Improving the resolution of single-molecule tracking using Minimal Photon Fluxes (MINFLUX)

Synopsis

The Abbé diffraction limit (≈250 nm) plays an important role in the study of biological systems because it imposes insufficient resolution needed to track important molecular dynamics inside the cell. During the 20^th century, many scientists believed that this limit will never be overcome. But, in recent years super-resolution techniques have broken this limitation; in 2014 the Nobel Prize in Chemistry was given to scientists developing these techniques. Stefan Hell was awarded a share of this prize for the development of Simulated Emission Depletion (STED) microscopy that uses spatial patterning of excitation light to provide enhanced spatial resolution. In this seminar, I will present a newer technique developed in his lab called MINFLUX that minimizes the photons required for high-precision localization. It merges advantages of stochastic super-resolution techniques that localize molecules via light emitted from the sample, with targeted illumination methods such as STED. MINFLUX reaches up to 1 nm spatial resolution and enhances the temporal resolution and localization by 100-fold compared to popular centroid localization methods. To illustrate this, I will show an example of ribosomal subunits diffusing in living cells, and three-dimensional multicolor localization of labeled proteins in the mitochondria.