Cytologic appearance of cells dissociated from rat colon and their separation by isokinetic and isopyknic sedimentation in gradients of Ficol.

Several methods for obtaining colon epithelial cells in suspension were compared. The largest number of epithelial cells per gram of colon was obtained in suspension when the colon was dissociated with 0.1% Pronase. Fivefold more cells per gram of tissue were obtained from the proximal 5 cm of colon than from the terminal 5 cm of colon. Several well-defined types of cells were observed in low frequency. They have not been described previously in normal colon. Suspensions of cells from colons of F344 rats always contained copious mucoid gel that was partially eliminated by washing the cells three times in culture medium with 10% fetal calf serum. Velocity sedimentation in a previously described isokinetic gradient of Ficoll in tissue culture medium permitted the separation of epithelial cells from lymphocytes and red blood cells. Type 2 cells, believed to be a subpopulation of epithelial cells, were obtained in a maximum purity of 95.7 +/- 1.2%. The frequency of 8 other cell types and their purification, when possible, are presented. Epithelial cells were separated from most bacteria and could be cultured with antibiotics after separation in the density gradient.