Wei Wei, Yeung Edward S
Ames Laboratory, United States Department of Energy, Iowa State University, 50011, USA.
Anal Chem. 2002 Aug 1;74(15):3899-905. doi: 10.1021/ac025612b.
A novel approach for on-line concentration of proteins and peptides in capillary electrophoresis (CE) is presented. A short section (approximately 0.5-1 cm) along the capillary was etched with HF. The etched section became a porous membrane that allowed electrical conductivity but prevented passage of the analyte ions. The capillary was isolated into two parts by the etched section. Thus, we were able to use three buffer vials to perform CE experiments in the capillary by applying high voltages independently. Concentration and separation were performed at the two respective regions. When high voltage was applied to the concentration capillary (between the inlet end and the etched section), proteins and peptides were concentrated at the etched portion, because the porous capillary wall allowed only small buffer ions to pass through and there was no electric field gradient beyond that point. After focusing, the narrow sample zone was introduced into the separation capillary (between the etched section and the outlet end) by hydrodynamic flow or by electroosmotic flow. Finally, conventional CE was carried out for separation of the analytes. Several different concentration schemes for proteins and peptides were successfully demonstrated by using this new approach.
本文介绍了一种用于毛细管电泳（CE）中蛋白质和肽在线浓缩的新方法。沿着毛细管蚀刻一小段（约0.5 - 1厘米）。蚀刻部分变成了一个多孔膜，它允许导电但阻止分析物离子通过。毛细管被蚀刻部分隔离成两部分。因此，我们能够通过独立施加高电压，使用三个缓冲瓶在毛细管中进行CE实验。浓缩和分离在两个各自的区域进行。当对浓缩毛细管（入口端和蚀刻部分之间）施加高电压时，蛋白质和肽在蚀刻部分浓缩，因为多孔毛细管壁只允许小的缓冲离子通过，并且在该点之外没有电场梯度。聚焦后，通过流体动力流或电渗流将狭窄的样品区引入分离毛细管（蚀刻部分和出口端之间）。最后，进行常规CE以分离分析物。使用这种新方法成功展示了几种不同的蛋白质和肽浓缩方案。
