EP0170376A1
Expired / Lapsed
EP
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Photometric instruments, their use in methods of optical analysis, and ancillary devices therefor
Assignee: Applied Research Systems ARS Holding NV
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Filing: 1985-06-12
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Granted: —
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Expires: 2005-06-12
Abstract
Abstract A method of optical analysis of a test sample which comprises a sample material with light-absorbing, scattering, fluorescent, phosphorescent or luminescent properties, which sample is partly in a liquid phase and partly bound to an adjacent solid surface, to discriminate the respective parts of said sample material which are located in the liquid and bound to said solid surface: comprising the steps of providing as said solid surface a surface of a transparent solid optical waveguide, and measuring light from the sample material bound to said solid surface that has passed into and through said transparent solid optical waveguide with total internal reflections and emerged from said waveguide at an angle that deviates from the optical axis of said waveguide by an angle appreciably less than a, where where n 2 is the refractive index of the material of the waveguide and n 1 is the refractive index of the adjacent liquid, and excluding from said measurement substantially all light that has emerged from said waveguide at an angle that deviates from said optical axis by a or more.
Inventors
- 👤 Ian Alexander Shanks
- 👤 Alan Martin Smith
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 18:03
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/645; G01N21/01; G01N21/03; G01N21/648; G01N21/75; G01N21/77; G01N21/7703; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54366; G01N33/54373; G01N2021/0346; G01N2021/7769; G01N2021/7786
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
179 words
A method of optical analysis of a test sample which comprises a sample material with light-absorbing, scattering, fluorescent, phosphorescent or luminescent properties, which sample is partly in a liquid phase and partly bound to an adjacent solid surface, to discriminate the respective parts of said sample material which are located in the liquid and bound to said solid surface: comprising the steps of providing as said solid surface a surface of a transparent solid optical waveguide, and measuring light from the sample material bound to said solid surface that has passed into and through said transparent solid optical waveguide with total internal reflections and emerged from said waveguide at an angle that deviates from the optical axis of said waveguide by an angle appreciably less than α, where where n 2 is the refractive index of the material of the waveguide and n 1 is the refractive index of the adjacent liquid, and excluding from said measurement substantially all light that has emerged from said waveguide at an angle that deviates from said optical axis by α or more.
Claim 2
Independent Claim
179 words
A method of optical analysis of a test sample which comprises a sample material with light-absorbing, scattering, fluorescent, phosphorescent or luminescent properties, which sample is partly in a liquid phase and partly bound to an adjacent solid surface, to discriminate the respective parts of said sample material which are located in the liquid and bound to said solid surface: comprising the steps of providing as said solid surface a surface of a transparent solid optical waveguide, and measuring light from the sample material bound to said solid surface that has passed into and through said transparent solid optical waveguide with total internal reflections and emerged from said waveguide at an angle that deviates from the optical axis of said waveguide by an angle appreciably less than α, where where n 2 is the refractive index of the material of the waveguide and n 1 is the refractive index of the adjacent liquid, and excluding from said measurement substantially all light that has emerged from said waveguide at an angle that deviates from said optical axis by α or more.
Claim 3
Dependent Claim
24 words
A method according to claim 1 in which the waveguide used comprises a transparent solid plate or slide of glass, silica, or plastics material.
Claim 4
Dependent Claim
27 words
A method according to claim 2 in which the waveguide provides one wall of a cell containing the liquid phase in which the sample material is located.
Claim 5
Dependent Claim
42 words
A method according to claim 1, 2, or 3 in which the sample material is fluorescent, and in which a light source is provided to excite the fluorescence, and the light from the sample material which is measured is its fluorescent emission.
Claim 6
Dependent Claim
26 words
A method according to claim 3, in which the sample is illuminated by a source of excitation located substantially transversely to the axis of the waveguide.
Claim 7
Dependent Claim
17 words
A method according to claim 5, in which the excitation light is measured by an auxiliary photodetector.
Claim 8
Dependent Claim
68 words
A method according to claim 4, 5 or 6, in which the light that is measured is light that has exited from the waveguide at an angle off the axis that is both less than upper limit M and greater than a lower limit α 1 , and in which light that has exited at an angle less than α 1 off axis is excluded from the measurement.
Claim 9
Dependent Claim
35 words
A method according to claim 7, in which light that has exited from the waveguide at a zero angle off the axis, i.e. along the axis, is measured to provide a control or reference signal.
Claim 10
Independent Claim
29 words
A method according to any preceding claim, in which there is used an acrylic plastics waveguide, an aqueous liquid, and a fluorescein derivative, and angle α is about 41°.
Claim 11
Independent Claim
28 words
A method according to any preceding claim, in which there is used a glass waveguide, an aqueous liquid, and a fluorescein derivative, and angle α is about 47°.
Claim 12
Dependent Claim
215 words
A combination of a photometric instrument and a test object adapted therefor, suitable for example for carrying out immunoassays or other chemical or biological tests, comprising (i) a test object such as a slide or cell received and located at a test object location, for containing - a sample material with light-absorbing or fluorescence or luminescence properties, said test object comprising a transparent solid body, e.g. a prism, sheet or fibre, to act as a waveguide, and to the surface of which the sample material can become bound from a solution or liquid dispersion contacting the solid body; (ii) a photodetector arranged so that when a test object is at the test object location (the "in use" condition) the transparent solid body is optically coupled to the photodetector, so that light propagating in the transparent solid body can be received by the photodetector after its emergence; and (iii) a diaphragm or other limitation of the angle of view of the detector in order to discriminate that light which comes from material which is bound to the waveguide, from light from otherwise similar material that remains in solution or dispersion and thereby remains spaced from the surface of the transparent body, said limitation of the angle of view corresponding to an angle α as defined above.
Claim 13
Dependent Claim
215 words
A combination of a photometric instrument and a test object adapted therefor, suitable for example for carrying out immunoassays or other chemical or biological tests, comprising (i) a test object such as a slide or cell received and located at a test object location, for containing - a sample material with light-absorbing or fluorescence or luminescence properties, said test object comprising a transparent solid body, e.g. a prism, sheet or fibre, to act as a waveguide, and to the surface of which the sample material can become bound from a solution or liquid dispersion contacting the solid body; (ii) a photodetector arranged so that when a test object is at the test object location (the "in use" condition) the transparent solid body is optically coupled to the photodetector, so that light propagating in the transparent solid body can be received by the photodetector after its emergence; and (iii) a diaphragm or other limitation of the angle of view of the detector in order to discriminate that light which comes from material which is bound to the waveguide, from light from otherwise similar material that remains in solution or dispersion and thereby remains spaced from the surface of the transparent body, said limitation of the angle of view corresponding to an angle α as defined above.
Claim 14
Dependent Claim
53 words
An instrument and test object as claimed in claim 11, further comprising a light source arranged so that in the 'in use' condition it can illuminate the test material with light so that such light passes from the test material into and through the solid body, via total internal reflections, to the detector.
Claim 15
Dependent Claim
26 words
An instrument combination according to claim 12, wherein a reflective surface is provided to increase excitation light intensity at said surface of the transparent solid body.
Claim 16
Dependent Claim
57 words
A method according to claim 1, wherein a source of excitation light for fluorescence emission is used, and an auxiliary detector is used for measuring the intensity of source light emerged from the waveguide at an angle or angles limited to a range within the range ± α of deviation from the optical axis of the waveguide.
Claim 17
Dependent Claim
28 words
Methods according to claim 1 and instrument combinations according to claim 11, characterised by any one or more of the several features of the accompanying description and drawings.
References Cited (Backward Citations)
US3939350A
Cited
EP0075353B1
Cited
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