Preservation of Mucus in Histological Sections, Immunostaining of Mucins in Fixed Tissue, and Localization of Bacteria with FISH

As mucus is highly hydrated, special care has to be taken to preserve this in histological preparations during immunostaining. Here, we describe how to fix tissues in such a way that the mucus is preserved in paraffin-embedded tissue. We also describe how the major macromolecular components in the mucus, the mucins, are immunostained and how bacteria can be localized in preparations with preserved mucus by fluorescent in situ hybridization.