The Rapid Identification of Bacteria Using Time-Resolved Fluorescence and Fluorescence Excitation Spectral Methods

Time-resolved fluorescence spectra have been obtained for Escherichia coli, Pseudomonas fluorescens, Staphylococcus epidermidis, and Enterobacter cloacae. Pseudomonas fluorescenshas been shown to have distinctly different time-resolved spectra. Fluorescence excitation spectra for the three other organisms showing similar time-resolved spectra are very nearly alike, while spectra of Pseudomonas fluorescensare markedly different. This suggests that the changes in the average fluorescence lifetime with emission wavelength are due to the separate contributions from fluorophores of distinctly different lifetimes which have emission maxima at different wavelengths.