Apparatus and methods for multi-analyte homogeneous fluoro-immunoassays

• US 6,979,567 B2
• Filed: 11/13/2001
• Issued: 12/27/2005
• Est. Priority Date: 05/18/1993
• Status: Expired due to Fees

• Current Assignee: BioCentrex, LLC
• Original Assignee: BioCentrex, LLC
• Inventors: Caldwell, Karin, Christensen, Douglas A., Wang, Hsu-Kun, Herron, James N., Huang, Shao-Chie, Janatová, Vera
• Primary Examiner(s): Chin, Christopher L.
• Application Number:
  US10/008,339
• Publication Number:
  US 20020160535A1
• Time in Patent Office: 1,505 Days
• Field of Search: 422/55, 422/57, 422/58, 422/82.05, 422/82.08, 422/82.11, 435/287.1, 435/287.2, 435/287.9, 435/288.5, 435/288.7, 435/808, 436/164, 436/165, 436/518, 436/527, 436/531, 436/805, 436/807, 436/514, 385/12, 385/129, 385/130, 356/418
• US Class Current: 435/287.1
• CPC Class Codes: C07C 281/02 Compounds containing any of the groups , e.g. carbazates
• CPC Class Codes: C08G 65/329 with organic compounds
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/6452 Individual samples arranged in a regular 2D-array, e.g. multiwell plates
• CPC Class Codes: G01N 21/648 using evanescent coupling or surface plasmon coupling for the excitation of fluorescence
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 33/54353 with ligand attached to the carrier via a chemical coupling agent coatings G01N33/54393
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• 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: Y10S 435/808 Optical sensing apparatus
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/807 Apparatus included in process claim, e.g. physical support structures

Abstract

Methods and apparatus for evanescent light fluoroimmunoassays are disclosed. The apparatus employs a planar waveguide with an integral semicylindrical lens, and has multi-analyte features and calibration features, along with improved evanescent field intensity. A preferred embodiment of the biosensor and assay method has patches of capture molecules, each specific for a different analyte disposed adjacently within a single reservoir. The capture molecules are immobilized to the patches on the waveguide surface by site-specific coupling of thiol groups on the capture molecules to photo-affinity crosslinkers, which in turn are coupled to the waveguide surface or to a nonspecific binding-resistant coating on the surface. The patches of different antibodies are produced by selectively irradiating a portion of the waveguide surface during the process of coupling the photo-affinity crosslinkers, the selective irradiation involving a mask, a laser light source, or the like.

Claims

1. An assay system, comprising:

a receptor for receiving a sample solution that may include at least one selected analyte;

a reaction zone comprising at least a portion of said receptor or in fluid communication with said receptor, said reaction zone including at least one reagent configured to produce a reaction mixture with said sample solution;

at least one detection zone in fluid communication with said reaction zone and configured to receive at least a portion of said reaction mixture transported from said reaction zone, said at least one detection zone is carried upon a surface of at least a portion of a waveguide; and

a detector oriented to receive signals from said at least one detection zone and configured to sense a physically detectable change in said at least one detection zone, said physically detectable change correlating with at least one of an absence, a presence, and an amount of said at least one selected analyte in said sample solution, said detector configured to generate a signal correlating with at least one of said absence, said presence, and said amount.

2. The assay system of claim 1, wherein said at least said portion of said waveguide comprises a substantially planar structure.

3. The assay system of claim 1, wherein said waveguide comprises a planar waveguide.

4. The assay system of claim 1, wherein said detector is oriented to detect light emitted from said at least one detection zone.

5. The assay system of claim 4, wherein said detector is oriented to detect light emitted through at least said portion of said waveguide.

6. The assay system of claim 4, wherein said detector is positioned within a cone of collection angles having an axis oriented substantially orthogonal to the plane of at least said portion of said waveguide.

7. The assay system of claim 1, comprising a plurality of detection zones.

8. The assay system of claim 7, wherein said plurality of detection zones is carried upon a surface of at least said portion of said waveguide.

9. The assay system of claim 8, wherein detection zones of said plurality of detection zones are positioned at discrete locations from one another on said surface.

10. The assay system of claim 9, wherein said discrete locations are arranged in an array.

11. The assay system of claim 7, wherein at least two of said plurality of detection zones comprise different capture molecules capable of reacting with different analytes.

12. The assay system of claim 1, wherein said reaction mixture comprises a reaction product including said at least one selected analyte, said at least one reagent bound thereto, and a physically detectable label on said at least one reagent.

13. The assay system of claim 12, wherein said physically detectable label emits light when excited.

14. The assay system of claim 13, further comprising:

a source of electromagnetic energy of at least one wavelength capable of exciting said physically detectable label.

15. The assay system of claim 14, wherein said electromagnetic energy comprises an evanescent field.

16. The assay system of claim 1, further comprising:

a display for illustrating data representative of said amount of said at least one selected analyte in said sample solution.

17. An assay system, comprising:

a receptor for receiving a sample solution that may include at least one selected analyte;

a reaction zone comprising at least a portion of said receptor or in fluid communication with said receptor, said reaction zone including at least one reagent configured to produce a reaction mixture with said sample solution, said reaction mixture comprising a reaction product including said at least one selected analyte, said at least one reagent bound thereto, and a physically detectable label that emits light when excited by an evanescent field;

at least one detection zone in fluid communication with said reaction zone and configured to receive at least a portion of said reaction mixture transported from said reaction zone;

a source configured and oriented to cause the generation of said evanescent field at said at least one detection zone; and

a detector oriented to receive signals from said at least one detection zone and configured to sense a physically detectable change in said at least one detection zone, said physically detectable change correlating with at least one of an absence, a presence, and an amount of said at least one selected analyte in said sample solution, said detector configured to generate a signal correlating with at least one of said absence, said presence, and said amount.

18. The assay system of claim 17, wherein said at least one detection zone is carried by a substantially planar structure.

19. The assay system of claim 18, wherein said at least one detection zone is carried upon a surface of said substantially planar structure.

20. The assay system of claim 19, wherein said substantially planar structure comprises at least a portion of a planar waveguide.

21. The assay system of claim 18, wherein said detector is oriented to detect light emitted from said at least one detection zone.

22. The assay system of claim 21, wherein said detector is oriented to detect light emitted through said substantially planar structure.

23. The assay system of claim 21, wherein said detector is positioned within a cone of collection angles having an axis oriented substantially orthogonal to the plane of said substantially planar structure.

24. The assay system of claim 17, comprising a plurality of detection zones.

25. The assay system of claim 24, wherein at least two of said plurality of detection zones comprise different capture molecules capable of reacting with different analytes.

26. The assay system of claim 24, wherein said plurality of detection zones is carried upon a surface of a substantially planar structure.

27. The assay system of claim 26, wherein detection zones of said plurality of detection zones are positioned at discrete locations from one another on said surface.

28. The assay system of claim 27, wherein said discrete locations are arranged in an array.

29. The assay system of claim 28, wherein said substantially planar structure comprises a planar waveguide.

30. The assay system of claim 17, further comprising:

a display for illustrating data representative of said amount of said at least one selected analyte in said sample solution.