Figure 2: Repeat kinetic time courses showing infectivity in three different lines of mice after prion infection with a high saturation of time points.
Three different lines of FVB/N mice: Tg20 with ~eightfold overexpression of PrPC in blue, Prnp+/+ with wild-type PrPC expression in grey and Prnp+/0 with 50% wild-type PrPC expression in red, were infected with RML prions. Mice were culled at defined time points or at onset of disease and prion titres determined using scrapie cell assay (SCA) or scrapie cell assay in end-point format (SCEPA) for low-titre samples. Prion titres (log tissue-culture infectious units per gram brain; bars indicate s.e.m. and, in some cases, are smaller than the symbols used to designate mean) are closely similar to those described previously3. Normal interval regression was used to calculate mean and s.e.m for timed culls where one or more samples were below assay sensitivity cut-off. This only applied to samples up to day 37 of the time courses. All samples from three timed culls in the PrnP+/+ time course (5, 10 and 13 days) were below assay sensitivity cut-off and are not shown.
