Objective   To observe the adhesive property of epidermal stem cells onto Ⅳ collagen at different time points

in order to sort the epidermal stem cells.    Methods   Keratinocytes were isolated from adult human foreskins circumcision and inoculated on the 6-well plates precoated with Ⅳ collagen. The cell number was counted and the diameters were measured with a CASY at 10

20

30 and 60 min after implanting. The expressions of integrin β1 and CK19 on the adhered cells were examined with immunofluorescence and immunocytochemical methods to identify epidermal stem cells. The expression of integrin β1 was observed with flow cytometry (FCM). Morphological observation was carried out with the aid of contrast phase microscope.    Results   With the elapse of time

more and more cells adhered

and the number of those adhering within 20 min was significantly larger than those within 10 min (P0.05). Morphologically the epidermal stem cells were brighter

smaller and rounder after the adhesion. All adhered cells were positive to integrin β1 and had a positive rate of 31.03% to CK19. FCM indicated that the cells were 100% positive to integrin β1.    Conclusion    Most of epidermal stem cells can be sorted by adhering to Ⅳ collagen within 20 min

with no effect on the validity. This method can be used to sort epidermal stem cells.