Fig. 3
Analysis of long-term stability of proteinase K of strains 22A, Chandler, and BSE-G propagated in different mouse lines. PrPSc was purified from pooled mouse brain homogenates (mouse lines Tg20, C57BL/6, CD-1, and VM95) and exposed to proteinase K for 1, 3, 6, 24, or 48 hr at 37°C prior to immunoblot analysis. Combined PrPSc signals were recorded using the photoimager technique and arithmetic means of at least four runs per sample were calculated. Standard error values are indicated.