PrP^Sc-bearing MVs transmit disease to <i>Tga20</i> indicator mice.

Tga20 indicator mice were inoculated intracerebrally with either 30 µl (10 µg total proteins) of cell lysates or MVs or with 30 µl of different RML brain homogenate dilutions. Mock-inoculated animals were included as negative controls. Incubation time until development of terminal scrapie was determinated. The relationship y = 11.45−0.088 x, where y is logLD50/ml homogenate and x is incubation time in days to terminal disease, was used to calculate infectivity titres.