Intensities of E. coli nucleic acid Raman spectra excited selectively fromwhole cells with 251-nm light

Escherichia coli bacteria in the logarithmic growth phase have been investi gated by UV resonance Raman spectroscopy. Bacterial whole-cell Raman spectr a excited at 251 mm reflect nearly exclusively the nucleic acid composition even though a very large fraction of the bacterial mass is composed of pro tein. It has been demonstrated that if bacteria are grown under controlled (logarithmic growth) conditions, which give rise to organisms of known aver age biochemical composition, the intensities off. coil Raman spectra can be explained quantitatively from the knowledge of component nucleic acid base resonance Raman cross sections.