Electrical characterization of suspended HeLa cells using ECIS based biosensor

Impedance spectroscopy of biological cells has been used to monitor cell status, e.g. cell proliferation, viability, etc. It is also a fundamental method for the study of the electrical properties of cells which has been utilised for cell identification in investigations of cell behaviour under an applied electric field. Impedance measurement of cell suspensions i.e. a group of cells within a culture medium provides better information about the cell properties than that of single cell measurement. This paper presents electrical characterization of cervical carcinoma cell lines (HeLa) suspending in PBS medium using electric cell-substrate impedance sensing based biosensor. The impedance data are measured using commercially available ECIS device for without and with HeLa cells in the PBS culture medium over a frequency sweep of 100 Hz to 10 MHz. An electrical equivalent circuit of ECIS system with cells suspending in medium is developed and the corresponding electrical parameters are extracted by fitting the experimental data in fitting software. The result also shows that impedance data becomes constant after a certain time for a particular frequency and this response can be used to monitor the cell attachment and confluence.