The Quantikine Human SCF sR Immunoassay is a 4.5 hour solid-phase ELISA designed to measure human SCF sR in cell culture supernates, serum, and plasma. It contains Sf 21-expressed recombinant human SCF sR and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human SCF sR 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 SCF sR. Range: 1.56 - 50 ng/mL. Sensitivity: 0.339 ng/mL. Time: 4.5 hours