Huang Liang, Tu Long, Zeng Xueyong, Mi Lu, Li Xuzhou, Wang Wenhui
State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, Beijing, China.
Micromachines (Basel). 2016 Aug 12;7(8):141. doi: 10.3390/mi7080141.
Single cell manipulation technology has been widely applied in biological fields, such as cell injection/enucleation, cell physiological measurement, and cell imaging. Recently, a biochip platform with a novel configuration of electrodes for cell 3D rotation has been successfully developed by generating rotating electric fields. However, the rotation platform still has two major shortcomings that need to be improved. The primary problem is that there is no on-chip module to facilitate the placement of a single cell into the rotation chamber, which causes very low efficiency in experiment to manually pipette single 10-micron-scale cells into rotation position. Secondly, the cell in the chamber may suffer from unstable rotation, which includes gravity-induced sinking down to the chamber bottom or electric-force-induced on-plane movement. To solve the two problems, in this paper we propose a new microfluidic chip with manipulation capabilities of single cell trap and single cell 3D stable rotation, both on one chip. The new microfluidic chip consists of two parts. The top capture part is based on the least flow resistance principle and is used to capture a single cell and to transport it to the rotation chamber. The bottom rotation part is based on dielectrophoresis (DEP) and is used to 3D rotate the single cell in the rotation chamber with enhanced stability. The two parts are aligned and bonded together to form closed channels for microfluidic handling. Using COMSOL simulation and preliminary experiments, we have verified, in principle, the concept of on-chip single cell traps and 3D stable rotation, and identified key parameters for chip structures, microfluidic handling, and electrode configurations. The work has laid a solid foundation for on-going chip fabrication and experiment validation.
单细胞操作技术已在生物领域得到广泛应用，如细胞注射/去核、细胞生理测量和细胞成像。最近，通过产生旋转电场，成功开发了一种具有用于细胞三维旋转的新型电极配置的生物芯片平台。然而，该旋转平台仍有两个主要缺点需要改进。首要问题是没有片上模块来方便将单个细胞放置到旋转腔室中，这导致在实验中手动将单个10微米级的细胞移液到旋转位置的效率非常低。其次，腔室内的细胞可能会出现旋转不稳定的情况，这包括重力导致的下沉到腔室底部或电力导致的平面内移动。为了解决这两个问题，在本文中，我们提出了一种新型微流控芯片，它在一个芯片上同时具备单细胞捕获和单细胞三维稳定旋转的操作能力。这种新型微流控芯片由两部分组成。顶部捕获部分基于最小流动阻力原理，用于捕获单个细胞并将其输送到旋转腔室。底部旋转部分基于介电电泳（DEP），用于在旋转腔室内以增强的稳定性对单个细胞进行三维旋转。这两部分对齐并键合在一起，形成用于微流控操作的封闭通道。通过COMSOL模拟和初步实验，我们原则上验证了片上单细胞捕获和三维稳定旋转的概念，并确定了芯片结构、微流控操作和电极配置的关键参数。这项工作为正在进行的芯片制造和实验验证奠定了坚实的基础。
