title: The fluorescence decay kinetics of in vivo chlorophyll measured using low intensity excitation.
abstract: We report fluorescence lifetimes for in vivo chlorophyll a using a time-correlated single-photon counting technique with tunable dye laser excitation. The fluorescence decay of dark-adapted chlorella is almost exponential with a lifetime of 490 ps, which is independent of excitation from 570 nm to 640 nm. Chloroplasts show a two-component decay of 410 ps and approximately 1.4 ns, the proportion of long component depending upon the fluorescence state of the chloroplasts. The fluorescence lifetime of Photosystem I was determined to be 110 ps from measurements on fragments enriched in Photosystem I prepared from chloroplasts with digitonin.
mesh_terms: D002708:Chlorella / Q000187:drug effects / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism*; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism; D003624:Darkness; D004237:Diuron / Q000494:pharmacology; D007700:Kinetics; D008027:Light; D008274:Magnesium / Q000494:pharmacology; D013050:Spectrometry, Fluorescence
chemical_list: D002734:Chlorophyll; D004237:Diuron; D008274:Magnesium