Abstract: | beta-D-Galactosidase from Escherichia coli and horseradish peroxidase were compared as labels of anti-human ferritin Fab' by sandwich enzyme immunoassay technique using fluorogenic substrates for enzyme assay. The anti-human ferritin Fab'-peroxidase conjugates gave lower nonspecific bindings and higher specific bindings than the corresponding Fab'-beta-D-galactosidase conjugates. As a result, the former provided more sensitive dose response curves for human ferritin than the latter. However, the peroxidase conjugates were required in a larger quantity, since peroxidase assay was much less sensitive than beta-D-galactosidase assay. |