The radio-frequency dielectric properties of yeast cells measured with a rapid, automated, frequency-domain dielectric spectrometer

Abstract

SYMBOLS USED IN THIS PAPER E'real part of the complex permittivity 0' -0,' c'f = -imaginary part of the permittivity; dielectric loss 2afc.dielectric constant of free space = 8.854 X 10-14 F/cm real part of the complex conductivity E;) imaginary part of the complex conductivity measuring frequency (Hz) characteristic frequency of a dispersion (Hz) membrane capacitance per unit area volume fraction of cell-membrane-bounded space ratio of low frequency conductivity to conductivity of suspending medium cell radius thickness of cell membrane and wall relaxation time specific enclosed volume (cm3/g dry weight)Subscripts limiting value at low frequencies limiting value at high frequencies suspending medium* To whom all correspondence should be addressed.0302-4598/83/$03.00 0 1983 Elsevier Sequoia S.A. SUMMARY(1) A computerized, rapid-scanning, frequency-domain dielectric spectrometer, capable of operating in the range 5 Hz-13 MHz, and based on commercially available components, is described.(

Evidence from its temperature dependence that the ?-dielectric dispersion of cell suspensions is not due solely to the charging of a static membrane capacitance

“…The dielectric increment of ca. 8 permittivity units (rag dry wt/ml)-1 is in line with those observed previously by us (Harris and Kell 1983;Harris etal. 1987) and others (Asami et al 1980).…”

Numerical Determination of Transmembrane Voltage Induced on Irregularly Shaped Cells

“…The specific conductivity of the cell interior was set to 0.2 S/m, a typical conductivity of the cell cytoplasm, 14 and the specific conductivity of the rest of the block (the cell exterior) was set to 0.15 S/m, which is a typical value of the low conductivity extracellular medium. 34 Two of the opposite vertical faces of the block were modeled as electrodes, which was done by assigning fixed electric potentials; 1 V to one electrode, and 0 V to the other (ground).…”

Effect of the shape of human erythrocytes on the evaluation of the passive electrical properties of the cell membrane

“…Moreover, the frequency-dependent response of biological cell suspensions can be investigated in details. This technique has been applied to different types of biological systems, ranging from human normal and pathological erythrocytes [5][6][7], lymphocytes [8,9], yeast cells [10] to plant protoplasts [11]. The electrical characterization of the erythrocyte cell membrane has been generally developed on the basis of different models, at a different degree of complexity, involving spherical [12] or ellipsoidal shaped particle models [13,14].…”