title: Brownian motion of single molecules in electric fields.
abstract: The behavior of negatively charged single rhodamine-labeled molecules excited to fluorescence in confocal volume elements has been investigated in oscillating voltage gradients between 1 and 15 kV/cm. The effective charge of rhodamin labeled deoxy-uridine triphosphate (Rh-dUTP) is dependent on the field strength applied and likely is due to differences in the screening by counter ions. It can be shown that the attractive forces generated by an oscillating dipole can increase the concentration of Rh-dUTP by a factor 2. Likewise a substantial increase of concentration can be obtained for Rh-labeled DNA molecules when linear voltage gradients are applied. The importance for diagnostic analysis at the single molecule level is discussed.
authors.affiliation: Department of Medical Biophysics, Karolinska Institutet, Stockholm, Sweden. rudolf.rigler@mbb.ki.se
authors.forename: Rudolf
authors.initials: R
authors.lastname: Rigler
mesh_terms: D004247:DNA / Q000032:analysis*; D003856:Deoxyuracil Nucleotides; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D005456:Fluorescent Dyes; D008832:Microchemistry / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D003856:Deoxyuracil Nucleotides; D005456:Fluorescent Dyes; C027078:deoxyuridine triphosphate; D004247:DNA