Detection of ABO group-specific substances on the red cells of the cynomolgus monkey

Several attempts were made to demonstrate the presence of ABO blood group substances on the red blood cells (RBC) of the cynomolgus monkey. Neither the direct hemagglutination test nor the antibody absorption test was successful in detecting these substances from whole RBC, the stromata or the butanol extracts of RBC. By the heat elution of antibodies, however, the presence of ABH substances was demonstrated on RBC of every phenotype without fail. In all cases, there was a reciprocal relationship between the ABH substances of RBC and of saliva and the anti-A and anti-B antibodies in serum, being in good agreement with Landsteiner's rule. Accordingly, it can be concluded that a small amount of ABH substances must be present on RBC of the cynomolgus monkey.