BioRad Western Blot (10 min Detection). 15 μl of sample is loaded in each lane, giving a tissue equivalent of 0.02 g. Each sample is run in duplicate in adjacent lanes. Lanes 1 and 2 UK passive surveillance atypical scrapie (ARQ/AHQ; cortex). Lanes 3 and 4 UK passive surveillance atypical scrapie (AHQ/ARR; cortex). Lanes 5 and 6 UK active surveillance atypical scrapie (AHQ/ARR; medulla). Lanes 7 and 8 Donor sheep. UK active surveillance atypical scrapie (AHQ/AHQ; medulla). Lanes 9 and 10 Recipient sheep. Experimental atypical scrapie (AHQ/AHQ; medulla). Lane 11 UK classical scrapie positive control (VRQ/VRQ; medulla). Lane 12 Swedish Nor98 positive control (kindly supplied by Dr D Gavier-Widen, SVA, Sweden). Lane 13 UK bovine BSE positive active surveillance case control (brainstem). Lanes M Molecular mass markers.