Effect Of Temperature On The Electrorotation Behavior Of Human Red Blood Cells

Abstract

The dielectric parameters of Human Red Blood Cells (HRBCs) were investigated by Electrorotation (ER). Suspended HRBCs were exposed to rotating electric fields in the range from 50 kHz to 250 MHz in a rectangular 4–electrode microchip chamber. ER spectra was recorded at external conductivities ranging from 0.02 – 3.00 S/m. The electrode structures were fabricated on glass chips by laser ablation of a platinum layer. Different measuring temperatures were used. At low conductivities, the temperature of the microscopic stage was kept constant by a thermostat. At higher medium conductivities, the additional temperature increase in the measuring volume due to Joule heating was registered. Measured data in the range from 20 to 35°C were then sorted according to different temperature classes of a width of 5 K. The first and the second characteristic peak frequencies of ER were plotted over medium conductivity and interpreted using an oblate single shell model with a dispersive cytoplasm and temperature dependent electric cell parameters. Key words: Erythrocyte, AC-electrokinetics, impedance, dispersion, ellipsoidal cell model, electric cell properties