Whole-mount Fixation and Immunostaining of Brain Tissue

Immunocytochemistry on sectioned tissue is a powerful method for determining the cellular and subcellular distributions of an epitope. However, where the expression is patterned, understanding the distribution often requires extensive, time-consuming threedimensional reconstruction with all its attendant artifacts. The techniques described in this unit circumvent these problems. The distribution of an antigen can be mapped rapidly and reliably in the intact brain, and the tissue can subsequently be sectioned and examined. If necessary, the tissue can be immunostained again for the same antigen (e.g., where incomplete penetration is a problem) or another one (if double-labeling or counterstaining is needed).