Electrical properties of tissues and cell suspensions: mechanisms and models

The electrical properties of tissues and cell suspensions are most unusual. They change with frequency in three distinct steps and their dielectric constants reach enormous values at low frequencies. The author concentrates on the "linear" properties observed with applied fields less than about 1 V/cm. The linear properties of interest include the dielectric constant /spl epsiv/ and conductivity /spl sigma/. Extensive measurements have been carried out over a broad frequency range extending from less than 1 Hz to many GHz. A number of mechanism have been identified which explain the observed data. These mechanisms reflect the various compartments of the biological material. These include membranes and their properties, biological macromolecules and fluid compartments inside and outside membranes. The authors summarize the mechanisms which contribute to the total frequency response.<
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