US4177253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic particles for immunoassay
Assignee: Syngenta Ltd
•
Filing: 1977-07-06
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Granted: 1979-12-04
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Expires: 1997-07-06
Abstract
Abstract This invention relates to magnetic particles and to the use thereof. Each particle comprises a low density core and a component therewith, at least a portion of the surface of the core being coated with magnetic material.
Inventors
- 👤 George E. Davies
- 👤 Jiri Janata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:41
CPC Classifications
B; B03; B03C; B03C1/00; B03C1/005; B03C1/01; A; A61; A61K; A61K39/00; A61K39/395; A61K39/44; B01; B01J; B01J20/00; B01J20/28; B01J20/28002; B01J20/28009; B01J20/30; B01J20/32; B01J20/3202; B01J20/3204; B01J20/3231; B01J20/3242; B01J20/3268; B01J20/3272; B01J20/3274; C; C07; C07K; C07K16/00; C07K16/18; C07K16/26; C12; C12N; C12N11/00; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/5434; G01N2446/00; G01N2446/10; G01N2446/80; G01N2446/86; G01N2446/90; Y; Y10; Y10S; Y10S436/00; Y10S436/804
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
49 words
Composite magnetic particles each particle comprising a core having a density of less than 1.5 gm/cc, at least a proportion of the surface of the core being coated with a coating of magnetic material and a biologically active component on the surface of the core and/or the said coating.
Claim 2
Dependent Claim
49 words
Composite magnetic particles each particle comprising a core having a density of less than 1.5 gm/cc, at least a proportion of the surface of the core being coated with a coating of magnetic material and a biologically active component on the surface of the core and/or the said coating.
Claim 3
Dependent Claim
27 words
Composite magnetic particles as claimed in claim 1 wherein more than 50% of the surface of the core is coated with the said coating of magnetic material.
Claim 4
Dependent Claim
14 words
Composite magnetic particles as claimed in claim 1 wherein the core is a sphere.
Claim 5
Dependent Claim
15 words
Composite magnetic particles as claimed in claim 3 wherein the sphere is a thermoplastic material.
Claim 6
Dependent Claim
16 words
Composite magnetic particles as claimed in claim 3 wherein the sphere is a hollow glass sphere.
Claim 7
Dependent Claim
22 words
Composite magnetic particles as claimed in claim 4 wherein the diameter of the spheres is between 10 -4 cm and 1 cm.
Claim 8
Dependent Claim
15 words
Composite magnetic particles as claimed in claim 1 wherein the magnetic material is a metal.
Claim 9
Dependent Claim
13 words
Composite magnetic particles as claimed in claim 7 wherein the metal is nickel.
Claim 10
Dependent Claim
29 words
Composite magnetic particles as claimed in claim 1 wherein the biologically active component is chemically bound to the surface of the core and/or to the coating of magnetic material.
Claim 11
Dependent Claim
20 words
Composite magnetic particles as claimed in claim 9 wherein the biologically active component is bound via a silane coupling agent.
Claim 12
Dependent Claim
18 words
Composite magnetic particles as claimed in claim 1 wherein the associated component contains at least one functional group.
Claim 13
Dependent Claim
16 words
Composite magnetic particles as claimed in claim 1 wherein the biologically active component is a protein.
Claim 14
Dependent Claim
14 words
Composite magnetic particles as claimed in claim 12 wherein the protein is an antibody.
Claim 15
Dependent Claim
16 words
Composite magnetic particles as claimed in claim 1 wherein the biologically active component is an antigen.
Claim 16
Dependent Claim
17 words
Composite magnetic particles as claimed in claim 1 wherein the biologically active component comprises an antibody-antigen complex.
Claim 17
Dependent Claim
48 words
A method of preparing composite magnetic particles as claimed in claim 1 comprising the steps of depositing a metal on the surface of the core, chemically modifying the surface of the core and/or the coating of magnetic material, and then treating the core with the biologically active component.
Claim 18
Dependent Claim
42 words
A method of preparing composite magnetic particles as claimed in claim 16 in which a silane coupling agent is reacted with the surface of the core and/or the coating of magnetic material prior to treating the core with the biologically active component.
Claim 19
Dependent Claim
24 words
A method of preparing composite magnetic particles as claimed in claim 17 in which reaction with the silane coupling agent is effected in solution.
Claim 20
Dependent Claim
44 words
A method of preparing composite magnetic particles as claimed in claim 18 in which the silane coupling agent is reacted with the surface of the core and/or the coating of magnetic material and then with a terminal and/or pendant reactive group of a protein.
Claim 21
Dependent Claim
30 words
A method of preparing composite magnetic particles as claimed in claim 19 in which the biologically active group of the protein is blocked before reaction with the silane coupling agent.
Claim 22
Dependent Claim
59 words
An affinity chromatographic process comprising the steps of bringing a liquid medium containing a substance into contact with composite magnetic particles as claimed in claim 1, recovering the composite magnetic particles by magnetic means and removing the substance from the recovered composite magnetic particle, the substance and the biologically active component having a specific biological affinity for each other.
Claim 23
Dependent Claim
51 words
A method of immunoassay comprising the steps of reacting an antigen with an antibody, one of which is the biologically active component of a composite magnetic particle as claimed in claim 1 separating the composite magnetic particles and the reaction mixture and assaying the recovered composite magnetic particles or reaction mixture.
Claim 24
Dependent Claim
18 words
A method of immunoassay as claimed in claim 22 in which assay is effected by a radioisotope technique.
Claim 25
Dependent Claim
17 words
A method of immunoassay as claimed in claim 23 in which the radioisotope is H 3 .
Claim 26
Dependent Claim
15 words
Composite magnetic particles as claimed in claim 1 wherein the said coating is not magnetized.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |