title: Quantitation of ultraviolet radiation-induced cyclobutyl pyrimidine dimers in DNA by video and photographic densitometry.
abstract: 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 dimer-specific 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 10(3) bases (pyrimidine dimers) was 1.2 (+/- 0.1) X 10(-4) uv-endonuclease-sensitive sites per J/m2 for the video analysis and 1.3 (+/- 0.04) X 10(-4) uv-endonuclease-sensitive sites per J/m2 for the photographic analysis. Results for pyrimidine dimer determination by either method were statistically comparable.
authors.affiliation: Lovelace Medical Foundation, Southeast, Albuquerque, New Mexico 87108.
authors.forename: S E
authors.initials: SE
authors.lastname: Freeman
authors.forename: B D
authors.initials: BD
authors.lastname: Thompson
mesh_terms: D000703:Analog-Digital Conversion; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D003720:Densitometry / Q000295:instrumentation / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D004587:Electrophoresis, Agar Gel; D005470:Fluorometry / Q000295:instrumentation; D007091:Image Processing, Computer-Assisted; D010781:Photography; D011740:Pyrimidine Dimers / Q000032:analysis*; D014466:Ultraviolet Rays; D014741:Video Recording
chemical_list: D011740:Pyrimidine Dimers; D004247:DNA