The Biosensis GDNF Rapid enzyme-linked immunosorbent assay (ELISA) Kit is a sandwich ELISA that allows the quantification of GDNF in less than 4 hours in cell culture supernatants, cell lysates, and guinea pig serum. This GDNF ELISA kit employs a recombinant human GDNF standard obtained from the National Institute for Biological Standards and Control (NIBSC) and is therefore designed to accurately measure the human form of GDNF. The antibodies used in this kit cross-react with guinea pig, rat and mouse GDNF.