Fluorescence lifetime distributions of DNA-4',6-diamidino-2-phenylindole complex.
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.
Barcellona
M L
ML
Instituto di Chimica Biologica, Università di Catania, Italy.
Gratton
E
E
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
D005456:Fluorescent Dyes; D007211:Indoles; D011089:Polydeoxyribonucleotides; D011067:Poly dA-dT; C019530:poly(dC-dG); C007293:DAPI; D004247:DNA