Electrophoretic separation of linear and supercoiled DNA in uncoated capillaries

We report electrophoretic separation of supercoiled plasmids (2-16 kilo base pairs) and linear double-stranded DNA (0.6-23 kilo base pairs) in uncoated capillaries filled with dilute hydroxyethylcellulose. Because electroosmotic flow reverses the order of elution, long plasmids spend less time in the capillary and their bandwidths are narrower than observed in coated capillaries. However, resolution is similar to that obtained in coated capillaries, because it is governed by the distribution of unresolved topoisomers. In the presence of electroosmotic how migration of supercoiled plasmids does not follow the elastic rod model that has been observed in coated capillaries. (C) 1999 Elsevier Science B.V. All rights reserved.