Figure 1. Kinetics of bystander signal production after ionizing radiation treatment: Time required for cells to generate sufficient bystander signal to induce significant levels of gene mutation.

Aliquots of WTK1 cells were irradiated with 2 Gy of γ-rays, and the medium was harvested by centrifugation at the indicated times. It was applied to naïve cells for 24 hours, and the mutant fractions were subsequently determined. BMF is background mutation frequency. Data are mean of three experiments and error bars are SD.