Patent ID: 6589754
Filing Date: 2003-07-08
Classification: G01N

Abstract:
An immunoassay element for quantitatively analyzing an amount of a macromolecular antigen in a sample by determining the change in enzymatic activity of a labelling enzyme caused by a reaction between1) the macromolecular antigen, and 2) an antibody which can react and bind specifically with the macromolecular antigen and which is labelled with the labelling enzyme; said element comprising: (a) a substrate layer containing a non-diffusible substrate composed of a polymer which is capable of being digested by the labelling enzyme into a diffusible oligomer which migrates from the substrate layer; and (b) a reagent layer containing a digesting enzyme for further digesting the diffusible oligomer, which has migrated from said substrate layer, into a detectable monomer; wherein the labelling enzyme is an endo-active hydrolase capable of digesting the polymer into the diffusible oligomer and the digesting enzyme is an exo-active hydrolase which digests the diffusible oligomer into the detectable monomer.