title: Spectral changes of the fluorescent acriflavine--(Feulgen) DNA dye complex at different temperatures: application of a new cryostat for measurements in reflected and transmitted light.
abstract: The fluorometric behaviour of cellular objects is influenced during excitation by two nearly independent phenomena: (1) by the photochemical reaction of the DNA/AF dye complex, and (2) by the energy transfer among several DNA/AF dye complexes. Both processes show a distinct temperature-dependent behaviour and can therefore be characterized by the analysis of the fluorescence spectra at different temperatures. All microfluorometric measurements were performed with a self-constructed cooling device. The cryostat permits measurements of the cellular fluorescence within a range of temperatures between 4 K and 300 K. The cooling unit operates in accordance with the 'Continuous Flow Principle' and allows the application of objectives up to a numerical aperture of 0.6.
mesh_terms: D000166:Acridines; D000167:Acriflavine; D003080:Cold Temperature; D004247:DNA; D005456:Fluorescent Dyes; D005470:Fluorometry / Q000379:methods*; D008027:Light; D008853:Microscopy / Q000295:instrumentation; D013050:Spectrometry, Fluorescence / Q000379:methods; D013696:Temperature; D013821:Thermometers
chemical_list: D000166:Acridines; D005456:Fluorescent Dyes; D000167:Acriflavine; D004247:DNA