Purpose | This immunoassay kit allows for the in vitro quantitative determination of human SOD concentrations in serum, plasma and other biological fluids. |
Sample Type | Serum, Plasma, Biological Fluids |
Analytical Method | Quantitative |
Detection Method | Colorimetric |
Specificity | This assay recognizes recombinant and natural human SOD. |
Cross-Reactivity (Details) | No significant cross-reactivity or interference was observed. |
Sensitivity |
< 1 U/L The sensitivity of this assay, or Lower Limit of Detection (LLD) was defined as the lowest detectable concentration that could be differentiated from zero. |
Characteristics | Homo sapiens,Human,Superoxide dismutase [Cu-Zn],Superoxide dismutase 1,hSod1,SOD1,1.15.1.1 |
Components | Reagent (Quantity): Assay plate (1), Standard (2), Sample Diluent (1×20ml), Assay Diluent A (1×10ml), Assay Diluent B (1×10ml), Detection Reagent A (1×120 μl), Detection Reagent B (1×120 μl), Wash Buffer(25 x concentrate) (1×30ml), Substrate (1×10ml), Stop Solution (1×10ml), Plate sealer for 96 wells (5), Instruction (1) |
Material not included | Microplate reader. Pipettes and pipette tips. EP tube Deionized or distilled water. |
Alternative Name | SOD1 (SOD1 ELISA Kit Abstract) |
Background | Superoxide Dismutases (SODs), originally identified as Indophenoloxidase (IPO), are enzymes that catalyze the converversion of naturally-occuring but harmful superoxide radicals into molecular oxygen and hydrogen peroxide. SOD is a metalloenzyme whose active center is occupied by copper and zinc, sometimes manganese or iron. SOD plays an extremely important role in the protection of all aerobic life-systems, including man, against oxygen toxicity (and the free radicals derived from oxygen). The enzyme superoxide dismutase, or SOD, catalyzes the dismutation of superoxide into oxygen and hydrogen peroxide. SOD is an endogenously produced intracellular enzyme present in essentially every cell in the body. There are at least three forms of superoxide dismutase in nature. Human erythrocytes contain an SOD enzyme with divalent copper and divalent zinc. Chicken liver mitochondria and E. coli contain a form with trivalent manganese. E. coli also contains a form of the enzyme with trivalent iron. The Cu-Zn enzyme is a dimer of molecular weight 32,500. The two subunits are joined by a disulfide bond. Superoxide dismutases are enzymes that play major roles in the protection of cells against oxidative damage. The two major forms of superoxide dismutase (SOD) in humans are the mitochondrial manganese SOD and the cytosolic copper/zinc SOD. A copper/zinc SOD, isolated from beef liver, has been used intra-articularly for degenerative joint disorders as an anti-inflammatory agent. SOD is also marketed as a nutritional supplement. Cellular SOD is actually represented by a group of metalloenzymes with various prosthetic groups. The prevalent enzyme is cupro-zinc (CuZn) SOD, which is a stable dimeric protein (32,000 D). SOD is an enzyme associated with copper, zinc, and manganese by body cells, and breaks down the superoxide free radicals. It is said that SOD protects the lens of the eyes by guarding against free radical damage. |
Pathways | Sensory Perception of Sound, Transition Metal Ion Homeostasis |
Sample Volume | 100 μL |
Plate | Pre-coated |
Protocol | The microtiter plate provided in this kit has been pre-coated with an antibody specific to SOD. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated polyclonal antibody preparation specific for SOD. Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB substrate solution is added to each well. Only those wells that contain SOD, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm 2 nm. The concentration of SOD in the samples is then determined by comparing the O.D. of the samples to the standard curve. |
Reagent Preparation |
Bring all reagents to room temperature before use. Wash Buffer - If crystals have formed in the concentrate, warm to room temperature and mix gently until the crystals have completely dissolved. Dilute 30 mL of Wash Buffer Concentrate into deionized or distilled water to prepare 750 mL of Wash Buffer. Standard - Reconstitute the Standard with 1.0 ml of Sample Diluent. This reconstitution produces a stock solution of 400 U/L. Allow the standard to sit for about 10 minutes with gentle agitation prior to making serial dilutions (Making serial dilution in the wells directly is not permitted). Please firstly dilute the stock solution to 100 U/L and the diluted standard serves as the high standard (100 U/L). The Sample Diluent serves as the zero standard (0 U/L). U/L 400 100 50 25 12.5 6.25 3.12 1.56 0 Detection Reagent A and B - Dilute to the working concentration using Assay Diluent A or B (1:100), respectively. 4 |
