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574601 Superoxide Dismutase Assay Kit II

Superoxide Dismutase Assay Kit II MSDS (material safety data sheet) or SDS, CoA and CoQ, dossiers, brochures and other available documents.
574601
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Overview

Replacement Information

Products

Catalog NumberPackaging Qty/Pack
574601-1KIT Glass bottle 1 kit
Description
OverviewA sensitive spectrophotometric assay (450 nm) for the measurement of all three types (Cu/Zn, Mn, and Fe) of SOD.
Catalogue Number574601
Brand Family Calbiochem®
Materials Required but Not Delivered• Plate reader capable of reading absorbance at 450 nm.
• Adjustable pipettors and a repeat pipettor.
• A source of pure water. Glass distilled water or HPLC-grade water is acceptable.
References
ReferencesMaier, C.M. and Chan, P.H 2002. The Neuroscientist 8, 323.
Mattiazz, M., et al. 2002. J. Biol. Chem. 277, 29626.
Beckman, J.S. and Koppenol, W.H. 1996. Am. J. Physiol. 271, C1424.
Liu, D. 1996. J. Mol. Neuro. 7, 159.
MacMillan-Crow, L.A., et al. 1996. Proc. Natl. Acad. Sci. USA 93, 11853.
Sun, E., et al. 1995. Biol. Trace Elem. Res. 48, 231.
Sandstrom, J., et al. 1994. J. Biol. Chem. 269, 19163.
Marklund, S. 1980. Acta Physiol. Scand. Suppl. 492, 19.
Malstrom, B. 1975. in The Enzymes. Boyer, P., editor. XIIB, Academic Press, New York, 533.
Product Information
Unit of DefinitionThe amount of enzyme needed to exhibit 50% dismutation of the superoxide radical.
Detection methodColorimetric
Form96 Tests
Format96-well plate
Kit containsAssay Buffer, Sample Buffer, Radical Detector, SOD Standard, Xanthine Oxidase, 96-Well Plate, Plate Cover, and a user protocol.
Positive controlBovine erythrocyte SOD (Cu/Zn)
Quality LevelMQ100
Applications
Biological Information
Assay range0.025-0.25 units per ml SOD
Assay time1.5 h
Sample TypePlasma, serum, erythrocyte lysates, and other lysates, tissue homogenates, and cell lysates
Physicochemical Information
Dimensions
Materials Information
Toxicological Information
Safety Information according to GHS
Safety Information
Product Usage Statements
Storage and Shipping Information
Ship Code Dry Ice Only
Toxicity Standard Handling
Storage -20°C
Storage ConditionsUpon arrival store entire contents of the kit at -20°C.
Do not freeze Ok to freeze
Packaging Information
Transport Information
Supplemental Information
Kit containsAssay Buffer, Sample Buffer, Radical Detector, SOD Standard, Xanthine Oxidase, 96-Well Plate, Plate Cover, and a user protocol.
Specifications
Global Trade Item Number
Catalog Number GTIN
574601-1KIT 07790788051822

Documentation

Superoxide Dismutase Assay Kit II Certificates of Analysis

TitleLot Number
574601

References

Reference overview
Maier, C.M. and Chan, P.H 2002. The Neuroscientist 8, 323.
Mattiazz, M., et al. 2002. J. Biol. Chem. 277, 29626.
Beckman, J.S. and Koppenol, W.H. 1996. Am. J. Physiol. 271, C1424.
Liu, D. 1996. J. Mol. Neuro. 7, 159.
MacMillan-Crow, L.A., et al. 1996. Proc. Natl. Acad. Sci. USA 93, 11853.
Sun, E., et al. 1995. Biol. Trace Elem. Res. 48, 231.
Sandstrom, J., et al. 1994. J. Biol. Chem. 269, 19163.
Marklund, S. 1980. Acta Physiol. Scand. Suppl. 492, 19.
Malstrom, B. 1975. in The Enzymes. Boyer, P., editor. XIIB, Academic Press, New York, 533.
User Protocol

