Imaging cycler microscopy.

The article in PNAS by Gerdes et al. (1) adds to the evidence that spectral resolution limits of fluorescence microscopy can be overcome by reiterative cycles of tagging, imaging, and bleaching of fluorophores attached to ligands for target biomolecules. In fact, the robotic imaging cycler microscopes are based on this principle and have been used for decades (2⇓⇓–5). The current ready-to-use robotic Toponome Imaging System (TIS) for biomarker discovery and cell research can comap at least 100 molecules in individual cells and tissue sections and, because of its high functional resolution (<40 nm) (5), provides insights into their organization, including their supramolecular clusters.* Now Gerdes et al. offer a modified protocol using H2O …