Western blot analysis of TgOvPrP59 mice infected with Sh294. Brains and spleens were dissected from Sh294-infected TgOvPrP59 mice at the second passage. CH1641-like PrPres banding patterns were detectable in the brains of five individual mice (lanes 1–5 in A), but not in the spleens of these mice (lanes 1–5 of B). The arrow shows the ~12-kDa C-terminal small fragment that was specific to CH1641 and CH1641-like scrapie isolates. Brain homogenates from TgOvPrP59 mice infected with classical (Cl) and CH1641-like (Sh294: Ch) scrapie isolates were loaded, for comparison of the molecular mass of unglycosylated PrPres B. Mr: molecular mass marker. Tissues subjected to the analysis and the equivalent tissue quantities loaded per lane are indicated on top of each panel.