Recombinant Human IL-3 (carrier-free)

Pricing & Availability
Regulatory Status
Other Names
Interleukin-3, Burst promoting activity, Eosinophil colony stimulating factor (Eo-CSF), Hematopoietic cell growth factor (HCGF), Mast (MGF/MCGF), Multi-colony stimulating (Multi-CSF), P cell stimulating activity (PCSA), Thy1 inducing factor
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Product Citations
TF-1 cell proliferation induced by human IL-3.
  • IL-3_Human_100411
    TF-1 cell proliferation induced by human IL-3.
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578002 10 µg £121
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578004 25 µg £238
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578006 100 µg £398
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578008 500 µg £943
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Interleukin-3 is a hemopoietic growth factor involved in the survival, proliferation, and differentiation of multipotent hemopoietic cells. IL-3 is the most potent growth factor for basophils, followed by granulocyte-macrophage colony-stimulating factor and IL-5. These cytokines also act on mature basophils through specific receptors, thereby mediating adhesion, migration, and releasability. IL-3 is highly expressed by mast cells, and large and rapidly released amounts of autocrine IL-3 production are responsible for mast cell survival by IgE in the absence of antigen. IL-3 has also been implicated in the pathogenesis of several chronic inflammatory diseases, including asthma, atherosclerosis, and neurodegenerative disorders, such as multiple sclerosis.  IL-3 stimulates colony formation of megakaryocytes, neutrophils, and macrophages from bone marrow cultures. IL-3 plays a vital role in stimulating basophils and mast cell responses to parasite infections, and since basophils play an important role in Th2 immune responses, IL-3 is a critical regulator of allergic inflammation. IL-3 is expressed in the major embryonic vessels and regulates the survival and proliferation of hematopoietic stem cells in the early stages of embryonic development.

Product Details
Technical Data Sheet (pdf)

Product Details

Human IL-3, amino acids Ala20-Phe152 (Accession# P08700), was expressed in Insect cells. The C-terminus contains a linker-8His-tag.
Molecular Mass
The 150 amino acid recombinant protein has a predicted molecular mass of 17 kD. The DTT-reduced protein migrates in the range of 18 to 25 kD by SDS-PAGE.
>98%, as determined by Coomassie stained SDS-PAGE.
0.22 µm filtered protein solution is in 20 mM NaH2PO4, 0.30 M NaCl, pH 6.0.
Endotoxin Level
Less than 0.01 ng per µg cytokine as determined by the LAL method.
10 and 25 µg sizes are bottled at 200 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial. To obtain lot-specific concentration and expiration, please enter the lot number in our Certificate of Analysis online tool.
Storage & Handling
Unopened vial can be stored between 2°C and 8°C for up to 2 weeks, at -20°C for up to six months, or at -70°C or colder until the expiration date. For maximum results, quick spin vial prior to opening. The protein can be aliquoted and stored at -20°C or colder. Stock solutions can also be prepared at 50 - 100 µg/mL in appropriate sterile buffer, carrier protein such as 0.2 - 1% BSA or HSA can be added when preparing the stock solution. Aliquots can be stored between 2°C and 8°C for up to one week and stored at -20°C or colder for up to 3 months. Avoid repeated freeze/thaw cycles.
Human IL-3 stimulates the proliferation of TF-1 human erythroleukemic cells in a dose-dependent manner. The ED50 = 0.05 – 0.3 ng/mL.

The specific activity of recombinant human IL-3 is approximately 1.64 x 103 IU/µg when compared against the 1st WHO International Standard for Human IL-3 (NIBSC code: 91/510).

For more information on specific activity, please visit the Recombinant Protein Unit Conversions page.


Application Notes

BioLegend carrier-free recombinant proteins provided in liquid format are shipped on blue-ice. Our comparison testing data indicates that when handled and stored as recommended, the liquid format has equal or better stability and shelf-life compared to commercially available lyophilized proteins after reconstitution. Our liquid proteins are verified in-house to maintain activity after shipping on blue ice and are backed by our 100% satisfaction guarantee. If you have any concerns, contact us at

Product Citations
  1. Nenasheva T, et al. 2020. Front Immunol. 1.163888889. PubMed
  2. Zhai K, et al. 2021. Nat Cancer. 2:1136. PubMed
  3. Rexach JE, et al. 2020. Cell Rep. 33:108398. PubMed

Antigen Details


Activated T cells, Th1, Th2, mast cells, eosinophils, keratinocytes, NK cells, and endothelial cells.

