Soft inertial microfluidics for high throughput separation of bacteria from human blood cells
Soft inertial microfluidics for high throughput separation of bacteria from human blood cells
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DOI：
10.1039/b817611f
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发表时间：
2009-01-01
期刊：
影响因子：
6.1
通讯作者：
Hjort, Klas
中科院分区：
文献类型：
--
作者：
Wu, Zhigang;Willing, Ben;Hjort, Klas
我们开发了一种新的方法来分离细菌从人血细胞的基础上软惯性力诱导的迁移与流动定义的弯曲和集中的样品流内的微流体装置。这种方法依赖于不对称鞘流和适当的通道几何形状的组合，以在弯曲和聚焦的样品流段中的样品流体上产生软惯性力，以使较大的颗粒偏转离开，而较小的颗粒保持在原始流动流线上或附近。弯曲和聚焦的样品流和惯性效应是可视化的，并使用在装置中引发的荧光染料进行验证。首先，使用9.9和1.0 μ m的颗粒与基于聚合物的原型的颗粒行为进行了详细研究。原型装置结构紧凑，有效尺寸为3 mm（2）。软惯性效应和偏转距离分别与流体雷诺数（Re）和颗粒雷诺数（Re（p））成正比。我们成功地证明了使用高达18 mL/min的样品流速从高细胞浓度（高于10（8）/mL）的人红细胞中分离细菌（大肠杆菌）。这导致在宽范围的流速下至少300倍富集细菌，并控制流动扩散。分离的细胞被证明是活的。通过凝胶电泳和染色分析细胞分离之前和之后的组分中的蛋白质，以验证红细胞蛋白质从细菌细胞组分中的去除。与其他细胞分选系统相比，这种新的微流体过程是稳健的、可重复的、执行简单的，并且具有高通量。基于这些原理的微流体系统可以很容易地制造用于临床实验室和生物医学应用。
We developed a new approach to separate bacteria from human blood cells based on soft inertial force induced migration with flow defined curved and focused sample flow inside a microfluidic device. This approach relies on a combination of an asymmetrical sheath flow and proper channel geometry to generate a soft inertial force on the sample fluid in the curved and focused sample flow segment to deflect larger particles away while the smaller ones are kept on or near the original flow streamline. The curved and focused sample flow and inertial effect were visualized and verified using a fluorescent dye primed in the device. First the particle behaviour was studied in detail using 9.9 and 1.0 mu m particles with a polymer-based prototype. The prototype device is compact with an active size of 3 mm(2). The soft inertial effect and deflection distance were proportional to the fluid Reynolds number (Re) and particle Reynolds number (Re(p)), respectively. We successfully demonstrated separation of bacteria (Escherichia coli) from human red blood cells at high cell concentrations (above 10(8)/mL), using a sample flow rate of up to 18 mL/min. This resulted in at least a 300-fold enrichment of bacteria at a wide range of flow rates with a controlled flow spreading. The separated cells were proven to be viable. Proteins from fractions before and after cell separation were analyzed by gel electrophoresis and staining to verify the removal of red blood cell proteins from the bacterial cell fraction. This novel microfluidic process is robust, reproducible, simple to perform, and has a high throughput compared to other cell sorting systems. Microfluidic systems based on these principles could easily be manufactured for clinical laboratory and biomedical applications.