RBP4 ELISA Kit

Catalog No. ABIN5564584

Product Details RBP4 ELISA Kit

Target: RBP4 (Retinol Binding Protein 4, Plasma (RBP4))

Reactivity: Mouse

Detection Method: Colorimetric

Method Type: Sandwich ELISA

Detection Range: 0.625-20 ng/mL

Minimum Detection Limit: 0.625 ng/mL

Application: ELISA

Purpose: The AssayMax™ Mouse Retinol-Binding Protein 4 (RBP4) ELISA (Enzyme-Linked Immunosorbent Assay) kit is designed for detection of RBP4 in mouse plasma, serum, urine, and cell culture samples. This assay employs a quantitative sandwich enzyme immunoassay that measures mouse RBP4 in approximately 4 hours. A polyclonal antibody specific for mouse RBP4 has been pre-coated onto a 96-well microplate with removable strips. RBP4 in standards and samples is sandwiched by the immobilized antibody and a biotinylated polyclonal antibody specific for mouse RBP4, which is recognized by a streptavidin-peroxidase (SP) conjugate. All unbound material is washed away and a peroxidase enzyme substrate is added. The color development is stopped and the intensity of the color is measured.

Brand: AssayMax™

Sample Type: Cell Culture Cells, Plasma, Serum, Urine

Analytical Method: Quantitative

Components: Mouse RBP4 Microplate: A 96-well polystyrene microplate (12 strips of 8 wells) coated with a polyclonal antibody against mouse RBP4. Sealing Tapes: Each kit contains 3 precut, pressure sensitive sealing tapes, that can be cut to fit the format of the individual assay. Mouse RBP4 Standard: Mouse RBP4 in a buffered protein base (100 ng, lyophilized). Biotinylated Mouse RBP4 Antibody (50x): A 50-fold concentrated biotinylated polyclonal antibody against mouse RBP4 (120 l). MIX Diluent Concentrate (10x): A 10-fold concentrated buffered protein base (30 ml). Wash Buffer Concentrate (20x): A 20-fold concentrated buffered surfactant (30 ml, 2 bottles). SP Conjugate (100x): A 100-fold concentrate (80 l). Chromogen Substrate (1x): A stabilized peroxidase chromogen substrate tetramethylbenzidine (8 ml). Stop Solution (1x): A 0.5 N hydrochloric acid solution to stop the chromogen substrate reaction (12 ml).

Material not included: Microplate reader capable of measuring absorbance at 405 nm. Pipettes (1-20 µL, 20-200 µL, and multiple channel). Deionized or distilled reagent grade water Incubator (37 °C)

Application Details

Plate: Pre-coated

Protocol:

• Step 1. Add 50 μL of Standard or Sample per well. Incubate 2 hours.
• Step 2. Wash, then add 50 μL of Biotinylated Antibody per well. Incubate 1 hour.
• Step 3. Wash, then add 50 μL of SP Conjugate per well. Incubate 30 minutes.
• Step 4. Wash, then add 50 μL of Chromogen Substrate per well. Incubate 25 minutes.
• Step 5. Add 50 μL of Stop Solution per well. Read at 450 nm immediately.

Reagent Preparation:

Freshly dilute all reagents and bring all reagents to room temperature before use. MIX Diluent Concentrate (10x): If crystals have formed in the concentrate, mix gently until the crystals have completely dissolved. Dilute the MIX Diluent Concentrate 10-fold with reagent grade water to produce a 1x solution. Store for up to 30 days at 2-8 °C. Mouse RBP4 Standard: Reconstitute the Mouse RBP4 Standard (100 ng) with 2.5 mL of MIX Diluent to generate a 40 ng/mL standard stock solution. Allow the vial to sit for 10 minutes with gentle agitation prior to making dilutions. Prepare duplicate or triplicate standard points by serially diluting from the standard stock solution (40 ng/mL) 2-fold with MIX Diluent to produce 20, 10, 5, 2.5, 1.25, and 0.625 ng/mL solutions. MIX Diluent serves as the zero standard (0 ng/mL). Any remaining stock solution should be stored at -20 °C and used within 30 days. Standard Point Dilution [Mouse RBP4] (ng/mL) P1 1 part Standard (40 ng/mL) 40 P2 1 part P1 + 1 part MIX Diluent 20 P3 1 part P2 + 1 part MIX Diluent 10 P4 1 part P3 + 1 part MIX Diluent 5.0 P5 1 part P4 + 1 part MIX Diluent 2.5 P6 1 part P5 + 1 part MIX Diluent 1.25 P7 1 part P6 + 1 part MIX Diluent 0.625 P8 MIX Diluent 0.0 5 Biotinylated Mouse RBP4 Antibody (50x): Spin down the antibody briefly and dilute the desired amount of the antibody 50-fold with MIX Diluent to produce a 1x solution. The undiluted antibody should be stored at -20 °C. Wash Buffer Concentrate (20x): If crystals have formed in the concentrate, mix gently until the crystals have completely dissolved. Dilute the Wash Buffer Concentrate 20-fold with reagent grade water to produce a 1x solution. SP Conjugate (100x): Spin down the SP Conjugate briefly and dilute the desired amount of the conjugate 100-fold with MIX Diluent to produce a 1x solution. The undiluted conjugate should be stored at -20 °C.

