Development of a sensitive enzyme immunoassay for human epidermal growth factor (urogastrone).

A sensitive two-site enzyme immunoassay (EIA) for human epidermal growth factor (hEGF) was developed, based on the sandwiching of an antigen between anti-hEGF IgG-coated polystyrene beads and anti-hEGF Fab'-linked peroxidase complex (horseradish peroxidase, EC. 1.11.1.7). This method has four advantages: the anti-hEGF Fab'-linked peroxidase complex is more stable than 125I-labelled antibody; the procedure is simple and rapid compared to bioassay; its discriminatory sensitivity is as low as 0.1 pg/assay tube; and serial dilution curves of unextracted human serum and urine samples all paralleled that of standard hEGF. The validity of the measurement of hEGF-like immunoreactivity in human serum and plasma is discussed.