Dielectric Properties and Ion Mobility in Erythrocytes

Abstract

The impedance of erythrocytes of man, cattle, sheep, dog, cat, rabbit, and chicken was measured in the range from 0.5 to 250 Mc. The dielectric constant of the red cell interior is 50 at 250 Mc, varies but little with species, and can readily be accounted for by the cells' hemoglobin content. The electrical conductivity of the red cell interior was determined between 70 and 100 Mc. The values differ from species to species within the rather limited range from 4.4 to 5.3 mmho/cm. Removal of the cell membranes does not affect the conductivity. Hence, the cell interior behaves, from an electrical point of view, like a highly concentrated hemoglobin solution. A theoretical value for the electrical conductivity of erythrocyte interiors, which is calculated on the basis of the salt content of the cell, ion mobility, and the volume concentration of the hemoglobin, is roughly twice as large as the measured value. This discrepancy is typical not only of the red blood cell. Pertinent measurements show that it is probably caused by hydrodynamic and possibly by electrostatic effects also, which lower the mobility of the ions. From the lower electrical mobility it appears that a lowered diffusion constant of the electrolytes and nonelectrolytes within the cell is indicated.

Mathematical modeling of electro-rotation spectra of small particles in liquid solutions: Application to human erythrocyte aggregates

“…The frequency response of the electro- In the present case, the rouleaux are approximated to solid homogeneous cylinders of length = 2L × s ( Figure 1C) with a relative permittivity ε p = 50 and conductivity σ p = 0.5 S m -1 (32). For s ≥ 4, the aggregation length corresponds to short cylinders whose symmetry axis lines up with the external electric field vector, while for s ≤ 3 a reorientation will occur with the erythrocyte radius vector now in parallel to the external field.…”

Impedance spectroscopy using maximum length sequences: Application to single cell analysis

“…In particular, impedance ͑or dielectric͒ spectroscopy has been used to measure the passive electrical properties of biological cells for many years. [25][26][27][28] The complex electrical impedance of a system Z ͑j ͒ is calculated from the measured current I r ͑t͒ passing through the system when a spectrally dense voltage source U s ͑t͒ is applied to the sample.…”

Dielectric spectroscopy of energy coupling membranes: Chloroplast thylakoids

“…The electrode cell was contained within a thermostatted water jacket, and all measurements were carried out at 20°C. The Pt electrodes, which led directly to the impedance analyser, were of the pin-type [48] and were given a heavy coat of Pt black. The dimensions of the electrodes were 1 mm x 8 mm and their separation cu.…”