Electroorientation Studies on Electrophysical Properties of Erythrocytes in Radio-Frequency Range of Alternating Electric Field

Influence of Cytoplasm Electrolyte Concentration on Maxwell−Wagner Polarizability of Bacteria E. coli

“…Its relaxation takes place in the megahertz range and does not depend on the particle’s size. In the case of biological cells , this polarization type is due to accumulation of ions in the cytoplasm nearby the bilayer lipid membrane, which is practically nonconductive. So, the value of the MW polarizability increases with the increase in the ionic strength of the electrolyte inside the bacteria cells.…”

“…The electric properties of bacteria, especially of E. coli, have been widely studied by electrophoresis, , dielectric spectroscopy, , and electro-optics. ,, The electrophoretic mobility depends on the surface charge density only on the external side of the bacteria, whereas the dielectric spectroscopy and the electro-optics give information about all charges in the cells. The electro-optical methods are based on orientation of colloid particles in an electric field; the degree of orientation is proportional to the electric polarizability .…”

“…An alternative approach is the so-called electrophysical (EPh) model of bacteria, based on the MW type polarization . In that case the bacterium is considered like a homogeneous ellipsoid with complex dielectric permittivity.…”

“…The values of the electric conductivity and dielectric permittivity are frequency-dependent and have characteristic frequencies for α- and β-dispersions . The EPh model in its more advanced variant considers the bacterial cell as a hollow ellipsoid having one or more layers with specific conductivity and permittivity of the core and each of the layers, respectively . The EPh model shows a presence of few dispersion regions with different relaxation frequencies and polarizability values along and across the bacterium .…”

“…The EPh model in its more advanced variant considers the bacterial cell as a hollow ellipsoid having one or more layers with specific conductivity and permittivity of the core and each of the layers, respectively . The EPh model shows a presence of few dispersion regions with different relaxation frequencies and polarizability values along and across the bacterium . By adjustment of the parameters of the model it is possible to fit the theoretical frequency dependence of the polarizability to the experimental one.…”