The Quantikine Human Carbonic Anhydrase IX Immunoassay is a 4.5 hour solid-phase ELISA designed to measure human CA9 in cell culture supernates, serum, plasma, and urine. It contains NS0-expressed recombinant human CA9 ectodomain and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human CA9 showed linear curves that were parallel to the standard curves obtained using the Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for naturally occurring human CA9. Range: 15.60 - 1000 pg/mL. Sensitivity: 4.39 pg/mL. Time: 4.5 hours