Free-flow zone electrophoresis and isoelectric focusing using a microfabricated glass device with ion permeable membranes
Free-flow zone electrophoresis and isoelectric focusing using a microfabricated glass device with ion permeable membranes
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DOI：
10.1039/b514731j
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发表时间：
2006-03-01
期刊：
影响因子：
6.1
通讯作者：
Schasfoort, RBM
中科院分区：
文献类型：
--
作者：
Kohlheyer, D;Besselink, GAJ;Schasfoort, RBM
本文介绍了一种集成离子渗透膜的微加工自由流电泳装置。为了获得分离组分的连续泳道，垂直于样品流动方向施加电场。通过流体动力学聚焦，该样品流被夹在两个鞘流之间。分离室具有两个插入电极的开放侧床，以允许电解期间产生的气体通风。为了流体动力学地将分离隔室与侧电极隔离，通过狭缝掩模将可光聚合的单体溶液暴露于UV光以用于原位膜形成。这些所谓的盐桥抵抗压力驱动的流体，但允许离子传输以实现电连接。在早期的装置中，通过使用开放侧通道阵列来实现相同的效果。然而，在自由流动电泳和自由流动等电聚焦过程中，只有一小部分施加的电压被有效地利用在整个分离室中。此外，载体两性电解质扩散到侧通道中导致分离室内非常有限的pH梯度。这里提出的芯片允许至少10倍更有效地利用所施加的电位，并且可以建立在自由流动等电聚焦期间从pH 3到10的几乎线性的pH梯度。此外，流体动力学聚焦与自由流动电泳相结合的应用可用于将分离的组分引导至特定的芯片出口。作为示范，通过自由流动区带电泳和通过自由流动等电聚焦，采用横跨分离室的高达150 V的横向电压，分离和聚焦几种标准荧光标记物。
This paper describes a microfabricated free-flow electrophoresis device with integrated ion permeable membranes. In order to obtain continuous lanes of separated components an electrical field is applied perpendicular to the sample flow direction. This sample stream is sandwiched between two sheath flow streams, by hydrodynamic focusing. The separation chamber has two open side beds with inserted electrodes to allow ventilation of gas generated during electrolysis. To hydrodynamically isolate the separation compartment from the side electrodes, a photopolymerizable monomer solution is exposed to UV light through a slit mask for in situ membrane formation. These so-called salt- bridges resist the pressure driven fluid, but allow ion transport to enable electrical connection. In earlier devices the same was achieved by using open side channel arrays. However, only a small fraction of the applied voltage was effectively utilized across the separation chamber during free-flow electrophoresis and free-flow isoelectric focusing. Furthermore, the spreading of the carrier ampholytes into the side channels resulted in a very restricted pH gradient inside the separation chamber. The chip presented here allows at least 10 times more efficient use of the applied potential and a nearly linear pH gradient from pH 3 to 10 during free-flow isoelectric focusing could be established. Furthermore, the application of hydrodynamic focusing in combination with free-flow electrophoresis can be used for guiding the separated components to specific chip outlets. As a demonstration, several standard fluorescent markers were separated and focused by free-flow zone electrophoresis and by free-flow isoelectric focusing employing a transversal voltage of up to 150 V across the separation chamber.