Detection Method:Sandwich
Test principle:This assay employs a two-site sandwich ELISA to quantitate IL5 in samples. An antibody specific for IL5 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and anyIL5 present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for IL5 is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of IL5 bound in the initial step. The color development is stopped and the intensity of the color is measured.
Product Overview:IL-5 is secreted by a restricted number of mesenchymal cell types. In its native state, mature IL-5 is synthesized as a 115 aa, highly glycosylated 22 kDa monomer that forms a 40-50 kDa disulfide-linked homodimer. Although the content of carbohydrate is high, carbohydrate is not needed for bioactivity. Monomeric IL-5 has no activity and requires a homodimer for function, which is in contrast to the receptor-related IL-3 and GM-CSF cytokines that exist only as monomers. Just as one IL-3 and GM-CSF monomer binds to one receptor, one IL-5 homodimer is able to engage only one IL-5 receptor. It has been suggested that IL-5 (as a dimmer) undergoes a general conformational change after binding to one receptor molecule and this change precludes binding to a second receptor.