Sample Collection: Plasma: Collect plasma using one-tenth volume of 0.1 M sodium citrate as an anticoagulant. Centrifuge samples at 3000 x g for 10 minutes and collect plasma. An 8000-fold sample dilution is suggested into MIX Diluent, however, user should determine optimal dilution factor depending on application needs. The undiluted samples can be stored at -20 °C or below for up to 3 months. Avoid repeated freeze-thaw cycles (EDTA or Heparin can also be used as an anticoagulant). Serum: Samples should be collected into a serum separator tube. After clot formation, centrifuge samples at 3000 x g for 10 minutes and remove serum. An 8000-fold sample dilution is suggested into MIX Diluent, however, user should determine optimal dilution factor depending on application needs. The undiluted samples can be stored at -20 °C or below for up to 3 months. Avoid repeated freeze-thaw cycles. Urine: Collect urine using sample pot. Centrifuge samples at 800 x g for 10 minutes. The sample is suggested for use at 1x, however, user should determine optimal dilution factor depending on application needs. Samples can be stored at -20 °C or below for up to 3 months. Avoid repeated freeze-thaw cycles. Cell Culture Supernatants: Centrifuge cell culture media at 3000 x g for 10 minutes at 4 °C to remove debris and collect supernatants. Samples can be stored at -20 °C or below. Avoid repeated freeze-thaw cycles.

Assay Procedure:

Prepare all reagents, standard solutions, and samples as instructed. Bring all reagents to room temperature before use. The assay is performed at room temperature (20-25 °C). Remove excess microplate strips from the plate frame and return them immediately to the foil pouch with desiccants inside. Reseal the pouch securely to minimize exposure to water vapor and store in a vacuum desiccator. Add 50 l of Mouse RBP4 Standard or sample to each well. Gently tap plate to thoroughly coat the wells. Break any bubbles that may have formed. Cover wells with a sealing tape and incubate for 2 hours. Start the timer after the last addition. Wash five times with 200 l of Wash Buffer manually. Invert the plate each time and decant the contents, hit 4-5 times on absorbent material to completely remove the liquid. If using a machine, wash six times with 300 l of Wash Buffer and then invert the plate, decanting the contents, hit 4-5 times on absorbent material to completely remove the liquid. Add 50 l of Biotinylated Mouse RBP4 Antibody to each well. Gently tap plate to thoroughly coat the wells. Break any bubbles that may have formed. Cover wells with a sealing tape and incubate for 1 hour. Wash the microplate as described above. Add 50 l of SP Conjugate to each well. Gently tap plate to thoroughly coat the wells. Break any bubbles that may have formed. Cover wells with a sealing tape and incubate for 30 minutes. Turn on the microplate reader and set up the program in advance. Wash the microplate as described above. Add 50 l of Chromogen Substrate to each well. Gently tap plate to thoroughly coat the wells. Break any bubbles that may have formed. Incubate for 25 minutes or until the optimal blue color density develops. Add 50 l of Stop Solution to each well. The color will change from blue to yellow. Gently tap plate to ensure thorough mixing. Break any bubbles that may have formed. 6 Read the absorbance on a microplate reader at a wavelength of 450 nm immediately. If wavelength correction is available, subtract readings at 570 nm from those at 450 nm to correct optical imperfections. Otherwise, read the plate at 450 nm only. Please note that some unstable black particles may be generated at high concentration points after stopping the reaction for about 10 minutes, which will reduce the readings.

