Human BD3 immunoassay is a 3.5 - 4.5 hour solid phase ELISA designed to measure human BD3 in SALIVA, cell culture supernates, and EDTA plasma. It contains recombinant human BD3 and antibodies raised against this protein. It has been shown to accurately quantify recombinant human BD3. Results obtained with naturally occurring BD3 samples showed linear curves that were parallel to the standard curves obtained using the kit standards. These results indicate that the Immunoassay kit can be used to determine relative mass values for natural human BD3.