Patent US4554088A successfully refreshed from Google Patents.
US4554088A
Expired / Lapsed
US
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Magnetic particles for use in separations
Assignee: Amag Pharmaceuticals Inc
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Filing: 1983-05-12
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Granted: 1985-11-19
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Expires: 2003-05-12
Abstract
Abstract A process is provided for the preparation of magnetic particles to which a wide variety of molecules may be coupled. The magnetic particles can be dispersed in aqueous media without rapid settling and conveniently reclaimed from media with a magnetic field. Preferred particles do not become magnetic after application of a magnetic field and can be redispersed and reused. The magnetic particles are useful in biological systems involving separations.
Inventors
- 👤 Roy A. Whitehead
- 👤 Mark S. Chagnon
- 👤 Ernest V. Groman
- 👤 Lee Josephson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:08
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/5434; B; B01; B01D; B01D15/00; B01D15/08; B01D15/10; B01D15/18; B01D15/1807; B01J; B01J20/00; B01J20/02; B01J20/0203; B01J20/0225; B01J20/0229; B01J20/06; B01J20/22; B01J20/26; B01J20/262; B01J20/28; B01J20/28002; B01J20/28004; B01J20/28009; B01J20/28054; B01J20/28057; B01J20/281; B01J20/286; B01J20/30; B01J20/32; B01J20/3202; B01J20/3204; B01J20/3231; B01J20/3242; B01J20/3268; B01J20/3272; B01J20/3274; B01J20/3291; B01J20/3293; B01J20/34; B01J20/3425; B01J20/3433; B01J20/3441; B03; B03C; B03C1/00; B03C1/005; B03C1/01; C; C12; C12Q; C12Q1/00; C12Q1/34; C12Q1/42; C12Q1/54; C12Q1/68; C12Q1/6813; C12Q1/6834; B01D15/26; B01D15/38; B01D15/3804; B01D15/3857; B01J2220/00; B01J2220/50; B01J2220/54; G01N2446/00; G01N2446/20; G01N2446/80; G01N2446/90; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2995
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
134 words
A coupled magnetically-responsive particle comprising a magnetic metal oxide core generally surrounded by a coat of polymeric silane to which molecules of at least one type of bioaffinity adsorbent are covalently coupled, a mass of the uncoupled particles being dispersable in aqueous media to form an aqueous dispersion having (a) a fifty-percent-turbidity-decrease settling time of greater than about 1.5 hours in the absence of a magnetic field, and (b) a ninety-five-percent-turbidity-decrease separation time of less than about 10 minutes in the presence of a magnetic field, the magnetic field being applied to the aqueous dispersion by bringing a vessel containing a volume of the dispersion into contact with a pole face of a permanent magnet, the permanent magnet having a volume which is less than the volume of the aqueous dispersion in the vessel.
Claim 2
Dependent Claim
134 words
A coupled magnetically-responsive particle comprising a magnetic metal oxide core generally surrounded by a coat of polymeric silane to which molecules of at least one type of bioaffinity adsorbent are covalently coupled, a mass of the uncoupled particles being dispersable in aqueous media to form an aqueous dispersion having (a) a fifty-percent-turbidity-decrease settling time of greater than about 1.5 hours in the absence of a magnetic field, and (b) a ninety-five-percent-turbidity-decrease separation time of less than about 10 minutes in the presence of a magnetic field, the magnetic field being applied to the aqueous dispersion by bringing a vessel containing a volume of the dispersion into contact with a pole face of a permanent magnet, the permanent magnet having a volume which is less than the volume of the aqueous dispersion in the vessel.
Claim 3
Dependent Claim
182 words
A coupled magnetically-responsive particle comprising a superparamagnetic iron oxide core generally surrounded by a coat of polymeric silane to which molecules of at least one type of bioaffinity adsorbent are covalently coupled, the iron oxide core including a group of crystals of iron oxide, the uncoupled particle having a mean diameter as measured by light scattering between about 0.1μ and about 1.5μ and a surface area as measured by nitrogen gas adsorption of at least about 100 m 2 /gm, a mass of the uncoupled particles being dispersable in aqueous media to form an aqueous dispersion having (a) a fifty-percent-turbidity-decrease settling time of greater than about 1.5 hours in the absence of a magnetic field, and (b) a ninety-five-percent-turbidity-decrease separation time of less than about 10 minutes in the presence of a magnetic field, the magnetic field being applied to the aqueous dispersion by bringing a vessel containing a volume of the dispersion into contact with a pole face of a permanent magnet, the permanent magnet having a volume which is less than the volume of the aqueous dispersion in the vessel.
Claim 4
Dependent Claim
182 words
A coupled magnetically-responsive particle comprising a superparamagnetic iron oxide core generally surrounded by a coat of polymeric silane to which molecules of at least one type of bioaffinity adsorbent are covalently coupled, the iron oxide core including a group of crystals of iron oxide, the uncoupled particle having a mean diameter as measured by light scattering between about 0.1μ and about 1.5μ and a surface area as measured by nitrogen gas adsorption of at least about 100 m 2 /gm, a mass of the uncoupled particles being dispersable in aqueous media to form an aqueous dispersion having (a) a fifty-percent-turbidity-decrease settling time of greater than about 1.5 hours in the absence of a magnetic field, and (b) a ninety-five-percent-turbidity-decrease separation time of less than about 10 minutes in the presence of a magnetic field, the magnetic field being applied to the aqueous dispersion by bringing a vessel containing a volume of the dispersion into contact with a pole face of a permanent magnet, the permanent magnet having a volume which is less than the volume of the aqueous dispersion in the vessel.
