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 serum. This GDNF ELISA kit employs a recombinant rat GDNF standard and is therefore designed to measure the rat form of GDNF. Note that the antibodies used in this kit cross-react with mouse, human and guinea pig GDNF.