Figure 5.

Purified PrP^res from Bv-Scr and human GSS-A117V isolates. P2 and P4 fractions obtained with the PK purification method from Bv-Scr (A) and from two GSS-A117V cases, indicated as GSS-A117V #1 and #2 (B), were analysed by western blot (WB) and silver staining to evaluate the presence and purity of PrP^res. Fractions were loaded at 1.5 mg equivalent for western blot analysis and at 10 mg equivalent for silver staining. Blots were probed with antibody 9A2; SDS gels were used for the silver staining as indicated in the ‘Materials and methods’ section. Arrows on the right of silver-stained P4 fractions indicate the major SDS-PAGE silver-stained bands, which were consistent with PrP^res detected with 9A2 by western blot. Asterisks indicate protein bands detected in the P2 fractions of both Bv-Scr and GSS-A117V that were absent in P4 pellets.