Complex viscosity of bovine red blood cells in suspensions

Abstract

The complex viscosity ${\mathit{\eta }}^{\ast }$ has been measured of bovine red blood cells suspended in a medium of isotonic NaCl solutions including dextran and buffered with potassium phosphate at pH 7.0. A multiple lumped resonator apparatus was used at the frequencies of 144, 572, 1491, 3742, and 8026 Hz at 20.0°C. Due to the high molecular weight of dextran the medium also exhibited some viscoelasticity ${\mathit{\eta }}_{\mathrm{s}}^{\ast }$ . So we adopted the complex specific viscosity ${\mathit{\eta }}_{\mathrm{sp}}^{\ast }=\mathrm{(}{\mathit{\eta }}^{\ast }-{\mathit{\eta }}_{\mathrm{s}}^{\ast }\mathrm{)}\mathrm{/}|{\mathit{\eta }}_{\mathrm{s}}^{\ast }|$ . At 20.0°C ${\mathit{\eta }}_{\mathrm{sp}}^{\ast }$ decreased with the frequency where the hematocrit was 0.233 and η_s 0.34 poise. The measurements were made for the medium with different viscosity at 5.0°C and 25.0°C. The results are compared with the theory of elastic shells.