Aspects of nonlinear dielectric spectroscopy of biological cell suspensions

In this paper the technique of nonlinear dielectric spectroscopy is employed to examine the nonlinear response of a suspension of the yeast S. cerevisiae to a low frequency perturbating ac electric field. Metabolically active and resting yeast states, as well as the electrolyte medium are considered, and experimental time-course spectral data are presented. Conductivity is found to increase in the active case, resulting in variations in magnitude of the applied field. An empirical model is fitted to the experimental data at discrete points over time, enabling simulation and resulting in a software-based method to compensate for these variations in effective field strength.