Figure 1

Evaluation of cytotoxicity by radiation. MDA-MB-231 cells were treated with the indicated dose of radiation and incubated for 24, 48, or 72 h. Cell viability was determined by trypan blue exclusion assay (A), MTT assay (B), and FACS analysis using propidium iodide (PI) fluorescent dye (C). (D) MDA-MB-231 cells were treated with a single dose of radiation (10 Gy) or fractionated dose of radiation (2 Gy per day for 5 days). Viable cells were determined by trypan blue exclusion assay 24, 48, or 72 h after final irradiation.