Human TNF alpha ELISA Kit

Human TNF alpha ELISA kit (ab181421) is a single-wash 90 min sandwich ELISA designed for the quantitative measurement of TNF alpha protein inhuman serum, plasma and culture media. It uses our proprietary SimpleStep ELISA® technology. Quantitate human TNFa with 4.32 pg/mL sensitivity.

SimpleStep ELISA® technology employs capture antibodies conjugated to an affinity tag that is recognized by the monoclonal antibody used to coat our SimpleStep ELISA® plates. This approach to sandwich ELISA allows the formation of the antibody-analyte sandwich complex in a single step, significantly reducing assay time. See the SimpleStep ELISA® protocol summary in the image section for further details. Our SimpleStep ELISA® technology provides several benefits:

-Single-wash protocol reduces assay time to 90 minutes or less
-High sensitivity, specificity and reproducibility from superior antibodies
-Fully validated in biological samples
-96-wells plate breakable into 12 x 8 wells strips

A 384-well SimpleStep ELISA® microplate (ab203359) is available to use as an alternative to the 96-well microplate provided with SimpeStep ELISA® kits.

ASSAY SPECIFICITY This kit recognizes both native and recombinant human TNF alpha protein in serum, plasma, and cell culture supernatant samples only.

CROSS REACTIVITY Recombinant proteins were prepared at 1000 pg/mL and assayed for cross reactivity. No cross reactivity was found for the following targets: - Human IL-2 - Human IL-4 - Human IL-1 alpha - Human IFN gamma - Human TNF beta - Human TNF R1.

INTERFERENCE Recombinant Human TNF R1 was prepared at 1000 pg/mL and tested for interference. No interference with was observed.

SPECIES REACTIVITY This kit recognizes human TNF alpha protein. Other species reactivity was determined by measuring 1000 pg/mL recombinant proteins of various species, interpolating the protein concentrations from the human standard curve, and expressing the interpolated concentrations as a percentage of the protein concentration assayed at the same dilution. Reactive species: Primate
Reactivity < 3% was determined for the following species: Mouse/Rat

CALIBRATION This immunoassay is calibrated against a highly purified human TNF alpha. The NIBSC/WHO unclassified purified human TNF alpha preparation 12/154 was evaluated in this kit. The dose response curve of the unclassified standard TNF alpha parallels the SimpleStep standard curve. To convert sample values obtained with the SimpleStep Human TNF alpha kit to approximate NIBSC 12/154 International units, use the equation below.

NIBSC (12/154) approximate value (IU/mL) = 0.094 x SimpleStep Human TNF alpha value (pg/mL).

TNF-alpha, also known as cachectin or TNFSF1A, is the prototypic ligand of the TNF superfamily which plays a central role in inflammation, apoptosis, proliferation, invasion, angiogenesis, metastasis and morphogenesis. It is expressed on macrophages, endothelial, epithelial and tumor cells as a 26kDa transmembrane protein. TNF-alpha is cleaved by proteolytic processing into six chains: (1) TNF membrane form, (2) Intracellular domain 1, (3) Intracellular domain 2, (4) C-domain 1, (5) C-domain 2 and (6) TNF soluble form. Signaling from TNF-alpha differs depending on the type of ligand initiating the signaling event (intracellular, membrane or soluble). As an example, the membrane form of TNF-alpha appears to mediate anti-tumorigenic therapeutic responses whereas the soluble ligand is linked to inflammation and proliferation.