Differences in Survival Variations during the Growth Cycle of Cultured Chinese Hamster Cells Treated with Sulfur Mustard and X-rays1

Although the survival of surface-attached Chinese hamster cells varies through the growth cycle after either X-irradiation or sulfur mustard treatment, the variations differ. Cells in the latter part of the DNA synthetic phase yield maximum survival after X-rays, while cells in the postsynthetic phase are the most resistant after sulfur mustard. As a result, when asyn chronous cells are treated with either agent, they are ren dered partially synchronized although out of phase. The differences in the cyclic variations of survival after treatment with sulfur mustard compared to X-rays indicates that the damaging influences of these agents cannot be the same in all respects.