FIG. 1.

Ovine TSE strain discrimination by thermolysin digestion. Caudal medulla samples from TSE-affected sheep of various PrP genotypes were digested by the addition of 150 μg/ml thermolysin every hour for a total of 8 h. (A) Resulting PrP fragments after 1, 4, 6, and 8 h of digestion are shown in lanes 1 to 4, respectively. Densitometric analysis of the Western blots is also shown for the 8-h time points for BSE (B) and scrapie (C) samples. TSE type, animal references, and PrP genotype are indicated. Digested brain homogenate was loaded at 3.3 μl of 10% (wt/vol) per lane, and PrP was detected on Western blots with monoclonal antibody P4. Molecular mass markers are indicated in kilodaltons.