Dielectric spectroscopy reveals nanoholes in erythrocyte ghosts

Abstract

When blood is diluted with water, erythrocytes swell and then burst to release haemoglobin molecules, viz. hypotonic hemolysis. The remaining membranes, so-called “ghosts”, have transient holes, which are resealed under physiological conditions. About 50 years ago it was reported that ghost suspensions showed peculiar dielectric dispersion below 10 kHz, termed α-dispersion, which was not found for intact erythrocyte suspensions. The finding, however, has never been traced because of difficulty in low-frequency measurement due to electrode polarization (EP) effects, and therefore the origin of the α-dispersion has not been understood. In this study, the α-dispersion has been revealed using a new type of measurement cell capable of reducing the EP effects. The properties of the α-dispersion were exactly interpreted by modelling ghosts as a spherical cell with a single hole. The numerical simulation with the cell model provided a linear relation between the characteristic frequency of the α-dispersion and the hole radius, the hole radius thereby being determined straightforwardly.