Recombinant Human CNTF (Animal-Free)

Pricing & Availability
Other Names
Ciliary neurotrophic factor (CNTF)
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710104 20 µg $215
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CNTF is a member of the four-helix bundle cytokine family and is structurally related to other family members such as IL-6, IL-11, and LIF. Binding of CNTF to its receptor CNTFRα triggers the association with the IL-6 receptor gp130 and the LIF receptor LIFRβ, followed by activating the JAK-STAT, the ERK, and the PI3K signaling pathways. CNTF was first identified as a neuroprotective factor that supported the survival of embryonic chick ciliary neurons. CNTF has been shown to regulate the differentiation and survival of a variety of neuronal cells and has been applied as the treatment for retinal degenerative diseases caused by genetic defect or damage induced by toxins, auto-antibodies, or strong light. CNTF is also revealed as a myotrophic factor for denervated skeletal muscle and a modulator for AMPK-mediated energy balance control.

Product Details
Technical data sheet

Product Details

Human CNTF, amino acids (Ala2 - Met200) (Accession# NP_000032.1), was expressed in E. coli.
Molecular Mass
The 199 amino acid recombinant protein has a predicted molecular mass of approximately 22.8 kD. The predicted N-terminal amino acid is Ala.
>98%, as determined by Coomassie stained SDS-PAGE.
Lyophilized, carrier-free.
Endotoxin Level
Less than 0.1 ng per µg of protein.
Storage & Handling
Unopened vial can be stored at -20°C or -70°C. For maximum results, quick spin vial prior to opening. Reconstitute in 5-10 mM sodium phosphate, pH 7.5 to a concentration of 0.1-1.0 mg/ml. It is recommended to further dilute in a buffer, such as 5% Trehalose, and store working aliquots at -20°C to -80°C. Avoid repeated freeze/thaw cycles.
ED50 = 50 - 150 ng/ml, corresponding to a specific activity of 0.67 - 2.0 x 104 units/mg, as measured by its ability to stimulate proliferation of human TF-1 cells in a dose dependent manner.


Application Notes

This product is reactive with human, mouse, rat, bacteria, frog, and hamster.

Antigen Details

Growth factor
CNTF is mainly expressed in glial cells.
CNTF has neuroprotective function, regulating survival and differentiation of neurons in the nervous system. CNTF can also act as a myotrophic factor.
CNTF interacts with skeletal muscle and a variety of neurons in the nervous system.
CNTF binds to a receptor complex that consists of CNTF receptor alpha (CNTFRα), gp130, and LIF receptor beta (LIFRβ).
Human CNTF is able to stimulate proliferation of TF-1 cells.
Cell Type
Neural Stem Cells, Hematopoietic stem and progenitors, Embryonic Stem Cells
Biology Area
Cell Biology, Neuroscience, Stem Cells, Synaptic Biology
Molecular Family
Growth Factors, Cytokines/Chemokines
Antigen References

1. Wen R, et al. 2012. Prog. Retin. Eye Res. 31:136.
2. Purser MJ, et al. 2013. PLoS One. 8:e61616.
3. Rhee KD, et al. 2013. Proc Natl Acad Sci USA. 110:E4520.
4. Garcia N, et al. 2012. J. Peripher. Nerv. Syst. 17:312.
5. Vergara C, et al. 2004. Brain Res. Brain Res. Rev. 47:161.
6. Ji JZ, et al. 2004. Eur. J. Neurosci. 19:265.

Gene ID
1270 View all products for this Gene ID
View information about CNTF on

Related FAQs

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.

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.

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)
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.

Go To Top Version: 3    Revision Date: 05/06/2014

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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