[Effect of cycloheximide on DNA replication. III. Results of autoradiography of the DNA of lysed cells].

With the help of DNA-fiber autoradiography on L cells, the question of mechanism of a rapid block of DNA replication by cycloheximide, an inhibitor of protein synthesis, was examined. The presented data show that the elongation of labeled regions in replicating units is blocked. In non-treated cells the replication rate was 0.4 mcm/min; the mean size of replicon was 21 mcm. The difficulties encountered in the explanation of the data obtained are discussed.