Low Frequency Impedimetric Cell Counting: Analytical Modeling and Measurements.

• Analytical model of capacitive nature of lymphocyte suspension. • Dielectric anisotropy in the cell and nuclear membranes has been considered. • Variation of electrical parameters with cell count has been observed. • Low frequency phenomenon has been observed. • The study is focused on the rapid count of lymphocytes in a suspension. Biological constituents have unique dielectric properties by virtue of which these can be analyzed both quantitatively and qualitatively by employing bio-dielectric measurement techniques and electrical impedance spectroscopy exhibits immense potential in this context. In this study, an analytical impedimetric model has been developed to describe bio-dielectric behavior of the lymphocyte suspensions with different cell counts. Emphasis has been given to incorporate the effect of dielectric anisotropy which is apparent between the cell and nuclear membranes and measured in the low frequency range. The relatively low frequency range is chosen to probe the strong dependence of complex membrane behavior provided by the cells. Such dielectric anisotropy originates from the flow dynamics of ions through the hydrophobic interior of polar lipid-bilayer membrane. Successive models have been developed and compared with the relevant experimental data for formulating the system capacitance in a most generalized approach. The capacitance values have been observed to decrease with both the increase of measuring frequency and cell count, however, its impedance decreases with frequency and increases with cell count. Such nature is attributed to the localization of polar response in the membrane-base solution interfaces. The work demonstrates a rapid and deterministic approach to estimate lymphocyte count which will augment the existing prediction techniques for relevant physiological disorders. [ABSTRACT FROM AUTHOR]