Figure 1.

Fluorescence‐activated cell sorting (FACS) analysis of PMA‐mediated G₂‐phase arrest. HeLa cells were synchronized at G₁/S boundary and released back into the cell cycle. (a) Cells were left untreated (control) or treated with PMA (0.1 µm) at 7 h after G₁/S release, with the bisindolylmaleimide (Bis, 1 µm) at 6.5 h after G₁/S release, or with PMA and Bis together. (b) FACS analysis of synchronized hTERT cells treated in the absence (control) or presence of PMA at 7 h after G₁/S‐phase release. Cells were harvested at the times indicated after release from G₁/S and the number of cells (Y axis) containing 2N or 4N DNA content (X axis) were determined by FACS.