Department of Nano Engineering, Center for Nano Manufacturing, Inje University, 607 Obang-dong, Gimhae 621-749, Republic of Korea.
Analyst. 2013 Mar 7;138(5):1529-37. doi: 10.1039/c3an36261b.
This paper presents an effective electrorotation technique for measuring the dielectric properties of cells using a superposed electrical signal, which can simultaneously generate negative quadrupolar dielectrophoretic (nQDEP) force and electrorotational (ROT) torque. The proposed technique involves a three-dimensional (3D) octode, which includes four electrodes arranged in a crisscross pattern on the top and bottom of a microchannel, respectively. A single cell was trapped in the center of the 3D octode by the nQDEP force and simultaneously rotated by the ROT torque. Using the proposed electrorotation technique, ROT spectra of human leukocyte subpopulations (T and B lymphocytes, granulocytes, and monocytes) and metastatic human breast (SkBr3) and lung (A549) cancer cell lines were accurately measured without any disturbance. Torque on the cells generated by the ROT signal was analyzed theoretically based on the single-shell dielectric model for the cells. Furthermore, the dielectric properties of the cells, such as area-specific membrane capacitance and cytoplasm conductivity, were extracted using the measured ROT spectra and the analyzed torque.
本文提出了一种利用叠加电信号测量细胞介电特性的有效旋电技术，该技术可同时产生负四极介电泳（nQDEP）力和旋电（ROT）扭矩。所提出的技术涉及一个三维（3D）八角形，它包括四个电极，分别在微通道的顶部和底部以十字交叉的方式排列。单细胞被 nQDEP 力困在 3D 八角形的中心，并同时被 ROT 扭矩旋转。使用所提出的旋电技术，可以在没有任何干扰的情况下准确测量人白细胞亚群（T 和 B 淋巴细胞、粒细胞和单核细胞）和转移性人乳腺癌（SkBr3）和肺癌（A549）癌细胞系的 ROT 谱。基于细胞的单壳介电模型，从理论上分析了 ROT 信号对细胞产生的扭矩。此外，使用测量的 ROT 谱和分析的扭矩提取了细胞的介电特性，如面积特异性膜电容和细胞质电导率。
