Dielectrophoretic concentration and separation of live and dead bacteria in an array of insulators
Dielectrophoretic concentration and separation of live and dead bacteria in an array of insulators
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DOI：
10.1021/ac034804j
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发表时间：
2004-03-15
影响因子：
7.4
通讯作者：
Fintschenko, Y
中科院分区：
文献类型：
--
作者：
Lapizco-Encinas, BH;Simmons, BA;Fintschenko, Y
基于绝缘体的（无电极）介电泳（iDEP）是一种创新方法，其中驱动DEP所需的非均匀电场由绝缘体产生，避免了与使用电极相关的问题。活的和死的大肠杆菌集中和选择性地释放，通过施加步进直流电压通过微通道包含一个阵列的绝缘柱蚀刻在玻璃中。唯一存在的电极是放置在入口和出口储存器中的两根铂丝，在绝缘体上产生高达200 V/mm的平均电场。用Syto 9和碘化丙啶标记细胞，并通过荧光显微镜成像。细胞捕获和释放的控制，通过修改的相对反应的电动力和DEP通过调整所施加的电压的大小。死细胞被观察到有显着较低的介电电泳迁移率比活细胞，而5和死细胞的电动迁移率是无法区分的。差异，捕获的细胞带的位置与预测一致。此外，细胞被选择性地捕获和浓缩对1-和0.2-妈妈的羧酸盐改性的聚苯乙烯颗粒的背景。iDEP首次应用于同时分离和浓缩活/死细菌，说明了其作为细菌分析前端方法的潜力。
Insulator-based (electrodeless) dielectrophoresis (iDEP) is an innovative approach in which the nonuniform electric field needed to drive DEP is produced by insulators, avoiding problems associated with the use of electrodes. Live and dead Escherichia coli were concentrated and selectively released by applying stepped DC voltages across a microchannel containing an array of insulating posts etched in glass. The only electrodes present were two platinum wires placed in the inlet and outlet reservoirs, producing mean electric fields of up to 200 V/mm across the insulators. The cells were labeled with Syto 9 and propidium iodide and imaged through a fluorescent microscope. Cell trapping and release were controlled by modifying the relative responses of electrokinesis and DEP by adjusting the magnitude of the applied voltage. Dead cells were observed to have significantly lower dielectrophoretic mobility than live cells, whereas the electrokinetic mobilities of five and dead cells were indistinguishable. The locations of the bands of differentially, trapped cells were consistent with predictions. In addition, cells were selectively trapped and concentrated against backgrounds of 1- and 0.2-mum carboxylate-modified polystyrene particles. This first application of iDEP for simultaneous live/dead bacteria separation and concentration illustrates its potential as a front-end method for bacterial analysis.