BD, 554613, BD Pharmingen™ Recombinant Human IL-12 (p70)

Preparation And Storage: Preparation And Storage 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. This preparation contains no preservatives, thus it should be handled under aseptic conditions.
Recommended Assay Procedures: Recommended Assay Procedures Upon initial thawing, recombinant human IL-12 p70 (Cat. No. 554613) 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 in vitro biological assay use, carrier-protein concentrations of 0.5 - 1 mg/mL are recommended.  For use as an ELISA standard, carrier-protein concentrations of 5 - 10 mg/mL are recommended.  Failure to add carrier protein or store at indicated temperatures may result in a loss of activity.  The product should not be diluted to less than 25 μg/mL for long term storage.  Carrier proteins should be pre-screened for possible effects in each investigator's experimental system.  Carrier proteins may have an undesired influence on experimental results due to toxicity, high endotoxin levels or possible blocking activity. ELISA Standard: Recombinant human IL-12 p70 (Cat. No. 554613) can be useful as a quantitative standard for measuring human IL-12 protein levels using sandwich ELISA with the purified 20C2 antibody (Cat. No.555065) as a capture antibody and biotinylated C8.6 antibody (Cat. No. 554660) as the detection antibody.  To obtain linear standard curves, investigators may want to consider using doubling dilutions of recombinant human IL-12 from 2,000 - 15 pg/mL to be included in each ELISA plate.  For measuring human IL-12 in serum or plasma, investigators are highly encouraged to use the BD OptEIA™ Human IL-12 ELISA Set (Cat. No. 555171 for human IL-12 p40 and Cat. No. 555183 for human IL-12 p70) or the BD OptEIA™ Human IL-12 ELISA Kit II (Cat. No. 551116 for human IL-12 p40 and Cat. No. 559258 for human IL-12 p70). Bioassay: Investigators are advised that the Bioassay application is not routinely tested for this material and are highly encouraged to both titrate this material and include appropriate controls in relevant experiments.  An  activity range of 0.2 - 5.0 x 10^8 units/mg, encompassing an ED50= 20 - 500 pg/mL, has previously been reported using PHA/IL-2 -activated human peripheral blood mononuclear cell (PBMC) for proliferation, with a unit defined as the amount of material needed to stimulate a half-maximal response at cytokine saturation.