Figure 4. Effect on cell survival of etoposide- and CLM-induced DSBs and TSBs.

SV40-transformed fibroblasts were treated with 0–150 µM etoposide or 0–5 nM CLM for 40 minutes at 37°C before analysis of colony survival and levels of (a) TSBs or (b) DSBs by neutral and alkaline CFGEs calculated as described in materials and methods. Error bars represent variation in two separate experiments performed on two different days.