PrPSc and infectivity in tissues from experimental (IC challenged) Atypical/Nor98 scrapie cases and natural or experimental (oral or intra-cerebral challenge) classical scrapie cases.

Animals were sampled at clinical stage of the disease. Mice were considered positive when abnormal PrP deposition was detected in brain. Incubation periods are presented as mean +/−SD except for that dilution with which less than 50% of mice were found positive. In that case (*) incubation periods of the positive mice are individually presented. ND: not done.Two different methods were applied to detect PrPSc presence in tissue homogenate that were used for mice inoculation: WB (TeSeE WB kit – BioRad, using SHa31 as anti-PrP antibody) and ELISA (TeSeE Sheep and Goat– BioRad). Additionally when formalin fixed tissue was available PrPSc immunohistochemistry was also carried out (using 8G8 antibody). Infectious titres in the different tissues were estimated on the basis of incubation period in mice (Figure 4). This calculation was only performed when the attack rate was 100% and data from more than 5 animals were available.