Recombinant Human IL-3 Protein, Animal-Free

Equivalent bioactivity of GMP (BT-003-GMP), Animal-Free (Catalog # BT-003-AFL) and RUO (203-IL) grades of Recombinant Human IL-3 as measured in a cell proliferation assay using TF‑1 human erythroleukemic cells. (orange, green, red, respectively).

Animal-Free™ Recombinant Human IL‑3 Protein (Catalog # BT-003-AFL) stimulates cell proliferation of the TF-1 human erythroleukemic cell line. The ED50 for this effect is 0.015-0.150 ng/mL.

2 μg/lane of Animal-Free™ Recombinant Human IL‑3 Protein (Catalog # BT-003-AFL) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing a band at 14 kDa under reducing conditions.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human IL-3 Protein, Animal-Free Summary

• Details of Functionality: Measured in a cell proliferation assay using TF‑1 human erythroleukemic cells. Kitamura, T. et al. (1989) J. Cell Physiol. 140:323. The ED₅₀ for this effect is 0.015-0.150 ng/mL.
  The specific activity of recombinant human IL-3 is >1.7 x 10⁶ IU/mg, which is calibrated against the human IL-3 WHO International Standard (NIBSC code: 91/510).
• Source: E. coli-derived human IL-3 protein
  Ala20-Phe152, with and without an N-terminal Met
  Produced using non-animal reagents in an animal-free laboratory.
• N-terminal Sequence: Ala20 and Met
• Protein/Peptide Type: Animal-Free Recombinant Proteins
• Purity: >97%, by SDS-PAGE with quantitative densitometry by Coomassie® Blue Staining
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 15 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 14 kDa, under reducing conditions.

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >97%, by SDS-PAGE with quantitative densitometry by Coomassie® Blue Staining
• Reconstitution Instructions: Reconstitute at 500 μg/mL in water.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human IL-3 Protein, Animal-Free

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

Background

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 murine mast cells, murine keratinocytes and neurons/astrocytes can also produce IL-3. At the amino acid sequence level, mature human and murine 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 murine 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 at least two subunits, an IL-3 specific alpha chain which binds IL-3 with low affinity and a common beta chain that is shared by the IL-5 and GM-CSF high-affinity receptors. Although the beta chain itself does not bind IL-3, it confers high-affinity IL-3 binding in the presence of the  alpha chain. Receptors for IL-3 are present on bone marrow progenitors, macrophages, mast cells, eosinophils, megakaryocytes, basophils and various myeloid leukemic cells.