I am running a native gel for SOD assay. I have used the thermo/novex native page marker (Catalog number: LC0725) in the same gel. Strangely I am detecting 7 sod positive band between 66 kDa and 20 kDa but there are not in cbb bands in this range when the gel is stained. So I need to know what are the protein components in the native marker? Also could there be SOD contaminants in the marker?