MINFLUX can localize single fluorophores with unprecedented precision by targeted detection with a scanned, patterned beam. In combination with switchable fluorophores, this allows for super-resolution imaging with single nanometer resolution. As MINFLUX uses the photon budget of a single fluorophore very efficiently, it is also a very promising technique for single-fluorophore tracking, improving speed, precision, and track length by one order of magnitude compared to camera-based tracking.
Here, I will introduce the principle of MINFLUX and its opportunities and limitations for dynamic cellular imaging. I will then discuss our recent result in which we used MINFLUX to track the stepping motion of the motor protein kinesin-1 as it walks on microtubules in living cells and present first results on using dual-color MINFLUX to monitor conformational changes of proteins during their action in living cells. I will end by presenting a new MINLFUX approach called PhaseFLUX with reduced complexity and improved stability and speed.