Revision26-April-2011 RB
Form96 Tests
Format96-well plate
Detection methodColorimetric
StorageUpon arrival store entire contents of the kit at -20°C.
BackgroundSuperoxide dismutases (SODs) are metalloenzymes that catalyze the dismutation of the superoxide anion to molecular oxygen and hydrogen peroxide and thus form a crucial part of the cellular antioxidant defense mechanism. 2O2-• + 2H+ + SOD Ø H2O2 + O2 Three types of SODs have been characterized according to their metal content: copper/zinc (Cu/Zn), manganese (Mn), and iron (Fe). SOD is widely distributed in both plants and animals. It occurs in high concentrations in brain, liver, heart, erythrocytes, and kidney. In humans, there are three forms of SOD: cytosolic Cu/Zn-SOD, mitochondrial Mn-SOD, and extracellular SOD. Extracellular SOD is found in the interstitial spaces of tissues and also in extracellular fluids, accounting for the majority of the SOD activity in plasma, lymph, and synovial fluid. The amount of SOD present in cellular and extracellular environments is crucial for the prevention of diseases linked to oxidative stress. Mutations in SOD account for approximately 20% of familial amyotrophic lateral sclerosis (ALS) cases. SOD also appears to be important in the prevention of other neurodegenerative disorders such as Alzheimer's, Parkinson's, and Huntington's diseases. The reaction catalyzed by SOD is extremely fast, having a turnover of 2 x 109 M-1sec-1 and the presence of sufficient amounts of the enzyme in cells and tissues typically keeps the concentration of superoxide (O2-) very low. However, in a competing reaction, nitric oxide (NO) reacts with O2- with a rate constant of 6.7 x 109 M-1sec-1 to form the powerful oxidizing and nitrating agent, peroxynitrite. Under conditions in which SOD activity is low or absent (i.e., SOD mutation) or which favor the synthesis of µM concentrations of NO (i.e., ischemia/reperfusion, iNOS up regulation, etc.), NO out-competes SOD for superoxide, resulting in the formation of peroxynitrite. The presence of nitrotyrosine as a "footprint" for peroxynitrite, and hence the prior co-existence of both O2- and NO, has been observed in a variety of medical conditions, including atherosclerosis, sepsis, and ALS.
Principles of the assayThe Calbiochem® Superoxide Dismutase Assay Kit II utilizes a tetrazolium salt for detection of superoxide radicals generated by xanthine oxidase and hypoxanthine. One unit of SOD is defined as the amount of enzyme needed to exhibit 50% dismutation of the superoxide radical. The SOD assay measures all three types of SOD (Cu/Zn-, Mn-, and Fe-SOD). The assay provides a simple, reproducible, and fast tool for assaying SOD activity in plasma, serum, erythrocyte lysates, tissue homogenates, and cell lysates. Mitochondrial Mn-SOD can be assayed separately following the procedure outlined under sample preparation.
Materials provided• Assay Buffer (10X) (Kit Component No. KP31620): 1 vial
• Sample Buffer (10X) (Kit Component No. KP31621): 1 vial
• Radical Detector (Kit Component No. KP31622): 1 vial
• SOD (standard) (Kit Component No. KP31623): 1 vial
• Xanthine Oxidase (Kit Component No. KP31624): 3 vials
• 96 Well Plate (Kit Component No. KP31625): 1 plate
• Plate Sealer (Kit Component No. KP31626): 1 each
Materials Required but not provided• Plate reader capable of reading absorbance at 450 nm.
• Adjustable pipettors and a repeat pipettor.
• A source of pure water. Glass distilled water or HPLC-grade water is acceptable.
Precautions and recommendations• Please read these instructions carefully before beginning this assay.
• WARNING: This product is not intended or approved for use in humans or veterinary animals and is not for diagnostic use.
• Pipetting hints
a. It is recommended that a repeat pipettor be used to deliver reagents to the wells.
b. Before pipetting each reagent, equilibrate the pipet tip in that reagent (i.e., slowly fill the tip and gently expel the contents, repeat several times).
c. Do not expose the pipet tip to the reagent(s) already in the well.
• The final volume of the assay is 230 ml in all the wells.
• It is not necessary to use all the wells on the plate at one time.
• The assay temperature is 25°C.
• All reagents except samples and xanthine oxidase must be equilibrated to room temperature before beginning the assay.
• It is recommended that the samples and SOD standards be assayed at least in duplicate.
• Monitor the absorbance at 450 nm using a plate reader.
PreparationThe procedures listed below for tissue homogenates and cell lysates will result in assaying total SOD activity (cytosolic and mitochondrial). To separate the two enzymes, centrifuge the 1,500 x g supernatant at 10,000 x g for 15 min at 4°C. The resulting 10,000 x g supernatant will contain cytosolic SOD and the pellet will contain mitochondrial SOD. Suspend the mitochondrial pellet in cold buffer (i.e., 20 mM HEPES, pH 7.2, containing 1 mM EGTA, 210 mM mannitol, and 70 mM sucrose). If not assaying on the same day, freeze the samples at -80°C. The samples will be stable for at least one month. The addition of 1-3 mM potassium cyanide to the assay will inhibit both Cu/Zn-SOD and extracellular SOD, resulting in the detection of only Mn-SOD activity.

