Fig. 1.

Stability of purified oligomers. Aβ samples were subjected to PICUP and SDS/PAGE. Individual gel bands were stained with Coomassie blue, excised, and then extracted under alkaline conditions. The extracts then were reconstituted in F12K medium and analyzed by SDS/PAGE and silver staining. Lane 1, cross-linked Aβ immediately after PICUP (cross-linking control). Lane 2, cross-linked Aβ subjected to the entire protocol, but with all bands pooled together (control for unfractionated Aβ subjected to alkaline extraction). Lane 3, monomer band. Lane 4, dimer band. Lane 5, trimer band. Lane 6, tetramer band. Lane 7, a “band-equivalent”-sized piece of gel (“no protein” control). The data are representative of results from each of three independent experiments.