Comparative Intrinsic and Enhanced Total Photoluminescence of Endospore Material

摘要

Two techniques are compared using total luminescence spectroscopy to detect endospore material in preparations equivalent to 3.0 X 10~5 / ml spores. The first method applied intrinsic, steady-state photoluminescence for detection. The second approach used a binding fluorochrome derived from 4-p-dimethylaminostyrylpyridinium (DASP) to signal the presence of spore material. Comparative fluorescence emission signatures (excited at 469 nm) showed greater calibrated signal recovery (4 X 10~6 cps) for spore material at longer wavelengths using DASP. The intrinsic fluorescence emission of endospores (excited at 346 nm) occurred at shorter wavelengths and showed a reduced calibrated intensity (1.4 X 10~5 counts per second (cps). One major advantage of DASP appears to be its longer wavelength excitation (469 nm) that is out of the range of associated biological materials that compete for absorption at shorter UV wavelengths.