Figure 4. Determination of the critical free concentration of Aβ required for fibril polymerisation.

2 µM Aβ solution was injected for 30 s at a flow rate of 20 µl/min in PBS at 25°C. 100 µl of Aβ (0–400 nM) was then immediately injected. Measurements were carried out to determine the critical free concentrations for (A) Aβ^40WT monomers with Aβ^40WT fibrils, (B) Aβ^40Arc monomers with Aβ^40Arc fibrils, and (C) Aβ^40Arc monomers with Aβ^40WT fibrils.