*5.14. Preparation of Aβ Peptides*

Aβ<sup>40</sup> and Aβ<sup>42</sup> solutions were prepared by dissolving lyophilised peptides in 2 mM NaOH (pH~10.5). By avoiding the isoelectric point of Aβ (5.5) in the initial solvation step, aggregation and oligomerisation of the peptide is minimised [89]. For fluorescence quenching assays, Aβ<sup>40</sup> and Aβ<sup>42</sup> peptides were prepared fresh at 385 mM and 221 mM, respectively. For ELISA standards, Aβ<sup>40</sup> and Aβ<sup>42</sup> 2× solutions were prepared and stored at −80 ◦C in single-use aliquots. These stock solutions were diluted in PBS (1:1) immediately prior to use to readjust the pH from 10.5 to physiological 7.4.
