Figure 2.

Representative agarose gels used to analyze the incubations of supercoiled ³HT-pUC19 plasmid DNA with ¹²⁵I-labeled Hoechst (H) derivatives (¹²⁵I–EH, ¹²⁵I–BH, ¹²⁵I-C₈–H, and ¹²⁵I-C₁₂–H) at 4°C in PBS (pH 7.4): – and + indicate absence and presence of DMSO (0.2 M), respectively. Lane C is the control ³HT-pUC19 plasmid DNA incubation that does not contain ¹²⁵I-labeled compound and remains intact throughout the course of the incubation period. SC, L and N represent supercoiled, linear and relaxed-circular forms of ³HT-pUC19 plasmid DNA. Gels (containing ethidium bromide) were visualized using ultraviolet (320 nm) transillumination.