Abstract
It has been proved that the duration of each phase in cell cycle of Xenopus cells can easily be determined by counting cells in G1, S, G2 and M in autoradiographed and stained preparations, and multiplying the fraction of cell number in each phase with generation time (Tg). At some different incubation temperatures, the following results were obtained: (1) at 18°C, G1, S, G2 and M were 30.2h, 29.5h, 10.1h and 2.2h with the total generation time of 72h; (2) at 23°C, G1, S, G2 and M were 15.1h, 16.2, 4.3h and 0.4h with the total generation time of 36h; and (3) at 28°C, G1, S, G2 and M were 12h, 13.8h, 3.9h and 0.3h with the total generation time of 30h.
