Interleukin-3, also known as mast cell growth factor, P-cell stimulating factor, burst promoting activity, multicolony stimulating factor, thy-1 inducing factor and WEHI-3 growth factor, is a pleiotropic factor produced primarily by activated T cells that can stimulate the proliferation and differentiation of pluripotent hematopoietic stem cells as well as various lineage committed progenitors. In addition, IL-3 also affects the functional activity of mature mast cells, basophils, eosinophils and macrophages. In addition to activated T cells, other cell types such as human thymic epithelial cells, activated murine mast cells, murine keratinocytes and neurons/astrocytes can also produce IL-3. Mature human IL-3 share only 29% aa sequence identity with murine IL-3. IL-3 activity is highly speciesspecific and human IL-3 does not show activity on murine cells. IL-3 is involved in a variety of cell activities such as cell growth, differentiation and apoptosis. This cytokine has been shown to also possess neurotrophic activity, and it may be associated with neurologic disorders.

This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IL-3 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any IL-3 present is bound by the immobilized antibody. Following incubation unbound samples are removed during a wash step, and then a detection antibody specific for IL-3 is added to the wells and binds to the combination of capture antibody- IL-3 in sample. Following a wash to remove any unbound combination, and enzyme conjugate is added to the wells. Following incubation and wash steps a substrate is added. A coloured product is formed in proportion to the amount of IL-3 present in the sample. The reaction is terminated by addition of acid and absorbance is measured at 450nm. A standard curve is prepared from seven IL-3 standard dilutions and IL-3 sample concentration determined.

Figure 1:Schematic diagram of the assay

1. Aluminium pouches with a Microwell Plate coated with antibody to human IL-3 (812)

2. 2 vials human IL-3 Standard lyophilized, 2000 pg/ml upon reconstitution

3. 2 vials concentrated Biotin-Conjugate anti-human IL-3 antibody

4. 2 vials Streptavidin-HRP solution

5. 1 bottle Standard /sample Diluent

6. 1 bottle Biotin-Conjugate antibody Diluent

7. 1 bottle Streptavidin-HRP Diluent

8. 1 bottle Wash Buffer Concentrate 20x (PBS with 1% Tween-20)

9. 1 vial Substrate Solution

10. 1 vial Stop Solution

11. 4 pieces Adhesive Films

12. package insert

NOTE: [96 Tests]

Unopened Kit：Store at 2 -8° C. Do not use past kit expiration date. opened/ReconstitutedReagents：Please refer to the datasheets for detail information.

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