The Rapid Detection of Single Bacterial Cells by Deep UV Micro Raman Spectroscopy.
Final rept. 1 Oct 88-31 Dec 91,
RHODE ISLAND UNIV KINGSTON DEPT OF CHEMISTRY
Pagination or Media Count:
A specially-designed micro-Raman spectrograph capable of selectively exciting single bacterial cells has been constructed. Detection limits have been shown to be one bacterial cell. With modest redesign, but with no change in basic technology, sensitivity is sufficient to allow identification of single bacterial cells in a matter of seconds. Live bacteria were immobilized on glass slides by means of 0.1 M polylysine solution. The wet sample was placed on a microscope stage adjusted to maintain a temperature of 0 C. The sample was illuminated by the CW 257 nm output of a Spectra Physics Model 395B argon ion laser cavity extender. Ten percent of the beamless than 3 mw was directed by a beam splitter down the microscope optical axis and focussed onto a 5 micron spot on the sample. A Cassagrain objective focussed the beam and collected the back- scattered resonance Raman light. The Raman-scattered light was analyzed using a Spex Triplemate equipped with a blue-sensitive EG and G OMAII optical multichannel analyzer which was able to obtain a spectrum in 16 microseconds. Best sensitivity required scans of 30-60 seconds. Detection, Identification, Bacteria UV Micro Raman Spectra, Instrumentation