Western blot analysis. The brain regions analysed were cerebral cortex (frontal cortex, FC, temporal cortex, TC, parietal cortex, PC, occipital cortex, OC), cerebellum, (Cb), hippocampus (Hip), thalamus (Thal), midbrain, pons major (PM), and medulla (Me). Samples were homogenised in extraction buffer, digested with 50 μg/ml PK, and separated by gel electrophoresis and immunoblotted using 3F4 as the primary antibody. Frontal cortex from a case of sCJD VV2 was analysed in the lane on the far right for both western blots (VV2). The positions of the molecular mass markers (in kDa) are indicated on the right.