The combination of hydrodynamic actuation with an opposing electrophoretic force in viscoelastic liquids enables the separation, concentration, and purification of DNA. Obtaining good analytical performances despite the use of hydrodynamic flow fields, which dramatically enhance band broadening due to Taylor dispersion, constitutes a paradox that remains to be clarified. Here, we study the mechanism of band broadening in electrohydrodynamic migration with an automated microfluidic platform that allows us to track the migration of a 600 bp band in the pressure-electric field parameter space. We demonstrate that diffusion in the electrohydrodynamic regime is controlled predominantly by the electric field and marginally by the hydrodynamic flow velocity. We explain this response with an analytical model of diffusion based on Taylor dispersion arguments. Furthermore, we demonstrate that the electric field can be modulated over time to monitor and minimize the breadth of a DNA band, and suggest guidelines to enhance the resolution of DNA separation experiments. Altogether, our report is a leap towards to the development of high-performance analytical technologies based on electrohydrodynamic actuation.

中文翻译：

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表征和最小化DNA电流体动力学迁移中的能谱带宽度，以增强尺寸分离。

粘弹性液体中的流体动力学驱动和相反的电泳力相结合，可以分离，浓缩和纯化DNA。尽管使用了流体动力流场，但仍获得了良好的分析性能，该流体流场由于泰勒色散而显着增强了谱带展宽，这是一个有待澄清的悖论。在这里，我们使用自动微流体平台研究了电动流体动力学迁移中的谱带展宽机制，该平台使我们能够跟踪压力电场参数空间中600 bp谱带的迁移。我们证明，在电流体动力学范围内的扩散主要受电场控制，而受流体动力学流速的影响很小。我们使用基于泰勒色散参数的扩散分析模型来解释此响应。此外，我们证明了可以随时间调节电场，以监视和最小化DNA谱带的宽度，并提出指导方针以增强DNA分离实验的分辨率。总而言之，我们的报告是向基于电液动力致动的高性能分析技术发展的飞跃。