CellaQuant™ Human IL-4 (Interleukin 4) ELISA Kit (CQH018)

This ELISA kit uses the Sandwich-ELISA principle. The micro ELISA plate provided in this kit has been pre-coated with an antibody specific to Human IL-4. Standards or samples are added to the micro ELISA plate wells and combined with the specific antibody. Then a biotinylated detection antibody specific for Human IL-4 and Avidin-Horseradish Peroxidase (HRP) conjugate are added successively to each micro plate well and incubated. Free components are washed away. The substrate solution is added to each well. Only those wells that contain Human IL-4, biotinylated detection antibody and Avidin-HRP conjugate will appear blue in color. The enzyme-substrate reaction is terminated by the addition of stop solution and the color turns yellow. The optical density (OD) is measured spectrophotometrically at a wavelength of 450 nm ± 5 nm. The OD value is proportional to the concentration of Human IL-4. You can calculate the concentration of Human BK in the samples by comparing the OD of the samples to the standard curve.

Interleukin-4 (IL-4) is a pleiotropic type I cytokine, predominantly produced by activated Th2 cells, with additional sources including mast cells, basophils, eosinophils, and innate lymphoid cells (ILC2s). It is a helical-bundle protein that signals through two distinct receptor complexes: the type I receptor (IL-4Rα/common γ chain) expressed on hematopoietic cells, and the type II receptor (IL-4Rα/IL-13Rα1) expressed on non-hematopoietic cells.IL-4 is a central regulator of type 2 immunity, orchestrating Th2 cell differentiation, IgE class switching in B cells, and the alternative (M2) activation of macrophages. It also promotes mast cell and eosinophil proliferation, upregulates adhesion molecules on endothelium, and suppresses pro-inflammatory Th1 and Th17 responses. These actions position it as a key player in allergic diseases such as asthma, atopic dermatitis, and allergic rhinitis, as well as in parasitic infection control and tissue repair.