title: Ultrasonic-trap-enhanced selectivity in capillary electrophoresis.
abstract: We combine ultrasonic trapping and capillary electrophoresis (CE) with the goal to detect ultra-low concentrations of proteins via size-selective separation and enrichment of antibody-coated latex spheres. An 8.5 MHz standing ultrasonic wave is longitudinally coupled into the sub-100- micro m diam capillary of the CE system. Competition between acoustic and viscous forces result in in-flow separation of micro m-diam spheres according to their size. Experiments separating 2.8- and 2.1- micro m-diam fluorescent latex particles, which model a protein-specific immunocomplex/free particle mixture, indicate a potential improvement of the concentration limit of detection of 10(4) compared to current CE systems. Theoretical calculations show room for further improvement.
authors.affiliation: Biomedical and X-Ray Physics, Royal Institute of Technology, SE-106 91, Stockholm, Sweden. martin.wiklund@biox.kth.se
authors.forename: M
authors.initials: M
authors.lastname: Wiklund
authors.forename: P
authors.initials: P
authors.lastname: Spégel
authors.forename: S
authors.initials: S
authors.lastname: Nilsson
authors.forename: H M
authors.initials: HM
authors.lastname: Hertz
mesh_terms: D019075:Electrophoresis, Capillary; D006801:Humans; D007840:Latex; D008863:Microspheres; D014465:Ultrasonics
chemical_list: D007840:Latex