Iterative expansion microscopy using lipid and protein labels for nano-scale imaging of brain circuits

Abstract

Expansion microscopy(ExM) and iterative expansion microscopy(iExM) enables nanometer resolution by physically expanding fixed specimens using a conventional diffraction limited optical microscope. Here, we introduce a polymer-anchorable lipid intercalating label that binds to membranes of fixed tissue to perform ExM and iExM, which we call membrane expansion microscopy (mExM) and membrane iterative expansion microscopy (imExM), respectively. The technology is also compatible with immunohistochemistry to visualize proteins of interest (i.e. nuclear pore complex, Golgi apparatus, etc.). With the technology, we can reconstruct structural and molecular information at a resolution between approximately 15nm to 20 nm.