Dittrich Petra S, Schwille Petra
Experimental Biophysics Group, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
Anal Chem. 2003 Nov 1;75(21):5767-74. doi: 10.1021/ac034568c.
Presented is a novel approach for an integrated micro total analysis system (microTAS) based on a microfluidic on-chip device that supports ultrasensitive confocal detection of fluorescent cells and particles and subsequently allows for their precise sorting in the fluid phase with respect to spectroscopic properties, such as brightness and color. The hybrid silicone elastomer/glass chip first comprises a branched channel system to initiate fluid mixing and to hydrodynamically focus the sample solution down to a thin flow layer, matching the size of the confocal detection volume placed at that position and, thus, providing a high detection efficiency. In the subsequent on-chip module, the dispersed cells or particles can be sorted into two different output channels. The sorting process is realized by a perpendicular deflection stream that can be switched electrokinetically. The performance of the automated sorting routine is demonstrated by precise partition of a mixture of differently colored fluorescent beads. Moreover, the specifically branched channel geometry allows for direct implementation of reaction steps prior to detection and sorting, which is demonstrated by inducing a selective recognition reaction between the fluorescent protein R-phycoerythrin and a mixture of live bacterial cells exhibiting or lacking the respective surface antigens.
本文介绍了一种基于微流控芯片装置的新型集成微全分析系统（microTAS）方法，该装置支持对荧光细胞和颗粒进行超灵敏共聚焦检测，并随后能够根据光谱特性（如亮度和颜色）在流体相中对其进行精确分选。这种硅橡胶弹性体/玻璃混合芯片首先包括一个分支通道系统，用于启动流体混合并通过流体动力学将样品溶液聚焦成一个薄流动层，使其与位于该位置的共聚焦检测体积大小相匹配，从而提供高检测效率。在随后的芯片模块中，分散的细胞或颗粒可被分选到两个不同的输出通道。分选过程通过一个可电动切换的垂直偏转流来实现。通过对不同颜色荧光珠混合物的精确分离，展示了自动分选程序的性能。此外，这种特殊的分支通道几何结构允许在检测和分选之前直接实施反应步骤，通过诱导荧光蛋白R-藻红蛋白与具有或缺乏相应表面抗原的活细菌细胞混合物之间的选择性识别反应来证明这一点。
