The Quantikine Human IL-12 p40 Immunoassay is a 3.5 or 4.5 hour solid phase ELISA designed to measure IL-12 p40 in cell culture supernates, serum, and plasma. It contains recombinant human IL-12 p40 and antibodies raised against the recombinant factor. This immunoassay has been shown to accurately quantitate recombinant human IL-12 p40. Results obtained using natural human IL-12 p40 showed dose-response curves that were parallel to the standard curves obtained using the recombinant Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for natural human IL-12 p40. Range: 31.20 - 2000 pg/mL. Sensitivity: 15 pg/mL. Time: 3.5 hours or 4.5 hours