Effects of digitonin and glutaraldehyde on the preservation of erythrocyte membrane structures

In erythrocyte membranes digitonin induces different structural alterations. Crosslinking of the membrane proteins by a pretreatment with glutaraldehyde cannot suppress these alterations completely. The bulged, elongated and the flat, rectangular particle-free areas are by their appearance two types of lipid domains. The other structures are derived from these domains, as supported by the observed transition stages. An analysis of the behaviour of the structures by different digitonin concentrations, after a pretreatment of the intact erythrocytes and ghosts with glutaraldehyde, and after an incubation at 37 degrees C or at 2 degrees C, results in a differentiation between "phase-separation" and "phase-formation". "Phase-separation" occurs at a low digitonin concentration, is suppressed to a high extent by glutaraldehyde pretreatment and is stabilized by low temperature. "Phase-formation" occurs at higher digitonin concentrations, is not suppressed by glutaraldehyde pretreatment and can be suppressed by low temperature.