The dielectric behaviour of living cell suspensions

The dielectric permittivity of suspensions of arbitrarily shaped, shelled and charged particles is calculated in the limit of small concentrations and weak applied electrical fields. It is proved that the dielectric behaviour at low frequencies is dominated by the effects of the diffusion of the free charges on the shell surfaces. Our theoretical formula is valid in the low range of frequencies (alpha dispersion) as well as in the high range of frequencies (beta dispersion). It will result that one can measure the membrane electrical potential by a simple investigation of the dielectric properties of living cell suspensions.