Patent ID: 6750031
Filing Date: 2004-06-15
Classification: G01N

Abstract:
A quantitative assay method for detecting a target analyte, comprising the steps of:providing a porous membrane having binding elements immobilized thereon, each of said binding elements having at least one binding site capable of specifically binding to said target analyte; exposing said binding sites to a labelled analog of the target analyte to form complexes of membrane-immobilized binding elements and labelled analogs; pumping a first aqueous liquid sample, suspected of containing the target analyte, so as to flow said first liquid sample normal to and through said membrane having said complexes thereon, at a flow rate allowing the target analyte to displace the labelled analog from the complexes under non-equilibrium conditions to form downstream of said membrane a flowable liquid effluent including said displaced labelled analog, said flow rate also providing an interaction time between said analyte and said membrane of about 0.1 sec through about 30 sec; iterrogating said flowable liquid effluent to detect and quantitatively determine the amount of the displaced labelled analog, the amount of said displaced labelled analog being proportional to the concentration of said target analyte in said first sample.