Diagnostic methods

• US 20030124632A1
• Filed: 06/10/2002
• Published: 07/03/2003
• Est. Priority Date: 12/31/2001
• Status: Active Grant

• Current Assignee: Bionavis, Ltd.
• Original Assignee: Bionavis, Ltd.
• Inventors: Kleimola, Vesa, Eerola, Erkki, Viander, Markku
• Granted Patent: US 7,544,504 B2
• Time in Patent Office: Days
• US Class Current: 435/7.32
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/56922 Campylobacter
• CPC Class Codes: Y10S 435/808 Optical sensing apparatus
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property

Abstract

The present invention relates to novel methods for the diagnosis of Helicobacter pylori infection. Specifically, the present invention relates to novel non-invasive methods for the detection of the presence or absence of a Helicobacter pylori antigen or a metabolite produced by the bacterium in a biological sample with a biosensor-based measurement. The present invention also related to the use of a biosensor containing specific antibodies against H. pylori or antigen-binding fragments thereof immobilized thereto together with bio-molecule-repellent polymers preventing the non-specific binding. The invention also relates to test kits useful in the methods.

Claims

1. A non-invasive method for the detection of the presence or absence of a Helicobacter pylori antigen or a metabolite produced by the bacterium in a biological sample comprising

contacting a biological sample obtained from a patient suffering or suspected of suffering from H. pylori infection with a biosensor comprising a carrier substrate on which antibodies against H. pylori or antigen-binding fragments together with biomolecule-repellent molecules have been attached, and

detecting the signal resulting from the formation of an antibody-antigen-complex.

2. A method according to claim 1, wherein the biomolecule-repellent molecules are neutral hydrophilic monomers or polymers.

3. A method according to claim 2, wherein the biomolecule-repellent molecules are selected from polyacrylamide, poly-N,N-dimethylacrylamide, polyvinylalcohol, ethylene-vinylalcohol copolymer, poly(hydroxyethyl-methacrylate), poly(ethyleneoxide) and poly(ethyleneglycol), and polyethylenephalate, polytetrafluoroethylene, polyurethane and similar biocompatible polymers.

4. A method according to claim 2 or 3, wherein the biomolecule-repellent molecules are selected from polyacrylamide and poly-N,N-dimethyl-acrylamide.

5. A method according to claim 3, wherein the biomolecule-repellent molecules are N-[tris(hydroxy-methyl)methyl]acrylamide molecules.

6. A method according to any one of claims 1-5, wherein the H. pylori antigens are directly attached on to the solid surface of the carrier substrate.

7. A method according to any one of claims 1-6, wherein the biomolecule-repellent molecules are directly attached on to the solid surface of the carrier substrate.

8. A method according to any one of claims 1-7, wherein the solid surface of the surface of the carrier substrate is a film of a surface plasmon resonance (SPR) compatible material.

9. A method according to claim 8, wherein the solid surface of the surface of the carrier substrate is a film of gold, silver, copper, aluminium, palladium, or other suitable metal.

10. A method according to claim 9, wherein the solid surface of the surface of the carrier substrate is a film of gold.

11. A method according to any one of claims 1-7, wherein the detection is performed by surface plasmon resonance (SPR) method.

12. A method of using a biosensor comprising a carrier substrate onto which specific antibodies against H. pylori or antigen-binding fragments thereof have been directly attached together with biomolecule-repellent molecules, which cover the surface between the immobilized antibodies or the antigen-binding fragments thereof, for the detection of the presence or absence of a Helicobacter pylori antigen or a metabolite produced by the bacterium in a biological sample.

13. A test kit for the detection of the presence or absence of a H. pylori antigen or a metabolite produced by the bacterium in a biological sample, the test kit containing

a biosensor comprising a carrier substrate onto which specific antibodies against H. pylori or antigen-binding fragments thereof have been directly attached together with biomolecule-repellent molecules, which cover the surface between the immobilized antibodies or the antibody fragments, reagents needed for the calibration and quality control, and auxiliary reagents such as wash solutions and dilution buffers.