Western blots comparing PrPSc levels in thalamus at 40 and 60 dpi from three scrapie strains.

<p>(A) 40 dpi. (B) 60 dpi. On each western blot, two representative thalamus samples are shown for each scrapie strain. Scrapie strains shown are indicated across the top of each western blot. Lanes 1–6 were loaded with 0.36 mg of brain equivalents. In both panels, lane 7 (Bl) indicates an intentional blank lane, and lane 8 (C) is a positive control thalamus from a 60 dpi 22L sample loaded with 0.24 mg brain equivalents. Western blots were probed with anti-PrP antibody D13 and exposed to film for 8 minutes. To avoid issues with pixel saturation, densitometry was performed on a 4 minute exposure to film. The adjusted volumes (immunoreactive band volume with global background subtracted) in arbitrary units are given below each lane. At both time points shown the mice inoculated with scrapie strain ME7 had significantly less detectable PrPSc (lanes 5&6) than was seen in samples from 22L- and RML-infected mice.