US5512332A
Expired / Lapsed
US
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Process of making resuspendable coated magnetic particles
Assignee: Immunivest Corp
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Filing: 1994-04-22
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Granted: 1996-04-30
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Expires: 2014-04-22
Abstract
Abstract A method is provided for direct coating of transiently stable, colloidal particulate magnetic substrates with various synthetic or naturally-occurring polymers, particularly biologically-active peptides and proteins. The resulting coated resuspendable, colloidal magnetic particles are particularly adapted for use in bioanalytical procedures involving affinity separation, or the like. There is also provided a method for selectively binding chemically-treated colloidal magnetic particles to polyelectrolytes, e.g., to facilitate extraction of nucleic acids from cell lysates.
Inventors
- 👤 Paul A. Liberti
- 👤 Steven P. Piccoli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:25
CPC Classifications
A; A61; A61K; A61K49/00; A61K49/06; A61K49/18; A61K49/1818; A61K49/1821; A61K49/1824; A61K49/1827; A61K49/1875; A61K49/1833; A61K49/1836; A61K49/1851; A61K49/1854; A61K49/1857; A61K49/186; A61K49/1863; A61K49/1866; A61K49/1869; A61K9/00; A61K9/48; A61K9/50; A61K9/5094; B; B03; B03C; B03C1/00; B03C1/005; B03C1/01; C; C12; C12N; C12N11/00; C12N11/14; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/54333; G01N33/5434; G01N33/54393; H; H01; H01F; H01F1/00; H01F1/44; H01F1/445; G01N2333/00; G01N2333/435; G01N2333/76; G01N2333/765; G01N2446/00; G01N2446/20; G01N2446/30; G01N2446/80
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
104 words
A process for making resuspendable, coated magnetic particles by direct application of a coating material to a particulate magnetic substrate, said process comprising: a. dividing at least one particle of a magnetic starting material into a plurality of aggregable, smaller sized particles, thereby to provide an uncoated particulate magnetic substrate; b. forming a suspension of said uncoated particulate magnetic substance in a liquid medium; and c. contacting said uncoated, suspended particulate magnetic substance with said coating material, before substantial particulate magnetic substrate aggregation occurs, for a time sufficient for said coating material to adhere to said substrate, thereby forming said resuspendable, coated magnetic particles.
Claim 2
Dependent Claim
104 words
A process for making resuspendable, coated magnetic particles by direct application of a coating material to a particulate magnetic substrate, said process comprising: a. dividing at least one particle of a magnetic starting material into a plurality of aggregable, smaller sized particles, thereby to provide an uncoated particulate magnetic substrate; b. forming a suspension of said uncoated particulate magnetic substance in a liquid medium; and c. contacting said uncoated, suspended particulate magnetic substance with said coating material, before substantial particulate magnetic substrate aggregation occurs, for a time sufficient for said coating material to adhere to said substrate, thereby forming said resuspendable, coated magnetic particles.
Claim 3
Dependent Claim
13 words
A process according to claim 1, wherein said suspension is an aqueous suspension.
Claim 4
Dependent Claim
16 words
A process according to claim 1, wherein said magnetic starting material is a transition metal oxide.
Claim 5
Dependent Claim
13 words
A process according to claim 3, wherein said transition metal oxide is magnetite.
Claim 6
Dependent Claim
16 words
A process according to claim 1, wherein said coating material is a natural or synthetic polymer.
Claim 7
Dependent Claim
18 words
A process according to claim 1, wherein said coating material is a polypeptide, a protein, or an antibody.
Claim 8
Dependent Claim
25 words
A process according to claim 1, wherein said magnetic starting material is divided under the influence of irradiation, vibration, pH modification, or a combination thereof.
Claim 9
Dependent Claim
15 words
A process according to claim 1, wherein said magnetic starting material is divided by sonication.
Claim 10
Dependent Claim
20 words
A process according to claim 1, wherein said coated magnetic particles generally have a maximum dimension of less than 0.2μ.
Claim 11
Dependent Claim
19 words
A process according to claim 1, wherein said coated magnetic particles have a maximum dimension of less than 0.1μ.
Claim 12
Dependent Claim
26 words
A process according to claim 1, wherein the weight ratio of said particulate magnetic substrate to said coating material is from about 1000:1 to about 1:10.
Claim 13
Dependent Claim
21 words
A process according to claim 1, including the further step of recovering said resuspendable coated particles by high gradient magnetic separation.
Claim 14
Dependent Claim
20 words
A process according to claim 1, further comprising resuspending the magnetic coated particles in water or an aqueous buffer solution.
Claim 15
Dependent Claim
16 words
A process according to claim 13, wherein said resuspension is conducted under the influence of sonication.
Claim 16
Dependent Claim
24 words
A process according to claim 1, further including the step of reacting said coated magnetic particles with a bifunctional compound specific to said coating.
Claim 17
Dependent Claim
26 words
A process according to claim 1, further including the step of reacting said coated magnetic particles with a bifunctional compound adapted to form primarily intraparticulate bonds.
Claim 18
Dependent Claim
29 words
A process according to claim 1, further including the step of reacting said coated magnetic particles with a biofunctional compound and reacting the product particles with a bifunctional ligand.
Claim 19
Dependent Claim
29 words
A process according to claim 1, further including the step of reacting said coated magnetic particles with an activating agent and reacting the product particles with a biofunctional ligand.
Claim 20
Dependent Claim
97 words
A process for making a stable suspension of resuspendable magnetic particles, said process comprising: a. forming a liquid mixture of a particulate magnetic starting material; b. sonicating said mixture to divide said particulate magnetic starting material into a plurality of uncoated aggregable, smaller sized particles suspended in a liquid; c. contacting said uncoated, suspended smaller sized particles with said coating material, before substantial aggregation of said smaller sized particle occurs, for a time sufficient for said coating material to adhere to said substrate, thereby forming said resuspendable, coated magnetic particles. d. recovering said resuspendable, coated magnetic particle.
Claim 21
Dependent Claim
97 words
A process for making a stable suspension of resuspendable magnetic particles, said process comprising: a. forming a liquid mixture of a particulate magnetic starting material; b. sonicating said mixture to divide said particulate magnetic starting material into a plurality of uncoated aggregable, smaller sized particles suspended in a liquid; c. contacting said uncoated, suspended smaller sized particles with said coating material, before substantial aggregation of said smaller sized particle occurs, for a time sufficient for said coating material to adhere to said substrate, thereby forming said resuspendable, coated magnetic particles. d. recovering said resuspendable, coated magnetic particle.
Claim 22
Dependent Claim
39 words
A process according to claim 1, wherein said uncoated, suspended particulate magnetic substrate is contacted with said coating material in an amount no greater than that which is sufficient to provide complete coverage of said resuspendable, coated magnetic particles.
Claim 23
Dependent Claim
17 words
A process according to claim 20, wherein a secondary coating material is applied to said coated particles.
Claim 24
Dependent Claim
15 words
A process according to claim 21, wherein said secondary coating material is a dispersion aid.
References Cited (Backward Citations)
US3215572A
Cited
US4152210A
Cited
US3970518A
Cited
US4018886A
Cited
US4070246A
Cited
US4335094A
Cited
US4230685A
Cited
US4329241A
Cited
US4454234A
Cited
US4452773A
Cited
US4554088A
Cited
US4672040A
Cited
US4775636A
Cited
US4795698A
Cited
EP0230768A1
Cited
EP0391608A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-30 | 1999-10-30 | 2000-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-30 | 2003-10-30 | 2004-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-30 | 2007-10-30 | 2008-04-30 | $7700.00 | Window Closed / Lapsed |