CHAMPAIGN, Ill. -- A new measurement technique that simultaneously can identify and measure more than 30 compounds found in a single cell has been developed by a team of chemists and physiologists at the University of Illinois. The method -- which uses nanoliter sampling, capillary electrophoresis and fluorescence spectroscopy -- is direct, convenient and highly sensitive.
"By combining a nanoliter-volume separation technique with an information-rich spectroscopic detection scheme, we can obtain both qualitative and quantitative chemical information about the target species," said Jonathan Sweedler, a professor of chemistry and a researcher at the university's Beckman Institute for Advanced Science and Technology. "We can therefore more completely identify and measure biologically important compounds in individual cells without performing any chemical reactions to make the compounds detectable."
The measurement technique was developed by Sweedler, graduate research assistant Robert Fuller, physiology professor Rhanor Gillette and visiting scholar Leonid Moroz. The researchers describe the technique in the February issue of the journal Neuron.
"We begin by placing a freshly isolated cell in a microvial where it is homogenized and then drawn into a capillary tube," Fuller said. "The chemicals then separate in the capillary by electrophoresis and move into a flow cell where they are stimulated by a laser. The laser-induced fluorescence is then collected by a CCD/spectrograph and analyzed by a computer.
"We can identify compounds not only by the separation time, but also by the spectral fingerprints in the fluorescence emission," Fuller said. "This means we are able to distinguish between compounds that migrate at the same time, thereby avoiding potential misidentification."
In addition, because the detection scheme is based upon the native fluorescence
of individual molecules, the researchers need not perform any additional
'"/>
Contact: James E. Kloeppel, Physical Sciences Editor
kloeppel@uiuc.edu
217-244-1073
University of Illinois at Urbana-Champaign
2-Mar-1998