An Investigation of the Effect of X-rays on the Rate of DNA-synthesis in Mouse L-cells

Summary

Mouse L-strain cells were grown in tissue culture on glass coverslips and part of each culture was exposed to x-radiation. Tritiated thymidine was administered and the cultures were then fixed and Feulgen stained. The DNA content of individual cells was estimated by microspectrophotometry, and the rate of DNA-synthesis was estimated autoradiographically. The results show an increased sensitivity of DNA-synthesis to a moderate dose of x-radiation in cells nearing the end of the DNA-synthetic period, but this difference in sensitivity is not maintained if a larger dose of radiation is used.