Colorectal cancer, originating in tissues of epithelial origin, is one of the most prolific among human malignant diseases. The prevalence of this disease creates a need for colon epithelial cell lines to facilitate the study of the etiology of this disease and the biochemical and molecular characteristics of epithelial cells. Several approaches for the isolation of colon epithelial cell cultures have previously been reported (1 -8 ). Methods vary, ranging from enzymatic, mechanical disruption, and explant procedures. The enzymatic and mechanical approaches employed to isolate individual cell types are not always practical because they generally result in a homogeneous cell population of fibroblasts (2 ,3 ). This is owing to the fact that fibroblasts adhere to a matrix more efficiently preventing other cell types from propagating and because few epithelial cells survive harsh treatments (2 ). The method described herein is based on a noninjurious approach using minimal primary tissue manipulation to isolate colon epithelial cells in culture (1 ). The colon epithelial cell lines are developed through long-term observation of untreated explants. Epithelial cell lines are obtained through the use of cloning rings. The isolation of colon epithelial cancer cells is obtained by differential attachment of the epithelial cells and/or the use of cloning rings.