Proopiomelanocortin (POMC) ELISA Kit

Antigen: Proopiomelanocortin (POMC)

Synonyms: MSH, ACTH, pomc, SI:bZ36D5.1, SI:bZ36D5.4, si:bz36d5.2, POMC, LPH, NPP, POC, CLIP

Reactivity: Sheep (Ovine)

Application: ELISA

Certificates: ISO 9001:2008

Catalog no.: ABIN367589

Additional Information

Characteristics: This immunoassay kit allows for the in vitro quantitative determination of Small Tailed Han Sheep POMC concentrations in cell culture supernates, serum, plasma and other biological fluids.

Sample Type: Serum, Plasma

Description: Pro-opiomelanocortin (POMC) is a precursor polypeptide with 241 amino acid residues. This gene encodes a polypeptide hormone precursor that undergoes extensive, tissue-specific, post-translational processing via cleavage by subtilisin-like enzymes known as prohormone convertases. There are eight potential cleavage sites within the polypeptide precursor and, depending on tissue type and the available convertases, processing may yield as many as ten biologically active peptides involved in diverse cellular functions. The encoded protein is synthesized mainly in corticotroph cells of the anterior pituitary where four cleavage sites are used, adrenocorticotrophin, essential for normal steroidogenesis and the maintenance of normal adrenal weight, and lipotropin beta are the major end products. In other tissues, including the hypothalamus, placenta, and epithelium, all cleavage sites may be used, giving rise to peptides with roles in pain and energy homeostasis, melanocyte stimulation, and immune modulation. These include several distinct melanotropins, lipotropins, and endorphins that are contained within the adrenocorticotrophin and beta-lipotropin peptides. Mutations in this gene have been associated with early onset obesity, adrenal insufficiency, and red hair pigmentation. Alternatively spliced transcript variants encoding the same protein have been described.

Specificity: This assay recognizes recombinant and natural Small Tailed Han Sheep POMC. No significant cross-reactivity or interference was observed. 3

Application Details

Principle: The microtiter plate provided in this kit has been pre-coated with an antibody specific to POMC. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated polyclonal antibody preparation specific for POMC and Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB (3,3',5,5' tetramethyl-benzidine) substrate solution is added to each well. Only those wells that contain POMC, 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 POMC in the samples is then determined by comparing the O.D. of the samples to the standard curve.

Protocol: Preparation of Reagents: Bring all reagents to room temperature before use. 1. Wash Buffer If crystals have formed in the concentrate, warm up 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. 2. Standard Reconstitute the Standard with 1.0 ml of Sample Diluent. This reconstitution 4 produces a stock solution of 50 ng/ml. 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 (50 ng/ml). The Sample Diluent serves as the zero standard (0 ng/ml). 3. Biotin-antibody Dilute to the working concentration specified on the vial label using Biotin-antibody Diluent(1:100), respectively. 4. HRP-avidin Dilute to the working concentration specified on the vial label using HRP-avidin Diluent(1:100), respectively. Precaution: The Stop Solution provided with this kit is an acid solution. Wear eye, hand, face, and clothing protection when using this material. 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 1000 g. Remove serum and assay immediately or aliquot and store samples at -20° C. Avoid repeated freeze-thaw cycles. Plasma Collect plasma using citrate, EDTA, or heparin as an anticoagulant. Centrifuge for 15 minutes at 1000 g within 30 minutes of collection. Assay immediately or aliquot and store samples at -20° C. Avoid repeated freeze-thaw cycles. Assay Procedure: 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 POMC 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. Limitations of the Procedure: The kit should not be used beyond the expiration date on the kit label. Do not mix or substitute reagents with those from other lots or sources. It is important that the Calibrator Diluent selected for the standard curve be consistent with the samples being assayed. If samples generate values higher than the highest standard, dilute the samples with the appropriate Calibrator 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. 6 This assay is designed to eliminate interference by soluble receptors, 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.

Assay Procedure: Assay Time: 1-3h
Sample Volume: 50-100ul

Application Notes: Detection Wavelength: 450 nm

Components: Reagent Quantity Assay plate 1 Standard 2 Sample Diluent 1 x 20 ml Biotin-antibody Diluent 1 x 10 ml HRP-avidin Diluent 1 x 10 ml Biotin-antibody 1 x 120µl HRP-avidin 1 x 120µl Wash Buffer 1 x 20 ml (25×concentrate) TMB Substrate 1 x 10 ml Stop Solution 1 x 10 ml STORAGE 1. Unopened test kits should be stored at 2-8°C 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. 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 10 nm or less and an optical density range of 0-3 OD or greater at 450nm wavelength is acceptable for use in absorbance measurement.

Material not included: Microplate reader capable of measuring absorbance at 450 nm, with the correction wavelength set at 540 nm or 570 nm. Pipettes and pipette tips. Deionized or distilled water. Squirt bottle, manifold dispenser, or automated microplate washer.

Storage: 1. Unopened test kits should be stored at 2-8°C 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. 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 10 nm or less and an optical density range of 0-3 OD or greater at 450nm wavelength is acceptable for use in absorbance measurement. Expiration date: six months from the date of manufacture.

Restrictions: For Research Use only