title: Dynamics of DNA during pulsed field electrophoresis in entangled and dilute polymer solutions.
abstract: Using fluorescence video microscopy, DNA electrophoretic behavior under field inversion conditions has been investigated in hydroxyethyl cellulose (HEC) solutions both above and below its entanglement limit. DNA conformational fluctuation periods are found to be strongly influenced by the frequency of the applied electric field. DNA maximum extension is found to be dependent on both the frequency and the strength of the applied field. It is proposed that both above and below the HEC entanglement limit, field inversion serves to keep the average DNA conformation in a size-dependent regime intermediate between full extension and random coil. In this time-averaged geometry, efficient long-chain DNA electrophoretic separation is enabled.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor 48109-1055, USA.
authors.forename: X
authors.initials: X
authors.lastname: Shi
authors.forename: R W
authors.initials: RW
authors.lastname: Hammond
authors.forename: M D
authors.initials: MD
authors.lastname: Morris
mesh_terms: D004271:DNA, Fungal / Q000737:chemistry*; D004586:Electrophoresis; D008856:Microscopy, Fluorescence; D011108:Polymers
chemical_list: D004271:DNA, Fungal; D011108:Polymers