title: The degree of unwinding of the DNA helix by ethidium. I. Titration of twisted PM2 DNA molecules in alkaline cesium chloride density gradients.
mesh_terms: D001435:Bacteriophages / Q000032:analysis*; D001665:Binding Sites; D002499:Centrifugation, Density Gradient; D004267:DNA Viruses / Q000032:analysis; D004279:DNA, Viral; D004996:Ethidium; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008433:Mathematics; D009690:Nucleic Acid Conformation; D011549:Pseudomonas / Q000032:analysis*
chemical_list: D004279:DNA, Viral; D004996:Ethidium