Evaluation of monoclonal antibodies to blood group A.

Balb/c mice were immunized with human blood-group A2 active cyst fluid glycoprotein. Fusion of spleen cells with NS-1 myeloma cell line produced a total of 11 blood group antibody secreting hybridomas of which seven were apparently specific for blood-group A and were subjected to further evaluation. Of these 2 were IgM class and 5 IgG class. Two anti-A supernatants showed a significant decrease in avidity time against A2B cells when ionic strength was increased to 0.25. Tube titres of all anti-A supernatants were unaffected by ionic strength. pH had no effect on the avidity time or tube titre of any of the antibodies tested. The supernatant from one hybrid (ES-9) was selected for further evaluation as a blood grouping reagent. This supernatant had a tube titre of 1:128 and was used without concentration for comparison of its serological reactivity with two examples of commercial monoclonal anti-A and one example of human anti-A. Monoclonal anti-A (ES-9) was found to be a potentially useful red cell grouping reagent.