Laboratory of Life Sciences Electronics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Electrophoresis. 2019 Jul;40(14):1830-1838. doi: 10.1002/elps.201900097. Epub 2019 Jun 3.
This paper reports a method for label-free single-cell biophysical analysis of multiple cells trapped in suspension by electrokinetic forces. Tri-dimensional pillar electrodes arranged along the width of a microfluidic chamber define actuators for single cell trapping and selective release by electrokinetic force. Moreover, a rotation can be induced on the cell in combination with a negative DEP force to retain the cell against the flow. The measurement of the rotation speed of the cell as a function of the electric field frequency define an electrorotation spectrum that allows to study the dielectric properties of the cell. The system presented here shows for the first time the simultaneous electrorotation analysis of multiple single cells in separate micro cages that can be selectively addressed to trap and/or release the cells. Chips with 39 micro-actuators of different interelectrode distance were fabricated to study cells with different sizes. The extracted dielectric properties of Henrietta Lacks, human embryonic kidney 293, and human immortalized T lymphocytes cells were found in agreements with previous findings. Moreover, the membrane capacitance of M17 neuroblastoma cells was investigated and found to fall in in the range of 7.49 ± 0.39 mF/m .
本文报道了一种通过电动力学力将悬浮在溶液中的多个细胞无标记单细胞生物物理分析的方法。沿着微流控室的宽度排列的三维柱状电极定义了用于通过电动力学力捕获和选择性释放单细胞的执行器。此外，与负 DEP 力结合，可以诱导细胞旋转以抵抗流动保留细胞。作为电场频率函数的细胞旋转速度的测量定义了允许研究细胞介电特性的电动旋转谱。本文提出的系统首次展示了可用于捕获和/或释放细胞的多个单个细胞在单独的微笼中的同时电动旋转分析。制造了具有 39 个不同电极间距离的微执行器的芯片，以研究不同大小的细胞。从亨丽埃塔·拉克斯（Henrietta Lacks）、人胚肾 293 和人永生化 T 淋巴细胞细胞中提取的介电特性与先前的发现一致。此外，还研究了 M17 神经母细胞瘤细胞的膜电容，并发现其范围在 7.49 ± 0.39 mF/m 之间。
