Differences in the AC electrodynamics of viable and non-viable yeast cells determined through combined dielectrophoresis and electrorotation studies

An electrode system is described for the near-simultaneous application and measurement of translational, levitational and rotational forces induced by AC electric fields, and this has been used to investigate the differences in the AC electrodynamics of viable and non-viable yeast cells. A new approach to the theoretical modelling of the experimental data has enabled these differences to be quantified in terms of changes in the conductivity of the cytoplasmic membrane and cell interior. The results are considered to have potentially important biomedical and biotechnological applications.