School of Mechanical Engineering, Korea University, 136-713, Seoul, Korea.
Lab Chip. 2012 Apr 7;12(7):1347-54. doi: 10.1039/c2lc21304d. Epub 2012 Feb 15.
Pure separation and sorting of microparticles from complex fluids are essential for biochemical analyses and clinical diagnostics. However, conventional techniques require highly complex and expensive labeling processes for high purity separation. In this study, we present a simple and label-free method for separating microparticles with high purity using the elasto-inertial characteristic of a non-Newtonian fluid in microchannel flow. At the inlet, particle-containing sample flow was pushed toward the side walls by introducing sheath fluid from the center inlet. Particles of 1 μm and 5 μm in diameter, which were suspended in viscoelastic fluid, were successfully separated in the outlet channels: larger particles were notably focused on the centerline of the channel at the outlet, while smaller particles continued flowing along the side walls with minimal lateral migration towards the centerline. The same technique was further applied to separate platelets from diluted whole blood. Through cytometric analysis, we obtained a purity of collected platelets of close to 99.9%. Conclusively, our microparticle separation technique using elasto-inertial forces in non-Newtonian fluid is an effective method for separating and collecting microparticles on the basis of size differences with high purity.
从复杂流体中纯分离和分选微粒对于生化分析和临床诊断至关重要。然而，传统技术需要高度复杂和昂贵的标记过程才能实现高纯度分离。在这项研究中，我们提出了一种简单且无需标记的方法，利用微通道流中非牛顿流体的弹惯性特性，以高纯度分离微粒。在入口处，通过从中心入口引入鞘液，将含有微粒的样品流推向侧壁。直径为 1μm 和 5μm 的微粒悬浮在黏弹性流体中，在出口通道中成功分离：较大的微粒明显集中在通道的中心线上，而较小的微粒则继续沿着侧壁流动，几乎没有向中心线的横向迁移。同样的技术进一步应用于从稀释全血中分离血小板。通过细胞计数分析，我们获得了接近 99.9%的收集血小板纯度。总之，我们使用非牛顿流体中的弹惯性力的微粒分离技术是一种基于大小差异的高效分离和收集微粒的方法，具有高纯度。
