Patent ID: 7579195

Claim:
A simple membrane assay method for detecting or quantitating an analyte in a specimen sample using an assay device equipped with a membrane bound with a capture-substance to capture the analyte and a filter tube consisting of a body part and a tip part, comprising the steps of: filtering the specimen sample using a filter attached to the tip part of the filter tube by applying pressure in the filter tube, dropping the filtrate onto said membranes, and detecting or quantitating the presence of the analyte in said specimen sample, wherein the method is a lateral-flow type membrane assay method, and wherein the core size or the particle retention size of the membrane is not less than the pore size or the particle retention size of the filter, the pore size or the particle retention size of said filter is from 0.2 to 1.0 μm, and the material of said membrane is nitrocellulose and its pore size is from 0.4 to 12 μm.