US3872312A
Expired / Lapsed
US
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Method and apparatus for detecting and classifying nucleic acid particles
Assignee: Bio Rad Laboratories Inc
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Filing: 1973-07-02
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Granted: 1975-03-18
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Expires: 1993-07-02
Abstract
Abstract Free floating viruses are detected and sized by a method which combines fluorescent staining with the observation of a modulation of the fluorescence intensity by Brownian motion of the particles in combination with a spatial filter. Intensity modulation and fluorescence data provides a set of descriptors useful in distinguishing the type of virus involved, particularly if also combined with data regarding the scattering of light by the particles. The method and apparatus are also usable in connection with detection and classification of other biological particles having the same order of magnitude of size as viruses.
Inventors
- 👤 Tomas Hirschfeld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:23
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/02; G01N15/0205; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6428
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
93 words
APPARATUS FOR DETECTING AND CLASSIFYING, IN FLUID SPECIMEN, SUBMICRON-DIMENSIONED PARTICLES CONTAINING A NUCLEIC ACID AND STAINED WITH A FLUORESCENT DYE SPECIFIC TO SAID NUCLEIC ACID, SAID APPARATUS COMPRISING, A RADIATION SOURCE FOR PROVIDING ILLUMINATION WITHIN AN EXCITATION BAND OF SAID DYE, MEANS FOR DIRECTING SAID ILLUMINATION INTO SAID SPECIMEN, MEANS FOR VIEWING FLUORESCENCE EMISSION PRODUCED FROM SAID DYE RESPONSIVELY TO SAID ILLUMINATION, AND MEANS FOR SPATIALLY FILTERING AT LEAST ONE OF SAID ILLUMINATION AND SAID FLUORESCENCE EMISSION SO AS TO PROVIDE INTENSITY MODULATION OF SAID EMISSION DUE TO BROWNIAN MOTION OF SAID PARTICLES.
Claim 2
Dependent Claim
93 words
APPARATUS FOR DETECTING AND CLASSIFYING, IN FLUID SPECIMEN, SUBMICRON-DIMENSIONED PARTICLES CONTAINING A NUCLEIC ACID AND STAINED WITH A FLUORESCENT DYE SPECIFIC TO SAID NUCLEIC ACID, SAID APPARATUS COMPRISING, A RADIATION SOURCE FOR PROVIDING ILLUMINATION WITHIN AN EXCITATION BAND OF SAID DYE, MEANS FOR DIRECTING SAID ILLUMINATION INTO SAID SPECIMEN, MEANS FOR VIEWING FLUORESCENCE EMISSION PRODUCED FROM SAID DYE RESPONSIVELY TO SAID ILLUMINATION, AND MEANS FOR SPATIALLY FILTERING AT LEAST ONE OF SAID ILLUMINATION AND SAID FLUORESCENCE EMISSION SO AS TO PROVIDE INTENSITY MODULATION OF SAID EMISSION DUE TO BROWNIAN MOTION OF SAID PARTICLES.
Claim 3
Dependent Claim
24 words
Apparatus as defined in claim 1 wherein said means for spatial filtering is disposed in the optical path between said source and said specimen.
Claim 4
Dependent Claim
26 words
Apparatus as defined in claim 1 wherein said means for spatial filtering is disposed in the optical path between said means for viewing, and said specimen.
Claim 5
Dependent Claim
44 words
Apparatus as defined in claim 1 wherein said means for spatial filtering includes one or more light transmissive portions, substantially all of which are dimensioned to be as closely matched to the average dimension of said particles as the wavelengths of said illumination permits.
Claim 6
Dependent Claim
29 words
Apparatus as defined in claim 1 including means for detecting intensity modulation of fluorescence produced by Brownian motion of said particles in combination with said means for spatially filtering.
Claim 7
Dependent Claim
14 words
Apparatus as defined in claim 5 including means for frequency analyzing said intensity modulation.
Claim 8
Dependent Claim
54 words
Apparatus as defined in claim 5 including means for dividing said fluorescence emission into a plurality of beams, said means for detecting including a plurality of wavelength filters each disposed in the path of a respective one of said beams and a corresponding photodetector responsive to the wavelength passed by its corresponding wavelength filter.
