Western blot analysis. Western blot analysis of PrPres derived from C-type BSE- and H-type BSE-challenged cattle, with mAbs 6H4 (a and c) and SAF84 (b and d). Lanes 1 and 8, C-type BSE tissue; lanes 6 and 7, PrPres-negative bovine brain. Other lanes show banding for H-type BSE tissue: lane 2, Canadian case; lane 3, case 1 (code 7749); lane 4, case 2 (code 9458); and lane 5, case 3 (code 0728). In panel d, the band near 14 kDa is of lower molecular mass than 14 kDa. All the samples were digested with 50-μg/mL PK at 37°C for 1 h, and then treated with PNGase F (c and d). Molecular mass markers (kDa) are shown on the left.