Western blot analysis of brain lysates from RML-infected wt and transgenic mice for total PrP C and PrP Sc using monoclonal antibody 4H11. ( A ) Brain homogenates from terminally ill wt and PrP(TetraH > G) line 34 mice were either left untreated (- PK) or subjected to digestion with proteinase K (+ PK). Blots were reprobed for β-actin to control for equal loading. Bands corresponding to total PrP are marked on the left. Irrelevant lanes have been excised at two positions. Molecular weight standards are given on the right (in kDa). ( B ) Corresponding immunoblot analysis of brain homogenates extracted from RML-infected PrP(H95G) mice from the three different lines 11, 13, and 4, respectively, and corresponding wt control (lanes 1 and 2) before (-) and after (+) treatment with PK. Molecular weight standards are given on the right (in kDa).