In vitro cell proliferation analysis

The rate of cellular proliferation was analyzed with an RT-CES system (ACEA Bioscience, San Diego, CA, USA). Cells were grown on the surfaces of microelectronic sensors, which are composed of circle-online electrode arrays and are integrated into the bottom surfaces of the microtiter plate. Changes in cell number were monitored and quantified by detecting sensor electrical impedance. Cell index values obtained on the RT-CES system were quantitatively correlated with the cell numbers.³¹ HepG2 cells were harvested after different treatments and seeded into a 16-well strip at a density of 1 × 10³ cells/well. The sensor devices were placed into the 5% CO₂ incubator and the cell index value was determined every 2 h automatically by the RT-CES system for up to 84 h.³²