Relative swa resistance of various prion populations.

aPrion samples were assayed by the Standard Scrapie Cell Assay (SSCA) on PK1 cells in the absence or presence of swainsonine (swa, 1 µg/ml).bas shown in Figure 2 (cell-derived samples) or Figure 8 (brain-derived samples).cQrel = Qsample/QRML where Q = RIPK1/RIPK1+swa and RIcell = reciprocal of the dilution required to yield specified designated number of PrPres positive cells per 20000 cells.nid = no infectivity detected; nrd = no ratio determinable.*QRML was exceptionally high in the experiments of Figures 4C and 5B (about 2.7 rather than 1.5–2 logs), resulting in what may be misleadingly low values for Qrel in the associated samples.