Sample Collection | Serum - Use a serum separator tube and allow samples to clot for 30 minutes before centrifugation for 20 minutes at approximately 1000 g. Remove serum and assay immediately or aliquot and store samples at -20 or -80 . Plasma - Collect plasma using EDTA or heparin as an anticoagulant. Centrifuge samples for 15 minutes at 1000 g at 2 - 8 within 30 minutes of collection. Store samples at -20 or -80 . Avoid repeated freeze-thaw cycles. Other biological fluids - Remove particulates by centrifugation and assay immediately or aliquot and store samples at -20 or -80 . Avoid repeated freeze-thaw cycles. Sample preparation - Serum/plasma samples require a 10 fold dilution. A suggested 10-fold dilution is 100uL Sample + 900uL Sample Diluent. Sample should be diluted by 3 0.02 M PBS(PH=7.0-7.2). Note: Serum and plasma to be used within 7 days may be stored at 2-8 , otherwise samples must stored at -20 ( 1 month) or -80 ( 2 months) to avoid loss of bioactivity and contamination. Avoid freeze-thaw cycles. When performing the assay slowly bring samples to room temperature. |
Assay Procedure |
Allow all reagents to reach room temperature (Please do not dissolve the reagents at 37 directly.). All the reagents should be mixed thoroughly by gently swirling before pipetting. Avoid foaming. Keep appropriate numbers of strips for 1 experiment and remove extra strips from microtiter plate. Removed strips should be resealed and stored at 4 until the kits expiry date. Prepare all reagents, working standards and samples as directed in the previous sections. Please predict the concentration before assaying. If values for these are not within the range of the standard curve, users must determine the optimal sample dilutions for their particular experiments. |
Calculation of Results |
Average the duplicate readings for each standard, control, and samples and subtract the average zero standard optical density. Create a standard curve by reducing the data using computer software capable of generating a four parameter logistic (4-PL) curve-fit. As an alternative, construct a standard curve by plotting the mean absorbance for each standard on the x-axis against the concentration on the y-axis and draw a best fit curve through the points on the graph. The data may be linearized by plotting the log of the SOD concentrations versus the log of the O.D. and the best fit line can be determined by regression analysis. It is recommended to use some related software to do this calculation, such as curve expert 13.0. This procedure will produce an adequate but less precise fit of the data. If samples have been diluted, the concentration read from the standard curve must be multiplied by the dilution factor. |
Restrictions | For Research Use only |
Handling Advice |
1. The kit should not be used beyond the expiration date on the kit label. 2. Do not mix or substitute reagents with those from other lots or sources. 3. If samples generate values higher than the highest standard, further dilute the samples and repeat the assay. Any variation in standard diluent, operator, pipetting technique, washing technique,incubation time or temperature, and kit age can cause variation in binding. 4. This assay is designed to eliminate interference by soluble receptors, ligands, binding proteins, and other factors present in biological samples. Until all factors have been tested in the Immunoassay, the possibility of interference cannot be excluded. 5. Limited by the current condition and scientific technology, we can't completely conduct the comprehensive identification and analysis on the raw material provided by suppliers. So there might be some qualitative and technical risks to use the kit. |
Storage | 4 °C/-20 °C |
Storage Comment | The Standard, Detection Reagent A, Detection Reagent B and the 96-well strip plate should be stored at -20 °C upon being received. The other reagents can be stored at 4 °C. |