Cryosectioning method for microdissection of murine colonic mucosa

The barrier function of mucosal tissues is a vital component of innate immunity in the colon. This barrier is provided by a monolayer of simple columnar epithelial cells. It is a highly regenerative tissue, with resident stem cells replenishing the epithelium every few days. This process of regeneration requires the maintenance of a proliferative stem cell compartment within structures called the crypts of lieberkuhn. Over time, the newly produced daughter cells lose their proliferative potential, migrate toward the surface of the gut, and are finally shed into the lumen. Failure of this differentiation program is thought to contribute to diseases such as inflammatory bowel disease and colon cancer. In order to study these processes at the molecular level, we have developed a simple method for the microdissection of two spatially distinct regions of the colon; the proliferative crypt zone, and the differentiated surface cells. Our objective is to isolate specific crypt and surface cell epithelial populations from mouse colonic mucosa for the isolation of mRNA and protein. Colonic tissue was harvested from wild‐type mice, cleaned and bisected. The tissue was then frozen between two metal plates and sectioned on a cryotome. Isolation of spatial distinct epithelial layers was confirmed by examining serial sections histologically, for protein content, and mRNA. In conclusion, we have developed a simple method for isolating crypt and surface epithelial cells from murine colonic tissue.