title: Prototype for automatable, dielectrophoretically-accessed intracellular membrane-potential measurements by metal electrodes.
abstract: Functional access to membrane proteins, for example, ion channels, of individual cells is an important prerequisite in drug discovery studies. The highly sophisticated patch-clamp method is widely used for electrogenic membrane proteins, but is demanding for the operator, and its automation remains challenging. The dielectrophoretically-accessed, intracellular membrane-potential measurement (DAIMM) method is a new technique showing high potential for automation of electrophysiological data recording in the whole-cell configuration. A cell suspension is brought between a mm-scaled planar electrode and a μm-scaled tip electrode, placed opposite to each other. Due to the asymmetric electrode configuration, the application of alternating electric fields (1-5 MHz) provokes a dielectrophoretic force acting on the target cell. As a consequence, the cell is accelerated and pierced by the tip electrode, hence functioning as the internal (working) electrode. We used the light-gated cation channel Channelrhodopsin-2 as a reporter protein expressed in HEK293 cells to characterize the DAIMM method in comparison with the patch-clamp technique.
authors.affiliation: Department of Biophysical Chemistry, Max Planck Institute of Biophysics, Frankfurt am Main, Germany. ulrich.terpitz@uni-wuerzburg.de
authors.forename: Ulrich
authors.initials: U
authors.lastname: Terpitz
authors.forename: Vladimir L
authors.initials: VL
authors.lastname: Sukhorukov
authors.forename: Dirk
authors.initials: D
authors.lastname: Zimmermann
mesh_terms: D057205:Automation, Laboratory / Q000295:instrumentation / Q000379:methods; D000075402:Channelrhodopsins; D004566:Electrodes; D004586:Electrophoresis / Q000295:instrumentation / Q000379:methods*; D057809:HEK293 Cells; D006801:Humans; D007425:Intracellular Membranes / Q000502:physiology*; D015640:Ion Channel Gating / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology*; D008670:Metals; D018408:Patch-Clamp Techniques
chemical_list: D000075402:Channelrhodopsins; D008670:Metals