A MONOCLONAL ANTIBODY-BASED IMMUNOPEROXIDASE MONOLAYER (MICRO-ISOLATION) ASSAY FOR DETECTION OF TYPE-1 AND TYPE-2 BOVINE VIRAL DIARRHEA VIRUSES

A monoclonal antibody (mAb)-based immunoperoxidase monolayer assay (IP MA) for detection of bovine viral diarrhea virus (BVDV) cr as develope d and compared with an existing bo cine polyclonal antibody (pAb)-base d IPMA, A pool of 5 mAbs, 4 mAbs produced to a type 1 BVDV and 1 mAb p roduced to a type 2 BVDV, was utilized in the mAb-IPMA. The mAbs mere chosen for inclusion in the pool because of their broad cross-reactivi ties with type 1 and/or type 2 BVDV, their apparent acidities for anti gen, their reactivity to different BVDV proteins, and their lack of co mpetition for binding sites or their binding to unusual BVDV isolates, The mAb-IPMA outperformed the pAb-IPMA in staining, ease of reading t est results, and relative sensitivity with a panel of known BVDV posit ive and negative sera, The relative sensitivities of the mAb-IPMA and pAb-IPMA. were 100% and 93.5%, respectively, for 62 positive samples i ncluding several that mere known to contain type 2 BVDV, with retestin g, the pAb-IPMA gave a similar level of sensitivity as that of the mAb -IPMA. Both tests gave a specificity of 100% for 40 negative serum sam ples obtained from a BVDV-free herd.