Additional file 3: Figure S3. of Enhanced neuroinvasion by smaller, soluble prions

Membrane bound prions are removed by trypsin. Uninfected N2a cells were cooled to 4 °C for 10 min and then exposed to partially purified 87V prions for 45 min at 4 °C. Cells were then washed three times with cold PBS, exposed to 0.25% trypsin for 3 min, centrifuged for 5 min at 2000 g, and washed three times in cold PBS prior to cell lysis, proteinase K digestion, and immunoblotting for prion protein. (TIFF 1 kb)