title: Existence of the colicinogenic factor-sex factor ColI-b-P9 as a supercoiled circular DNA-protein relaxation complex.
mesh_terms: D002247:Carbon Isotopes; D002499:Centrifugation, Density Gradient; D003087:Colicins / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000302:isolation & purification; D004926:Escherichia coli; D014316:Tritium; D014461:Ultracentrifugation
chemical_list: D002247:Carbon Isotopes; D003087:Colicins; D004269:DNA, Bacterial; D014316:Tritium