摘要：Aim: Identification of human limbal stem cell by p63, a specific stem cell marker in cadaveric limbal tissue and in in-vitro limbal stem culture. Methods: Identification of limbal stem cell was done on cadaveric limbal biopsy sample using immuno-histo-chemistry analysis with p63 staining and a secondary anti mouse (GOAT) Fab fragment antibody staining. In- vitro cultured limbal stem cells over amniotic membrane were also stained by p63 marker. Results: Basal layer of limbus shows intense staining for p63. Stained cells showed brown color (due to DAB chromogen). There was no uniform staining of basal layer. Some cells showed intense staining while other cells did not show stain. This indicates that limbal stem cells are not uniformly distributed in basal limbal layer but are present in small groups. The time taken by human limbal epithelial cells to form a monolayer on denuded amniotic membrane was 2-3 week and 4-6 layers sheet was obtained after 4 weeks. Conclusion: p63 was maximally expressed in limbal basal layer which is highly mitotic layer and is responsible for epithelial cell proliferation. Similarly p63 also stained cultured stem cells over denuded amniotic membrane which proves that cultured limbal cells have high mitotic activity and therefore are true stem cells rather than differentiated epithelial cells.
