title: Fluorescence lifetime distributions of DNA-4',6-diamidino-2-phenylindole complex.
abstract: Time-resolved fluorescence of 4',6-diamidino-2-phenylindole (DAPI) complexes show that for a homogeneous polymer (polyd(AT) or polyd(A).polyd(T)) at high P/D (phosphate/dye) ratio, a single exponential component adequately describes the fluorescence decay. For the AT polymers at low P/D ratio or for native DNA, the decay cannot be described by a single-exponential term. A continuous distribution of lifetime values of Gaussian shape gives a good fit to the decay data. We propose that the lifetime distribution method for the analysis of the fluorescence decay of DNA-DAPI complexes provides a useful method of characterizing the microheterogeneity of site binding.
authors.affiliation: Instituto di Chimica Biologica, Università di Catania, Italy.
authors.forename: M L
authors.initials: ML
authors.lastname: Barcellona
authors.forename: E
authors.initials: E
authors.lastname: Gratton
mesh_terms: D004247:DNA / Q000378:metabolism*; D005456:Fluorescent Dyes; D007211:Indoles / Q000378:metabolism*; D007700:Kinetics; D011067:Poly dA-dT / Q000378:metabolism; D011089:Polydeoxyribonucleotides / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D007211:Indoles; D011089:Polydeoxyribonucleotides; D011067:Poly dA-dT; C019530:poly(dC-dG); C007293:DAPI; D004247:DNA