• Tissue Homogenate

1. Prior to dissection, either perfuse or rinse tissue with phosphate buffered saline (PBS), pH 7.4, containing 0.16 mg/ml heparin to remove any red blood cells and clots.
2. Homogenize the tissue in 5-10 ml of cold 20 mM HEPES buffer, pH 7.2, containing 1 mM EGTA, 210 mM mannitol, and 70 mM sucrose per gram tissue.
3. Centrifuge at 1,500 x g for 5 min at 4°C.
4. Remove the supernatant for assay and store on ice. If not assaying on the same day, freeze the sample at -80°C. The sample will be stable for at least one month.

• Cell Lysate

1. Collect cells by centrifugation at 1,000-2,000 x g for 10 min at 4°C. For adherent cells, do not harvest using proteolytic enzymes; rather use a rubber policeman.
2. Homogenize or sonicate the cell pellet in cold 20 mM HEPES buffer, pH 7.2, containing 1 mM EGTA, 210 mM mannitol, and 70 mM sucrose.
3. Centrifuge at 1,500 x g for 5 min at 4°C.
4. Remove the supernatant for assay and store on ice. If not assaying on the same day, freeze the sample at -80°C. The sample will be stable for at least one month.

• Plasma and Erythrocyte Lysate

1. Collect blood using an anticoagulant such as heparin, citrate, or EDTA.
2. Centrifuge the blood at 700-1,000 x g for 10 min at 4°C. Pipette off the top yellow plasma layer without disturbing the white buffy layer. Store plasma on ice until assaying or freeze at -80°C. The plasma sample will be stable for at least one month.
3. Remove the white buffy layer (leukocytes) and discard.
4. Lyse the erythrocytes (red blood cells) in 4 times its volume of ice-cold HPLC-grade water.
5. Centrifuge at 10,000 x g for 15 min at 4°C.
6. Collect the supernatant (erythrocyte lysate) for assaying and store on ice. If not assaying the same day, freeze at -80°C. The sample will be stable for at least one month.

