Beckman Coulter, Inc.

Daniel Joseph Fitzgerald

Howard Milne Chandler

Larry LaPointe

Paul David Magginetti

A chromatographic assay device according to the present invention provides a unidirectional immunoassay for an analyte in a whole blood sample with improved sensitivity and freedom from interference. Such a device comprises: (1) a first opposable component including: (a) a sample application zone containing a matrix of porous material permeable to the liquid portion of blood but capable of trapping the cellular components of blood; and (b) a chromatographic medium having first and second ends and including: (i) a detection zone having immobilized thereon a first specific binding partner for the analyte; and (ii) a conjugate zone having a labeled second specific binding partner for the analyte in a resolubilizable form; the sample application zone being in operable contact with the first end of the chromatographic medium and the conjugate zone being located closer to the first end of the chromatographic medium than the detection zone; and (2) a second opposable component including: (a) an applicator; and (b) an absorber. In the device, the first and second opposable components are brought into operable contact to cause the applicator to come into operable contact with the sample application zone to apply a wash liquid thereto and cause the absorber to come into operable contact with the second end of the chromatographic medium. Also within the scope of the invention are multiplex devices that can perform more than one assay simultaneously and test kits.

Opposable-element chromatographic assay device for detection of analytes in whole blood samples

An assay device for detection or determination of an analyte in a sample uses opposable components and is suitable for assay of human chorionic gonadotropin and other protein or glycoprotein hormones. One embodiment of the device comprises: (1) a first opposable component including: (a) a first chromatographic medium having first and second ends and an immobilized first specific binding partner for the analyte in a detection zone; (b) a conjugate pad in operable contact with the first end of the first chromatographic medium, the conjugate pad containing a labeled second specific binding partner for the analyte in resolubilizable form; and (c) a second chromatographic medium having first and second ends and having immobilized thereon in a reference zone a third specific binding partner that specifically binds the labeled second specific binding partner for the analyte and does not bind the analyte, the first end of the second chromatographic medium being in operable contact with the conjugate pad; and (2) a second opposable component including a sample application zone. The assay device can include a timing control to indicate when flow through the chromatographic medium has occurred and the assay can be read, and can also contain a validation zone ensuring that interference from human anti-mouse antibody is not present. Other embodiments of devices are included, as well as methods of use.

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Campbell, CA, United States of America

Daniel Joseph Fitzgerald