Improved method for impedance measurements of mammalian cells

This study describes the use of impedance spectroscopy as a non-invasive tool to monitor cell proliferation and morphology and to obtain better measurements of cell kinetics. The goal was to determine test frequencies at which the cell behaviour towards different chemicals and toxins can be monitored with good time resolution. For optimisation of the test frequency it is in the first instance necessary to measure an impedance spectrum of the confluent cell layer. Secondly, the frequency of the highest peak in the spectrum will be determined and further experiments will be carried out at this fixed test frequency. In contrast to measurements at the mainly used 10 kHz (33%), signal differences between a confluent cell layer and cells after treatment with 0.2% Triton X-100 of up to 60% were obtained. In this work the measurements were carried out using interdigitated electrode structures (IDES) on a glass substrate. Impedance spectra of confluent L929 and MDA cell layers were obtained with the Solartron response analyzer.