Fig. 2

Autoradiogram of ³²P-5’-end-labeled DNA fragments treated with RA in the presence of Cu(II). The reaction mixtures contained the ³²P-5’-end-labeled 337-bp fragment, 20 µM/base calf thymus DNA, 20 µM CuCl₂, and the indicated concentrations of RA in 200 µl of 10 mM sodium phosphate buffer (pH 7.8) containing 5 µM DTPA. After incubation at 37 °C for 16 h, the DNA fragments were treated with or without hot piperidine and electrophoresed on a polyacrylamide gel