Figure 4. Detection of proteinase K–resistant prions (PrPres) by using Western blotting and paraffin-embedded tissue (PET) blotting of brains of transgenic mice expressing bovine PrP (tgBov). A) PrPres WB of a vCJD sample (frontal cortex), tgBov mice (brain) inoculated with the same vCJD reference isolate, bone marrow samples from vCJD-affected patients (vCJD 1–vCJD-4 [P1–P4]; Table 2), and a non–vCJD control (NC-1; Table 2). A scrapie isolate (WB cont) and a noninoculated tgBov brain (vCJD brain) homogenate were included as controls. PrPres immunodetection was performed by using Sha31 monoclonal antibody (epitope 145YEDRYYRE152) and 12B2 epitope (epitope 89WGQGG93). B) PET blotting of PrPres distribution in coronal section (thalamus level) of tgBov mice inoculated with a reference vCJD isolate (10% brain homogenate) or bone marrow (10% tissue homogenate) from 2 vCJD patients (vCJD-1 and vCJD-3; Table 2) at the clinical stage of disease. Immunodetection of PrPres was performed by using Sha31 monoclonal antibody (epitope 145YEDRYYRE152). Cont, control; NI, not inoculated; WB, Western blot. Scale bar indicates 120 μm.