Development of a monoclonal antibody blocking-ELISA for detection of antibodies against Maedi-Visna virus

A monoclonal antibody (MAb) blocking ELISA (Blck-ELISA) was developed to de tect antibodies against Maedi-Visna virus (MW) in sheep sera. The assay emp loys a MAb directed against the envelope protein p90 of the virus in a sand wich blocking procedure. To determine whether the MAb was a potential antib ody for developing a Blck-ELISA, a collection of three hundred sera obtaine d from several sheep flocks known to be infected with MW were used to exami ne the sensitivity of the Blck-ELISA. A total of 50 serum samples originati ng from a flock free of MW were tested to assess the specificity of the ass ay. The results were compared with a commercial indirect ELISA (I-ELISA) an d samples giving a conflicting or doubtful result were tested by immunoblot . The Blck-ELISA proved to be specific, sensitive and it showed high reprod ucibility and low variability. (C) 1999 Elsevier Science B.V. All rights re served.