Claim 9
Dependent Claim
17 words
Apparatus as defined in claim 7 including means for frequency analyzing the signals produced by said photodetectors.
Claim 10
Dependent Claim
22 words
Apparatus as defined in claim 1 wherein said radiation source comprises a source of broadband radiation and at least one wavelength filter.
Claim 11
Dependent Claim
29 words
Apparatus as defined in claim 1 including means for detecting and measuring scattering of said illumination from said particles substantially simultaneously with viewing of fluorescence emission from said particles.
Claim 12
Dependent Claim
96 words
Process for detection and classification, in a fluid specimen, of submicron dimensioned particles which contain a nucleic acid, which particles are stained by a fluorescent stain specific to said nucleic acid, said process comprising the steps of illuminating said fluid with radiation at an excitation wavelength of said stain observing substantially any fluorescent emission produced from said stain responsively to the excitation illumination; and spatially filtering at least one of the excitation illumination and said fluorescent emission so that the observed fluorescent emission is modulated as a function of the Brownian velocity of the stained particles.
Claim 13
Dependent Claim
96 words
Process for detection and classification, in a fluid specimen, of submicron dimensioned particles which contain a nucleic acid, which particles are stained by a fluorescent stain specific to said nucleic acid, said process comprising the steps of illuminating said fluid with radiation at an excitation wavelength of said stain observing substantially any fluorescent emission produced from said stain responsively to the excitation illumination; and spatially filtering at least one of the excitation illumination and said fluorescent emission so that the observed fluorescent emission is modulated as a function of the Brownian velocity of the stained particles.
Claim 14
Dependent Claim
18 words
Process as defined in claim 11 including the step of first staining saiD specimen with said fluorescent stain.
Claim 15
Dependent Claim
22 words
Process as defined in claim 11 including the steps of suspending the stained particles in a fluid to form said fluid specimen.
Claim 16
Dependent Claim
13 words
Process as defined in claim 11 wherein said stain is specific to DNA.
Claim 17
Dependent Claim
13 words
Process as defined in claim 11 wherein said stain is specific to RNA.
Claim 18
Dependent Claim
44 words
Process as defined in claim 11 including the steps of staining said particles with both DNA-specific and RNA-specific fluorochromes, and filtering the fluorescence emission at separate wavelengths corresponding to fluorescent wavelengths of stains produced by linkage of said fluorochromes to DNA and RNA, respectively.
Claim 19
Dependent Claim
44 words
Process as defined in claim 11 and further comprising the steps of viewing light scattered from said particles and correlating the observation thereof with the observed spatially filtered fluorescent emissions to determine the ratio of nucleic acid mass to total mass of suspended particles.
Claim 20
Dependent Claim
16 words
Process as defined in claim 17 wherein the fluorescent emissions and scattered light are viewed simultaneously.
Claim 21
Dependent Claim
14 words
Process as defined in claim 11 wherein only said excitation illumination is spatially filtered.
Claim 22
Dependent Claim
15 words
Process as defined in claim 11 wherein only said observed fluorescent emission is spatially filtered.
Claim 23
Dependent Claim
19 words
Process as defined in claim 11 wherein both said excitation illumination and said observed fluorescent emission are spatially filtered.
Claim 24
Dependent Claim
21 words
Process as defined in claim 11 including the step of measuring the frequency spectrum of the modulation of said fluorescent emission.
Claim 25
Dependent Claim
23 words
Process as defined in claim 22 wherein said frequency spectrum is measured at separate fluorescent emission wavelengths respectively characteristic of DNA and RNA.
Claim 26
Dependent Claim
22 words
Apparatus as defined in claim 10 wherein said means for detecting and measuring scattering is sensitive to polarization of the scattered illumination.
Claim 27
Dependent Claim
19 words
Process as defined in claim 17 including the step of measuring polarization of the light scattered from said particles.
References Cited (Backward Citations)
US3497690A
Cited
US3657537A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |