FIGURE 5.

Flow cytometry verified the efflux of free BPD. Following 22‐h incubation of the EGFR‐negative cell line CHO‐K1 with 1 μM BPD equivalent PIC or 23.4 nM free BPD, cells were washed, and the BPD fluorescence was measured at various time points. The BPD fluorescence decreased strikingly as the post‐wash incubation time increased. (A) Fluorescence of cells incubated with PIC. (B) Fluorescence of cells incubated with free BPD. Results are mean ± standard deviation of the median fluorescence intensities of three replicates.