The quantikine Human Cyclosporin A (CsA) immunoassay is a 4.5 hour solid phase elisa designed to measure Human Cyclosporin A (CsA) levels in cell culture supernates, serum, and plasma. It contains e. Coli-expressed recombinantHuman Cyclosporin A (CsA) and antibodies raised against recombinantHuman Cyclosporin A (CsA). This immunoassay has been shown to accurately quantitate the recombinant factor. Results obtained using natural Human Cyclosporin A (CsA) 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 Cyclosporin A (CsA)