[Determination of heterogeneity in human and monoclonal anti-A antibodies using the absorption test].

After saturation of the anti-A monoclonal antibody USOL by A1 erythrocytes sensitized with various human anti-A sera and or by several specimens of A1 blood cells sensitized with the same anti-A serum the authors detected a different decline of the titre and score of antibody. Similar results were obtained also in attempts to saturate various human anti-A sera with A1 erythrocytes sensitized with monoclonal anti-A. This means that A epitopes on A1 blood cells of different subjects are not identical as regards the content of A determinants, and that different human anti-A sera an d anti-A monoclonal antibodies differ as to the structure of anti-A specificities.