Figure 3. TUNEL cell-death detection. A: Representative images of lenticules stained with terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) after 48 h storage for different groups. B: Representative images of lenticules stained with TUNEL after 4 weeks of storage for different groups. Nuclei were counterstained with 4',6-diamidino-2-phenylindole dihydrochloride (DAPI; blue). Original magnification: 200X; scale bar = 100 μm. C: Mean percentage of TUNEL-positive cells in all groups after 48 h. D: Mean percentage of TUNEL-positive in all groups after 4 weeks of storage. No statistically significant inter-group differences were found at each time point.