HIGH-RESOLUTION CAPILLARY ELECTROPHORETIC SEPARATION OF SUPERCOILED PLASMID DNAS AND THEIR CONFORMERS IN DILUTE HYDROXYPROPYLMETHYL CELLULOSE SOLUTIONS CONTAINING NO INTERCALATING AGENT

The three conformers of plasmid pBR322, Linear, supercoiled and nicked circular forms, were separated by capillary electrophoresis (CE) in 0 .1% hydroxypropylmethyl cellulose (HPMC) solution in the absence of in tercalating agents and the migration order was confirmed by co-migrati on of enzymatically prepared corresponding DNAs. The previously observ ed broad peaks of supercoiled DNAs in CE are results of unresolved pea ks of topoisomers which differ only in the degrees of twisting. We hav e demonstrated the separation of an artificial topoisomer ladder made from pBR322 and topoisomerase I. The population of topoisomers of a su percoiled DNA is dependent on sample matrices and separation condition s. (C) 1998 Elsevier Science B.V. All rights reserved.