Utilization of hydroxyurea for detection of DNA repair synthesis in liver following dimethylnitrosamine action by means of scintillation counting.

We detected DNA repair synthesis by employing hydroxyurea as an inhibitor of DNA semiconservative synthesis in various time schedules of experiments. We came to the conclusion that prolongation of the time interval between [3H]thymidine administration and sacrifice of the animals from 0.5 h to 7.5 h increases the sensitivity of examination. Some artifacts associated with detection of the repair (hydroxyurea-resistant) synthesis of DNA are discussed.