Separation of Erythrocytes of Different Ages.

Several methods have been evaluated for the separation of red cells of different ages on the basis of density differences. Simple sedimentation and flotation technics have been found to be unsatisfactory. Centrifugation, followed by a modified sampling procedure, has been demonstrated to provide excellent separation of erythrocyte populations of different ages. Standardization of centrifuge conditions and special precautions against redistribution of red-cell layers have contributed toward an improved and reproducible method for the separation of erythrocytes for subsequent study.