AFM imaging (Figure ) reveals that the aggregated samples prepared from amylin 20-29 and Aβ 25-35 peptides resulted in the formation of amyloid fibrils. The two polymorphs produced from amylin 20-29 exhibit similar average diameters of (9.1±2.9) nm for polymorph 1 (Figure ) and (9.7±4.4) nm for polymorph 2 (Figure ). They also show similar morphologies consisting of unbranched fibrils that are several microns in length. In contrast, the fibrils prepared from Aβ 25-35 are shorter, being only several hundred nanometers to a few microns in length, and exhibit an average diameter of (5.7 ± 1.8) nm (Figure ).