What methods can I use to analyze superoxide dismutase (SOD)?

SOD activity can be measured by enzymatic activity assays and activity gels. Enzymatic activity assays such as xanthine oxidase system, NBT assay, and the cytochrome c reduction assay can all be used to measure SOD activity. These assays function on the ability of SOD to inhibit the production of the activity of superoxide radicals. SOD activity is measured by monitoring the change in absorbance or fluorescence resulting from the enzymatic reaction. Activity gels such as gel electrophoresis can be used to separate SOD isoforms based on their molecular weights. Different SOD isoforms like copper/zinc SOD and manganese SOD can be distinguished based on their migration patterns in the gel. MS is another technique to identify and quantify SOD proteins. MS uses ionization and fragmentation of proteins, followed by the analysis of the resulting spectra to identify the SOD protein in the sample.