Figure 1.

Hypofractionated irradiation reduces the colony formation and induces apoptosis and necrosis of CT26 cells. The colony formation was determined by standard colony formation assay (A). After incubation for approximately 2 weeks, the cells were fixed and colonies with >50 cells were scored. The cell death analyses were performed 24 h after single or double irradiation of CT26 colorectal tumor cells with 5 Gy. Cell death was determined by flow cytometry; apoptotic cells (gray) are defined as AxV⁺/PI⁻ cells and necrotic (black) as AxV⁺/PI⁺ cells (B). Joint data of three independent experiments, each performed in duplicates, are presented as mean ± SEM and analyzed by Student’s t-test; **p < 0.01.