Figure 7.

Saline brain extracts of tg mouse exists principally in assemblies >500 kDa in native form. a, Bicine/urea SDS-PAGE shows the principal Aβ peptides present and their relative expression levels in ISF and TBS extracts of 3-, 12-, and 24-month-old tg mice. IP was performed with AW8; WB was performed with 6E10. b, Quantification (by ImageJ software) of Aβ₄₂/Aβ₄₀ ratios in plaque-free 3-month-old tg mice (p value by one-tailed t test; n = 3 each). c, Non-denaturing SEC of TBS extracts (ext) of 3- and 24-month-old tg mice performed on a Superdex 200 SEC column followed by SDS-PAGE of each SEC fraction. Synthetic (synth.) Aβ₄₀ run on the same SEC column for comparison. WB was performed with 3D6. d, TBS extracts from a 24-month-old tg mouse and its wt littermate subjected to clear native PAGE and blotted for Aβ. WB was performed with 2G3 plus 21F12. e, Excision of the >300 kDa region and subsequent electrophoresis by denaturing SDS-PAGE showed that this high MW material is disassembled into low MW SDS-stable Aβ species. WB was performed with 3D6. T, Trimers; D, dimers; M, monomers; MWM, MW marker.