Figure 4.

Extent of G₂-phase delay at 24 h after irradiation. Transfected and untransfected cells were treated with 5 μM CdCl₂ 16 h prior to irradiation. Cells were irradiated (3 Gy), incubated for 24 h, harvested, and analyzed for DNA content by flow cytometry as described (7). *Values represent the ratio of G₂- to G₁-phase cell numbers, which was chosen as a more exact representation of delay in G₂ phase (48).