Figure 5:Observation of ITL intermediate. (A) and (B), electrophoresis of plasmid pBR322 DNA treated with HindIII for various time at 20ºC and 37ºC, respectively. Lane 1, supercoiled DNA control (0.1 µg); lane 2, 30 s; lane 3, 1min; lane 4, 5min; lane 5, 10min; lane 6, 30min. I, interlinked intermediate; L, linear DNA; SC, supercoiled DNA. (C) AFM image of pBR322 DNA treated by HindIII for 1min at 20ºC. Arrows indicate ITL intermediates.