Figure 4. . Western blot analysis of brain extracts from RIII (A) and VM (B) wild-type mice inoculated with variant Creutzfeldt-Jakob disease (vCJD) brain tissue. Lane M, positive control; lane 1, human vCJD brain homogenate (UK origin) showing the typical abnormal prion protein (PrPSc) type 2B; lane 2, United Kingdom; lane 3, The Netherlands; lane 4: Italy (cortex); lane 5, Italy (cerebellum); lane 6, France; lane 7, United States; lane 8, human sporadic Creutzfeldt-Jakob disease brain homogenate showing the typical PrPSc type 1. Type 2B and 1 differ in mobility of the unglycosylated band (≈19 kDa and ≈20 kDa, respectively). All samples were treated with proteinase K. The anti–prion protein detection antibody used was 6H4.