@article {49346, title = {Expansion microscopy: protocols for imaging proteins and RNA in cells and tissues.}, journal = {Current Protocols in Cell Biology}, volume = {80}, year = {2018}, month = {2018 Aug 02}, pages = {e56}, abstract = {

Expansion microscopy (ExM) is a recently developed technique that enables nanoscale-resolution imaging of preserved cells and tissues on conventional diffraction-limited microscopes via isotropic physical expansion of the specimens before imaging. In ExM, biomolecules and/or fluorescent labels in the specimen are linked to a dense, expandable polymer matrix synthesized evenly throughout the specimen, which undergoes 3-dimensional expansion by \~{}4.5 fold linearly when immersed in water. Since our first report, versions of ExM optimized for visualization of proteins, RNA, and other biomolecules have emerged. Here we describe best-practice, step-by-step ExM protocols for performing analysis of proteins (protein retention ExM, or proExM) as well as RNAs (expansion fluorescence in situ hybridization, or ExFISH), using chemicals and hardware found in a typical biology lab. Furthermore, a detailed protocol for handling and mounting expanded samples and for imaging them with confocal and light-sheet microscopes is provided. {\textcopyright} 2018 by John Wiley \& Sons, Inc.

}, issn = {1934-2616}, doi = {10.1002/cpcb.56}, author = {Asano, Shoh M and Gao, Ruixuan and Wassie, Asmamaw T and Tillberg, Paul W and Chen, Fei and Boyden, Edward S} }