Description

Nori Bovine IL-4 ELISA Kit Summary

Alternative names for IL-4: Interleukin 4, IL4

Alternative name for bovine: Cow, cattle, bull

Standard Curve

Kit Components
1. Pre-coated 96-well Microplate
2. Biotinylated Detection Antibody
3. Streptavidin-HRP Conjugate
4. Lyophilized Standards
5. TMB One-Step Substrate
6. Stop Solution
7. 20 x PBS
8. Assay Buffer

Other Materials Required but not Provided:
1. Microplate Reader capable of measuring absorption at 450 nm
2. Log-log graph paper or computer and software for ELISA data analysis
3. Precision pipettes (1-1000 µl)
4. Multi-channel pipettes (300 µl)
5. Distilled or deionized water

Protocol Outline
1. Prepare all reagents, samples and standards as instructed in the datasheet.
2. Add 100 µl of Standard or samples to each well and incubate 1 h at RT.
3. Add 100 µl of Working Detection Antibody to each well and incubate 1 h at RT.
4. Add 100 µl of Working Streptavidin-HRP to each well and incubate 20 min at RT.
5. Add 100 µl of Substrate to each well and incubate 5-30 min at RT.
6. Add 50 µl of Stop Solution to each well and read at 450 nm immediately.

Background: 

Interleukin-4 (IL-4) is a cytokine that is expressed in a variety of tissues including lymphocytes and leukocytes, is a key regulator in humoral and adaptive immunity and has many biological roles, including the stimulation of activated B-cell and T-cell proliferation, and the differentiation of CD4+ T-cells into Th2 cells. IL-4 induces differentiation of naive helper T cells (Th0 cells) to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4. 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.^[1] It is closely related and has functions similar to Interleukin 13. Like IL-13, Interleukin 4 (IL-4) is critical for responses to parasitic helminthes. ^[2] IL-4 up-regulates MHC class II production and decreases the production of Th1 cells, macrophages, IFN-gamma, and dendritic cell IL-12. Tissue macrophages play an important role in chronic inflammation and wound repair. The presence of IL-4 in extravascular tissues promotes alternative activation of macrophages into M2 cells and inhibits classical activation of macrophages into M1 cells. An increase in repair macrophages (M2) is coupled with secretion of IL-10 and TGF-β that result in a diminution of pathological inflammation. This cytokine was co-discovered by Maureen Howard and William Paul^[3] and by Dr. Ellen Vitetta and her research group in 1982. The nucleotide sequence for human IL-4 was isolated four years later confirming its similarity to a mouse protein called B-cell stimulatory factor-1 (BCSF-1).^[4]

References

1. Sokol, C.L., et al. (2008). Nat Immunol 9 (3): 310–318.
2. Liang, H-E, et al. (2012) Nature Immunology, 13: 58–66.
3. Howard M, Paul WE (1982). “Interleukins for B lymphocytes”. Lymphokine Res. 1 (1): 1–4.
4. Yokota T et al. (1986). Proc. Natl. Acad. Sci. U.S.A. 83 (16): 5894–8.

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