Fig. 10
Scanning electron microscopy (SEM) images of glass spheres recovered after a PMSA round. To definitively address if rec-PrPres generated during the PMSA process was being adsorbed to the surface of glass beads, we utilized glass spheres with a diameter of 9 to 13 µm in an unseeded 24 h PMSA reaction. Afterwards, the spheres were let to settle, the supernatant was discarded, and the spheres were thoroughly washed with PBS before being completely dried in an oven at 42 °C. Upon resuspension, the sphere suspension was divided in two portions. One half underwent digestion with proteinase K while the other half was simply incubated in the same conditions without digestion. Finally, both PK-digested and undigested spheres were thoroughly washed and air dried before sputtering with gold for visualization using SEM. The micrographs reveal that both digested and undigested spheres exhibit a substantial coating, which diminished upon digestion, and shows fibrillary structures attached to the surface of the spheres. This observation confirms the strong adsorption of rec-PrPres to glass surfaces