Claims
- 1. An apparatus for performing assays, comprising:
a light source providing light in a desired wavelength range; a biosensor including a planar waveguide comprising a first surface, a second surface opposite said first surface, and a side end between said first and second surfaces, said side end being configured to receive said light and to convey said light into a remainder of said planar waveguide; a plurality of capture molecules immobilized to said first surface, each of said capture molecules including a binding site which selectively binds at least one selected analyte; and a light detector positioned to detect light passing through said second surface of said planar waveguide.
- 2. The apparatus of claim 1, wherein at least a portion of said planar waveguide is coated with a coating that inhibits nonspecific binding.
- 3. The apparatus of claim 2, wherein said coating comprises at least one of a polymethacryloyl polymer, a polyethylene glycol polymer, and avidin.
- 4. The apparatus of claim 1, wherein said first surface is configured to receive a sample.
- 5. The apparatus of claim 4, wherein said sample comprises a buffer, a plurality of molecules of said selected analyte, and a plurality of tracer molecules, each tracer molecule of said plurality of tracer molecules including a component that is excitable by evanescent light extending from said planar waveguide into said sample.
- 6. The apparatus of claim 5, wherein said component of each said tracer molecule emits fluorescent light when activated by evanescent light extending from said planar waveguide into said sample.
- 7. The apparatus of claim 6, wherein said light detector detects fluorescent light emitted by said component.
- 8. The apparatus of claim 1, wherein said light detector comprises at least one of a charge-coupled device, a photomultiplier, a semiconductor photodiode, and array of photomultipliers, and an array of semiconductor photodiodes.
- 9. The apparatus of claim 1, further comprising an optical element for directing said light into side end of said planar waveguide.
- 10. The apparatus of claim 9, wherein said optical element comprises at least one lens.
- 11. The apparatus of claim 10, wherein said at least one lens comprises a curved surface.
- 12. The apparatus of claim 1, wherein said plurality of capture molecules is configured to form an array of reaction sites on said first surface of said planar waveguide.
- 13. The apparatus of claim 1, wherein binding of said at least one selected analyte by at least one of said capture molecules is detectable within an excitation zone adjacent to said first surface of said planar waveguide.
- 14. The apparatus of claim 13, wherein constituents of a sample that are located outside of said excitation zone are not detected.
- 15. The apparatus of claim 1, wherein said light detector is positioned within a cone of collection angles having an axis oriented substantially orthogonal to said second surface of said planar waveguide.
- 16. An apparatus for performing assays, comprising:
a light source providing light in a desired wavelength range; a biosensor including a planar waveguide comprising a first surface, a second surface opposite said first surface, and a side end between said first and second surfaces, said side end being configured to receive said light and to convey said light into a remainder of said planar waveguide; and a light detector positioned within a cone of collection angles having an axis oriented substantially orthogonal to at least one of said first surface and said second surface of said planar waveguide.
- 17. The apparatus of claim 16, wherein said first surface of said planar waveguide is configured to receive a sample.
- 18. The apparatus of claim 17, wherein said biosensor further comprises a plurality of capture molecules on said first surface, each capture molecule of said plurality of capture molecules having a binding site which selectively binds at least one selected analyte.
- 19. The apparatus of claim 18, wherein said biosensor further includes at least one sample reservoir configured to contain said sample adjacent to at least a portion of said first surface.
- 20. The apparatus of claim 19, further comprising at least one gasket surrounding said at least one sample reservoir for preventing said sample from leaking from said at least one sample reservoir.
- 21. The apparatus of claim 20, wherein said at least one gasket is formed of a resilient material having an index of refraction less than an index of refraction of said planar waveguide.
- 22. The apparatus of claim 18, wherein said sample comprises a solution including a buffer, a plurality of molecules of a selected analyte, and a plurality of tracer molecules, said tracer molecules including a component that is excitable by evanescent light extending from said planar waveguide into said solution.
- 23. The apparatus of claim 18, wherein said plurality of capture molecules is configured to form an array of reaction sites on said first surface of said planar waveguide.
- 24. The apparatus of claim 18, wherein said light detector is positioned to receive light passing through said second surface of said planar waveguide.
- 25. The apparatus of claim 16, wherein said planar waveguide is at least partially coated with a coating that inhibits nonspecific binding.
- 26. The apparatus of claim 25, wherein said coating comprises at least one of a polymethacryloyl polymer, a polyethylene glycol polymer, and avidin.
- 27. The apparatus of claim 16, further comprising an optical element for directing light into said planar waveguide.
- 28. The apparatus of claim 27, wherein said optical element comprises at least one lens.
- 29. The apparatus of claim 28, wherein said at least one lens comprises a curved surface.
- 30. The apparatus of claim 16, wherein said light detector comprises at least one of a charge-coupled device, a photomultiplier, a semiconductor photodiode, an array of photomultipliers, and an array of semiconductor photodiodes.
- 31. A method for conducting a specific binding assay, comprising:
providing a planar waveguide comprising a surrounding edge and a surface with a plurality of capture molecules immobilized thereon, each of said plurality of capture molecules having at least one binding site which selectively binds at least one selected analyte; providing a light source capable of emitting light in a desired wavelength range; directing light emitted from said light source into said planar waveguide through said surrounding edge; positioning a light detector within a cone of collection angles having an axis oriented substantially orthogonal to a direction of propagation of said light through said planar waveguide; introducing a sample believed to contain said at least one selected analyte onto said surface; permitting said at least one selected analyte or at least one tracer molecule which includes a component that emits fluorescent light in response to exposure to light of at least one wavelength within said desired wavelength range to selectively bind to at least one of said plurality of capture molecules; and measuring an amount of fluorescent light emitted collectively from said component of said tracer molecules.
