title: Preparative separation of DNA--ethidium bromide complexes by zonal density gradient centrifugation.
mesh_terms: D002501:Centrifugation, Zonal; D004269:DNA, Bacterial / Q000302:isolation & purification*; D004926:Escherichia coli / Q000378:metabolism; D004996:Ethidium; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization
chemical_list: D004269:DNA, Bacterial; D004996:Ethidium