mouse IL-4 ELISA kit (48 Wells)

Interleukin 4 (IL-4) is a pleiotropic cytokine produced primarily by activated T lymphocytes, mast cells and basophils (1-3).
The cDNA sequence of mouse IL-4 predicts a 140 amino acid (aa) residue precursor protein containing a 20 aa residue signal peptide that is cleaved to form the mature protein (4). At the amino acid sequence level, mature mouse IL-4 is approximately 50% identical to human IL-4 but there is no species cross-reactivity for biological activity for the two proteins (1, 2). Mouse IL-4 also shares approximately 30% amino acid sequence identity to mouse IL-13 and the two cytokines exhibit overlapping biological activities (5, 6). The gene for IL-4 has been mapped to mouse chromosome 11, in close proximity to the genes for IL-3, IL-5, IL-13 and GM-CSF (1, 2).
IL-4 has multiple immune response-modulating activities on a variety of cell types. It is an important regulator of isotype switching, inducing IgE production in B lymphocytes. It is an important modulator of the differentiation of precursor T helper cells to the Th2 subset that mediates humoral immunity and modulates antibody production. In addition, IL-4 has also been shown to have anti-tumor activity both in vivo and in vitro (1-3). The biological effects of IL-4 are mediated by specific cell surface receptor complexes. Although IL-4 R does not bind IL-13 directly, it has been shown to complex with the low-affinity IL-13 R to form the functional high-affinity receptor complex for IL-13 (7, 8). In addition to the membrane-bound form of IL-4 R, a naturally occurring soluble form of IL-4 R has been identified in human and mouse biological fluids and in mouse cell culture supernates (9-11). Soluble IL-4 R has been to shown to bind IL-4 with high affinity in solution.

For the quantitative determination of mouse interleukin 4 (IL-4) concentrations in cell culture supernates, serum, and plasma.

Principle of the assay: This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IL-4 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any IL-4 present is bound by the immobilized antibody. Following incubation unbound samples are removed during a wash step, and then a detection antibody specific for IL-4 is added to the wells and binds to the combination of capture antibody-IL-4 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-4 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-4 standard dilutions and IL-4 sample concentration determined.