The value of a serum and albumin mixture for use in the detection of blood group antigen-antibody reactions.

It has been suggested by Wiener and Hurst (1947) and Wiener, Hurst, and Sonn-Gordon (1947) that mixtures of bovine albumin and human plasma are more effective as diluents for the detection of incomplete antibodies than the widely employed 20% bovine albumin introduced by Diamond and Abelson (1945) or the human plasma alone used by Wiener (1945). This has been confirmed by other workers, and Mollison (1951) has recommended mixing a suspension of red cells in 20% albumin with the test serum diluted in group AB human plasma. The present investigation was undertaken to determine whether the 20% bovine albumin test, which is open to criticism on a number of grounds, could be improved by substituting a mixture of human serum and bovine albumin for the diluent. Human plasma was not used because of clotting difficulties. After initial experiments it was decided to compare 20% bovine albumin with an equal parts mixture of human serum and 30% bovine albumin. Saline, and often human serum alone, was also included in the comparisons which were made with respect to different blood group antigenantibody reactions.