Description
Upon initial thawing, recombinant human IFN-γ (Cat. No. 554616) 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 1 - 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 1 - 2 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 IFN-γ (Cat. No. 554616) can be useful as a quantitative standard for measuring human IFN-γ protein levels using sandwich ELISA with the purified NIB42 antibody (Cat. No. 551221) as a capture antibody and biotinylated 4S.B3 antibody (Cat. No. 554550) as the detection antibody. To obtain linear standard curves, investigators may want to consider using doubling dilutions of recombinant human IFN-γ standard from 2000 - 15 pg/mL to be included in each ELISA plate. For measuring human IFN-γ in serum or plasma, investigators are highly encouraged to use the BD OptEIA™ Human IFN-γ ELISA Set (Cat. No. 555142 ) or BD OptEIA™ Human IFN-γ ELISA Kit II (Cat. No. 550612 ). 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 0.1 - 2.0 x 10^8 units/mg, encompassing an ED50= 0.05 - 1.0 ng/mL, has previously been reported using A549 as indicator cells in an anti-viral bioassay, with a unit defined as the amount of material needed to stimulate a half-maximal response at cytokine saturation.
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.
1. Since applications vary, each investigator should titrate the reagent to obtain optimal results.
2. Source of all serum proteins is from USDA inspected abattoirs located in the United States.
3. Please refer to www.bdbiosciences.com/us/s/resources for technical protocols.
