Patent EP0180384A2 successfully refreshed from Google Patents.
EP0180384A2
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Magnetically responsive reagent carrier and method of preparation
Assignee: Bayer Corp
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Filing: 1985-10-17
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Granted: —
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Expires: 2005-10-17
Abstract
Abstract A stable magnetically responsive, substantially remanence-free reagent carrier comprises an iron oxide colloidally dispersed in a smooth particulate polymeric matrix having preferentially a hydrated diameter of from about 0.5 to about 100 µm. The reagent carrier is prepared by a process which includes incorporating iron salts by passive transport into substantially spherical, water-swellable polymeric matrices, converting in situ the iron salts so-incorporated into their respective iron oxides. The carrier with a reagent attached thereto is useful inter alia in immunoassays.
Inventors
- 👤 Beri Cohen
- 👤 Tak K. Wong
- 👤 Bartholomew Hargitay
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 19:15
CPC Classifications
B; B03; B03C; B03C1/00; B03C1/005; B03C1/01; C; C12; C12N; C12N11/00; C12N11/02; C12N11/08; C12N11/089; C12N11/14; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/5434; G01N33/544; G01N33/545; G01N2446/00; G01N2446/10; G01N2446/20
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
32 words
A stable magnetically responsive reagent carrier, comprising a matrix consisting of a polymeric material which is swellable in an aqueous medium, and a superparamagnetic substance colloidally and stably dispersed within said matrix.
Claim 2
Dependent Claim
32 words
A stable magnetically responsive reagent carrier, comprising a matrix consisting of a polymeric material which is swellable in an aqueous medium, and a superparamagnetic substance colloidally and stably dispersed within said matrix.
Claim 3
Dependent Claim
20 words
A carrier according to claim 1, wherein the magnetic response is greater than 20% of the magnetic response of magnetite.
Claim 4
Dependent Claim
28 words
A carrier according to claim 1 or 2, wherein said matrix comprises an organic polymeric material, and/or a crosslinked gel, and preferably has a smooth surface when hydrated.
Claim 5
Dependent Claim
18 words
A carrier according to any of claims 1 to 3, wherein said superparamagnetic substance comprises oxides of iron.
Claim 6
Dependent Claim
40 words
A carrier according to any of claims 1 to 4, wherein said superparamagnetic substance is dispersed in the polymeric matrix in sufficient quantity to impart a specific gravity of about between 1.2 and 2.7 to said reagent carrier when hydrated.
Claim 7
Dependent Claim
39 words
A carrier according to any of claims 1 to 5, wherein the colloidally dispersed superparamagnetic substance comprises granules having a diameter smaller than about 50 nm, and/or it constitutes at least about 20% by weight of said reagent carrier.
Claim 8
Dependent Claim
40 words
A carrier according to any of claims 1 to 6, wherein said matrix is substantially spherical and has an axial ratio of less than about 4:1, and preferably has a diameter of between about 0.5 and 100 pm when hydrated.
Claim 9
Dependent Claim
39 words
A carrier according to any of claims 1 to 7, wherein a reagent is immobilized on the surface of said matrix, the reagent preferably being an enzyme, or an antibody, or an antigen, or a hapten or another ligand.
Claim 10
Dependent Claim
65 words
A process for preparing a magnetically responsive particulate reagent carrier by generating in situ a colloidally dispersed superparamagnetic moiety in the interior of a preformed polymeric matrix, said process comprising the steps of: (a) incorporating by passive transport iron compounds into a water-insoluble swellable polymeric matrix; (b) converting the iron compounds so-incorporated to iron oxides; and (c) washing the polymeric matrix to remove soluble by-products.
Claim 11
Dependent Claim
65 words
A process for preparing a magnetically responsive particulate reagent carrier by generating in situ a colloidally dispersed superparamagnetic moiety in the interior of a preformed polymeric matrix, said process comprising the steps of: (a) incorporating by passive transport iron compounds into a water-insoluble swellable polymeric matrix; (b) converting the iron compounds so-incorporated to iron oxides; and (c) washing the polymeric matrix to remove soluble by-products.
Claim 12
Dependent Claim
20 words
A process according to claim 9, wherein said polymeric matrix is selected from polymers and copolymers of acrylamide and methacrylamide.
Claim 13
Dependent Claim
49 words
A process according to claim 9 or 10, wherein the step of incorporating said iron compounds comprises diffusing said iron compounds into said matrix, or introducing said polymeric matrix into a solution of iron compounds, to effect passive transport of said iron compounds through swelling of said polymeric matrix.
Claim 14
Dependent Claim
20 words
A process according to claim 9, 10 or 11, wherein said iron compounds are salts of divalent and/or trivalent iron.
Claim 15
Dependent Claim
42 words
A process according to any of claims 9 to 12, wherein the step of converting said iron salts comprises reacting said iron salts with a base to form iron hydroxides and subsequently converting said iron hydroxides to iron oxides, preferably by heating.
Claim 16
Dependent Claim
55 words
A process according to any of claims 9 to 13, including the step of washing said particles following conversion of said iron compounds to the iron oxides, to remove any soluble by-products contained in and/or adhering to said carrier particles, the said step of washing preferably including the step of ultrasonically washing said polymeric matrix.
Claim 17
Dependent Claim
34 words
A process according to any of claims 9 to 14, comprising the further step of heating the dried particles to permanently anchor to their surface any extraneous particulate reaction products adhering to said particles.
Claim 18
Dependent Claim
42 words
A process according to any of claims 9 to 15, including repeating the steps of (a) (b) and (c), so as to increase the concentration of said iron oxides in said polymeric matrix and thereby enhance the magnetic response of said particles.
Claim 19
Dependent Claim
46 words
A process according to any of claims 9 to 16, comprising the additional steps of drying the particles followed by heating them to elevated temperatures to increase the crosslink density of the polymeric matrix, thereby reducing their swelling capacity when exposed to water or aqueous solutions.
Claim 20
Dependent Claim
22 words
A process according to any of claims 9 to 17, comprising the further step of bonding a reagent onto said polymeric matrix.
Claim 21
Dependent Claim
46 words
The use of a reagent carrier as claimed in any of claims 1 to 8 or as made by the process of claim 18, in an immunoassay procedure, or in a manufacturing process involving enzymatic reactions, or in an isolation or purification process utilizing chemical affinity.
References Cited (Backward Citations)
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