Chinese Hamster Ovary cell line, CHO-derived human IFN-alpha 21/IFNA21 protein Cys24-Glu189
>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
<0.10 EU per 1 μg of the protein by the LAL method.
N-terminal sequence Analysis
Predicted Molecular Mass
18-22 kDa, under reducing conditions.
Measured in anti-viral assays using HeLa human cervical epithelial carcinoma cells infected with encephalomyocarditis (EMC) virus. Meager, A. (1987) in Lymphokines and Interferons, a Practical Approach. Clemens, M.J. et al. (eds): IRL Press. 129. The ED50 for this effect is 1.00-30.0 pg/mL.
Recombinant Human IFN-alpha 21/IFNA21 Protein, CF Scientific Data Examples
Recombinant Human IFN-alpha 21/IFNA21 Protein Bioactivity.
Recombinant Human IFN-alpha 21/IFNA21 Protein (Catalog # 11159-IF) demonstrates anti-viral activity in HeLa human cervical epithelial carcinoma cells infected with encephalomyocarditis (EMC) virus. The ED50 for this effect is 1.00-30.0 pg/mL.
Recombinant Human IFN-alpha 21/IFNA21 Protein SDS-PAGE.
2 μg/lane of Recombinant Human IFN-alpha 21/IFNA21 Protein (Catalog # 11159-IF) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 18-22 kDa, under reducing conditions.
Formulation, Preparation and Storage
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our
Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant
protein to be stored at a more dilute concentration.
The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or
as an ELISA standard.
In contrast, the carrier free protein is recommended for applications, in which the presence of BSA
Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
Reconstitute at 100 μg/mL in PBS.
The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & 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.
Background: IFN-alpha 21/IFNA21
Interferons (IFN) are a family of cytokines with potent antiviral, anti-proliferative and immunomodulatory properties, classified based on their binding specificity to cell surface receptors (1). Human IFNA2 was originally cloned in the early ‘80s and now more than a dozen closely related IFN alpha subtypes have been identified in both the human and mouse genome, each sharing about 80% amino acid (aa) sequence homology (2-4). Structurally, type I IFNs belong to the class of five helical‑bundle cytokines, with the IFNA subtypes containing 2 conserved disulfide bonds (5). There is not a mouse homolog for IFNA21, but mature human IFNA21 is identical to chimpanzee IFNA21. The type I IFNs bind to the interferon alpha receptor (IFNAR), which consists of two subunits: IFNAR1 (alpha -subunit) and IFNAR2 (beta -subunit) (6, 7). Individual IFNA subtypes are known to display unique efficacies to viral protection, with IFNA21 displaying intermediate activity inducing interferon stimulating genes (8). Further, human IFNA21 has shown weak anti-viral activity against viruses such as metapneumovirus (9).
Pestka, S. et al. (1987) Annu Rev Biochem. 56:727.
Goeddel, D.V. et al. (1980) Nature 287:411.
Matsumiya, T. et al. (2007) J. Immunol. 179:4542.
Schreiber, G. and J. Piehler (2015) Trends Immunol. 36:139.
Wittling, M.C. et al. (2021) Front Immunol. 11:605673.
van Pesch, V. et al. (2004) J. Virol. 78:8219.
James, C.M. et al. (2007) Vaccine. 25(10):1856.
Moll, H.P. et al. (2011) Cytokine. 53:52.
George, J. and Mattapallil, J.J. (2018) Frontiers in immunology 9:299.
Which Brands are Currently Available on bio‑techne.com? R&D Systems, Tocris Bioscience and ProteinSimple branded products are available to purchase through bio‑techne.com. ProteinSimple branded instruments are available to quote. ACD branded products will be available on bio‑techne.com in the near future. Novus Biologicals branded products are not currently available on bio‑techne.com and can be found at novusbio.com.
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