The Quantikine Human CD40 Ligand Immunoassay is a 4.5 hour solid-phase ELISA designed to measure human CD40 Ligand in cell culture supernates, serum, and plasma. It contains E. coli-expressed recombinant human CD40 Ligand and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human CD40 Ligand 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 CD40 Ligand. Range: 62.50 - 4000 pg/mL. Sensitivity: 10.1 pg/mL. Time: 4.5 hours