title: Circular DNA forms of colicinogenic factors E1, E2 and E3 from Escherichia coli.
mesh_terms: D002499:Centrifugation, Density Gradient; D002501:Centrifugation, Zonal; D002875:Chromosomes / Q000032:analysis; D003087:Colicins / Q000032:analysis* / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis*; D004926:Escherichia coli; D008722:Methods; D010636:Phenols; D010759:Phosphorus Isotopes; D014316:Tritium
chemical_list: D003087:Colicins; D004269:DNA, Bacterial; D010636:Phenols; D010759:Phosphorus Isotopes; D014316:Tritium