title: Self-rotation of cells in an irrotational AC E-field in an opto-electrokinetics chip.
abstract: The use of optical dielectrophoresis (ODEP) to manipulate microparticles and biological cells has become increasingly popular due to its tremendous flexibility in providing reconfigurable electrode patterns and flow channels. ODEP enables the parallel and free manipulation of small particles on a photoconductive surface on which light is projected, thus eliminating the need for complex electrode design and fabrication processes. In this paper, we demonstrate that mouse cells comprising melan-a cells, RAW 267.4 macrophage cells, peripheral white blood cells and lymphocytes, can be manipulated in an opto-electrokinetics (OEK) device with appropriate DEP parameters. Our OEK device generates a non-rotating electric field and exerts a localized DEP force on optical electrodes. Hitherto, we are the first group to report that among all the cells investigated, melan-a cells, lymphocytes and white blood cells were found to undergo self-rotation in the device in the presence of a DEP force. The rotational speed of the cells depended on the voltage and frequency applied and the cells' distance from the optical center. We discuss a possible mechanism for explaining this new observation of induced self-rotation based on the physical properties of cells. We believe that this rotation phenomenon can be used to identify cell type and to elucidate the dielectric and physical properties of cells.
authors: Centre for Micro and Nano Systems, The Chinese University of Hong Kong, Hong Kong.
authors: Long-Ho
authors: LH
authors: Chau
authors: Wenfeng
authors: W
authors: Liang
authors: Florence Wing Ki
authors: FW
authors: Cheung
authors: Wing Keung
authors: WK
authors: Liu
authors: Wen Jung
authors: WJ
authors: Li
authors: Shih-Chi
authors: SC
authors: Chen
authors: Gwo-Bin
authors: GB
authors: Lee
mesh_terms: D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D004566:Electrodes; D004586:Electrophoresis / Q000295:instrumentation*; D004867:Equipment Design; D007962:Leukocytes / Q000166:cytology / Q000502:physiology; D008264:Macrophages / Q000166:cytology / Q000502:physiology; D051379:Mice; D008962:Models, Theoretical; D055096:Optical Devices; D012399:Rotation; D059010:Single-Cell Analysis / Q000295:instrumentation*