Calculation of Results:

• Calculate the mean value of the duplicate or triplicate readings for each standard and sample.
• To generate a standard curve, plot the graph using the standard concentrations on the x-axis and the corresponding mean 450 nm absorbance (OD) on the y-axis. The best-fit line can be determined by regression analysis using log-log or four-parameter logistic curve-fit.
• Determine the unknown sample concentration from the standard curve and multiply the value by the dilution factor.

Restrictions: For Research Use only

Handling

Handling Advice: This product is for Research Use Only and is not intended for use in diagnostic procedures. Prepare all reagents (diluent buffer, wash buffer, standard, biotinylated antibody, and SP conjugate) as instructed, prior to running the assay. 2 Prepare all samples prior to running the assay. The dilution factors for the samples are suggested in this insert. However, the user should determine the optimal dilution factor. Spin down the SP conjugate vial and the biotinylated antibody vial before opening and using contents. The Stop Solution is an acidic solution. The kit should not be used beyond the expiration date.

Storage: 4 °C,-20 °C

Storage Comment: Upon arrival, immediately store components of the kit at recommended temperatures up to the expiration date. Store SP Conjugate and Biotinylated Antibody at -20°C. Store Microplate, Diluent Concentrate (10x), Wash Buffer, Stop Solution, and Chromogen Substrate at 2-8°C. Unused microplate wells may be returned to the foil pouch with the desiccant packs and resealed. May be stored for up to 30 days in a vacuum desiccator. Diluent (1x) may be stored for up to 30 days at 2-8°C. Store Standard at 2-8°C before reconstituting with Diluent and at -20°C after reconstituting with Diluent. 3

Target Details for RBP4

Target: RBP4 (Retinol Binding Protein 4, Plasma (RBP4))

Alternative Name: Retinol-Binding Protein 4 (RBP4) (RBP4 Products)

Synonyms: RDCCAS ELISA Kit, RBP ELISA Kit, RNBP ELISA Kit, rbp4 ELISA Kit, MGC54038 ELISA Kit, srbp ELISA Kit, PRBP ELISA Kit, RBPA ELISA Kit, Rbp-4 ELISA Kit, fb23c12 ELISA Kit, rbp ELISA Kit, wu:fb23c12 ELISA Kit, wu:fb58d04 ELISA Kit, wu:fb72b04 ELISA Kit, zgc:86911 ELISA Kit, retinol binding protein 4 ELISA Kit, renin binding protein ELISA Kit, retinol binding protein 4 S homeolog ELISA Kit, retinol binding protein 4 A, plasma ELISA Kit, retinol binding protein 4, plasma ELISA Kit, retinol binding protein 4 L homeolog ELISA Kit, RBP4 ELISA Kit, RENBP ELISA Kit, rbp4.S ELISA Kit, rbp4 ELISA Kit, Rbp4 ELISA Kit, RBP4A ELISA Kit, rbp4.L ELISA Kit

Background: Plasma retinol-binding protein (RBP4), secreted by the liver and adipocytes, is implicated in systemic insulin resistance. RBP4 transports retinol and circulates in the plasma by binding to the larger transthyretin (TTR) homotetramer forming a protein complex that reduces renal clearance of RBP4. In insulin-resistant ob/ob mice, urinary fractional excretion of RBP4 was reduced, which is consistent with increased retention, while TTR level is elevated (1). RBP4 is encoded by the RBP4 gene that maps to chromosome 10q23-q24 (2, 3). Transgenic overexpression of RBP4 or injection of recombinant RBP4 in normal mice causes insulin resistance. Conversely, genetic deletion of RBP4 enhances insulin sensitivity. Increasing serum RBP4 induces hepatic expression of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase and impairs insulin signaling in muscle tissue (4). Expression of RBP4 is induced in adipose tissue as a consequence of the decreased glucose transporter GLUT4 expression.

Gene ID: 19662

UniProt: Q00724

Pathways: Regulatory RNA Pathways, Positive Regulation of Peptide Hormone Secretion, Carbohydrate Homeostasis, Production of Molecular Mediator of Immune Response