Open AccessExpansion Microscopy: Protocols for Imaging Proteins and RNA in Cells and Tissues
Author(s) -
Asano Shoh M.,
Gao Ruixuan,
Wassie Asmamaw T.,
Tillberg Paul W.,
Chen Fei,
Boyden Edward S.
Publication year - 2018
Publication title -
current protocols in cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.149
H-Index - 38
eISSN - 1934-2616
pISSN - 1934-2500
DOI - 10.1002/cpcb.56
Subject(s) - biomolecule , microscopy , microscope , fluorescence microscope , confocal , rna , resolution (logic) , nanoscopic scale , visualization , materials science , biomedical engineering , chemistry , biophysics , fluorescence , nanotechnology , computer science , biology , optics , physics , biochemistry , artificial intelligence , medicine , gene
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. © 2020 The Authors.