Figure 7:Relevance of ITL to the contour of DNA molecules. (A) Diameters of plasmid pBR322 DNA. 1, pBR322 DNA; 2, pBR322DNA treated with E. coli topoisomerase I. (B) Ratio of diameter to perimeter of plasmid DNAs. 1, pUC18; 2. pBR322; 3, pJGX15A. In panel A and B, data graphs are mean ± SD. (C) AFM image of pJGX15A DNA. (D) AFM image of pBR322 DNA. (E) AFM image of pUC18 DNA.