EXAMINATION OF ANTIGEN PREPARATIONS FROM THE VIRUS OF ENZOOTIC BOVINELEUKOSIS WITH REGARD FOR SUITABILITY IN IMMUNOBLOTTING

8 different leukosis antigen preparations for immunodiffusion from 6 E uropean countries were examined regarding their suitability for immuno blotting. Emphasis was made on demonstration of immunoreactions at 51 kDa beside reactions at 24 kDa. The whole protein content of the diffe rent preparations varied very much. gp 51 could be detected only by mo noclonal antibodies at a molecular weight of 53 kDa, in one preparatio n at 26 kDa. With sera from field or with the European reference serum E4 none or only weak reactions could be observed at these molecular w eights. All antigen preparations contained bovine IgG that is divided in L- and H-chains by SDS-electrophoresis under reducing conditions. T hese single chains reacted also with anti-bovine-IgG-biotin conjugate und disturbed the detection of the leukosis specific reactions. The bo vine IgG could be removed by a Protein-G-column. One of all tested leu kosis antigens, which are prepared for immunodiffusion, was suitable f or immunoblotting. This antigen preparation contained only few bovine IgG and had strong reactions at 24 kDa. A special antigen preparation for detection of other reliable immunoreactions in the immunoblot has to be developed.