Abstract
Optical super-resolution microscopy is a key technology for structural biology that offers high imaging contrast and live-cell compatibility. Minimal (fluorescence) photon flux microscopy, or MINFLUX, is an emerging super-resolution technique that localizes single fluorophores with high spatiotemporal precision by targeted scanning of a patterned excitation beam featuring a minimum. MINFLUX offers super-resolution imaging with nanometre resolution. When tracking single fluorophores, MINFLUX can achieve nanometre spatial and submillisecond temporal resolution over long tracks, greatly outperforming camera-based techniques. In this Review, we present the basic working principle of MINFLUX and explain how it can reach high photon efficiencies. We then outline the advantages and limitations of MINFLUX, describe recent extensions and variations of MINFLUX and, finally, provide an outlook for future developments.