Purpose | This immunoassay kit allows for the in vitro quantitative determination of bovine SAA 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 bovine SAA. |
Cross-Reactivity (Details) | No significant cross-reactivity or interference was observed. |
Sensitivity |
< 0.78 ng/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 | Bos taurus,Bovine,Serum amyloid A protein,SAA,SAA1,SAA |
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 | SAA1 (SAA1 ELISA Kit Abstract) |
Background | Serum amyloid A (SAA) proteins are a family of apolipoproteins found predominantly associated with high-density lipoprotein (HDL) in plasma, with different isoforms being unequally expressed constitutively and in response to inflammatory stimuli. Although synthesized primarily in the liver, extrahepatic tissue_cellular expression of SAA has been widely documented. SAA has been linked to functions related to inflammation, pathogen defense, HDL metabolism, and cholesterol transport and thereby has been implicated in several pathological conditions including atherosclerosis, rheumatoid arthritis, Alzheimer's disease, and cancer. SAA is known best for its role during the acute phase response to an inflammatory stimulus such as infection, tissue injury, and trauma. During active inflammation the concentration of SAA in plasma can increase up to 1,000-fold within 24 h. It is believed that persistently high levels of SAA during chronic inflammation may contribute to the occasional development of the potentially fatal disease reactive amyloidosis (amyloid A (AA) amyloidosis). In AA amyloidosis, AA, an N-terminal (1-76) fragment of SAA, frequently is found to form amyloid deposits in the liver, kidney, and spleen. However, the presence, in vivo, of full-length SAA in amyloid deposits and the ability of various SAA isoforms to form fibrils in vitro suggest that proteolytic cleavage may not be a prerequisite for AA deposition but rather a postdeposition event. There is very limited structural information about SAA because of its inherent poor solubility in the apolipoprotein form. It is intriguing to understand how such a small protein is able to mediate or directly carry out such a wide range of functions related to inflammatory reaction and other hostdefense mechanisms. The various functions of SAA may be modulated by factors such as conformational changes induced by ligand binding or by the ability to adopt more than one oligomeric state. Deciphering the molecular basis of the functional and potentially pathological properties of SAA will require understanding its structure under various conditions. |
Pathways | Toll-Like Receptors Cascades |
Sample Volume | 100 μL |
Plate | Pre-coated |
Protocol | 2 The microtiter plate provided in this kit has been pre-coated with an antibody specific to SAA. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated polyclonal antibody preparation specific for SAA. 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 SAA, 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 SAA 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 200 ng/mL. 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). The undiluted standard serves as the highest standard (200 ng/mL). The Sample Diluent serves as the zero standard (0 ng/mL). ng/mL 200 100 50 25 12.5 6.25 3.12 0 Detection Reagent A and B - Dilute to the working concentration using Assay Diluent A or B (1:100), respectively. |
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 200 fold dilution. Sample should be diluted by 0.1 M PBS(PH=7.0-7.2). Note: Serum and plasma to be used within 7 days may be stored at 2-8 , otherwise 3 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 4 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 SAA 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. |