Fig. 2

Effects of ROS scavengers and bathocuproine on purpurin-induced DNA damage in ³²P-5′-end-labeled DNA fragments. Reaction mixtures contained the ³²P-5′-end-labeled 147-bp fragment, 20 μM/base calf thymus DNA, 50 μM purpurin, each scavenger or bathocuproine and 20 μM CuCl₂ in 200 μl of 4 mM sodium phosphate buffer (pH 7.8) containing 5 μM DTPA. After incubation at 37 °C for 1 h under light shielding, the DNA fragments were treated with piperidine and electrophoresed on a polyacrylamide gel. The concentrations of each scavenger and bathocuproine were as follows: 0.2 M ethanol, 0.1 M mannitol, 0.1 M sodium formate, 0.6 M methional, 50 U catalase, 50 μM bathocuproine