The Determination of the Survival of Transfused

The technique of differential agglutination of red cells, introduced by Ashby ( 1 ), has been widely used to measure the life span of red cells following transfusion. The technique of differential hemolysis was investigated as a possible alternative to this method in an attempt to separate more easily the surviving donor cells from those of the recipient. Differential hemolysis was first used by Todd and White (2) in studies on the survival of the red cells of one bull when transfused into the circulation of a second bull. Willenegger (3) employed a method of differential hemolysis to study the survival of normal human erythrocytes transfused into the circulation of normal human recipients. Differential hemolysis is employed in the study of survival of red cells in a manner similar to differential agglutination. Compatible but antigenically distinct red cells are introduced by transfusion into the circulation of a suitable recipient. The survival of these transfused red cells can then be followed during their life span in the recipient by taking samples of blood containing the mixed cell population, eliminating the cells of the recipient by exposing the mixture to the appropriate hemolytic antiserum, and counting the remaining number of donor cells which are not subject to hemolysis. The method of differential hemolysis is different from that of differential agglutination in that hemolysins are used instead of the corresponding agglutinins in the separation of the mixed cell population. Since Anti-A and Anti-B