Fig. 3.

Radioimmunoprecipitation showing the binding of rotavirus antigens by bovine antibodies from various preparations which have been used in clinical trials. Briefly, 5 μl of the bovine immunoglobulin sample were mixed with 10 μl of radiolabelled rotavirus-infected cell lysate or mock-infected cell lysate in a total volume of 600 μl of RIPA buffer. After overnight incubation, protein G-coupled Sepharose beads were added and allowed to incubate for 1 h. After repeated washes and boiling, the samples were analysed by SDS–PAGE. Lane 1 represents molecular size markers and lanes 2–7 represent three immunoglobulin preparations (H7, SSA and N3) which have been incubated with rotavirus antigens or a mock control. Lane 8 represents the result using a MoAb against the NSP4 protein. The relative amounts of anti-NSP4 antibodies were calculated on the intensities of the corresponding band (3%, 1.2% and 2.5%, respectively).