Claim 5
Dependent Claim
182 words
A coupled magnetically-responsive particle comprising a ferromagnetic metal oxide core generally surrounded by a coat of polymeric silane to which molecules of at least one type of bioaffinity adsorbent are covalently coupled, the metal oxide core including a group of crystals of metal oxide, the uncoupled particle having a mean diameter as measured by light scattering between about 0.1μ and about 1.5μ and a surface area as measured by nitrogen gas adsorption of at least about 100 m 2 /gm, a mass of the uncoupled particles being dispersable in aqueous media to form an aqueous dispersion having (a) a fifty-percent-turbidity-decrease settling time of greater than about 1.5 hours in the absence of a magnetic field, and (b) a ninety-five-percent-tubidity-decrease separation time of less than about 10 minutes in the presence of a magnetic field, the magnetic field being applied to the aqueous dispersion by bringing a vessel containing a volume of the dispersion into contact with a pole face of a permanent magnet, the permanent magnet having a volume which is less than the volume of the aqueous dispersion in the vessel.
Claim 6
Dependent Claim
182 words
A coupled magnetically-responsive particle comprising a ferromagnetic metal oxide core generally surrounded by a coat of polymeric silane to which molecules of at least one type of bioaffinity adsorbent are covalently coupled, the metal oxide core including a group of crystals of metal oxide, the uncoupled particle having a mean diameter as measured by light scattering between about 0.1μ and about 1.5μ and a surface area as measured by nitrogen gas adsorption of at least about 100 m 2 /gm, a mass of the uncoupled particles being dispersable in aqueous media to form an aqueous dispersion having (a) a fifty-percent-turbidity-decrease settling time of greater than about 1.5 hours in the absence of a magnetic field, and (b) a ninety-five-percent-tubidity-decrease separation time of less than about 10 minutes in the presence of a magnetic field, the magnetic field being applied to the aqueous dispersion by bringing a vessel containing a volume of the dispersion into contact with a pole face of a permanent magnet, the permanent magnet having a volume which is less than the volume of the aqueous dispersion in the vessel.
Claim 7
Dependent Claim
53 words
The coupled magnetically-responsive particle of claim 1, 2 or 3 wherein the bioaffinity adsorbent is selected from the group consisting of antibodies, antigens, haptens, enzymes, apoenzymes, enzymatic substrates, enzymatic inhibitors, cofactors, binding proteins, carrier proteins, compounds bound by binding proteins, compounds bound by carrier proteins, lectins, monosaccharides, polysaccharides, hormones, receptors, repressors and inducers.
Claim 8
Dependent Claim
65 words
The coupled magnetically-responsive particle of claim 2 or 3 wherein the covalently coupled bioaffinity adsorbent is an antibody selected from the group consisting of anti-thyroxine, anti-triiodothyronine, anti-thyroid stimulating hormone, anti-thyroid binding globulin, anti-thyroglobulin, anti-digoxin, anti-cortisol, anti-insulin, anti-theophylline, anti-vitamin B 12 , anti-folate, anti-ferritin, anti-human chorionic gonadotropin, anti-follicle stimulating hormone, anti-leuteinizing hormone, anti-progesterone, anti-testosterone, anti-estriol, anti-estradiol, anti-prolactin, anti-human placental lactogen, anti-gastrin and anti-human growth hormone antibodies.
Claim 9
Dependent Claim
40 words
The coupled magnetically-responsive particle of claim 2 wherein the coat of polymeric silane is a coat of p-aminophenyltrimethoxysilane polymer and wherein the bioaffinity adsorbents are anti-thyroxine antibodies, which antibodies are covalently coupled to the coat of polymeric silane by diazotization.
Claim 10
Dependent Claim
40 words
The coupled magnetically-responsive particle of claim 2 wherein the coat of polymeric silane is a coat of p-aminophenyltrimethoxysilane polymer and wherein the bioaffinity adsorbents are anti-theophylline antibodies, which antibodies are covalently coupled to the coat of polymeric silane by diazotization.
Claim 11
Dependent Claim
55 words
The coupled magnetically-responsive particle of claim 2 wherein the coat of polymeric silane is a coat of carboxylic-acid terminated glutaric-anhydride-treated 3-aminopropyltrimethoxysilane polymer and wherein the bioaffinity adsorbents are molecules of vitamin B 12 binding protein, which molecules of vitamin B 12 binding protein are covalently coupled to the coat of polymeric silane by carbodiimide coupling.
Claim 12
Dependent Claim
41 words
The coupled magnetically-responsive particle of claim 2 wherein the coat of polymeric silane is a coat of N-2-aminoethyl-3-aminopropylsilane polymer and wherein the bioaffinity adsorbents are anti-triiodothyronine antibodies, which antibodies are covalently coupled to the coat of polymeric silane by glutaraldehyde coupling.
Claim 13
Dependent Claim
43 words
The coupled magnetically-responsive particle of claim 2 wherein the coat of polymeric silane is a coat of N-2-aminoethyl-3-aminopropylsilane polymer and wherein the bioaffinity adsorbents are anti-thyroid stimulating hormone antibodies, which antibodies are covalently coupled to the coat of polymeric silane by glutaraldehyde coupling.
Claim 14
Dependent Claim
50 words
The coupled magnetically-responsive particle of claim 2 wherein the coat of polymeric silane is a coat of N-2-aminoethyl-3-aminopropylsilane polymer and wherein the bioaffinity adsorbents are enzymes selected from the group consisting of alkaline phosphatase and β-galactosidase, which enzymes are covalently coupled to the coat of polymeric silane by glutaraldehyde coupling.
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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) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |