IL-12 is a heterodimeric cytokine of disulfide-linked p35 and p40 subunits. It is secreted by monocytes, macrophages, dendritic cells, neutrophils, Langerhans cells, keratinocytes, microglia, and peripheral B cells. In humans, the p40 subunit can also associate with a p19 subunit to form IL-23. IL-12 signals through a receptor complex consisting of IL-12 R beta 1 and IL-12 R beta 2. It promotes Th1 immune responses by inducing IFN-gamma secretion from NK cells, T cells, and macrophages and by enhancing NK cell and T cell mediated cytotoxicity. It also cooperates with IL-18 in the generation of Th1 memory cells.
Source
Spodoptera frugiperda, Sf21 (baculovirus)
Molecular Weight
Apparent molecular mass of 60 kDa in SDS-PAGE under non-reducing conditions, 41 kDa and 29 kDa under reducing conditions, a disulfide-linked heterodimer consisting of the 306 amino acid rHuIL-12 p40 and the 197 amino acid rHuIL-12 p35 subunits.
Biological Activity
Measured in a cell proliferation assay using PHA-stimulated human T lymphoblasts. The ED50 for this effect is 0.01-0.05 ng/mL. The specific activity of rHuIL-12 is approximately 1.1 × 104 units/ug, which is calibrated against rHuIL-12 WHO Standard (NIBSC code: 95/544).
Appearance
Sterile filtered white lyophilized (freeze-dried) powder.
Formulation
Lyophilized from a 0.2 um filtered concentrated solution in PBS, pH 7.2.
Endotoxin
Less than 1.0 EU/ug of rHuIL-12 as determined by LAL method.
Reconstitution
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile PBS to a concentration of 0.1 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20 °C. Further dilutions should be made in appropriately buffered solutions.
Stability and Storage
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.- 12 months from date of receipt, -20 to -70 °C as supplied.- 1 month, 2 to 8 °C under sterile conditions after reconstitution.- 3 months, -20 to -70 °C under sterile conditions after reconstitution.
