DYNAMICS OF T2 DNA DURING ELECTROPHORESIS IN ENTANGLED AND ULTRADILUTE HYDROXYETHYL CELLULOSE SOLUTIONS

Video microscopy has been used to investigate the conformational chang es that double stranded DNA undergoes during capillary electrophoresis in buffered solutions of hydroxyethyl cellulose (HEC). DNA of a fixed size (T2, 167 kbp) was used to quantitate the degree of extension. At HEC concentrations below the entanglement limit, C, extension of DNA under DC fields is much less than in gels. Pulsed fields serve to lim it extension even further, with DNA strands approaching a time-average d irregular conformation that yields rapid sizing of long nucleic acid s. (C) 1996 John Wiley & Sons, Inc.