[Characteristics of enzyme substrate used for enzyme immunoassay]

Enzyme immunoassay in measured its enzyme activity as a signal. This signal detection method have been progressing from colorimetric to fluorometric determination, and most recently amongst for more sensitive substrate chemiluminescent determination is popular. The methods, colorimetric determination is recognized to be less sensitive. We confirmed that the alkaline phosphatase labeled enzyme, cycling method significantly increased its sensitivity by changing the substrate. If the minimum detection limit is not sensitive enough by colorimetric determination, fluorometric is useful, and chemiluminescence can be applied when ultra sensitive method is required. We briefly described the characteristics of the main substrates which may very the sensitivity in these assays.