• Purity

  >97%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured in a cell proliferation assay using NFS‑60 mouse myelogenous leukemia lymphoblast cells. Holmes, K.L.     et al. (1985) Proc. Natl. Acad. Sci. USA     82:6687. The ED    ₅₀ for this effect is 20-100 pg/mL.

• Source

  E. coli-derived Asp33-Cys166, with an N-terminal Met

• Accession #

• N-terminal Sequence    
  Analysis

  Asp33

• Predicted Molecular Mass

  15 kDa

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Data Images

Background: IL-3

Interleukin 3 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. Because of its multiple functions and targets, it was originally studied under different names, including mast cell growth factor P-cell stimulating factor, burst promoting activity, multi-colony stimulating factor, thy-1 inducing factor and WEHI-3 growth factor. In addition to activated T cells, other cell types such as human thymic epithelial cells, activated mouse mast cells, mouse keratinocytes and neurons/astrocytes can also produce IL-3. At the amino acid sequence level, mature human and mouse IL-3 share only 29% sequence identity. Consistent with this lack of homology, IL-3 activity is highly species-specific and human IL-3 does not show activity on mouse cells.

IL-3 exerts its biological activities through binding to specific cell surface receptors. The high affinity receptor responsible for IL-3 signaling is composed of alpha and beta subunits. The IL-3R alpha is a member of the cytokine receptor super family and binds IL-3 with low affinity. Two distinct beta subunits, AIC2A ( beta _IL-3) and AIC2B ( beta _c) are present in mouse cells. beta _IL-3 also binds IL-3 with low affinity and forms a high affinity receptor with the alpha subunit. The beta _c subunits does not bind any cytokine but forms functional high affinity receptors with the alpha subunit of the IL-3, IL-5 and GM-CSF receptors. Receptors for IL-3 are present on bone marrow progenitors, macrophages, mast cells, eosinophils, megakaryocytes, basophils and various myeloid leukemic cells.

• References:

1. Yokota, T. et al., 1984, Proc. Natl. Acad. Sci. USA 81:1070.

2. Fung, M.C. et al., 1984, Nature 307:233.

3. Miyatake, S. et al., 1985, Proc. Natl. Acad. Sci. USA 82:316.

• Long Name:

  Interleukin 3

• Entrez Gene IDs:

  3562 (Human); 16187 (Mouse); 24495 (Rat)

• Alternate Names:

  Hematopoietic growth factor; IL3; IL-3; IL-3MGC79398; interleukin 3 (colony-stimulating factor, multiple); interleukin-3; Mast cell growth factor; mast-cell growth factor; MCGFMGC79399; MULTI-CSF; multilineage-colony-stimulating factor; Multipotential colony-stimulating factor; P-cell stimulating factor; P-cell-stimulating factor