M.M.M. ELNASHARTY*,** A.M. GHONEIM**, G.M. TURKY**, M. KAMAL***, FATIMA H. LABEED*, M.P. HUGHES*, K. F. HOETTGES*

*Centre of Biomedical Engineering, Department of Mechanical Engineering Sciences, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom, k.hoettges@surrey.ac.uk
**National Research Centre, Elbehoth St., Dokki, Giza, Egypt
***Mansoura University, Gomhouria St., Mansoura, Egypt

Abstract. Dielectrophoresis – the manipulation of suspended particles by non-uniform AC electric fields – has been demonstrated to be an effective mechanism for determining the electrical properties of suspended cells. However, the use of the technique has been limited at low frequencies (typically below the kHz range) by the presence of other physical effects, such as AC electroosmosis and electrode screening that disrupt cell movement. This is a significant limitation, because these low frequencies potentially allow examination of the variation in membrane conductance due to conduction through ion channels and surface conductance of the membrane. In this paper we describe a method of examining this low-frequency region using a low frequency signal to modulate a 1 MHz carrier wave, allowing this region to be probed for the first time. Furthermore, by examining DEP spectra before and after the application of ion channel blockers show characteristic conductance peaks similar to those observed by patch-clamp methods.

Corresponding author’s e-mail: k.hoettges@surrey.ac.uk

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