Patent ID: 6632603
Filing Date: 2003-10-14
Classification: B01L,G01N,Y10S

Abstract:
A method for the quantitative or qualitative detection of an analyte in a liquid biological specimen comprising the steps of:(a) forming a test sample by adding to a biological specimen, (i) a binding substrate in a liquid phase selected from the group consisting of a ligand and an antiligand which specifically binds the analyte, and (ii) a detector substance in a liquid phase selected from the group consisting of a colloidal metal labeled ligand and a colloidal metal labeled antiligand, to form a test sample containing a precipitable complex if the analyte is present and forming no such complex in the absence of the analyte in the biological specimen; (b) applying the test sample to a defined zone on a porous support, the support having a maximum effective pore size smaller than a complex formed between the analyte, the binding substance and the detector substance and having minimal effective pore size larger than each of the analyte, the binding substance and the detector substance if a precipitable complex with an analyte is not formed, so that the analyte, the binding substance and the detector all can pass through the support, no solid phase particles or insoluble components being introduced into the defined zone on the porous support; and (c) assessing the defined zone for color development caused by the formation of the complex formed by the analyte, the binding substance and the detector substance, the color development correlating with the presence of the analyte in the test sample.