YIELDS OF SINGLE-STRAND BREAKS IN DOUBLE-STRANDED CALF THYMUS DNA IRRADIATED IN AQUEOUS-SOLUTION IN THE PRESENCE OF OXYGEN AND SCAVENGERS

Yields of radiation-induced single-strand breaks in double-stranded ca lf thymus DNA have been measured as a function of OH. scavenger concen tration in N2O/O-2-saturated aqueous solution. The experimental data a re well represented by a theoretical model based on non-homogeneous re action kinetics, without the need to adjust any parameter. The good ag reement between experimental and theoretical data is taken as evidence that, in the presence of oxygen, the main effect of added scavengers with respect to the formation of single-strand breaks in double-strand ed DNA is OH. radical scavenging.