FIG. 1.
Sublines vary in susceptibility to scrapie infection. Sublines derived as described in Materials and Methods were inoculated with 30 μl of a homogenate (107 cells/ml) of ScN2a cells. (A) Eight N2a sublines inoculated in duplicate and then passaged for 25 days. Each circular blot in the figure is from a single independently inoculated and passaged population, with pairs of blots from the same subline shown side by side. Sublines 4 and 7 are susceptible, sublines 1, 6, and 8 are of intermediate susceptibility, and sublines 2, 3, and 5 are resistant. (B) GT1-trk sublines inoculated and passaged in quadruplicate for 24 days prior to blotting. Sublines 1 and 4 are susceptible, subline 2 is of intermediate susceptibility, and subline 3 is resistant. Note that the level of PrPSc is consistent in each inoculated culture derived from the same subline. (Cells were confluent on each coverslip prior to blotting except for one coverslip for GT1-trk subline 4, which had a low cell density.)