• Assay Type Activity Assay
  • Sample Types Serum, Plasma, Cells, Tissue Culture Media, Erythrocytes
  • Sensitivity 0.044 U/mL
  • Species Identical across species
  • Assay Duration 20 Minutes
  • Samples/Plate 40 in Duplicate
  • Readout Colorimetric, 450 nm
  • Standard Curve
  • Description

    Assay Principle: 

    The Superoxide Dismutase (SOD) Activity Kit quantitatively measures SOD activity in serum, plasma, cells, tissue culture media, and erythrocytes. The Superoxide Dismutase (SOD) Activity Kit is an Activity Assay with a run time of 20 minutes. Please read the complete kit insert for more information before performing this assay.

    Use our provided Superoxide Dismutase Standard to generate a standard curve for the assay. Pipette the standards or diluted samples into a transparent microtiter plate. Add the Substrate Preparation mixture and Xanthine Oxidase Preparation mixture to each well, tapping the plate to ensure sufficient mixing of reagents. Then incubate the mixture at room temperature for 20 minutes. The color-generating reaction occurs between the Xanthine Oxidase, oxygen, and the colorless substrate within the sample or standard. 

    After the 20-minute incubation, use a plate reader to detect and record the generated signal at 450nm. Use the intensity and the standard curve to calculate the SOD activity in the samples.


    Short-lived and highly reactive oxygen species (ROS) such as O2-· (superoxide), ·OH (hydroxyl radical), and H2O2 (hydrogen peroxide) are continuously generated in vivo. Antioxidant enzymes and small molecule antioxidants control the cellular levels of ROS. The major antioxidant enzymes, superoxide dismutases (SODs), including copper-zinc superoxide dismutase (Cu/ZnSOD), manganese superoxide dismutase (MnSOD), and extracellular superoxide dismutase (EC-SOD). All play a critical role in scavenging O2-·. Reduced SOD activity can cause elevated levels of superoxide, leading to decreased NO and increased peroxynitrite concentrations.

    The major intracellular SOD is a 32-kDa copper and zinc-containing homodimer (Cu/Zn SOD). The mitochondrial SOD (MnSOD) is a manganese-containing 93-kDa homotetramer synthesized in the cytoplasm and translocated to the inner matrix of mitochondria. EC-SOD is the primary extracellular SOD enzyme with high expression in many organs. Increased SOD activity levels are seen in Downs Syndrome, while decreased activity is seen in diabetes, Alzheimer’s disease, rheumatoid arthritis, Parkinson’s disease, uremic anemia, atherosclerosis, some cancers, and thyroid dysfunction.