Thymic Stromal Lymphopoietin ELISA Kit

Catalog No. ABIN456579

Product Details Thymic Stromal Lymphopoietin ELISA Kit

Target: Thymic Stromal Lymphopoietin (TSLP)

Reactivity: Human

Detection Method: Colorimetric

Method Type: Sandwich ELISA

Detection Range: 31.2-2000 pg/mL

Minimum Detection Limit: 31.2 pg/mL

Application: ELISA

Purpose: This immunoassay kit allows for the specific measurement of Human thymic stromal lymphopoietin,TSLP concentrations in cell culture supernates, tissue homogenates, serum, and plasma.

Sample Type: Cell Culture Supernatant, Tissue Homogenate, Serum, Plasma

Analytical Method: Quantitative

Specificity: This assay recognizes recombinant and natural Human TSLP.

Cross-Reactivity (Details): No significant cross-reactivity or interference was observed.

Sensitivity: < 0.039 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: Homo sapiens,Human,Thymic stromal lymphopoietin,TSLP

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

Application Details

Sample Volume: 100 μL

Plate: Pre-coated

Protocol: This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for TSLP has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any TSLP present is bound by the immobilized antibody. An biotinylated polyclonal antibody specific for TSLP is added to the wells. Following a wash to remove any unbound reagent, an enzyme complex is added to the wells.After incubation and washing ,a substrate solution is added to the wells and color develops in proportion to the amount of TSLP bound in the initial step. The color development is stopped and the intensity of the color is measured.

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 20 ng/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 (10 ng/mL). The Sample Diluent serves as the zero standard (0 ng/mL). 3 Detection Reagent A and B - Dilute to the working concentration specified on the vial label using Assay Diluent A and B (1:100), respectively.

Sample Collection: 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.

Assay Procedure:

Allow all reagents to reach room temperature. Arrange and label required number of strips.
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. 4
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. 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 TSLP 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.

Restrictions: For Research Use only

Handling

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 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.

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.

Target Details for Thymic Stromal Lymphopoietin

Target: Thymic Stromal Lymphopoietin (TSLP)

Alternative Name: TSLP (TSLP Products)

Synonyms: TSLP ELISA Kit, thymic stromal lymphopoietin ELISA Kit, TSLP ELISA Kit, Tslp ELISA Kit

Background: The cytokine thymic stromal lymphopoietin (TSLP) drives immature B cell development in vitro and may regulate T helper type 2 responses.Thymic stromal lymphopoietin, also known as TSLP, is a human gene.This gene encodes a hemopoietic cytokine proposed to signal through a heterodimeric receptor complex composed of the thymic stromal lymphopoietin receptor and the IL-7R alpha chain. It mainly impacts myeloid cells and induces the release of T cell-attracting chemokines from monocytes and enhances the maturation of CD11c(+) dendritic cells. Alternative splicing of this gene results in two transcript variants. TSLP is an interleukin (IL)-7-like cytokine produced by epithelial cells and triggers dendritic cell-mediated Th2 type allergic inflammatory responses.Somestudys investigated whether Toll-like receptor (TLR) ligands, lipopolysaccharide (LPS) and poly-IC affect TSLP production in synovial fibroblasts. Enzyme-linked immunosorbent assay showed that LPS and poly-IC upregulated TSLP production in synovial fibroblasts obtained from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). In addition,it’s found that nuclear factor (NF)-kappaB inhibitor IMD-0354, dexamethasone, and interferon (IFN)-gamma inhibited the LPS- and poly-IC-induced TSLP production in RA and OA synovial fibroblasts. LPS and poly-IC can upregulate TSLP via a NF-kappaB pathway in synovial fibroblasts, which is downregulated by dexamethasone and interferon (IFN)-gamma. The current findings suggest that TSLP may be involved in the pathophysiology of inflammatory arthritis as well as allergic disease.