Proteins mostly achieve not work in isolation but rather originate up larger complexes like the molecular machines that enable cells to communicate with each other,move cargo around in their interiors or replicate their DNA. Our ability to observe and track each individual protein within these machines is crucial to our ultimate understanding of these processes. Yet, the advent of super-resolution microscopy that has allowed researchers to start visualizing closely positioned molecules or molecular complexes with 10-20 nanometer resolution is not powerful enough to distinguish individual molecular features within those densely packed complexes.
Source: phys.org