Western blot analysis of ovine transgenic mice inoculated with UK‐1. Detection of PrPSc in proteinase‐K‐treated brain homogenates by Sha31 and 12B2 monoclonal antibodies. Lane 1: original UK‐1 inoculum, lane 2: sheep bovine spongiform encephalopathy (BSE), lane 3: classical scrapie, lanes 4–8: UK‐1 inoculated tg338 mouse brains exhibiting (with Sha31 mAb) a 19‐kDa profile as referred to the migration of the unglycosylated band (lanes 4–5), a mixed profile (lane 6) or a 21‐kDa profile (lanes 7–8), lane 9: classical scrapie in tg338 mice, lane 10: sheep BSE in tg338 mice.