Centre for Micro and Nano Systems, The Chinese University of Hong Kong, Hong Kong.
PLoS One. 2013;8(1):e51577. doi: 10.1371/journal.pone.0051577. Epub 2013 Jan 8.
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.
由于光学介电泳（ODEP）在提供可重构电极图案和流道方面具有巨大的灵活性，因此其在操纵微粒子和生物细胞方面的应用变得越来越流行。ODEP 能够在被照射光的光导表面上并行且自由地操纵小粒子，从而无需复杂的电极设计和制造工艺。在本文中，我们证明了包含 melan-a 细胞、RAW 267.4 巨噬细胞、外周白细胞和淋巴细胞的小鼠细胞可以在具有适当 DEP 参数的光电动力学（OEK）装置中进行操纵。我们的 OEK 装置产生非旋转电场，并在光学电极上施加局部 DEP 力。迄今为止，我们是第一组报告称，在所研究的所有细胞中，在存在 DEP 力的情况下，发现 melan-a 细胞、淋巴细胞和白细胞在设备中发生自旋转。细胞的旋转速度取决于施加的电压和频率以及细胞与光学中心的距离。我们根据细胞的物理特性讨论了一种可能的机制来解释这种新的诱导自旋转观察结果。我们相信，这种旋转现象可用于识别细胞类型，并阐明细胞的介电和物理特性。
