Isolation of a purified epithelial cell population from human colon.

While in situ techniques have been valuable in identifying the presence and localization of cytoplasmic and membrane components in tissue (1), there is often a need to study directly one or more cell types, free from its own microenvironment. For the human colon, isolation techniques to allow direct study have been described for mononuclear cells in the lamina propria, smooth muscle cells at or below the muscularis mucosae, and cells of the enteric nervous system, located between the subserosa and the lamina propria (2-4). More recently, interest has risen to isolate populations of intestinal epithelial cells, for investigations of human colonic adenocarcinoma-which originates from colonic epithelia; as well as for study of the epithelial response to infection and inflammation. The technique for isolating epithelial cells from the human colon involves mechanical dissection to separate mucosa from the muscle layers which are discarded; and enzymatic digestion of collagen, followed by discontinuous gradient centrifugation in Percoll. The goal is to isolate>90% pure epithelial cells. Although the cells appear intact under the microscope, viability is variable from 50-80%. The yield depends on the size of the available tissue.