Fig. 1

Assessing the spontaneous formation of prions by PMSA using beads made of different materials. 1 mm beads made of 7 different materials as well as a negative control without beads were used to evaluate their propensity to spontaneously generate bank vole PrP^res. A substrate based on bank vole rec-PrP were subjected to three 24 h serial rounds of PMSA (1:10 dilutions). All the samples were concentrated approximately 50 times to improve detection limit and were visualized by total protein staining. Bank vole PrP^res was found from the first round of PMSA only when glass beads were used. rec-PrP^Sc: L-seeded-PMSA recombinant prion strain used as control [38]. rec-PrP: Untreated substrate. Mw: Molecular weight