Dai Jinhua, Ito Takashi, Sun Li, Crooks Richard M
Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, TX 77842-3012, USA.
J Am Chem Soc. 2003 Oct 29;125(43):13026-7. doi: 10.1021/ja0374776.
We report a simple and efficient method for enriching the concentration of charged analytes within microfluidic channels. The method relies on exerting spatial control over the electrokinetic velocity of an analyte. Specifically, the electroosmotic (eo) velocity of the buffer solution in one region of the microfluidic system opposes the electrophoretic (ep) velocity of the analyte in the other region. This results in ep transport of DNA to the location where the ep and eo velocities are equal and opposite. Accumulation of the analyte occurs at this location. This enrichment method is conceptually distinct from field-amplification stacking, isotachophoresis, micelle sweeping, size exclusion, and other methods that have been previously reported. The method requires no complex microfabricated structures, no special manipulation of the solvent, and the enriched analyte remains in solution rather than being captured on a solid support. A concentration enrichment factor of 800 can be achieved for 20mer DNA in a fluidic channel having dimensions of 100 mum x 25 mum x 5 mm. The time required to achieve this level of enrichment is 300 s, and the enriched zone has a minimum width of 100 mum.
我们报告了一种在微流控通道内富集带电分析物浓度的简单高效方法。该方法依赖于对分析物的电动速度进行空间控制。具体而言，微流控系统一个区域中缓冲溶液的电渗（eo）速度与另一区域中分析物的电泳（ep）速度相反。这导致DNA向ep和eo速度大小相等、方向相反的位置进行ep传输。分析物在该位置发生积累。这种富集方法在概念上与场放大堆积、等速电泳、胶束扫集、尺寸排阻以及先前报道的其他方法不同。该方法不需要复杂的微加工结构，无需对溶剂进行特殊处理，并且富集后的分析物仍保留在溶液中，而不是捕获在固体支持物上。在尺寸为100μm×25μm×5mm的流体通道中，对于20聚体DNA可实现800的浓度富集因子。达到这种富集水平所需的时间为300秒，富集区的最小宽度为100μm。
