Indretning og fremgangsmåde til fastfaseanalyse

An article for use in an assay for an analyte, comprising a solid support having at least a first portion and a second portion, the first and second portions being in capillary flow communication with each other whereby material may flow by capillarity from the first portion to the second portion and the second portion containing a binder immobilized wherein the binder being a binder for at least the analyte; a tracer comprised of a ligand portion and a detectable label portion conjugated to the ligand portion, the tracer being supported on the solid support on the first portion thereof, whereby when the first portion is wetted with a liquid sample suspected of containing analyte, tracer and any analyte flow by capillarity to the second portion for contact with the binder. A method of assay for an analyte comprises contacting a sample suspected of containing analyte to be assayed with the first portion of the above article; and determining at least one of tracer which is bound or not bound in the second portion.