Extended Data Fig. 2: Aβ assemblies from AD brain, ARPA and seeding activity.
a, PBS-homogenates from the frontal cortex of three AD subjects (Braak stage VI) were pooled to get a representative sample. ARPA (see Fig. 2 for a description) is shown for the various antibodies. Immunoblots were probed with Aβ-antibody 6E10. The experiment was repeated 3 times with similar results. b, AD brain fractions (F)1-7 and their dilutions were injected into the hippocampus of young, pre-depositing 2- to 3-month-old male APP23 host mice. Brains were immunohistochemically analyzed for Aβ deposition 8 months later. c, Results for F2 and F5 (both undiluted) is shown and reveal a high seeding activity for F2 and no seeding for F5. Scale bar: 500 μm. d, Number of mice with induced Aβ deposition/total mice per group at each dilution from the various fractions (initially all groups had 6-7 mice, of which 4 treated with the undiluted F2 fraction died). e, SD50 for the different fractions was defined as the negative log10 of the brain extract dilution at which 50% of the host mice showed induced Aβ deposition (see Methods). The specific seeding activity (SD50/total Aβ) for each fraction is shown and indicates a peak for F4.
