OBJECTIVETo establish a methodology of serum-free culture of human epidermal stem cells in vitro, and observe their biological characteristics.

METHODSEpidermal stem cells were isolated from child foreskin and purified with type IV collagen. They were then cultured in regular medium (S group), serum-free medium (SF1 group) and bovine pituitary extract but serum-free medium (SF2 group), respectively. The morphological changes, clone counting, passage time, expression of surface alpha(6) and CD(71), cell cycle analysis, and the expression of cytokeratin (CK) 19, CK5/8, CK10 in each group were determined 20 days after culture.

RESULTSThere was no significant difference in morphology, CK19, 5/8 and 10 positive cells between SF1 group and S group. The cells in these two groups could both form about 43 clones and be passaged for 10 times. About (48 + 6)% cells were alpha(6)(bri)CD71(dim) positive, (72.2 + 6.2)% cells were at G0-G1 phase, with similar expression of CK19, CK5/8, CK10. Despite more clone numbers were found in SF2 group, the levels of all other parameters were lower than those in S and SF1 groups.

CONCLUSIONHuman epidermal stem cells can be cultured successfully in serum-free culture for the study of their biological characteristics.