The Quantikine Human ENPP-2 Immunoassay is a 4.5 hour solid-phase ELISA designed to measure human ENPP-2 in cell culture supernates, serum, plasma, urine, and human milk. It contains NS0-expressed recombinant human ENPP-2 and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human ENPP-2 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 ENPP-2. Range: 0.78 - 50 ng/mL. Sensitivity: 0.157 ng/mL. Time: 4.5 hours