Counterflow centrifugation of red cell populations: a cell age related separation technique.

Red cell populations were fractionated on the basis of differences in density by a centrifugation method described by Murphy and on the basis of differences in mean cell volume (MCV) by counterflow centrifugation. By 59Fe-incorporation and determination of the HbA1c content, both methods were studied for their ability to separate red cell populations into fractions of different mean cell age. It can be concluded that separation on the basis of differences in cell volume results in a linear separation according to age whereas separation on the basis of density only results in an accumulation of very young cells in the top fractions. A gradual decrease in cell volume with age, combined with a constant haemoglobin concentration in the cells, indicates release of haemoglobin from the red cells during their lifespan.