Reactivity of sera from different groups of animals with biotinylated MDBK lysate in immunoprecipitation. Figure 1A: Reactivity of sera from eight BNP-dams (Group 1), which were previously vaccinated with PregSure® BVD, was tested with cell surface biotinylated MDBK lysate. For all experiments gel electrophoresis was employed under non-reducing conditions to prevent a cleavage of the biotin linker. Figure 1B: Eight sera of dams, which were vaccinated with a different inactivated BVD-vaccine (Bovilis® BVD, Intervet) (Group 2) were tested for their reactivity with cell surface biotinylated MDBK lysate. Figure 1C: Eight sera of dams which were not vaccinated against BVD (Group 3), and originated from farms free of BVD, were tested for their reactivity with cell surface biotinylated MDBK lysate. Figure 1D: Four sera of dams vaccinated with PregSure® BVD previously but without known BNP case in their offspring history (non-BNP-dams) (Group 4) were tested for alloantibodies recognizing protein species from cell surface biotinylated MDBK lysate (lane 1-4). Figure 1E: Deglycosylation of precipitate (from Figure 1A) with PNGase F. Lane 1: native precipitate. Lane 2: PNGase F digested precipitate.