title: A simple electrophoretic method for the determination of superhelix density of closed circular DNAs and for observation of their superhelix density heterogeneity.
mesh_terms: D001665:Binding Sites; D004270:DNA, Circular; D004279:DNA, Viral; D004587:Electrophoresis, Agar Gel / Q000379:methods; D004996:Ethidium; D008433:Mathematics; D009690:Nucleic Acid Conformation; D013539:Simian virus 40; D013045:Species Specificity
chemical_list: D004270:DNA, Circular; D004279:DNA, Viral; D004996:Ethidium