Figure 2. Transforming growth factor-beta suppresses proliferation of limbal epithelial stem cells. A and B: Limbal epithelial stem cell (LSC) proliferation was determined with bromodeoxyuridine (BrdU) labeling for 6 h. LSCs (∆Np63α) and BrdU were detected with immunofluorescence microscopy (original magnification, 400X). Scale bar = 20 µM. A representative picture of three independent experiments is shown. Ten randomly selected fields in each group were photographed, and the percentage of BrdU and ∆Np63α-double positive cells (pale pink) per total ∆Np63α-positive cells was calculated. C: Ki67 mRNA in LSCs assayed with quantitative real-time PCR (qPCR). The cycle threshold (Ct) value of the Ki67 PCR product and control mRNA (GAPDH) were used to calculate the relative quantities of mRNA between samples. Data represent three independent experiments.