The Quantikine Human IL-1 alpha Immunoassay is a 3.5 or 4.5 hour solid phase ELISA designed to measure IL-1 alpha in cell culture supernates, serum, and plasma. It contains recombinant human IL-1 alpha and antibodies raised against recombinant human IL-1 alpha and has been shown to accurately quantitate the recombinant factor. Results obtained using natural IL-1 alpha showed linear curves that were parallel to the standard curves obtained using the E. coli-expressed Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for natural human IL-1 alpha. Range: 3.90 - 250 pg/mL. Sensitivity: 1 pg/mL. Time: 3.5 hours or 4.5 hours