Heat and radiation sensitivity of Chinese hamster V79 cells and of nine clones selected from survivors of a thermal tolerant cell population

Chinese hamster V79 cells were heated for 12 hours at 420C. Surviving cells were cloned and grown as separate cell lines. Nine clones were tested for heat and/or X ray sensitivity after three weeks. Heat sensitivity to 420C or 450C was the same as the parent cell line. Also, the radiation sensitivity and response to the combined effects of heat and radiation remained unchanged compared to the original V79 cell line. Thus, no thermal mutants were selected in the thermal tolerant cell population and the thermal shock received by survivors did not permanently alter the response to heat and/or X rays