Red cell age by flow cytometry

A method is presented for the use of red cell markers to assess the age of red cells in clinical samples. The reticulocyte count and its variants are already in clinical use to measure the number of young circulating red cells, but tools have not been put into place for studying the overall distribution of red cell age. These data could be of significant value, not merely for hematologic investigations, but as a part of infectious disease, renal, and toxicologic studies.