Journal of Microbiological Methods, 106927<\/p>\n\n\n\n
Castagnini, D., Palma, K., Jara-Wilde, J., Navarro, M. N., Gonz\u00e1lez, M. J., Toledo, J., … & H\u00e4rtel, S.<\/p>\n\n\n\n
Bacterial biofilms form when bacteria attach to surfaces and generate an extracellular matrix that embeds and stabilizes a growing community. Detailed visualization and quantitative analysis of biofilm architecture by optical microscopy are limited by the law of diffraction. Expansion Microscopy (ExM) is a novel Super-Resolution technique where specimens are physically enlarged by a factor of \u223c4, prior to observation by conventional fluorescence microscopy. ExM requires homogenization of rigid constituents of biological components by enzymatic digestion. We developed an ExM approach capable of expanding 48-h old\u00a0Proteus mirabilis<\/em>\u00a0biofilms 4.3-fold (termed PmbExM), close to the theoretic maximum expansion factor without gross shape distortions. Our protocol, based on lytic and glycoside-hydrolase enzymatic treatments, degrades rigid components in bacteria and extracellular matrix. Our results prove PmbExM to be a versatile and easy-to-use Super-Resolution approach for enabling studies of\u00a0P. mirabilis<\/em>\u00a0biofilm architecture, assembly, and even intracellular features, such as DNA organization.<\/p>\n\n\n\n