Amyloid-β oligomer formation protocol

HFIP-treated Aβ_1-42 stored at -80°C in DMSO was oligomerised by dilution and vortexing in PBS followed by incubation overnight at 4°C [25 (link)]. Oligomer formation was confirmed by native tricine-SDS-polyacrylamide gel electrophoresis. Briefly, 2 μg oligomeric Aβ (oAβ) was resuspended in nondenaturing sample buffer (62.5 mM Tris-base, 25% glycerol, and 1% (w/v) Coomassie Blue R-250) and loaded onto a 10% acrylamide : bis-acrylamide gel and separated by electrophoresis alongside molecular weight markers. Gels were incubated with Coomassie stain (60 mg/l Coomassie Blue R-250 and 10% v/v acetic acid, both from Sigma-Aldrich, UK). Following 24 h destaining in 10% v/v acetic acid and 50% v/v methanol (Sigma-Aldrich, UK), gels were imaged using a ChemiDoc MP Imaging System (Bio-Rad Ltd., UK). Oligomeric Aβ migrated at approximately 35 kDa, indicating the presence of hexamers/heptamers (Supplementary Figure 1).