Figure 2. Levels of corneal ROS/RNS and superoxide radicals in C57BL/6 wild type, SOD-3 null, SOD-1 null, and SOD-1/3 null mice expressed as arbitrary units. The ROS/RNS levels were quantified using fluorimetry with 10 µM 2',7'-dichlorodihydrofluorescein diacetate (H₂DCFDA), and the superoxide levels were determined similarly with 10 µM OxyBURST Green dye assay (excitation=488 nm, emission=520 nm). Both the ROS/RNS and superoxide levels are significantly elevated in all three knockout genotypes (p<0.05), except for the ROS/RNS levels in the SOD-1/3 null genotype (p=0.078). WT, wild type; A.U., arbitrary units.