To develop a simple and fast purifingmethod of dental follicle cell by the character of different velocity of attachment of detachment between dental follicle cells and enamel organ cells.

The lower first intact molar germs of SD rats with 5-6 days old were selected and separated. The dental follicle and enamel organ were stipped together under the stereo microscope. After minced into little pieces and degested with trypsin and cultured, the dental follicle cells were purified by diffierential adherence and differential passage. The final purified cells were identified by immunocytochemistry.

The primay cells were mixed, consisting of dental follice cells and enamel organ cells. After differential adherence and passage, the cells of 2-3th passage became purified dental follicle cells. Purified dental follicle cells were elongate spindle or triangle in shape, positive for vimentin and negative for cytokeratin.

Bidirectional differential method is an efficient and simple method for the purification of dental follicle cells.