Efficient Cell Impedance Measurement by Dielectrophoretic Cell Accumulation and Evaluation of Chondrogenic Phenotypes.

The quantitative and functional analyses of cells are important for cell-based therapies. In this study, to establish the quantitative cell analysis method, we propose an impedance measurement method supported by dielectrophoretic cell accumulation. An impedance measurement and dielectrophoresis device was constructed using opposing comb-shaped electrodes. Using dielectrophoresis, cells were accumulated to form chain-like aggregates on the electrodes to improve the measurement sensitivity of the electrical impedance device. To validate the proposed method, the electrical impedance and capacitance of primary and de-differentiated chondrocytes were measured. As a result, the impedance of the chondrocytes decreased with an increase in the passage number, whereas the capacitance increased. Therefore, the impedance measurement method proposed in this study has the potential to identify chondrocyte phenotypes.