Background & objectives: During lifetime, hair follicles undergo three cyclic changes: anagen, catagen, telogen. In hair follicles, stem cells located in Bulge area, which is part of the outer root sheath. Bulge cells proliferate new cells in anagen phase. Bulge region of hair follicle indicated as a source of stem cell for many years, but little studies done in vitro to characterize rat bulge region hair follicle stem cells.

  Methods: In this study Bulge cells of rat hair follicle were isolated and cultured, then morphological features of these cells surveyed. Nestin and CD34 as hair follicle stem cell markers, and K15 as a keratinocyte marker assessed by immunocytochemistry after one to three weeks.

  Results: In this study, we found that, 2 days after attachment of cells to floor of plates, the cells were initiated to proliferation and migration. These cells had good nestin and CD34 immunostaining, but after three week differentiation,were nestin and CD34 negative. Also these cells couldn’t express K15.

  Conclusion : Results showed that cultivated rat bulge cells, have high proliferative potential, and also could express nestin and CD34 as stem cell factors.