Epithelial cells are isolated from tissues which also contain fibroblasts and endothelial cells. One of the major problems in the cultivation of pure epithelial cells is that the cells can be overgrown with endothelial cells and fibroblasts.  

Methods to obtain pure epithelial cells
The most successful method is to inhibit the fibroblasts directly. There are a lot of different reagents in cell culture which help to inhibit the growth of fibroblasts. The effectiveness of the reagents depend on the origin of the tissue. In the table listed below different reagents are presented.  

Method	Reagent	Tissue
Selective Detachment	Trypsin	Epidermis, cardiac muscle
	Collagenase	Breast carzinoma
Selective Attachment &	Polyacrylamid	Various tumours
Substrate-modification	Teflon	Transformed cells
	Collagen	Epidermis
Selective Media	D-Valin	Kidney, Breast epithelium
	Cis-OH Proline	Cell lines
	Phenobarbitone	Liver
	MCDB 153	Epidermis
	MCDB 170	Breast
	Low Ca++	Epidermal Melanocytes