Lightsheet Imaging of Potassium Acrylate-based Expansion Microscopy data sets

To extend the resolution of optical microscopy towards that achievable by electron microscopy, whilst allowing multi-color visualization of tissues in 3D, we have developed a potassium (poly)acrylate-based expansion microscopy (ExM) platform, compatible with strong fixation reagents such as GA for better preserving transgenic fluorescence proteins, with an axicon-based Bessel lightsheet microscope equipped with long-working distance objectives and long travelling distance voice-coil stages. The good mechanical strength of our hydrogels could be mounted and translated in 3D for sample scanning via lightsheet imaging. At a tile scanning speed of ~1 min/mm3 with 1012 pixels over 14 hours, we imaged the centimeter-sized fly brain at an effective resolution comparable to electron microscopy.