Impedance monitoring of herpes simplex virus-induced cytopathic effect in Vero cells

New regulations like, e.g. the European Registration, Evaluation and Authorization of Chemicals Regulation (the REACH regulation) require efficient and easy to use cell-based systems to get toxicological data of chemicals or to detect viruses in small samples of serum. In this article, we investigate whether the effect of herpes simplex viruses (HSV) on Vero (green monkey kidney) cells can be detected by using a fabricated electrode-based chip and impedance spectroscopy at low virus concentrations. Using the fabricated electrode-based chip and impedance spectroscopy, we measured the impedance spectra of Vero cells during the cultivation or infection with HSV at the low multiplicity of infection (MOI) of 0.0006 even. The state of Vero cells during the cultivation or HSV infection was clearly reflected in impedance measurements and microscopic observations. From analyses of impedance spectra, it was shown that the monitoring of parameters related with cell/cell or cell/substrate junction is useful to understand the cell behaviour and also to quantify the influence of HSV infection on Vero cells sensitively. Further, the fitted parameters depended on the MOI of HSV.