The Quantikine Human Cystatin C Immunoassay is a 4.5 hour solid-phase ELISA designed to measure human Cystatin C in cell culture supernates, serum, plasma, saliva, urine, and human milk. It contains NS0-expressed recombinant human Cystatin C and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human Cystatin C 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 Cystatin C. Range: 3.12 - 100 ng/mL. Sensitivity: 0.227 ng/mL. Time: 4.5 hours