Fig. 1.

A: Representative image of pBR322 on an agarose gel following treatment with a radionuclide. Here, pBR322 was incubated with 1 MBq ¹¹¹In-chloride (¹¹¹In-Cl₃ or as external radiation (¹¹¹In (external)) for 72 h in the presence or absence of DMSO or cold indium chloride (InCl₃). B and C: Fraction of supercoiled (undamaged) plasmid, as measured from gels such as A. Plasmids were incubated with either ¹¹¹InCl₃ (B) or ⁶⁷GaCl₃ (C). Data points are average ± standard deviation (SD; n = 2–3). Relaxed bands represent single strand breaks; linear bands are double strand breaks.