IL-3 is a pleiotropic factor which promotes both self-renewal and differentiation of early multipotential progenitors and is involved in inducible hematopoiesis in response to infections.
Erythroid cells, megakaryocytes, neutrophils, eosinophils, basophils, mast cells, monocytic lineages.
Heterodimer IL-3Rα (CD123) and a common β subunit (βc) that is shared with the IL-5R and GM-CSFR.
Cell Type
Hematopoietic stem and progenitors
Biology Area
Cell Biology, Signal Transduction, Stem Cells
Molecular Family
Antigen References

1. Kitamura T, et al. 1989. J. Cell. Physiol. 140:323.
2. Kohno M, et al. 2005. Blood 105:2059.
3. Murphy JM and Young IG, 2006. Vitam. Horm. 74:1.
4. Kleemann R, et al. 2008. Cardiovasc. Res. 79:360.
5. Valent P, and Dahinden CA. 2010. Curr. Opin. Hematol. 17:60.
6. Mirza S, et al. 2010. J. Biol. Chem. 285:22370.

Gene ID
3562 View all products for this Gene ID
View information about IL-3 on

Related FAQs

Why choose BioLegend recombinant proteins?

     • Each lot of product is quality-tested for bioactivity as indicated on the data sheet.
     • Greater than 95% Purity or higher, tested on every lot of product.
     • 100% Satisfaction Guarantee for quality performance, stability, and consistency.
     • Ready-to-use liquid format saves time and reduces challenges associated with reconstitution.
     • Bulk and customization available. Contact us.
     • Learn more about our Recombinant Proteins.

How does the activity of your recombinant proteins compare to competitors?

We quality control each and every lot of recombinant protein. Not only do we check its bioactivity, but we also compare it against other commercially available recombinant proteins. We make sure each recombinant protein’s activity is at least as good as or better than the competition’s. In order to provide you with the best possible product, we ensure that our testing process is rigorous and thorough. If you’re curious and eager to make the switch to BioLegend recombinants, contact your sales representative today!

What is the specific activity or ED50 of my recombinant protein?

The specific activity range of the protein is indicated on the product datasheets. Because the exact activity values on a per unit basis can largely fluctuate depending on a number of factors, including the nature of the assay, cell density, age of cells/passage number, culture media used, and end user technique, the specific activity is best defined as a range and we guarantee the specific activity of all our lots will be within the range indicated on the datasheet. Please note this only applies to recombinants labeled for use in bioassays. ELISA standard recombinant proteins are not recommended for bioassay usage as they are not tested for these applications.

Have your recombinants been tested for stability?

Our testing shows that the recombinant proteins are able to withstand room temperature for a week without losing activity. In addition the recombinant proteins were also found to withstand four cycles of freeze and thaw without losing activity.

Does specific activity of a recombinant protein vary between lots?

Specific activity will vary for each lot and for the type of experiment that is done to validate it, but all passed lots will have activity within the established ED50 range for the product and we guarantee that our products will have lot-to-lot consistency. Please conduct an experiment-specific validation to find the optimal ED50 for your system.

How do you convert activity as an ED50 in ng/ml to a specific activity in Units/mg?

Use formula Specific activity (Units/mg) = 10^6/ ED50 (ng/mL)

Go To Top Version: 5    Revision Date: 05/20/2019

For research use only. Not for diagnostic use. Not for resale. BioLegend will not be held responsible for patent infringement or other violations that may occur with the use of our products.


*These products may be covered by one or more Limited Use Label Licenses (see the BioLegend Catalog or our website, BioLegend products may not be transferred to third parties, resold, modified for resale, or used to manufacture commercial products, reverse engineer functionally similar materials, or to provide a service to third parties without written approval of BioLegend. By use of these products you accept the terms and conditions of all applicable Limited Use Label Licenses. Unless otherwise indicated, these products are for research use only and are not intended for human or animal diagnostic, therapeutic or commercial use.


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