Changes in the properties of normal human red blood cells during in vivo aging.

The changes in red blood cells (RBC) as they age and the mechanisms for their eventual removal have been of interest for many years. Proposed age-related changes include dehydration with increased density and decreased size, increased membrane IgG, loss of membrane phospholipid asymmetry, and decreased activity of KCl cotransport. The biotin RBC label allows unambiguous identification of older cells and exploration of their properties as they age.