Huang Y, Wang X B, Becker F F, Gascoyne P R
Department of Experiment Pathology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Biophys J. 1997 Aug;73(2):1118-29. doi: 10.1016/S0006-3495(97)78144-X.
We present the principle of cell characterization and separation by dielectrophoretic field-flow fractionation and show preliminary experimental results. The operational device takes the form of a thin chamber in which the bottom wall supports an array of microelectrodes. By applying appropriate AC voltage signals to these electrodes, dielectrophoretic forces are generated to levitate cells suspended in the chamber and to affect their equilibrium heights. A laminar flow profile is established in the chamber so that fluid flows faster with increasing distance from the chamber walls. A cell carried in the flow stream will attain an equilibrium height, and a corresponding velocity, based on the balance of dielectrophoretic, gravitational, and hydrodynamic lift forces it experiences. We describe a theoretical model for this system and show that the cell velocity is a function of the mean fluid velocity, the voltage and frequency of the signals applied to the electrodes, and, most significantly, the cell dielectric properties. The validity of the model is demonstrated with human leukemia (HL-60) cells subjected to a parallel electrode array, and application of the device to separating HL-60 cells from peripheral blood mononuclear cells is shown.
我们介绍了介电泳场流分级法用于细胞表征和分离的原理，并展示了初步的实验结果。该操作装置采用薄腔室的形式，其底壁支撑着一排微电极。通过向这些电极施加适当的交流电压信号，产生介电泳力以使悬浮在腔室内的细胞悬浮，并影响它们的平衡高度。在腔室内建立层流剖面，使得流体离腔室壁越远流动越快。流动流中携带的细胞将基于其所经历的介电泳力、重力和流体动力升力的平衡达到平衡高度和相应的速度。我们描述了该系统的理论模型，并表明细胞速度是平均流体速度、施加到电极的信号的电压和频率的函数，最重要的是，是细胞介电特性的函数。该模型的有效性通过对人白血病（HL - 60）细胞施加平行电极阵列得到了证明，并展示了该装置用于从外周血单个核细胞中分离HL - 60细胞的应用。
