Center for Molecular Spectroscopy and Dynamics

2017 KPS Fall Meeting

Super-resolution fluorescence microscopy is a powerful imaging technique that overcome the diffraction limit by means of optics and spectroscopy.  Expansion microscopy has also recently emerged as a novel technique improving resolution, but dependent on physically expanded sample linked to swellable polymer matrix. The enlarged sample allows for going over the resolution limit under conventional diffraction-limited fluorescence microscopy. Combining the two methods (i.e. super-resolution imaging of expanded samples) may result in sub-10-nm resolution. However, the enlarged sample volume reduces labeling density and it makes difficult to apply expanded samples to super-resolution microscopy. To overcome the challenge, we first designed the biotin-avidin complex to amplify fluorescence intensity in expanded sample. The densely labeled fluorophores can boost the signal intensity. And then we observed subcellular structures with DNA points accumulation for imaging in nanoscale topography (DNA-PAINT), which is a method that utilizes transient hybridization of two short complementary DNA strands as a modality of localized-based super-resolution microscopy. In this study, we demonstrate the efficiency of amplified signals quantitatively and enhanced the spatial resolution from the combination of super-resolution microscopy and expansion microscopy.