Understanding the precise structure of this virus and the processes during and after infection are crucial to finding a cure or vaccine, ending lockdowns all around the world. Standard light microscopes are not of much help, since they are limited by diffraction (approx. 200 nm), while the virus particles have a much smaller diameter at about 100 nm. Because of this, SARS-CoV2 and important cellular structures that it attacks only show up blurry in standard, e.g. so-called confocal microscopes.
In the past, electron microscopy would have been used, but sample preparation for this instruments in tedious and they cannot image living matter, which is nevertheless vital to unraveling the workings of a corona infection on the cellular level. This is where STED microscopy comes into play: with a resolution 5-10 times below the diffraction limit, and much weaker constraints regarding sample preparation, it’s going to be an important tool for finding drugs against corona and similar viruses.
Image below: Taken with standard confocal microscope
Copyright: MDVA team/CNRS Montpellier, France (D. Muriaux, C. Favard, M.-P. Blanchard @MRI)