Fractionation of human erythrocytes on the basis of their age

HUMAN erythrocytes have a life-span in the circulation of approximately 120 days1. They are incapable of cell division and consequently leave no progeny. These characteristics make them attractive subjects for the study of biochemical changes incident to normal maturation and senescence, assuming it were possible to separate them into groups of old, middle-aged, and young cells without the use of artificial haematopoietic stimuli2. This communication presents a method of red cell fractionation which complies with these criteria.