Figure 4

Pulsed-field electrophoresis (PFGE) measurement of ionizing radiation-induced DNA double-strand breakage in MRC5 and WIDR cells (as indicated in the graphs). Fractions of electrophoretically mobile DNA (fragments < 9 Mbp), or FR-value, increases with dose according to the random breakage formalism (solid lines). DSB induction is not affected by TBB pretretment (200 μM for two hours) compared to the respective 2% DMSO controls. Data points represent mean values (and standard deviations) from three independent experiments.