Zhang Wenjing, He Muyi, Yuan Tao, Xu Wei
School of Life Science, Beijing Institute of Technology, Beijing, P. R. China.
College of Information Science, Shenzhen University, Shenzhen, P. R. China.
Electrophoresis. 2017 Dec;38(24):3130-3135. doi: 10.1002/elps.201700215. Epub 2017 Oct 12.
The measurement of electroosmotic flow (EOF) is important in a capillary electrophoresis (CE) experiment in terms of performance optimization and stability improvement. Although several methods exist, there are demanding needs to accurately characterize ultra-low electroosmotic flow rates (EOF rates), such as in coated capillaries used in protein separations. In this work, a new method, called the two-step method, was developed to accurately and rapidly measure EOF rates in a capillary, especially for measuring the ultra-low EOF rates in coated capillaries. In this two-step method, the EOF rates were calculated by measuring the migration time difference of a neutral marker in two consecutive experiments, in which a pressure driven was introduced to accelerate the migration and the DC voltage was reversed to switch the EOF direction. Uncoated capillaries were first characterized by both this two-step method and a conventional method to confirm the validity of this new method. Then this new method was applied in the study of coated capillaries. Results show that this new method is not only fast in speed, but also better in accuracy.
在毛细管电泳（CE）实验中，电渗流（EOF）的测量对于性能优化和稳定性提升而言至关重要。尽管存在多种方法，但准确表征超低电渗流速率（EOF速率）仍有迫切需求，比如在蛋白质分离中使用的涂层毛细管里。在这项工作中，一种名为两步法的新方法得以开发，用于精确且快速地测量毛细管中的EOF速率，特别是用于测量涂层毛细管中的超低EOF速率。在这种两步法中，EOF速率是通过测量中性标记物在两个连续实验中的迁移时间差来计算的，其中引入压力驱动以加速迁移，并反转直流电压来切换EOF方向。首先用这种两步法和传统方法对未涂层毛细管进行表征，以确认这种新方法的有效性。然后将这种新方法应用于涂层毛细管的研究。结果表明，这种新方法不仅速度快，而且精度更高。
