Description
Principle of the assay: This assay employs the competitive inhibition enzyme immunoassay technique. The microtiter plate provided in this kit has been pre-coated with an antibody specific to IL-4. Standards or samples are added to the appropriate microtiter plate wells with biotin-conjugated IL-4. A competitive inhibition reaction is launched between IL-4 (Standards or samples) and biotin-conjugated IL-4 with the pre-coated antibody specific for IL-4. The more amount of IL-4 in samples, the less antibody bound by biotin-conjugated IL-4. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Substrate solution is added to the wells and the color develops in opposite to the amount of IL-4 in the sample. The color development is stopped and the intensity of the color is measured.
Background: The interleukin 4 (IL4) is a cytokine that induces differentiation of naive helper T cells (Th0 cells) to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4 in a positive feedback loop. The cell that initially produces IL-4, thus inducing Th0 differentiation, has not been identified, but recent studies suggest that basophils may be the effector cell. It is closely related and has functions similar to Interleukin 13. It has many biological roles, including the stimulation of activated B-cell and T-cell proliferation, and the differentiation of B cells into plasma cells. It is a key regulator in humoral and adaptive immunity. IL-4 induces B-cell class switching to IgE, and up-regulates MHC class II production. IL-4 decreases the production of Th1 cells, macrophages, IFN-gamma, and dendritic cell IL-12. Overproduction of IL-4 is associated with allergies