Resonance Raman Spectra of Aqueous Pollen Suspensions with 222.5–242.4-nm Pulsed Laser Excitation

Excitation of resonance Raman spectra with wavelengths shorter than 257 nm, i.e., deep UV-excited resonance Raman spectroscopy, has been shown to have major advantages. This has been most apparent in the study of relatively simple biologically important molecules which have electronic transitions in the deep UV. Recently, such techniques have been extended in order to study much more complex systems such as whole bacterial cells and viruses. A variety of molecular components can be excited selectively and sensitively to a degree dependent upon the exciting wavelength. In this laboratory our primary emphasis has been on the investigation of the bases for the development of analytical methods aiding the rapid detection and identification of bacteria. A variety of taxonomic markers have been detected which allow rapid bacterial identification at the genus and perhaps even the species level. Most recently, it has been shown to be possible to determine bacterial G+C/A+T base pair molar ratios from bacterial spectra independent of cultural conditions or growth rates.