Comparsion of the oxygen-enhancement ratio for gamma-ray-induced double-strand breaks in the DNA of bacteriophage T7 as determined by two different methods of analysis.
Bacteriophage T7 was irradiated in a protecting medium under nitrogen and oxygen with 60Co gamma-rays. Double-strand breaks were measured by sucrose-gradient sedimentation and by boundary-sedimentation analysis. Both methods showed that the presence of oxygen during irradiation enhanced the production of double-strand breaks. This is at variance with a recent report which suggests that boundary-sedimentation analysis does not show an effect of oxygen. The discrepancy must be ascribed to differences in interpretation of the sedimentation data.
D002499:Centrifugation, Density Gradient; D003037:Cobalt Radioisotopes; D003090:Coliphages / Q000528:radiation effects*; D004279:DNA, Viral / Q000528:radiation effects*; D005720:Gamma Rays; D010100:Oxygen; D011830:Radiation Effects
D003037:Cobalt Radioisotopes; D004279:DNA, Viral; D010100:Oxygen