Growth kinetics of the G2-phase of Ehrlich ascites tumor cells, separated from anaerobically treated asynchronous cultures.

Cell cycle progression of G2 fractions (75-80% G2 (4C) cells) from 8 h anaerobically cultured asynchronous hyperdiploid Ehrlich ascites tumor cells strain Karzel, separated by centrifugal elutriation, was studied after reaeration by flow cytometric methods, including the BrdU-H33258 technique and dual parameter measurements. Analyses of the growth kinetics demonstrated that one fraction of the cell population proceeds through a normal cell cycle (2C----4C) with a generation time of about 20 h. Another portion entered a new cycle (4C----8C) to form cells with a DNA content up to 8C; mono-, bi- and polynucleate cells could be detected. After 15 h aerobic recultivation of the anaerobically cultured G2 cells, a fraction containing 80-85% with a DNA content of greater than 4C was separated. On recultivation, these cells pass a 4C----8C division cycle with a generation time of about 10 h, and a G1 period of less than 4 h.