US4115534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
In vitro diagnostic test
Assignee: 3M Co
•
Filing: 1977-06-20
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Granted: 1978-09-19
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Expires: 1997-06-20
Abstract
Abstract A method for determining the concentration of substances in biological fluids (e.g., drugs, hormones, vitamins and enzymes) is disclosed wherein magnetically responsive, permeable, solid, water-insoluble microparticles are employed.
Inventors
- 👤 Dionyssis S. Ithakissios
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:35
CPC Classifications
B; B03; B03C; B03C1/00; B03C1/005; B03C1/01; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/5434; G01N2333/00; G01N2333/435; G01N2333/76; G01N2333/765; G01N2446/00; G01N2446/20; G01N2446/30; Y; Y10; Y10S; Y10S436/00; Y10S436/815; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2989
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
158 words
A method for determining the concentration of substances present in biological fluids comprising the steps of: providing a mixture of (i) a known quantity of said biological fluid containing said substance whose concentration is to be determined, (ii) a known quantity of a radioactively labeled form of said substance and (iii) a known quantity of magnetically responsive composite microparticles comprising a magnetically responsive material and a permeable, solid, water-insoluble matrix selected from proteinaceous materials, polysaccharides, polyurethanes and mixtures thereof; wherein said magnetically responsive material is dispersed throughout said water-insoluble matrix; and wherein said water-insoluble matrix is capable of sorbing said substances; reacting said mixture so as to cause said substance and its radioactively labeled form to competitively complex with said composite microparticles; magnetically separating the complexed microparticles from the mixture; counting the radioactivity of either the separated complexes or the remaining mixture; and relating the counted radioactivity to a standard curve to determine the concentration of said substance.
Claim 2
Independent Claim
158 words
A method for determining the concentration of substances present in biological fluids comprising the steps of: providing a mixture of (i) a known quantity of said biological fluid containing said substance whose concentration is to be determined, (ii) a known quantity of a radioactively labeled form of said substance and (iii) a known quantity of magnetically responsive composite microparticles comprising a magnetically responsive material and a permeable, solid, water-insoluble matrix selected from proteinaceous materials, polysaccharides, polyurethanes and mixtures thereof; wherein said magnetically responsive material is dispersed throughout said water-insoluble matrix; and wherein said water-insoluble matrix is capable of sorbing said substances; reacting said mixture so as to cause said substance and its radioactively labeled form to competitively complex with said composite microparticles; magnetically separating the complexed microparticles from the mixture; counting the radioactivity of either the separated complexes or the remaining mixture; and relating the counted radioactivity to a standard curve to determine the concentration of said substance.
Claim 3
Dependent Claim
15 words
A method in accordance with claim 1 wherein said water-insoluble matrix is a proteinaceous material.
Claim 4
Dependent Claim
19 words
A method in accordance with claim 2 wherein said proteinaceous material is selected from albumins, gelatin, globulins and enzymes.
Claim 5
Dependent Claim
14 words
A method in accordance with claim 3 wherein said proteinaceous material is an albumin.
Claim 6
Dependent Claim
14 words
A method in accordance with claim 3 wherein said proteinaceous material is a globulin.
Claim 7
Dependent Claim
14 words
A method in accordance with claim 3 wherein said proteinaceous material is an enzyme.
Claim 8
Dependent Claim
13 words
A method in accordance with claim 3 wherein said proteinaceous material is gelatin.
Claim 9
Dependent Claim
15 words
A method in accordance with claim 1 wherein said water insoluble matrix is a polysaccharide.
Claim 10
Dependent Claim
16 words
A method in accordance with claim 1 wherein said magnetically responsive material is a ferromagnetic material.
Claim 11
Dependent Claim
37 words
A method in accordance with claim 9 wherein said ferromagnetic material is selected from BaFe 12 O 19 , Fe 3 O 4 , CoO, NiO, Mn 2 O 3 , CoMnP, iron particles and nickel particles.
Claim 12
Dependent Claim
24 words
A method in accordance with claim 1 wherein said composite microparticle has a maximum dimension in the range of about 5 to 400 microns.
Claim 13
Dependent Claim
51 words
A method in accordance with claim 1 wherein there is further included in said permeable, solid, water-insoluble matrix a combining agent capable of sorbing substances present in biological fluids, wherein said combining agent is selected from activated charcoal, ion-exchange resins, and binding agents which have a specific affinity for said substance.
Claim 14
Dependent Claim
14 words
A method in accordance with claim 12 wherein said combining agent is activated charcoal.
Claim 15
Dependent Claim
15 words
A method in accordance with claim 12 wherein said combining agent is an ion-exchange resin.
Claim 16
Dependent Claim
15 words
A method in accordance with claim 14 wherein said ion-exchange resin contains fixed electronegative charges.
Claim 17
Dependent Claim
15 words
A method in accordance with claim 14 wherein said ion-exchange resin contains fixed electropositive charges.
Claim 18
Dependent Claim
23 words
A method in accordance with claim 12 wherein said combining agent is a binding agent which has a specific affinity for said substances.
Claim 19
Dependent Claim
14 words
A method in accordance with claim 17 wherein said binding agent is a protein.
Claim 20
Dependent Claim
21 words
A method in accordance with claim 18 wherein said binding protein is selected from thyroxine antibody, intrinsic factor and fish serum.
Claim 21
Dependent Claim
12 words
A method in accordance with claim 1 wherein said substance is thyroxine.
Claim 22
Dependent Claim
15 words
A method in accordance with claim 1 wherein said substance is vitamin B 12 .
Claim 23
Dependent Claim
14 words
A method in accordance with claim 1 wherein said water-insoluble matrix is a polyurethane.
Claim 24
Dependent Claim
33 words
A method in accordance with claim 22 wherein said polyurethane is the reaction product of a polyisocyanate and a material having reactive hydroxyl groups, said material being selected from polyols, polyesters and polyethers.
Claim 25
Dependent Claim
18 words
A method in accordance with claim 22 wherein said polyurethane is prepared by reacting an isocyanate-terminated polyester prepolymer.
Claim 26
Dependent Claim
28 words
A method in accordance with claim 24 wherein said prepolymer is prepared by reacting 4,4'-diphenyl methane diisocyanate with the reaction product of a glycol and a dicarboxylic acid.
References Cited (Backward Citations)
US650760A
Cited
US2971916A
Cited
US3137631A
Cited
US3522346A
Cited
US3980764A
Cited
US3933997A
Cited
US3970518A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |