EDITORS: Black-and-white photograph is available on request.

ANN ARBOR---University of Michigan researchers have found a way to monitor changes in the biochemistry of living cells by shooting the cells full of PEBBLEs.

Made of polymers, instead of stone, PEBBLEs (Probes Encapsulated By BioListic Embedding) are the smallest biosensors ever developed, according to Raoul Kopelman, the U-M's Kasimir Fajans Professor of Chemistry, Physics and Applied Physics. They were designed to work inside mammalian cells where they can detect subtle changes in concentrations of ions and small molecules.

"PEBBLEs are self-contained sensors powerful enough to detect even slight changes in cell biochemistry, but small enough to avoid damaging the cell," said Heather Clark, a U-M graduate student in chemistry. Clark is part of a U-M team currently developing and testing the biosensing devices in a research project funded by the U.S. Defense Advanced Research Projects Agency (DARPA).

Clark will present results from her research this week in a presentation at PITTCON '98, the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, taking place in New Orleans.

"For the first time, we can observe real-time chemical processes inside a living cell," said Kopelman. "The goal of the DARPA project is to learn what happens inside the cell when it is exposed to neurotoxic agents. If we can learn exactly how these toxins trigger a flood of ions in and out of cells, we may be able to speed up development of antidotes or countermeasures for lethal biological warfare agents."

Kopelman added that the ability to "watch what's happeni
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Contact: Sally Pobojewski
pobojewski@umich.edu
(734) 647-1844
University of Michigan
2-Mar-1998