Isopycnic centrifugation of human, pigeon and guinea pig erythrocytes.

Abstract

The buoyant densities of human erythrocytes with normal (HbAA) and abnormal heterozygous haemoglobins (HbSS, HbAS, HbSC) as well as erythrocytes from guinea pig and pigeon were determined by centrifugation in discontinuous density gradients of metrizamide. Guinea pig, pigeon and human erythrocytes from normal human adult (HbAA) and from heterozygote HbAS were found to have the same density of 1.1381 g/cm3, while erythrocytes from a sickle-cell patient (HbS) and from a heterozygote HbSC, HbSS and HbSC, which are known to have a higher lipid content than isovolumic normal cells, had a lower density of 1.1261 g/cm3. When centrifugation was carried out under non-equilibrium conditions (rate zonal), several sedimentation bands were obtained from each erythrocyte preparation. Differences in the sedimentation rates were unrelated to the haemoglobin composition of the erythrocytes. It is suggested that the lower density of the erythrocytes associated with sickle-cell disease may have significant consequences in the circulation of such cells and in the clinical sequence of the sickling process.