Amyloid beta 1-40 (Abeta 1-40) ELISA Kit

Antigen: Amyloid beta 1-40 (Abeta 1-40)

Reaktivität: Affe

Applikation: ELISA

Produktnummer: ABIN454242

Produktbeschreibung

Produktmerkmale: This immunoassay kit allows for the specific measurement of monkey amyloid beta peptide 1-40, Abeta1-40 concentrations in cell culture supernates, serum and plasma.

Weitere Bezeichnung: amyloid beta peptide 1-40 (Abeta1-40)

Beschreibung: Alzheimer’s disease was first reported by the German neuropathologist A. Alzheimer in 1907, and it is now the most common cause of senile dementia. The numerous senile plaques that occur in the brain in Alzheimer’s disease are formed by amyloid beta-protein (Abeta). Abeta is a peptide composed of 40 to 42 (43) amino acids, and is said to be cleaved out of the precursor protein APP (a protein composed of 695, 751, or 770 amino acids) by the action of beta- or gamma-secretase.In addition, the presence of numerous variant A beta molecules has been demonstrated in the culture fluid of monkey neuroblastoma cells transfected with cDNA coding rat amyloid precursor protein (APP). Furthermore, in 1995 Saido et al. discovered another type of Abetapeptide, Abeta(N3pE), that is predominant in senile plaques and differed from any type discovered until then. The molecule starts with a molecule in which the 3rd glutamine has been converted to proglutamine by an intramolecular dehydration reaction.

Spezifität: This assay recognizes recombinant and natural monkey Abeta1-40. No significant cross-reactivity or interference was observed.

Sensitivität: The minimum detectable dose of monkey Abeta1-40 is typically less than 3.9 pg/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. Detection Range: 15.6-1,000 pg/mL. The assay range was estimated by calculating the coefficient of variation (CV) of each standard constructing five independent standard curves. The standard curve concentrations used for the ELISA’s were 1,000 pg/mL, 500 pg/mL, 250 pg/mL, 125 pg/mL, 62.5 pg/mL, 31.2 pg/mL, 15.6 pg/mL.

Anwendungen

Prinzip: This assay employs the quantitative sandwich enzyme immunoassay technique. A antibody specific for Abeta1-40 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any Abeta1-40 present is bound by the immobilized antibody. An enzyme-linked antibody specific for Abeta1-40 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 Abeta1-40 bound in the initial step. The color development is stopped and the intensity of the color is measured.

Protokoll: Sample collection and storage:
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.
Limitations of the procedure:
FOR RESEARCH USE ONLY. NOT FOR USE IN DIAGNOSTIC PROCEDURES. 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.
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. Standard - Reconstitute the Standard with 1.0 mL of Sample Diluent. This reconstitution produces a stock solution of 2,000 pg/mL. Allow the standard to sit for a minimum of 15 minutes with gentle agitation prior to making serial dilutions. The diluted standard serves as the high standard (1,000 pg/mL). The Sample Diluent serves as the zero standard (0 pg/mL). Detection Reagent A and B - Dilute to the working concentration specified on the vial label using Assay Diluent A and B (1:100), respectively.
Assay procedure:
Allow all reagents to reach room temperature. Arrange and label required number of strips. 3 1. Prepare all reagents, working standards and samples as directed in the previous sections. 2. Add 100 uL of Standard, Control, or sample per well. Cover with the adhesive strip. Incubate for 2 hours at 37° C. 3. Remove the liquid of each well, don’t wash. 4. Add 100 uL of Detection Reagent A to each well. Incubate for 1 hour at 37°C. Detection Reagent A may appear cloudy. Warm to room temperature and mix gently until solution appears uniform. 5. Aspirate each well and wash, repeating the process three times for a total of three washes. Wash by filling each well with Wash Buffer (350 uL) using a squirt bottle, multi-channel pipette, manifold dispenser or autowasher. Complete removal of liquid at each step is essential to good performance. After the last wash, remove any remaining Wash Buffer by aspirating or decanting. Invert the plate and blot it against clean paper towels. 6. Add 100 uL of Detection Reagent B to each well. Cover with a new adhesive strip.Incubate for 1 hours at 37° C. 7. Repeat the aspiration/wash as in step 5. 8. Add 90 uL of Substrate Solution to each well. Incubate for 30 minutes at room temperature. Protect from light. 9. Add 50 uL of Stop Solution to each well. If color change does not appear uniform, gently tap the plate to ensure thorough mixing. 10. Determine the optical density of each well within 30 minutes, using a microplate reader set to 450 nm.
Important Note:
1. The wash procedure is critical. Insufficient washing will result in poor precision and falsely elevated absorbance readings. 2. It is recommended that no more than 32 wells be used for each assay run if manual pipetting is used since pipetting of all standards, specimens and controls should be completed within 5 minutes. A full plate of 96 wells may be used if automated pipetting is available. 3. Duplication of all standards and specimens, although not required, is recommended. 4 4. When mixing or reconstituting protein solutions, always avoid foaming. 5. To avoid cross-contamination, change pipette tips between additions of each standard level, between sample additions, and between reagent additions. Also, use separate reservoirs for each reagent. 6. To ensure accurate results, proper adhesion of plate sealers during incubation steps is necessary.
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 Abeta1-40 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.

Bestandteile: Reagent (Quantity): Assay plate (1), Standard (2), Sample Diluent (1x20ml), Assay Diluent A (1x10ml), Assay Diluent B (1x10ml), 2 Detection Reagent A (1x120µl), Detection Reagent B (1x120µl), Wash Buffer(25 x concentrate) (1x30ml), Substrate (1x10ml), Stop Solution (1x10ml)

Lagerung: 1. Unopened test kits should be stored at 2-8C upon receipt and the microtiter plate should be kept in a sealed bag with desiccants to minimize exposure to damp air. The test kit may be used throughout the expiration date of the kit (six months from the date of manufacture). Refer to the package label for the expiration date. 2. Opened test kits will remain stable until the expiring date shown, provided it is stored as prescribed above. 3. A microtiter plate reader with a bandwidth of 10nm or less and an optical density range of 0-3 OD or greater at 450nm wavelength is acceptable for use in absorbance measurement.

Beschränkungen: Nur für Forschungszwecke einsetzbar