Inactivation DU virus leucémogène de gross par les radiations UV, X et γ

A passage cell‐free extract from AKR leukemia was irradiated: a) with UV light (2,537 Å); b) with X‐ and γ‐radiation acting under direct effect conditions. After irradiation, the residual activity of the extract was compared to those of serial dilutions of the non‐irradiated extract. The criterion for activity was the “acceleration test” in new‐born AKR mice. Four experiments were carried out with UV light, 3 with X‐, and 2 with γ‐rays. In each experiment, the effects of 4 doses of radiation were compared to those of 4 10‐fold dilutions of the non‐irradiated control. In all, 1,835 new‐born mice were utilized. The Gross virus is inactivated according to an exponential function of the dose of radiation. The doses D10, which reduce the viral activity of the extract to one tenth of its original value were found to be: The viral function, which is involved in these tests, seems to be the leukemogenic activity (transformation), rather than the infectivity (viral multiplication).