We report separation of genomic DNA (48 kbp) from bovine serum albumin (BSA) by the electro-hydrodynamic coupling between a pressure-driven flow and a parallel electric field. Electro-hydrodynamic extraction exploits this coupling to trap DNA molecules at the entrance of a microfluidic contraction channel, while allowing proteins and salts to be flushed from the device. Samples (10 μL) containing λ-DNA (1 ng) and BSA (0.3 mg) were injected directly into the device and convected to the contraction channel entrance by a flowing buffer solution. The DNA remains trapped in this region essentially indefinitely, while proteins and salts are eluted. The effectiveness of the concept has been assessed by fluorescence measurements of DNA and BSA concentrations. Electro-hydrodynamic extraction in a single-stage device was found to enhance the concentration of DNA 40-fold, while reducing the BSA concentration by four orders of magnitude. The relative concentrations of DNA to BSA at the contraction channel entrance can be as large as 1.5 : 1, corresponding to an A260/280 ratio of 1.9. The maximum yield of DNA from a salt-free solution is 50%, while salted (150 mM) solutions have a lower yield (38%).

中文翻译：

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从DNA和牛血清白蛋白的混合物中电流体动力学提取DNA。

我们报告了从基因组DNA（48 kbp）从牛血清白蛋白（BSA）分离通过压力驱动流和平行电场之间的电-液动力耦合。电液动力萃取利用这种耦合将DNA分子捕获在微流体收缩通道的入口，同时允许蛋白质和盐类从设备中冲洗掉。将包含λ-DNA（1 ng）和BSA（0.3 mg）的样品（10μL）直接注入设备中，并通过流动的缓冲溶液对流至收缩通道入口。DNA基本上无限期地保留在该区域中，而蛋白质和盐则被洗脱。该概念的有效性已通过DNA和BSA浓度的荧光测量来评估。发现在单级设备中进行电液动力萃取可将DNA浓度提高40倍，同时将BSA浓度降低四个数量级。收缩通道入口处DNA与BSA的相对浓度可能高达1.5：1，相当于A260 / 280的比例为1.9。无盐溶液中DNA的最大产率为50％，而盐溶液（150 mM）的产率较低（38％）。