Electrical characteristics analysis of various cancer cells using a microfluidic device based on single-cell impedance measurement

Electrical impedance spectroscopy (EIS) is used to analyze the characteristics of electrochemical materials for biomedical applications. This paper presents a method for differentiating four kinds of cell using impedance measurements at various voltages and frequencies. Four kinds of cell (HeLa, A549, MCF-7, and MDA-MB-231) are analyzed and characterized based on their impedance by a trap-and-measure device. The impedance spectra are obtained by the impedance analyzer at an operating voltage of 0.2–1.0 V and frequency of 20–101 kHz. According to the impedance measurements, HeLa, A549, and MCF-7 cells and the pathological stages of a given cancer cell line (MCF-7 and MDA-MB-231) can be distinguished. The equivalent circuit is modeled as a cell impedance in parallel with the impedance of the culture medium, a cell impedance that contains the cell membrane capacitance, and a cytoplasm resistance. With an increase in the operating voltage, the cytoplasm resistance decreases due to the opening of the ionic channel. For A549, MDA-MB-231, MCF-7, and HeLa cells, the maximum variation of the resistance was obtained in the voltage ranges of 0.8–1.0 V, 0.8–1.0 V, 0.6–0.8 V, and 0.4–0.6 V, respectively. The results reveal that different kinds of cell have different tolerances to an electric field.