Astorga-Wells Juan, Vollmer Susanne, Bergman Tomas, Jörnvall Hans
Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
Anal Chem. 2007 Feb 1;79(3):1057-63. doi: 10.1021/ac061699f.
Electrocapture is a multifunctional microfluidic tool that can be used for concentration, sample cleanup, multistep reactions, and separation of biomolecules. Herein, we investigate the mechanisms underlying the electrocapture principle. A microfluidic electrocapture device was found to be capable of generating regions of different electric field, which are maintained in the flow by electric and hydrodynamic forces, with the zones of lower electric field strength upstream of those with higher strength. In addition to detection of the local electric fields by direct measurements, the existence of the zones was observed by the capture of a solution containing Coomassie and myoglobin. The two molecules were captured at different spots in a steady-state manner and were released (separated) at different electric fields. Considering these observations and the experimental values for the electric field strengths, flow velocities, and electrophoretic mobilities of DNA, proteins, and peptides, it is concluded that the macromolecules are captured between the field zones by a stacking mechanism.
电捕获是一种多功能微流控工具，可用于生物分子的浓缩、样品净化、多步反应和分离。在此，我们研究电捕获原理背后的机制。发现微流控电捕获装置能够产生不同电场区域，这些区域通过电场力和流体动力维持在流动中，较低电场强度区域位于较高强度区域的上游。除了通过直接测量检测局部电场外，通过捕获含有考马斯亮蓝和肌红蛋白的溶液观察到了这些区域的存在。这两种分子以稳态方式在不同位置被捕获，并在不同电场下释放（分离）。考虑到这些观察结果以及DNA、蛋白质和肽的电场强度、流速和电泳迁移率的实验值，可以得出结论，大分子通过堆积机制捕获在场区之间。
