The protein is in a sterile-filtered solution comprised of PBS, pH 7.2, with 10% FBS as a carrier and stabilizer.
Endotoxin Level:
The endotoxin level is less than 0.1 ng per µg cytokine protein (< 1EU/µg).
Storage & Handling:
For greatest stability, the cytokine protein is best kept at relatively high concentrations and in the presence of a protein carrier. After thawing, quick spin vial. Make working aliquots for storage at ≤ -70°C to minimize repeated freeze/thaw cycles. Any further dilution of the cytokine should be done using a buffered diluent containing a protein carrier (e.g., 1% BSA or 10% FBS).
Application:
ELISA, Ligand Block, Bioassay
Recommended Usage:
Each lot of this protein is quality control tested by ELISA assay. For use as an ELISA standard, a standard curve comprised of doubling dilutions from 500 pg/ml to 2 pg/ml is suggested. It is recommended that the reagent be titrated for optimal performance for each application.
Application Notes:
ELISA: This IL-12 protein is useful as a standard for a mouse IL-12 sandwich ELISA, using unlabeled C15.6 antibody (Cat. No. 505202) for capture and biotinylated C17.8 antibody (Cat. No. 505302) for detection. Ligand Blocking: This IL-12 protein is useful as a ligand-blocking specificity control for immunohistochemical or immunofluorescent staining. Bioassay: This IL-12 p40 homodimer demonstrates antagonist activity against the bioactive p70 protein, and can be used for in vitro assays.
Description:
Bioactive IL-12 is a potent regulator of cell-mediated immune responses and key mediator of Th1 cell development. IL-12 is secreted by activated B lymphocytes, dendritic cells and macrophages as a 70 kD heterodimeric glycoprotein comprised of disulfide-bonded 35 kD and 40 kD subunits. The p40 is also a subunit of bioactive IL-23 when it is associated with IL-23 p19 subunit. The disulfide-linked p40 homodimer can bind to IL-12 receptors and antagonize the activities of bioactive IL-12. Recombinant mouse IL-12 p40 homodimer is a 96 kD protein containing two 313 amino acid subunits.