ABSTRACT
The best known label that can bind to erythrocytes and be used to monitor their survival in the circulation and thereby establish their life span is radioactive sodium chromate. When samples of erythrocytes are labeled in vitro ascorbic acid is added to the suspension at the end of the incubation period to convert any surplus chromate that has not been incorporated into the red cells to the reduced trivalent state. Labeled erythrocytes first appeared in the circulation after five days of administration of the isotopic tag, the interval required for erythroid precursors to conduct their proliferative and maturational processes in the bone marrow. The supplementation of the circulating volume of a bird’s erythrocytes with blood from another avian that is a blood transfusion is a new treatment in birds. Whenever possible homologous transfusions are desired because a donor’s erythrocytes survive longer in a conspecific avian.
