ELISA plates were coated with capture antibody FH11 (a, b) or A516 (c, d) as described in the Materials and methods section. Full-length ovine recombinant ARR (■), ARQ (◆), VRQ (●) or bovine (▲) recombinant PrP were detected by biotinylated monoclonal antibody 245 (a, c) or V24 (b, d). Results shown are means±S.D. for triplicate wells.