Figure 1

Western blot of PrP in treated brain homogenate from RML scrapie-affected C57Bl/6 mice without (A) or with (B) PK pretreatment prior to immunoblotting. PrP-immunoreactivity was faintly detectable in samples exposed to SPC-P_L alone followed by PK (lane 3) and undetectable in samples treated with either SPC-P_H alone or with SPC-P_L or SPC-P_H combined with SDS followed by PK (lanes 4–6). Control samples included untreated RML brain homogenate (lane 2), SDS treatment only (lane 7), SDS followed by PK (lane 8), and PK treatment only (lane 9). Additional exposure of samples to PK prior to immunoblotting (as part of the WB protocol for PrP^Sc) did not result in loss of PrP^Sc immunoreactivity in control samples. Lanes 1 and 10, molecular weight marker. Abbreviations: MW, molecular weight.