- 32. The method according to claim 31, wherein said measuring said amount of fluorescent light is effected by orienting said light detector to face a surface of said planar waveguide opposite said surface upon which said plurality of capture molecules is immobilized.
- 33. The method according to claim 32, wherein said measuring said amount of fluorescence is effected with substantially no interference from constituents of said sample located outside of an excitation zone adjacent to said surface upon which said plurality of capture molecules is immobilized.
- 34. The method according to claim 32, wherein said providing comprises providing said planar waveguide with said plurality of capture molecules being positioned at a plurality of discrete locations on said surface.
- 35. The method according to claim 32, wherein said measuring said amount of fluorescent light is effected by measuring amounts of fluorescent light emitted from a plurality of discrete locations adjacent to said surface of said planar waveguide.
- 36. The method according to claim 31, wherein said providing said planar waveguide comprises providing a planar waveguide including a surface having a plurality of capture molecules indirectly immobilized thereon via a coating comprising 3-aminopropyltriethoxy silane bonded to said substrate and a plurality of polymerized hydrophilic polymer chains selected from a group consisting of polyethyleneglycol and a hydrogel formed of polymethacryloyl.
- 37. The method according to claim 31, further comprising:
permitting said at least one tracer molecule to bind to said at least one selected analyte bound to said at least one capture molecule.
- 38. A method for conducting a specific binding assay, comprising:
providing a planar waveguide comprising a surrounding edge and a surface with a plurality of capture molecules immobilized thereon, each of said plurality of capture molecules having at least one binding site which selectively binds at least one selected analyte; providing a light source capable of emitting light in a desired wavelength range; directing light emitted from said light source into said planar waveguide through said surrounding edge; orienting a light detector so as to face another surface of said planar waveguide opposite said surface upon which said plurality of capture molecules are immobilized; introducing a sample believed to contain said at least one selected analyte onto said surface; permitting said at least one selected analyte or at least one tracer molecules which includes a component that emits fluorescent light in response to exposure to light of at least one wavelength within said desired wavelength range to selectively bind to at least one of said plurality of capture molecules; and measuring an amount of fluorescent light emitted collectively from said component of said tracer molecules.
- 39. The method according to claim 38, wherein said measuring said amount of fluorescence is effected with substantially no interference from constituents of said sample located outside of an excitation zone adjacent to said surface upon which said plurality of capture molecules is immobilized.
- 40. The method according to claim 38, wherein said providing comprises providing said planar waveguide with said plurality of capture molecules being positioned at a plurality of discrete locations on said surface.
- 41. The method according to claim 38, wherein said measuring said amount of fluorescent light is effected by measuring amounts of fluorescent light emitted from a plurality of discrete locations adjacent to said surface of said planar waveguide.
- 42. The method according to claim 38, further comprising:
permitting said at least one tracer molecule to bind to said at least one selected analyte bound to said at least one capture molecule.
- 43. A method for coupling a binding protein to an optical substrate, comprising:
providing an optical substrate; coating the substrate with a protein-resistant material to produce a protein-resistant coating; activating the protein-resistant material to produce free chemically reactive groups; providing a binding protein; modifying the binding protein to produce a moiety thereon which is reactive to bind to the free reactive groups of the activated protein-resistant coating; and reacting the modified binding protein with the activated protein-resistant coating to immobilize the modified binding protein to the substrate.
- 44. The method according to claim 43, wherein the protein-resistant coating and the modified binding protein are jointly selected from one of the following pair-wise combinations: avidin coating and biotin-conjugated binding protein; PEG-(ED)2 coating and oxidized binding protein; polymethacryloyl coating with free maleimido groups and oxidized binding protein.
- 45. An apparatus for performing assays, comprising:
a light source providing light in a desired wavelength range; a biosensor including a planar waveguide comprising a first surface, a second surface opposite said first surface, and a side end between said first and second surfaces, said side end being configured to receive said light and to convey said light into a remainder of said planar waveguide; and a plurality of capture molecules is configured to form an array of reaction sites on said first surface, each of said capture molecules including a binding site which selectively binds at least one selected analyte.
- 46. The apparatus of claim 45, wherein said first surface is configured to receive a sample.
- 47. The apparatus of claim 45, further comprising a light detector.
- 48. The apparatus of claim 47, wherein said light detector is positioned to detect light passing through said second surface of said planar waveguide.
- 49. The apparatus of claim 48, wherein binding of said at least one selected analyte by at least one of said capture molecules is detectable within an excitation zone adjacent to said first surface of said planar waveguide.
- 50. The apparatus of claim 49, wherein constituents of a sample that are located outside of said excitation zone are not detected.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No. 09/207,187, filed Dec. 8, 1998, pending, which is a divisional of application Ser. No. 08/640,141, filed Apr. 30, 1996, now U.S. Pat. No. 5,846,842, issued Dec. 8, 1998, which is a divisional of application Ser. No. 08/064,608, filed May 18, 1993, now U.S. Pat. No. 5,512,492, issued Apr. 30, 1996.
Divisions (3)
|
Number |
Date |
Country |
Parent |
09207187 |
Dec 1998 |
US |
Child |
09971467 |
Oct 2001 |
US |
Parent |
08640141 |
Apr 1996 |
US |
Child |
09207187 |
Dec 1998 |
US |
Parent |
08064608 |
May 1993 |
US |
Child |
08640141 |
Apr 1996 |
US |