Purpose | This immunoassay kit allows for the specific measurement of human Anti-gliadin IgG concentrations in serum and plasma. |
Sample Type | Serum, Plasma |
Analytical Method | Quantitative |
Detection Method | Colorimetric |
Specificity | This assay recognizes recombinant and natural human Anti-gliadin IgG. |
Cross-Reactivity (Details) | No significant cross-reactivity or interference was observed. |
Sensitivity | 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,N-alpha-acetyltransferase 20,N-acetyltransferase 5,N-terminal acetyltransferase B complex catalytic subunit NAA20,N-terminal acetyltransferase B complex catalytic subunit NAT5,NatB |
Components | Reagent (Quantity): Assay plate (1), Standard (2), Sample Diluent (1x20ml), Assay Diluent A (1x10ml), Assay Diluent B (1x10ml), Detection Reagent A 1×120μl Detection Reagent B 1×120μl 2 Wash Buffer(25 x concentrate) (1x30ml), Substrate (1x10ml), Stop Solution (1x10ml) |
Alternative Name | NAA20 (NAT5 ELISA Kit Abstract) |
Target Type | Antibody |
Background | Celiac disease (CD) is characterized by the presence of villous atrophy in a jejunal biopsy specimen. The disease is caused by hypersensitivity to gluten, and withdrawal of gluten from the diet cures the patient. Although the mechanisms are still unknown, recent studies strongly suggest an immunological pathogenesis (intraepithelial lymphocytes g/dand a/b- T- cells, cell mediated immunity, cytokines). Genetic factors, e.g. HLA-B8 or DR3/DR7, are known to be associated with susceptibility to celiac disease. During the last few years it has become evident that the determination of gliadin antibodies in serum offers a convenient non-invasive laboratory method for this purpose. Measurement of both anti-gliadin IgA and IgG antibodies is also important in the detection of IgA-deficient CD patients. |
Sample Volume | 100 μL |
Plate | Pre-coated |
Protocol | This assay employs the quantitative sandwich enzyme immunoassay technique. Gliadin antigen has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any Anti-gliadin IgG present is bound by the immobilized antibody. An enzyme-linked antibody gliadin is added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of Anti-gliadin IgG bound in the initial step. The color development is stopped and the intensity of the color is measured. |
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 20 mL of Wash Buffer Concentrate into deionized or distilled water to prepare 500 mL of Wash Buffer. Standardization: Standard - Reconstitute the Standard with 1.0 mL of Sample Diluent. This reconstitution produces a stock solution of 100 AU. The results of the AGA-IgG assay are expressed in arbitrary units (AU). In any assay measuring autoantibodies, it is not the concentration but the activity of the antibody present in the sample that is determined. Allow the standard to sit for a minimum of 15 minutes with gentle agitation prior to making serial dilutions. The undiluted standard serves as the high standard (100 AU). The Sample Diluent serves as the zero standard (0 AU). Detection Reagent A and B - Dilute to the working concentration specified on the vial label using Assay Diluent A and B (1:100), respectively. 3 |
Sample Collection | Cell culture supernates - Remove particulates by centrifugation and assay immediately or aliquot and store samples at ≤ -20 °C. Avoid repeated freeze-thaw cycles. Serum - Use a serum separator tube (SST) and allow samples to clot for 30 minutes before centrifugation for 15 minutes at approximately 1000 x g. Remove serum and assay immediately or aliquot and store samples at -20 °C. Plasma - Collect plasma using EDTA or heparin as an anticoagulant. Centrifuge samples for 15 minutes at 1000 x g at 2 - 8 °C within 30 minutes of collection. Store samples at ≤ -20 °C. Avoid repeated freeze-thaw cycles. Note: Citrate plasma has not been validated for use in this assay. |
Assay Procedure |
Allow all reagents to reach room temperature. Arrange and label required number of strips. |
Calculation of Results |
Average the duplicate readings for each standard, control, and sample 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 y-axis against the concentration on the x-axis and draw a best fit curve through the points on the graph. The data may be linearized by plotting the log of the Anti-gliadin IgG concentrations versus the log of the O.D. and the best fit line can be determined by regression analysis. 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 with the Assay Diluent 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. |
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. |