Figure 9. Expression of Hes1 in corneal epithelial cultures. The level of canonical Notch activity in human corneal epithelial cell cultures was determined by relative quantitative RT–PCR of the downstream target, Hes1. After normalization to 18S, the level of Hes1 in the low density cultures (20%–30% confluence) was arbitrarily set at 100%. High density cultures demonstrated a 1.5 fold increase (151%±5%, p<0.05) and high calcium cultures expressed a 2.2 fold (219%±48%, p<0.05) increase in the level of Hes1 relative to the low density cultures.