Purpose | This immunoassay kit allows for the in vitro quantitative determination of human apo-A1 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 apo-A1. |
Cross-Reactivity (Details) | No significant cross-reactivity or interference was observed. |
Sensitivity |
< 0.12 μg/mL 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,Apolipoprotein A-I,Apo-AI,ApoA-I,Apolipoprotein A1,APOA1 |
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 | Luminometer. Pipettes and pipette tips. EP tube Deionized or distilled water. |
Alternative Name | APOA1 (APOA1 ELISA Kit Abstract) |
Background | Apolipoprotein A-I is the major apoprotein of HDL and is a relatively abundant plasma protein. It is a single polypeptide chain with 243 amino acid residues of known primary amino acid sequence. ApoA-1 is a cofactor for LCAT, which is responsible for the formation of most cholesteryl esters in plasma. ApoA-1 also promotes efflux of cholesterol from cells. The liver and small intestine are the sites of synthesis of ApoA-1. The primary translation product of the ApoA-1 gene contains both a pre and a pro segment, and posttranslational processing of apoA-I may be involved in the formation of the functional plasma apoA-I isoproteins. Yui et al. found that apoA-1 is identical to serum PGI stabilizing factor (PSF). PGI, or prostacyclin, is synthesized by the vascular endothelium and smooth muscle, and functions as a potent vasodilator and inhibitor of platelet aggregation. The stabilization of PGI by HDL and apoA-1 may be an important protective action against the accumulation of platelet thrombi at sites of vascular damage. The beneficial effects of HDL in the prevention of coronary artery disease may be partly explained by this effect. A-I(Milano) and A-I(Marburg) give rise to HDL deficiency. Other HDL deficiency states are Tangier disease, LCAT deficiency, and 'fish-eye' disease. |
Pathways | Regulation of Lipid Metabolism by PPARalpha, Production of Molecular Mediator of Immune Response |
Sample Volume | 100 μL |
Plate | Pre-coated |
Protocol | The microtiter plate provided in this kit has been pre-coated with an antibody specific to apo-A1. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated polyclonal antibody preparation specific for apo-A1 and 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 apo-A1, 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 apo-A1 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 30 ug/ml. Allow the standard to sit for a minimum of 15 minutes with gentle agitation prior to making serial dilutions (Making serial dilution in the wells directly is not permitted). The undiluted standard serves as the high standard (30 ug/ml). The Sample Diluent serves as the zero standard (0 ug/ml). ug/ml 30 15 7.5 3.75 1.88 0.94 0.47 0 Detection Reagent A and B - Dilute to the working concentration using Assay Diluent A and B (1:100), respectively. |
Sample Collection | Serum - Use a serum separator tube (SST) and allow samples to clot for 30 minutes before centrifugation for 15 minutes at approximately 1000 × g. Remove serum and assay immediately or aliquot and store samples at -20 C or -80 C . Plasma - Collect plasma using EDTA or heparin as an anticoagulant. Centrifuge samples for 15 minutes at 1000 × g at 2 - 8 C within 30 minutes of collection. Store samples at -20 C or -80 C . Avoid repeated freeze-thaw cycles. Other biological fluids - Remove particulates by centrifugation and assay immediately or aliquot and store samples at -20 C or -80 C . Avoid repeated freeze-thaw cycles. Note: Serum and plasma to be used within 7 days may be stored at 2-8 C , otherwise samples must stored at -20 C ( ≤ 1 months) or -80 C ( ≤ 2 months) to avoid loss of bioactivity and contamination. Avoid freeze-thaw cycles. When performing the assay slowly bring samples to room temperature. Sample preparation - Serum/plasma samples require a 100 fold dilution. A suggested 100-fold dilution is 10uLsample + 990uL PBS. Sample should be diluted by 0.1 M PBS ( PH=7.0-7.2 ) . |
Assay Procedure |
Allow all reagents to reach room temperature (Please do not dissolve the reagents at 37 C 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 C 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 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 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 apo-A1 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 3 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. |