title: A buoyant method for the determination of the superhelix density of closed circular DNA.
mesh_terms: D001665:Binding Sites; D002499:Centrifugation, Density Gradient; D004279:DNA, Viral; D008967:Molecular Biology; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D000644:Quaternary Ammonium Compounds; D011804:Quinolines; D013539:Simian virus 40; D013053:Spectrophotometry; D014461:Ultracentrifugation
chemical_list: D004279:DNA, Viral; D000644:Quaternary Ammonium Compounds; D011804:Quinolines