The Quantikine Human IL-15 Immunoassay is a 4.25 or 4.5 hour solid phase ELISA designed to measure human IL-15 in cell culture supernates, serum, and plasma. It contains E. coli-expressed recombinant human IL-15 and antibodies raised against the recombinant factor. This immunoassay has been shown to accurately quantitate the recombinant factor. Results obtained using natural human IL-15 expressed by HuT-102 cells showed linear 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-15. Range: 3.90 - 250 pg/mL. Sensitivity: 2 pg/mL. Time: 4.25 hours or 4.5 hours