Studies on the Agglutinin Accompanying the Warm Haemolysin Active against Trypsinized Red Cells

Abstract

The titres of warm haemolysin and its accompanying agglutinin were determined (1) in sera stored at -30 and -72°C for about 3 months, (2) in sera obtained with short intervals during 1 month, (3) after treatment of red cells with various concentrations of trypsins, (4) after adding soybean trypsin inhibitor (STI) to the trypsin solution, (5) after exposure of the trypsin solutions to 55 °C for 30 min, and (6) with red cells to which bovine albumen had been added before adding the trypsin solution. Relatively small variations in the agglutinin titre were observed when testing the deep frozen sera in contrast to much greater variations when testing fresh samples drawn on different days. Variations in agglutinin titre were poorly related to the trypsin activity expressed in Anson units. The factor in the trypsin preparation which sensitizes the red cells for haemolysis is more temperature labile than the factor responsible for the agglutination. STI and albumen inhibit both haemolysis and agglutination.