Fibrils were diluted to 5 µM monomer equivalent concentration and 10 µL of the solution was pipetted onto freshly cleaved mica substrates. Following 10 min of incubation, the substrates were cleaned extensively with miliQ water and dried under air flow. All fibrils were imaged in tapping mode in air using a DriveAFM (Nanosurf, Liestal, Switzerland) using PPP-NCLAuD cantilevers (Nanosensors, Neuchatel, Switzerland).