[Monoclonal antibodies directed against equine blood group antigens].

The chief application of blood typing in domestic animals is in the verification of parentage. However, the acquisition of good standardized reagents in sufficient quantity remains an obstacle for the development of this work. The production of monoclonal antibodies directed against blood group determinants offers an attractive means of improving both the quality and quantity of serological reagents, and could facilitate the definition of new specificities. Fusions between a mouse myeloma line and splenocytes from mice immunized with horse red cells have resulted in four hybridomas producing antibodies against equine erythrocyte groups. Two are directed against the established groups Aa and Ca, while one reacts with a sub-group of De, and another, still under study, appears to be anti-Di. The anti-Aa and anti-Ca monoclonals have high affinity and fix complement, and are now in routine use as blood grouping reagents. This is remarkable since good antibodies to these specific sites are virtually impossible to obtain by allo-immunization. These results offer encouragement for the future production of monoclonal antibodies against red cell and lymphocyte antigens in the domestic species.