Dielectric cytometry with three-dimensional cellular Modeling

We have developed what we believe is an efficient method to determine the electric parameters (the specific membrane capacitance Cm and the cytoplasm conductivity kappa(i)) of cells from their dielectric dispersion. First, a limited number of dispersion curves are numerically calculated for a three-dimensional cell model by changing C-m and kappa(i), and their amplitudes Delta epsilon and relaxation times tau are determined by assuming a Cole-Cole function. Second, regression formulas are obtained from the values of Delta epsilon and tau and then used for the determination of C-m and kappa(i) from the experimental Delta epsilon and tau. This method was applied to the dielectric dispersion measured for rabbit erythrocytes (discocytes and echinocytes) and human erythrocytes (normocytes), and provided reasonable C-m and kappa(i) of the erythrocytes and excellent agreement between the theoretical and experimental dispersion curves.