Far-field autofluorescence nanoscopy
Authors: Bierwagen J, Testa I, Fölling J, Wenzel D, Jakobs S, Eggeling C, Hell SW
CellNetworks People: Hell Stefan
Journal: Nano Lett. 2010 Oct 13;10(10):4249-52.doi: 10.1021/nl1027638

We demonstrate far-field optical imaging at the nanoscale with unlabeled samples. Subdiffraction resolution images of autofluorescent samples are obtained by depleting the ground state of natural fluorophores by transferring them to a metastable dark state and simultaneously localizing those fluorophores that are transiently returning. Our approach is based on the insight that nanoscopy methods relying on stochastic single-molecule switching require only a single fluorescence on-off cycle to yield an image, a condition fulfilled by various biomolecules. The method is exemplified by recording label-free nanoscopy images of thylakoid membranes of spinach chloroplasts.