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Quantitation of ultraviolet radiation-induced cyclobutyl pyrimidine dimers in DNA by video and photographic densitometry

1990; Elsevier BV; Volume: 186; Issue: 2 Linguagem: Inglês

10.1016/0003-2697(90)90070-p

1096-0309

S. Freeman, Bryan D. Thompson,

Advanced biosensing and bioanalysis techniques

We have compared video and photographic methods for calculating the number of ultraviolet radiation (uv)-induced pyrimidine dimers in DNA from the bacteriophage T7 exposed to uv (0 to 800 J/m2) from an FS40 sunlamp. DNA was incubated with a pyrimidine dimerspecific Micrococcus luteus uv endonuclease, subjected to alkaline agarose gel electrophoresis, neutralized, and stained with ethidium bromide, and the DNA fluorescence was recorded either with a video camera or on photographic film. The slopes of the dose-response curves for the number of uv-endonuclease-sensitive sites per 103 bases (pyrimidine dimers) was 1.2 (±0.1) × 10−4 uv-endonuclease-sensitive sites per J/m2 for the video analysis and 1.3 (±0.04) × 10−4 uv-endonuclease-sensitive sites per J/m2 for the photographic analysis. Results for pyrimidine dimer determination by either method were statistically comparable.