Super-resolution microscopy is becoming an important tool to study biological structures. As super-resolution techniques like STED overcome the physical diffraction limit of light, new microscopes with ever-decreasing resolution limits are being developed. Using these exciting techniques, the constraints are now imposed by the probes used for labelling. With STED microscopy, reaching a resolution of 20–40 nm, antibodies are no longer suitable as labelling probes sinceconjugated fluorophores will seem to be located far away from their target and spatial constraints will lead to spotty images.
Due to their small size of less than 1 kDa and high affinity our fluorescent tracer mlecules are excellently suited for binding-activated localization microscopy (BALM). Since they are only fluorescent when binding, they can be localized with high precision before turning dark due to photobleaching. Amytracker have been used to obtain <20 nm resolution images of unlabeled α-synuclein fibrils using BALM.