Fluorescence nanoscopy by ground-state depletion and single-molecule return.
Fölling J., Bossi M., Bock H., Medda R., Wurm CA., Hein B., Jakobs S., Eggeling C., Hell SW.
We introduce far-field fluorescence nanoscopy with ordinary fluorophores based on switching the majority of them to a metastable dark state, such as the triplet, and calculating the position of those left or those that spontaneously returned to the ground state. Continuous widefield illumination by a single laser and a continuously operating camera yielded dual-color images of rhodamine- and fluorescent protein-labeled (living) samples, proving a simple yet powerful super-resolution approach.