Figure 5.
Aggregation of Aβ on graphite observed with in situ tapping mode AFM in a 10 μM solution of Aβ(1–42) in PBS. (A–C) The first phase of aggregation i.e., rapid appearance of highly elongated, narrow, sheet-like aggregates. The images were digitally zoomed in from 10- × 10-μm consecutive original scans; the time interval between the images is equal to 256 s. (D–G) The second phase of aggregation i.e., formation of parallel assemblies of sheets. The images correspond to the area marked with a rectangle in C. The images were digitally zoomed in from 4- × 4-μm original scans and were aligned with respect to the feature marked with a circle in D; the time interval between the images is equal to 512 s. (H) Quantitative analysis of aggregation. The effective thickness of adsorbed material, Deff, is shown as a function of time. Notice the presence of an incubation time and two regimes of growth.