Recombinant Human IGF-II (carrier-free)

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Other Names
Insulin-like growth factor II, somatomedin A
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Product Citations
MCF-7 cell proliferation induced by human IGF-II.
  • IGF-II_Human_Recombinant_Protein_BA_082713.jpg
    MCF-7 cell proliferation induced by human IGF-II.
Cat # Size Price Quantity Avail. Save
590604 25 µg 108€
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590606 100 µg 220€
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590608 500 µg 604€
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IGF-II is a member of the IGF family, comprised of three members (IGF-I, IGF-II, and insulin). IGF-I and IGF-II share approximately 50% similarity with insulin at the amino acid level. IGF-II is synthesized as a 180 amino acid prepro-IGF-II; pro-IGF-II is processed to its mature, active protein form by glucose regulating protein 94 (GRP94), which possesses chaperone activity towards IGF-II. GRP94 and IGF-II play a key role on muscle differentiation. Seven binding proteins have been described (IGFBP-1 to -7). IGFBPs extend the half life and regulate the availability of the IGFI and IGFII. It has been described that IGFBP3 is the main circulating binding protein for IGFs; in serum, approximately 75% of circulating IGF-I and IGF-II bind to IGFBP3 and the co-carrier acid labile subunit (ALS). IGF-II binds to three receptors, and the binding to IGFIR promotes cell proliferation, survival, differentiation, and migration as well as metabolic function of IGF-II. Embryonic stem cell differentiation into endothelial cells is promoted by the binding of IGF-II to IGFR1. IGF-II binding to IGF-IIR induces internalization and clearing of IGF-II. Osteogenic differentiation and bone formation is enhanced by IGF-II through bone morphogenetic protein-9 (BMP-9). Polymorphisms of IGF-II are associated with obesity, cardiovascular risk factors, and hypertension.

Product Details
Technical Data Sheet (pdf)

Product Details

Human IGF-II, amino acids (Ala25-Glu91) (Accession# X03562.1) was expressed in E. coli.
Molecular Mass
The 67 amino acid recombinant protein has a predicted molecular mass of approximately 7.47 kD. The DTT-reduced and non-reduced protein migrate at approximately 10 kD by SDS-PAGE. The N-terminal amino acid is Ala.
>95%, as determined by Coomassie stained SDS-PAGE.
0.22 µm filtered protein solution is in 5 mM citric acid, 5 mM NaHPO4, 0.15 M NaCl, pH 4.0.
Endotoxin Level
Less than 0.01 ng per µg cytokine as determined by the LAL method.
25 µg size is bottled at 100 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial (please contact technical support for concentration, or use our Lookup tool if you have a lot number.)
Please note, new lots of the 100 µg size will be lot-specific and may differ from previous lots that had a fixed concentration.
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.
ED50 = 4 - 20 ng/ml, corresponding to a specific activity of 0.5 - 2.5 x 105 units/mg, as determined by the dose dependent stimulation of MCF-7 cell proliferation.


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 validated 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


Astrocytes, podocytes, hepatocytes, microglia, osteoblast, myoblast.

IGF-II induces mitogenesis, proliferation, growth, differentiation, and angiogenesis. IGF-II is a mediator of GH action. IGF-II is involved in neuronal and muscular differentiation as well as organ development. TGFβ1 diminishes IGF-II gene expression and secretion in myoblasts.
IGF-I receptor, Insulin receptor isoform A, and IGF-II receptor (M-6-P-R).
Cell Type
Neural Stem Cells, Mesenchymal Stem Cells, Hematopoietic stem and progenitors, Embryonic Stem Cells
Biology Area
Cell Biology, Signal Transduction, Stem Cells
Molecular Family
Growth Factors, Cytokines/Chemokines
Antigen References

1. Bell GI, et al. 1984. Nature 310:775.
2. Chen L, et al. 2010. J. Bone Miner Res. 25:2447.
3. Ostrovsky O, et al. 2010. Biochim. Biophys. Acta. 1803:333.
4. Gardner S, et al. 2011. Mol. Endocrinol. 25:128.
5. Piecewicz SM, et al. 2012. PLoS One 7:e32191.
6. Church DN, et al. 2012. Oncogene 31:3635.
7. Hale LJ, et al. 2013. J. Pathol. 230:95.
8. Liu ZK, et al. 2012. PLoS One 7:e45224.

Gene ID
3481 View all products for this Gene ID
View information about IGF-II 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: 1    Revision Date: 09-06-2013

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.


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

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