CHO cell repair of single-strand and double-strand DNA breaks induced by gamma- and alpha-radiations.
Neutral and alkaline sucrose gradient sedimentation analysis was used to measure double- and single-strand breaks in the DNA of Chinese hamster ovary (CHO) cells exposed to either gamma- or alpha-radiation. After irradiation, cells were incubated for 15-180 min to test the ability of the cell to rejoin the DNA breaks. Essentially complete rejoining was observed for single-strand breaks induced by gamma- or alpha-doses below 20 krad and for double-strand breaks induced by gamma doses below 60 krad. Approximately 80% rejoining was observed for double-strand breaks induced by alpha doses below 40 krad. At higher doses, the repair system appeared to saturate in such a way that essentially no additional breaks were rejoined.
D000512:Alpha Particles; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D004247:DNA / Q000528:radiation effects*; D004260:DNA Repair; D004277:DNA, Single-Stranded / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D008970:Molecular Weight; D011830:Radiation Effects
D004277:DNA, Single-Stranded; D004247:DNA