Patent US4708927A successfully refreshed from Google Patents.
EP0254430A2
Expired / Lapsed
EP
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Light-scattering immunoassay system
Assignee: Ortho Clinical Diagnostics Inc
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Filing: 1987-06-25
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Granted: —
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Expires: 2007-06-25
Abstract
Abstract A new immunoassay system is provided for the detection of ligands or ligand binding partners in solution in a heterogeneous format. The invention relies upon the detection of back scattered light from an evanescent wave disturbed by the presence of a colloidal gold label brought to the interface by an immunological reaction. The evanescent wave existing at the interface in turn is the result of a totally internally reflected incident light wave. Placement of the detector at a back angle above the critical angle insures a superior signal-to-noise ratio.
Inventors
- 👤 Ernest G. Schutt
- 👤 Richard S. Dondero
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 21:05
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/557; G01N21/00; G01N21/17; G01N21/47; G01N33/543; G01N33/54313; G01N33/58; G01N33/585; G01N2021/4704; G01N2021/4709; G01N21/55; G01N21/552
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
139 words
Apparatus for use in an immunoassay system employing a light scattering particle labeled immunologically active component for the detection of a ligand or ligand binding partner in an aqueous solution comprising; a container for receiving the aqueous sample said container having a refractive index greater than that of the aqueous sample, a light source for providing illumination, optical coupling means for directing said illumination toward the interface between the container and the aqueous solution, alignment means for receiving said cuvette in fixed relationship to said optical means and said light source whereby said illumination is directed toward the interface between the container and the aqueous solution at an angle equal to or greater than the critical angle, and photodetector means for receiving light scattered above said critical angle by said light scattering particle and back toward said light source.
Claim 2
Dependent Claim
139 words
Apparatus for use in an immunoassay system employing a light scattering particle labeled immunologically active component for the detection of a ligand or ligand binding partner in an aqueous solution comprising; a container for receiving the aqueous sample said container having a refractive index greater than that of the aqueous sample, a light source for providing illumination, optical coupling means for directing said illumination toward the interface between the container and the aqueous solution, alignment means for receiving said cuvette in fixed relationship to said optical means and said light source whereby said illumination is directed toward the interface between the container and the aqueous solution at an angle equal to or greater than the critical angle, and photodetector means for receiving light scattered above said critical angle by said light scattering particle and back toward said light source.
Claim 3
Dependent Claim
27 words
The apparatus of Claim 1 wherein said light source provides collimated illumination and said optical coupling means is a prism which is optically coupled to said container.
Claim 4
Dependent Claim
15 words
The apparatus of claim 1 or claim 2 wherein said light source is a laser.
Claim 5
Dependent Claim
77 words
In an immunoassay system for the detection of ligands or ligand binding partners in an aqueous solution, the improvement comprising employing colloidal gold as a label in said immunoassay, conducting said immunoassay in the field of an evanescent wave, measuring light scattered by the presence of said colloidal gold particle in said evanescent field and correlating said colloidal gold scattered light as a function of the presence of the ligand or ligand binding partner to be determined.
Claim 6
Dependent Claim
77 words
In an immunoassay system for the detection of ligands or ligand binding partners in an aqueous solution, the improvement comprising employing colloidal gold as a label in said immunoassay, conducting said immunoassay in the field of an evanescent wave, measuring light scattered by the presence of said colloidal gold particle in said evanescent field and correlating said colloidal gold scattered light as a function of the presence of the ligand or ligand binding partner to be determined.
Claim 7
Independent Claim
177 words
A method for determining the presence of a ligand in an aqueous sample suspected of containing said ligand comprising the steps of: providing a first ligand binding partner specific for said ligand in said aqueous sample, said first ligand binding partner being labeled with a particle having light scattering characteristics in said aqueous sample; combining said first ligand binding partner and said aqueous sample with one side of an optically transmissive material thereby forming an interface between said material and said sample, said material having a plurality of second ligand binding partners bound to said material in contact with said aqueous sample and capable of binding to said ligand, said optically transmissive material having a refractive index greater than the refractive index of said aqueous sample; illuminating said interface through said optically transmissive material at an angle to said material to provide total internal reflectance within said material; and measuring the amount of light scattered from said interface, wherein said amount of scattered light is a function of the amount of ligand present in said assay medium.
Claim 8
Independent Claim
177 words
A method for determining the presence of a ligand in an aqueous sample suspected of containing said ligand comprising the steps of: providing a first ligand binding partner specific for said ligand in said aqueous sample, said first ligand binding partner being labeled with a particle having light scattering characteristics in said aqueous sample; combining said first ligand binding partner and said aqueous sample with one side of an optically transmissive material thereby forming an interface between said material and said sample, said material having a plurality of second ligand binding partners bound to said material in contact with said aqueous sample and capable of binding to said ligand, said optically transmissive material having a refractive index greater than the refractive index of said aqueous sample; illuminating said interface through said optically transmissive material at an angle to said material to provide total internal reflectance within said material; and measuring the amount of light scattered from said interface, wherein said amount of scattered light is a function of the amount of ligand present in said assay medium.
Claim 9
Dependent Claim
30 words
The method as provided in claim 5 wherein said measuring step is conducted at an angle greather than said critical angle and wherein substantially only back scattered light is detected.
Claim 10
Dependent Claim
27 words
The method according to claim 5 or claim 6 wherein said ligand binding partners are antibodies of monoclonal or polyclonal origin and said ligands react specifically therewith.
Claim 11
Dependent Claim
41 words
The method according to claim 5 or claim 6 wherein said ligand in said sample to be determined is an antibody and said second ligand binding partners bound to said material are antigens or haptens specifically reactive with said sample antibodies.
Claim 12
Independent Claim
36 words
A method as provided in any one of claims 5 to 8 wherein said particles are selected from the group consisting of colloidal gold, latex particles, glass particles, metallic particles, nonmetallic particles and red blood cells.
Claim 13
Independent Claim
26 words
A method as provided in any one of claims 5 to 9 wherein said illuminating step comprises irradiating said surface with light from a helium-neon laser.
Claim 14
Independent Claim
31 words
A method as provided in any one of claims 5 to 10 wherein said first ligand binding partner is added to said optically transmissive material prior to adding said aqueous sample.
Claim 15
Independent Claim
31 words
A method as provided in any one of claims 5 to 10 wherein said aqueous sample is added to said optically transmissive material prior to adding said first ligand binding partner.
Claim 16
Independent Claim
32 words
A method as provided in any one of claims 5 to 10 wherein said aqueous sample and said first ligand binding partner are mixed prior to combining with said optically transmissive material.
Claim 17
Independent Claim
18 words
A method as provided in any one of claims 5 to 13 wherein said particle is colloidal gold.
Claim 18
Independent Claim
39 words
A method as provided in any one of claims 5 to 14 wherein said measurement step is performed a plurality of times to derive a rate which may be correlated to the presence of ligand in said aqueous sample.
References Cited (Backward Citations)
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