Rapid Typing of Transmissible Spongiform Encephalopathy Strains with Differential ELISA
Figure 5. Analysis of different ovine strains by ELISA typing test and immunoblot. A) ELISA typing test. Three Nor98 isolates (Fiksdal, Stranda, and Seim) were analyzed by using the ELISA typing test. Absorbances obtained in the classic A′typing reagent are close to 0, preventing calculation of the A/A′ratio. Ratios obtained for a Norwegian scrapie isolate (Lavik) and for the 3 internal controls (classic Scr 99–1316, intermediate scrapie PG1259, and experimental ovine bovine spongiform encephalopathy [BSE] 397 BS) are indicated. B) Pattern of migration of different ovine strains. Lanes 1 and 9, untreated negative brain homogenate. Lanes 2–8, proteinase K–treated brain homogenates: French scrapie isolate 99–1316 (lane 2); experimental ovine BSE 397 BS (lanes 3 and 8); Norwegian scrapie isolate (Lavik) (lane 4); Nor98 Stranda and Nor98 Seim scrapie isolates (lanes 5 and 6, respectively); negative brain homogenate (lane 7). MW, molecular weight.