Stability of DNA in mammalian cells irradiated with near-uv light (uv-a).
The induction of lesions in human melanoma DNA by near-uv light (uv-a) has been investigated using a procedure to lyse the cells in dilute alkali. The alkaline treatment denatures the DNA, which results in fragmentation of the DNA in irradiated cells but not in control cells. The solution is neutralized to allow the larger fragments to renature. The smaller, single-stranded DNA fragments (2-10 kb) are then detected using agarose gel electrophoresis. With increasing dose of irradiation there are increasing amounts of the smaller fragments detected. The DNA fragmentation, which can be prevented by treating the cells with the radical scavenger DMSO, is not induced via the incubation medium. Hence uv-a has distinct effects on chromosomal DNA.
D004273:DNA, Neoplasm / Q000528:radiation effects*; D006801:Humans; D066298:In Vitro Techniques; D008545:Melanoma / Q000473:pathology*; D014466:Ultraviolet Rays
D004273:DNA, Neoplasm