Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, Arizona 85721, USA.
Analyst. 2012 Nov 21;137(22):5215-21. doi: 10.1039/c2an35707k. Epub 2012 Aug 31.
Active manipulation of cells, such as trapping, focusing, and isolation, is essential for various bioanalytical applications. Herein, we report a hybrid electrokinetic technique for manipulating mammalian cells in physiological fluids. This technique applies a combination of negative dielectrophoretic force and hydrodynamic drag force induced by electrohydrodynamics, which is effective in conductive biological fluids. With a three-electrode configuration, the stable equilibrium positions of cells can be adjusted for separation and focusing applications. Cancer cells and white blood cells can be positioned and isolated into specific locations in the microchannel under both static and dynamic flow conditions. To investigate the sensitivity of the hybrid electrokinetic process, AC voltage, frequency, and bias dependences of the cell velocity were studied systematically. The applicability of the hybrid electrokinetic technique for manipulating cells in physiological samples is demonstrated by continuous focusing of human breast adenocarcinoma spiked in urine, buffy coats, and processed blood samples with 98% capture efficiency.
主动操控细胞，如捕获、聚焦和隔离，对于各种生物分析应用至关重要。本文报道了一种用于在生理流体中操控哺乳动物细胞的混合电动技术。该技术结合了介电泳力和电动力学产生的流体动力曳力，在导电生物流体中效果显著。采用三电极构型，可以调整细胞的稳定平衡位置，以实现分离和聚焦应用。在静态和动态流动条件下，癌细胞和白细胞可以被定位并隔离到微通道中的特定位置。为了研究混合电动过程的灵敏度，系统研究了细胞速度与交流电压、频率和偏置的依赖关系。通过对人乳腺癌细胞在尿液、白细胞层和处理后的血液样本中的连续聚焦，证明了混合电动技术在生理样品中操控细胞的适用性，捕获效率达到 98%。
