Differences between Escherichia coli B-r and Salmonella typhimurium LT-2 in the sedimentation behavior of the deoxyribonucleic acid synthesized after x-irradiation.

After irradiation, nearly equal amounts of deoxyribonucleic acid (DNA) are synthesized in radiation-sensitive Salmonella typhimurium and in resistant Escherichia coli B/r. However, the DNA synthesized in S. typhimurium is of low molecular weight, whereas that made in the E. coli B/r is like that synthesized in the unirradiated controls.