Ms IL-12 p40 Recom 2ug

Interleukin 12 (IL-12) is a potent regulator of cell-mediated immune responses. Biologically active IL-12 is secreted by activated B lymphocytes and macrophages as a 70 kD heterodimeric glycoprotein comprised of disulfide-bonded 35 kD (p35) and 40 kD (p40) subunits. The IL-12 p40 monomer shares amino acid sequence homology with the IL-6 receptor. It has been reported that activated PBMC produce a large excess of IL-12 p40 monomer over the bioactive p70 heterodimer. The IL-12 p40 monomer has been reported to inhibit binding of IL-12 p70 to the IL-12 receptor, but with 20X less effectiveness than the IL-12 p40 homodimer. Formulation and Purity: Recombinant mouse IL-12 p40 is supplied as a frozen liquid comprised of 0.22 µm sterile-filtered Dulbecco's PBS (pH 7.2) and no preservatives. The recombinant mouse IL-12, p40 is > 95% pure, as determined by SDS-PAGE, and an absorption assay based on the Beer-Lambert law. The recombinant is not tested for endotoxin or sterility. Preparation and Storage This preparation contains no preservatives, thus it should be handled under aseptic conditions. Store product at -80°C prior to use or for long term storage of stock solutions. Rapidly thaw and quick-spin product prior to use. Avoid multiple freeze-thaws of product. Upon initial thawing the product should be aliquoted into polypropylene microtubes and frozen at -80°C for future use. Alternatively, the product can be diluted in sterile neutral buffer containing not less than 0.5 - 10 mg/ml carrier protein** such as human or bovine albumin, aliquoted and stored at -80°C. For use as an ELISA standard we recommend carrier-protein concentrations of 5 -10 mg/ml. NOTE: Failure to add carrier protein or store at indicated temperatures may result in a loss of activity. Carrier proteins should be pre-screened for possible effects in an appropriate experimental system. Carrier proteins may affect experimental results due to toxicity, high endotoxin levels or possible blocking activity.