The Quantikine Human Flt-3/Flk-2 Ligand Immunoassay is a 4.0 or 4.5 hour solid phase ELISA designed to measure soluble human Flt-3 Ligand in cell culture supernates, serum, and plasma. It contains NS0-expressed recombinant human Flt-3 Ligand and antibodies raised against the recombinant factor. This immunoassay has been shown to quantitate recombinant Flt-3 Ligand accurately. Results obtained measuring natural human Flt-3 Ligand 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 Flt-3 Ligand. Range: 15.60 - 1000 pg/mL. Sensitivity: 7 pg/mL. Time: 4 hours or 4.5 hours