14-8128

Contents: Recombinant Human IL-12/IL-23 p40 monomer
Catalog Number: 14-8128
Formulation: Sterile liquid; 10 mM NaH2PO4, pH 6.0, 300 mM NaCl, with 1.0% BSA as a carrier. 0.22 uM filtered.
Storage Conditions: For greatest stability, keep concentration of primary stock at or above 10 µg/ml. For long term storage, aliquot into polypropylene vials (volumes of 20 µl or greater) and store at or below -80°C. Avoid repeated freeze/thaw cycles.
Handling Conditions: For best recovery, always quick-spin vial prior to opening. For dilution of current stock, always include carrier protein (1% BSA or 10% FBS) in the buffered saline diluent.
Source: Insect cells infected with baculovirus: human P40, amino acids met 1-ser 328, (accession # NM_002187).
Molecular Mass: P40, amino acids met ile-ser 328, has a predicted molecular mass of 34,697. On reducing SDS-PAGE the DTT-reduced protein migrates as a 40 kDa polypeptide. The non-reduced protein migrates as a 39 kDa polypeptide.
Purity: Greater than 98% with less than 2% disulfide-linked homodimer, as determined by SDS-PAGE
Endotoxin Level: Less than 0.01 ng/ug cytokine as determined by the LAL assay.
Bioactivity: The p40 subunit of IL-12 as a monomer is reported not to exert biological or antagonistic activity.

Available Formats of This Product
Cat. No.	Format	Excite (nm)	Emit (nm)	Reported Applications
39-8128	Single-Use ELISA RSG Standard Recombinant Human IL-12 (Interleukin-12) p40 monomer	N/A	N/A	ELISA

Questions? Please consult our answers to frequently asked questions at http://www.ebioscience.com/faq.

Description

Interleukin-12 (IL-12) is a heterodimeric 70 kD (p70) cytokine composed of two covalently linked, glycosylated chains, 40kD (p40) and 35-kD (p35). IL-12 is mainly produced by monocytes, macrophages, and dendritic cells in response to bacterial products such as lipopolysaccharides (LPS), to intracellular pathogens or upon interaction with activated T cells. IL-12 was originally discovered because of its ability to induce interferon-γ production, cell proliferation, and cytotoxicity mediated by natural killer cells and T cells. It is now established that IL-12 also plays a key role in the development of Th1 responses, leading to IFN-γ and IL-2 production. These cytokines can in turn promote T-cell responses and macrophage activation. The p40 and p35 subunits by themselves have no IL-12 bioactivity, though the p40 homodimer has been shown to bind the IL-12 receptor and to be an antagonist of IL-12 p70. Free p40 is typically secreted in vast excess of IL-12 p70 by cells co-expressing both the p35 and p40 subunits. The p40 subunit of IL-12 has been shown to have extensive amino acid sequence homology to the extracellular domain of the IL-6 receptor, while the p35 subunit shows some homology to IL-6 and G-CSF.

Applications Reported

For research use only, not for diagnostic or therapeutic use. The recombinant human IL-12/IL-23 p40 monomer has been reported for use as an ELISA standard.

Applications Tested

The recombinant human IL-12/IL-23 p40 monomer has been tested as an ELISA standard in an ELISA measuring preferentially IL-12/IL-23 p40 monomer. The C8.3/C8.6 p40 monomer ELISA preferentially measures p40 monomer, exhibiting less than 1.0% cross reactivity with IL-12 p70 and IL-23.

For this assay, the (p40 monomer-specific) purified C8.3 antibody (14-7127) is used as the capture antibody in combination with the biotinylated C8.6 antibody (13-7129) for detection and recombinant human IL-12/IL-23 p40 (14-8128) as the standard. A standard curve consisting of doubling dilutions of the recombinant standard over the range of 10,000 pg/ml - 80.0 pg/ml should be included in each ELISA plate.

References

Chen, L., et al. 1997. Eradication of murine bladder carcinoma by intratumor injection of a bicistronic adenoviral vector carrying cDNAs for the IL-12 heterodimer and its inhibition by the IL-12 p40 subunit homodimer. J. Immunol. 159: 351-359.
Ling, P., et al. 1995. Human IL-12 p40 homodimer binds to the IL-12 receptor but does not mediate biologic activity. J. Immunol. 154: 116-127.
Russell, T., et al. 2003. IL-12 p40 homodimer-dependent macrophage chemotaxis and respiratory viral inflammation are mediated through IL-12 receptor beta1. J. Immunol. 171: 6866-6874.

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