• Serum

1. Collect blood without using an anticoagulant such as heparin, citrate, or EDTA. Allow blood to clot for 30 min at 25°C.
2. Centrifuge the blood at 2,000 x g for 15 min at 4°C. Pipette off the top yellow serum layer without disturbing the white buffy layer. Store serum on ice. If not assaying the same day, freeze at -80°C. The sample will be stable for at least one month.
Reagent preparation• Assay Buffer (10X): Dilute 3 ml of Assay Buffer concentrate with 27 ml of HPLC-grade water. This final Assay Buffer (50 mM Tris-HCl, pH 8.0, containing 0.1 mM diethylenetriaminepentaacetic acid (DTPA) and 0.1 mM hypoxanthine) should be used to dilute the radical detector. When stored at 4°C, this diluted Assay Buffer is stable for at least two months.
• Sample Buffer (10X): Dilute 2 ml of Sample Buffer concentrate with 18 ml of HPLC-grade water. This final Sample Buffer (50 mM Tris-HCl, pH 8.0) should be used to prepare the SOD standards and dilute the xanthine oxidase and SOD samples prior to assaying. When stored at 4°C, this diluted Sample Buffer is stable for at least two months.
• Radical Detector: This vial contains a solution of a tetrazolium salt. Prior to use, transfer 50 µl of the supplied solution to another vial and dilute with 19.95 ml of diluted Assay Buffer. Cover with aluminum foil. The diluted radical detector is stable for two h.
• SOD (standard): This vial contains a solution of bovine erythrocyte SOD (Cu/Zn). The enzyme is ready to use as supplied. Store the thawed enzyme on ice.
• Xanthine Oxidase: These vials contain a solution of xanthine oxidase. Prior to use, thaw one vial and transfer 50 µl of the supplied enzyme to another vial and dilute with 1.95 ml of Sample Buffer (dilute). Store the thawed and diluted xanthine oxidase on ice. The diluted enzyme is stable for 1 h. Do not refreeze the thawed enzyme.
Detailed protocol

Figure 1: Sample Plate Format

There is no specific pattern for using the wells on the plate. A typical layout of SOD standards and samples to be measured in duplicate is given (see Figure 1). We suggest you record the contents of each well on the template sheet provided.


1. Preparation of SOD Standards - Dilute 20 µl of the SOD standard with 1.98 ml of 1X Sample Buffer to obtain the SOD stock solution. Take seven clean glass test tubes and mark them A-G. Add the amount of SOD stock and 1X Sample Buffer to each tube as described in Table 1.

Table 1: Dilution Samples


2. SOD Standard Wells - add 200 µl of the diluted radical detector and 10 µl of standard (tubes A-G) per well in the designated wells on the plate (see suggested plate configuration, Figure 1).
3. Sample Wells - add 200 µl of the diluted radical detector and 10 µl of sample to the wells. [NOTE: If using an inhibitor, add 190 µl of the diluted radical detector, 10 µl of inhibitor, and 10 µl of sample to the wells. The amount of sample added to the well should always be 10 µl. Samples should be diluted with Sample Buffer (dilute) or concentrated with an Amicon centrifuge concentrator with a molecular weight cut-off of 10,000 to bring the enzymatic activity to fall within the standard curve range.]
4. Initiate the reactions by adding 20 µl of diluted xanthine oxidase to all the wells you are using. Make sure to note the precise time you started and add the xanthine oxidase as quickly as possible.
5.Carefully shake the 96 well plate for a few s to mix. Cover with the plate cover.
6. Incubate the plate on a shaker for 20 min at room temperature. Read the absorbance at 450 nm using a plate reader.
Calculations1. Calculate the average absorbance of each standard and sample.
2. Divide standard A's absorbance by itself and divide standard A's absorbance by all the other standards and samples absorbances to yield the linearized rate (LR) (i.e., LR for Std A = Abs Std A/Abs Std A; LR for Std B = Abs Std A/Abs Std B).
3. Plot the linearized SOD standard rate (LR) (from step 2 above) as a function of final SOD Activity (U/ml) from Table 1. See Figure 2 for a typical standard curve.
4. Calculate the SOD activity of the samples using the equation obtained from the linear regression of the standard curve substituting the linearized rate (LR) for each sample. One unit is defined as the amount of enzyme needed to exhibit 50% dismutation of the superoxide radical.

Figure 2: SOD standard curve
Limitations of the assayThe following reagents were tested for interference in the assay.

Table 2: Reagents Tested for Interference
Assay Range0.025-0.25 units per ml SOD
PrecisionIntra-assay Variance

Plasma: 5.9% (n = 82)
SOD Standard: 6.1% (n = 8)
Plate configuration

Figure 3: Plate Template
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