can be as short as 30 seconds, compared withtraditional tests that take at least 24 hours to complete, saidOwicki. The instrument can also monitor physiological changesin living cells for up to six days.

Owicki predicted that one of the best uses of the instrumentwill be to identify compounds that interact with receptors ofknown sequence but unknown function. Molecular Devices hasa collaboration with University of Oregon Health SciencesCenter to study dopamine receptors, he said.

Molecular Devices also has a collaboration with Biospan Corp. ofRedwood City, Calif., to identify drugs to treat autoimmunediseases, said Molecular Devices scientist Dr. H. Garrett Wada.The effort has already shown that specific protein complexesaffect the behavior of T cells, white blood cells that direct theimmune response. The Microphysiometer allows researchers torapidly measure T cell activation responses rather than wait upto two days to see if a compound can induce T cell growth, saidWada.

Molecular Devices said the Microphysiometer will havenumerous other uses in toxicology, microbiology and thedevelopment of anti-cancer and anti-viral drugs.

The privately held Menlo Park, Calif., company expects to beginsales in January, said Mulcahy. The machines will be priced toattract academic and other research institutions, which makeup 80 percent of the potential users, she said.

-- Carol Talkington Verser, Ph.D. Special to BioWorld

(c) 1997 American Health Consultants. All rights reserved.

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