Immunohistochemistry (IHC) is a technique used to visualize the presence and location of proteins within tissues. Drosophila larvae are particularly amenable to IHC because of the ease with which they can be processed for staining. Additionally, the larvae are transparent, meaning that some tissues can be visualized without the need for dissection.

In IHC, proteins are ultimately detected with antibodies that specifically bind to “epitopes” within the protein of interest. In order to preserve these epitopes, tissues must be fixed prior to staining. Furthermore, in order for antibodies to penetrate membranes, cells must be permeabilized with detergents. This video article offers a detailed view of the reagents, tools, and procedures necessary for the staining of dissected larval tissues, including fixation, blocking, and staining steps. Also featured is a demonstration of tissue mounting techniques for fluorescence microscopy. Finally, examples of the broad range of applications for these techniques (and some variations upon them) are provided.