In the version of this Letter originally published, the authors inadvertently omitted a key reference. The following reference has been added: '37. Chozinski, T. J. et al. Expansion microscopy with conventional antibodies and fluorescent proteins. Nat. Methods 13, 485–488 (2016).' Original reference 37 has been renumbered to reference 38 accordingly. Furthermore, a new sentence citing this reference has been added at the end of the 'Fixed and live cell imaging' section in the Methods: 'Super-resolution expansion microscopy was performed as described37.' These changes have been made in the online version of the Letter.