Product Information

Contents: Recombinant Human IL-12 p40 Monomer Single-Use ELISA RSG Standard
Catalog Number: 39-8128
Sizes: 4 pack
Formulation: Sterile liquid; phosphate buffered saline, pH 7.2, 150 mM NaCl, with 1.0% BSA. 0.22 µm filtered.
Storage Conditions: The frozen cytokine standard is already aliquoted at 20 µl per vial. Upon receipt, frozen cytokine standard should be immediately stored at -80°C; stable for at least 12 months. After thawing, quick-spin vial prior to opening. Do not re-aliquot into smaller fractions. These are single use vials. Use one time and discard.
Handling Conditions: For best recovery, always quick-spin vial prior to opening. For dilution of current stock, use ELISA Assay Diluent.
Source: Insect cells infected with baculovirus: human P40, amino acids met 1-ser 328, (accession # NM_002187).
Purity: Greater than 98%, as determined by SDS-PAGE

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 intended use of the Recombinant Human IL-12 p40 Single-Use ELISA RSG Standard is as a standard for human IL-12 p40 monomer matched antibody pair ELISA. Typically the standard is run in a series of 7 doubling dilutions from the ‘top’ standard described below.

Instructions for use:
For matched antibody pair ELISA (ABTS or Super AquaBlue substrate). Dilution: Add 10 ul of standard solution to 1 ml of assay diluent to prepare the top standard solution (10,000 pg/ml).

Note: These are single-use vials. Use one time and discard. Dilute as suggested above, not difficult-to-measure fractions of the suggested volumes (e.g., not 0.5 ul in 1.0 ml) or recovery may not be accurate. Use within 6 hours of dilution to top standard concentration.

Applications Tested

This cytokine standard has been calibrated, and subsequently tested by sandwich ELISA using the human IL-12 p40 ELISA pair (C8.3/C8.6).

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.