Recombinant Mouse IL-5Rα-Fc Chimera (carrier-free)

Pricing & Availability
Regulatory Status
Other Names
Interleukin-5 receptor subunit alpha (IL-5Rα), IL-5R alpha, IL-5R subunit alpha, CD125, IL-5Ra, IL-5RA
Ave. Rating
Submit a Review
Product Citations
When mouse IL-5 is immobilized at 1 µg/ml using a capture antibody, mouse IL-5Rα binds with EC50 of 0.025 - 0.1 µg/ml in a functional ELISA.
  • Mouse_IL-5Ralpha_RECOM_CF_053017
    When mouse IL-5 is immobilized at 1 µg/ml using a capture antibody, mouse IL-5Rα binds with EC50 of 0.025 - 0.1 µg/ml in a functional ELISA.
Cat # Size Price Quantity Check Availability Save
765004 25 µg $297
Check Availability

Need larger quantities of this item?
Request Bulk Quote

The IL-5 receptor is a heterodimer including a ligand-specific IL-5Rα and a β subunit (CSF2RB, also called common β subunit, βc), shared with IL-3 and GM-CSF. IL-5Rα, also known as CD125, belongs to the type I cytokine receptor family, which contains a conserved WSXWS motif in the extracellular domain and a box 1 motif in the cytoplasmic tail. In human, there are several isoforms present due to alternative splicing, including membrane-bound isoforms and soluble isoforms. Membrane-bound IL-5Rα initially binds to IL-5 and then recruits βc, which is required for preventing the complex from dissociating and triggering the downstream signaling transduction. Juxtamembraneous kinases, including Lyn and JAK are essential for IL-5R phosphorylation, leading to the recruitment and the activation of STAT family. Unlike membrane-bound isoform, soluble isoform is considered as an antagonist. IL-5Rα is mainly expressed on eosinophils, basophils and B cells, and it is known to regulate the differentiation and function of eosinophils, basophils and B cells in human and mice. Soluble IL-5Rα inhibits antigen-induced hyper-eosinophilia. IL-5Rα is required for IL-5-induced cell proliferation and immunoglobulin production during B cell development. It has reported that IL-5 can upregulate the expression of membrane form in murine myeloid cell line and human CD34+ progenitor cells. In contrast, membrane-bound IL-5Rα is downregulated in mature eosinophils upon IL-5, IL-3 or GM-CSF treatment. In mice, IL-5Rα is also detected in astrocytes and the expression of isoforms is highly regulated during brain development, but no expression in adulthood. However, the isoforms are produced upon inflammation in mice, indicating IL-5/IL-5Rα serves as an autocrine/paracrine function in mouse brain.

Product Details
Technical data sheet

Product Details

Mouse IL-5Rα, amino acid Asp18-His339 (Accession #: P21183), with a linker (GSSR) and a C-terminal human IgG1 (Pro100-Lys330), was expressed in 293E cells.
Molecular Mass
The 557 amino acid recombinant protein has a predicted molecular mass of approximately 63.1 kD. The non-reducing and DTT-reduced protein migrates at approximately 150 kD and 70 kD by SDS-PAGE. The predicted N-terminal amino acid is Asp.
>95%, as determined by Coomassie stained SDS-PAGE.
0.22 µm filtered protein solution is in 1x PBS.
Endotoxin Level
Less than 0.01 ng/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, please enter the lot number in our Concentration and Expiration Lookup or Certificate of Analysis online tools.
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.
When mouse IL-5 is immobilized at 1 µg/ml using a capture antibody, mouse IL-5Rα binds with EC50 of 25-100 ng/ml in a functional ELISA.


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

Antigen Details

Cytokine receptor (disulfide bond-linked dimer)

Eosinophils, basophils, B cells and astrocytes, membrane-bound and secreted

The L-5Rα/IL-5 complex regulates the differentiation and function of eosinophils, basophils and B cells.
Measured by its ability to bind mouse IL-5.
Biology Area
Cell Biology, Cell Proliferation and Viability, Immunology
Molecular Family
Cytokine/Chemokine Receptors, Soluble Receptors
Antigen References

1. Moon BG et al. 2001. Immunology 102: 289.
2. Ishino T et al. 2005. Vitam. Horm. 71: 321.
3. Gandhi NA et al. 2016. Nat. Rev. Drug Discov. 15: 35.
4. Takatsu K et al. 1994. Adv. Immunol. 57: 145.
5. Tavernier J et al. 1992. Proc. Natl. Acad. Sci. USA. 89: 7041.
6. Shakola F et al. 2015. Biomolecules 5: 2073.
7. Lins C et al. 2001. Growth Factors 19: 145.
8. Kikuchi Y et al. 1994. J. Immunol. Methods 167: 289.
9. Tavernier J et al. 2000. Blood 95: 1600.
10. Kouro T et al. 2009. Int. Immunol. 21: 1303.

Gene ID
16192 View all products for this Gene ID
View information about IL-5Ralpha 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) = 10e6/ ED50 (ng/mL)
Go To Top Version: 0    Revision Date: 05/31/2017

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.


8999 BioLegend Way, San Diego, CA 92121
Toll-Free Phone: 1-877-Bio-Legend (246-5343) Phone: (858) 768-5800 Fax: (877) 455-9587


Remember me
Forgot your password? Reset Password
Request an Account