Fig 1. Evaluation of PrP^Sc-specific binding to the stainless-steel beads.

(A) PK-immunoblot analysis demonstrating the binding of total PrP and PrP^Sc to the beads. NBH- and RML6-exposed beads were blotted after treating the samples without (-) or with (+) PK for the detection of total PrP and PrP^Sc. As controls RML6 and NBH without and with PK digestion were loaded. The in-house produced anti-PrP antibody POM-1 [36] was used for detection. The molecular weight standard (MW) is shown in kilodaltons (kDa). (B) TESSA analysis showing specific propagation activity for three different amounts of RML6-coated beads as indicated in the Figure. NBH-coated beads, unseeded reactions, NBH and RML6 brain homogenate (RML6 BH) were used as negative and positive controls, respectively. All reactions were performed in quadruplicates. The dashed line indicates the ThT fluorescence threshold for a positive reaction.