Figure 2. γ-H2AX intensity induction and loss after uniform exposure to X-rays, detected by flow cytometry.

(A) Mean γ-H2AX intensity observed between 1–48 hours post exposure. Linear regressions (lines) were fitted to all data points. (B) γ-H2AX intensity loss over 48 hours post exposure. Dashed lines represent bi-exponential fits for γ-H2AX loss for each dose. T_{1/2 fast} and T_{1/2 Slow} represent the individual half-lives of the two exponentials. (C) γ-H2AX intensity yields per cell per gray between 1–48 hours calculated using linear regression coefficients of γ-H2AX intensity yields from Figure 2A. The dashed line represents a bi-exponential fit for mean γ-H2AX loss per unit dose and solid lines the upper and lower 95% confidence limits. (D) Dose estimates in X-irradiated lymphocytes from 8 healthy donors. γ-H2AX intensity was measured and the dose estimated using the calibration curve from Figure 2C.