Human IL-18 ELISA Kit

Principle of the Assay

This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IL-18 has been pre-coated onto a microplate. Standard, control, or sample and the working solution of Biotin-Conjugate are pipetted into the wells. Following incubation and wash steps, any IL-18 present is bound by the immobilized antibody and the detection antibody specific for IL-18 is binds to the combination of capture antibody-IL-18 in sample. Following a wash to remove any unbound combination, and enzyme conjugate is added to the wells. Following incubation and wash steps a substrate is added. A coloured product is formed in proportion to the amount of IL-18 present in the sample. The reaction is terminated by addition of acid and absorbance is measured at 450nm. A standard curve is prepared from seven IL-18 standard dilutions and IL-18 sample concentration determined.

For Use with serum, plasma and cell culture supernatants. For Research Use Only. Not for use in diagnostic procedures.

Target Information

Interleukin 18 (IL-18) is an 18 kDa cytokine which is identified as a costimulatory factor for production of interferon-r (IFN-r) in response to toxic shock. It shares functional similarities with IL-12. IL-18 is synthesized as a precursor 24 kDa molecule without a signal peptide and must be cleaved to produce an active molecule. IL-1b converting enzyme (ICE, caspase-1) cleaves pro-IL-18 at aspartic acid in the P1 position, producing the mature, bioactive peptide that is readily released from the cells. It has been reported that IL-18 is produced from dendritic cells, activated macrophages, Kupffer cells, keratinocytes, intestinal epithelial cells, osteoblasts, adrenal cortex cells and murine diencephalons. IFN-r is produced by activated T and NK cells and plays critical roles in the defense against microbial pathogens. IFN-g activates macrophages, enhances NK activity and B cell maturation, proliferation and Ig secretion, induces MHC class I and II antigens expression, and inhibits osteoclast activation. IL-18 acts on T helper 1-type (Th1) cells, and in combination with IL-12 strongly induces production of IFN-g by these cells. Pleiotropic effects of IL-18 have also been reported, including enhancement production of IFN-g and GM-CSF in peripheral blood mononuclear cells, production of Th1 cytokines, IL-2, GM-CSF and IFN-g in T cells, enhancement of Fas ligand expression by Th1 cells.

GENE ID 3606
SWISS PROT Q14116
SYNONYMS IGIF; IL-18; IL-1g; IL1F4

Materials Supplied

Kit Components 96 Wells Quantity/Size
Aluminium pouches with a Microwell Plate coated with antibody to human IL-18 (812) 1 plate
Human IL-18 standard lyophilized, 2500 pg/ml upon reconstitution 2 vials
Concentrated Biotin-Conjugate anti-human IL-18 antibody 2 vials
Streptavidin-HRP solution 2 vials
Standard /sample Diluent 1 bottle
Biotin-Conjugate antibody Diluent 1 bottle
Streptavidin-HRP Diluent 1 bottle
Wash Buffer Concentrate 20x (PBS with 1% Tween-20) 1 bottle
Substrate Solution 1 vial
Stop Solution 1 vial
Adhesive Films 4 pieces
Product data sheet 1 copy

Storage

Storage Store at 2 - 8°C

Performance Characteristics

REPEATABILITY The coefficient of variation of both intra-assay and inter-assay were less than 10%.
SENSITIVITY The minimum detectable dose was 20pg/mL.
ASSAY RANGE 39 - 2500 pg/mL
SPECIFICITY This assay recognizes both natural and recombinant human IL-18. The factors listed below were prepared at 50ng/ml in standard /sample Diluent and assayed for cross-reactivity and no significant cross-reactivity or interference was observed.
Factors assayed for cross-reactivity
Recombinant human IFN-γ, IL-10, IL-12, IL-16, IL-17B, IL-17C, IL-17D, IL-17F
Recombinant mouse IL-17