Figure 4.

Intracellular cleavage activity of bipyridine conjugate Bpy5. (A) Detection of DNA breaks by phosphorylated H2AX immunolabeling 24 h after treatment by 10 µM Bpy5. (B) Quantitative PCR on DNA extracted from cells treated by Bpy5 or free bipyridine: DNA analyses were performed 24 h after treatment. PCR quantification of the target DNA was performed, using primers flanking different (A•T)-rich sequences as indicated. The values were normalized by quantification of a control sequence lacking (A•T)-rich sequences (see text for details).