Membrane surface charge and morphological and mechanical properties of young and old erythrocytes

Abstract

Abstract The membrane surface charge and the morphological and mechanical properties of living erythrocytes in normal physiological conditions were studied as a function of cell age. The young and old cells were separated from fresh rabbit blood by using Percoll density gradients. A novel multi-dimensional microscope was employed to perform real-time, non-invasive in situ measurements on the membrane bending elastic modulus and the cell shape and size. A phase-analysis micro-electrophoresis laser scattering technique was used to measure the surface charge density. The results show that the membrane Zeta potential of red blood cells is reduced when they become old, thus leading to an increase of their membrane bending elastic modulus and a marked change of their size and shape.