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The Human Interleukin 21 (IL-21) Uncoated ELISA Kit contains pre-matched antibody pairs, and reagents for performing quantitative enzyme linked immunosorbent assays (ELISA) to detect and quantify protein levels of human IL-21. Wash Buffer and Stop Solution are needed to complete the ELISA reaction and are sold separately.
Principle of the method
ELISAs are designed to measure the amount of the target bound between a matched antibody pair. A target-specific antibody is coated to the bottom of the wells of a microplate, which is an overnight process. Samples, standards, or controls are then added into these wells and bind to the immobilized (capture) antibody. A sandwich is formed by the addition of the second (detector) antibody, a substrate solution is added that reacts with the enzyme-antibody-target complex to produce measurable signal. The intensity of this signal is directly proportional to the concentration of target present in the original specimen.
IL-21 is a 17 kDa immunomodulatory cytokine produced mainly by Natural Killer Cells (NKT), T helper (Th) 17 and T follicular helper (TFH) cells. In TFH cells, IL-21 expression leads to autocrine signaling through the IL-21 receptor (IL-21R) and STAT3, which leads to additional transcriptional activation by Bcl6. As with IFN gamma for Th1 and IL-4 for Th2 cells, IL-21 is critical for TFH cell development and effector function. IL-21 plays a role in T cell-dependent B cell differentiation into plasma cells and memory cells, stimulation of IgG production and induction of apoptotic signaling in naive B cells. In Th17 cells, IL-21 expression and autocrine feedback through STAT3, IRF4 and ROR gamma t lead to upregulation of the IL-23R, thereby preparing Th17 cells for maturation and maintenance by the inflammatory cytokine IL-23. While upregulating IRF4 and ROR gamma t, IL-21 also mediates the downregulation of Foxp3. IL-21 deficient mice are protected from developing colitis upon chemical treatment by their inability to upregulate Th17-associated molecules. In comparison, elevated levels of IL-21 are present in chemically-induced colitis mouse models.
For Research Use Only. Not for use in diagnostic procedures. Not for resale without express authorization.
Gene aliases : CVID11, IL-21, IL21, Za11
Gene ID : (Human) 59067
Gene symbol : IL21
Protein Aliases : IL-21, Za11, Interleukin-21, interleukin-21 isoform
UniProt ID (Human) Q9HBE4
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