基于惯性微流原理的微流控芯片用于血浆分离

Separation of blood plasma by inertial focusing using microfluidic chips

血浆是临床生化检验中一类广泛使用的样品,从全血中分离血浆是生命医学研究领域中一项非常重要的技术.惯性微流(inertial microfluidics)原理的主要特点是无需施加任何外力如电磁力等,仅依靠液体流动就可以在微通道内实现一定尺寸的微粒或细胞的聚焦流动.本研究基于惯性微流原理,设计并制备了具有不对称弯管结构通道的微流控芯片.采用制备的荧光微球作为模型样品考察了装置的性能,发现尺寸越大的微球保持惯性聚集流动的流速范围也越大.在此基础上,利用发展的芯片平台成功实现从稀释的血液样品中将血浆分离.使用芯片对样品进行两次分离,即二级分离后,血液中血红细胞的分离效率超过90%.该装置具有结构简单、体积小巧、操作方便等特点,不仅可以快速分离血浆,而且对血细胞基本无损,易于作为功能模块与现有的一些芯片实验室(lab on a chip,LOC)系统集成结合.

Blood plasma is widely used in clinical and biochemical tests, and techniques for plasma separation are essential for biomedical research. The technique of inertial microfluidics provides the capability to focus microparticles or cells in microchannels without the need for active device components. Based on the theory of inertial focusing, we designed and fabricated microfluidic chips with asymmetrically curved channels. Focusing performance was evaluated using homemade fluorescent microspheres as models. We found that the flow velocities required for maintenance of stable inertial focusing varied significantly among microspheres of different sizes. The microdevice was further employed for the separation of plasma from diluted blood samples. We achieved a 90% separation efficiency when the sample was separated twice in the device. These data suggest that microdevices can separate plasma efficiently without damaging blood cells, and can be readily integrated with other analytical devices.