EP0230768A1
Expired / Lapsed
EP
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Particle separation method
Assignee: Syntex USA LLC
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Filing: 1986-12-19
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Granted: —
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Expires: 2006-12-19
Abstract
Abstract A method is disclosed for separating a substance from a liquid medium. The method comprises combining the liquid medium containing the substance with magnetic particles under conditions for non-specific chemical binding of the magnetic particles. Thereafter, the medium is subjected to a magnetic field gradient to separate the particles from the medium. The preferred non-specific binding is achieved as the result of charge interactions between the particles usually by means of a polyionic reagent. The method of the invention has particular application to the separation of cells and microorganisms from aqueous suspensions and also to the determination of an analyte in a sample suspected of containing the analyte. The analyte is a member of a specific binding pair (sbp). The sample is combined in an assay medium with magnetic particles and a sbp member complementary to the analyte. Magnetic or non-magnetic particles capable of specific binding to the analyte or its complementary sbp member must be included in the assay medium. The combination is made under conditions for non-specifically aggregating the magnetic particles or coaggregating the magnetic and non-magnetic particles when non-magnetic particles are present. The assay medium is subjected to a magnetic field gradient to separate the aggregated particles from the medium. Then, the medium or the particles are examined for the presence or amount of the analyte or an sbp member, the binding of which is affected by the presence of the analyte.
Inventors
- 👤 Edwin F. Ullman
- 👤 Nurith Kurn
- 👤 Vartan E. Ghazarossian
- 👤 Litai Weng
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 14:47
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/54333; B; B03; B03C; B03C1/00; B03C1/005; B03C1/01; C; C12; C12Q; C12Q1/00; C12Q1/02; C12Q1/24; G01N33/536; G01N33/537; G01N33/538
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
53 words
A method of separating suspended non-magnetic particles from a liquid medium, which comprises - combining a liquid medium containing non-magnetic particles with magnetic particles under conditions for non-specifically binding said non-magnetic particles and said magnetic particles, and subjecting said medium to a magnetic field gradient to separate said bound particles from said medium.
Claim 2
Independent Claim
53 words
A method of separating suspended non-magnetic particles from a liquid medium, which comprises - combining a liquid medium containing non-magnetic particles with magnetic particles under conditions for non-specifically binding said non-magnetic particles and said magnetic particles, and subjecting said medium to a magnetic field gradient to separate said bound particles from said medium.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein said non-specific binding is the result of charge interactions.
Claim 4
Dependent Claim
40 words
The method of claim 2 wherein said conditions for non-specifically binding said non-magnetic particles with said magnetic particles includes addition to said medium of a polyionic reagent, which is a polycation selected from polybrene, polyethyleneimine, calcium ion and barium ion.
Claim 5
Dependent Claim
40 words
The method of claim 2 or claim 3 wherein said bound non-magnetic particles are treated with a reagent to reverse their binding to said magnetic particles, preferably wherein said reagent to reverse said binding is a polycationic or polyanionic reagent.
Claim 6
Independent Claim
29 words
The method of any one of claims 1 to 4 wherein said non-magnetic particles are selected from biological particles and synthetic particles, preferably wherein said biological particles are erythrocytes.
Claim 7
Independent Claim
25 words
The method of any one of the preceding claims wherein said magnetic particles are present in a ferrofluid prior to combination with said non-magnetic particles.
Claim 8
Dependent Claim
116 words
A method of claim 1 for the determination of an analyte in a sample suspected of containing said analyte, wherein said analyte is a member of a specific binding pair (sbp), and wherein a labelled sbp member is separated from the assay mixture in relation to the concentration of said analyte, which method further comprises - combining in an assay medium said sample, said magnetic particles, and said labelled sbp member, where said particles are capable of binding to said labelled sbp member, separating said labelled sbp member from said medium by non-specifically aggregating by chemical means said magnetic particles, and examining said medium or said magnetic particles for the presence of said labelled sbp member.
Claim 9
Dependent Claim
28 words
The method of claim 7 wherein said labelled sbp member is a non-magnetic particle or a component thereof and said non-magnetic particles and said magnetic particles non-specifically coaggregate.
Claim 10
Dependent Claim
27 words
The method of claim 7 or claim 8 wherein said non-magnetic particles are selected from biological particles and synthetic particles, preferably wherein said biological particles are erythrocytes.
Claim 11
Dependent Claim
28 words
A method of claim 2 for separating cells from whole blood, which comprises - combining in said liquid medium a whole blood sample and said charged magnetic particles.
Claim 12
Independent Claim
79 words
A method for separating a substance that is dispersed in a liquid medium from said medium where said substance is caused to bind to magnetic particles, said magnetic particles are caused to aggregate and said medium is subjected to a magnetic field gradient to separate said aggregated mag netic particles from said medium, characterised in that the method comprises causing the magnetic particles to aggregate by inclusion in said medium of chemical means for non-specifically aggregating said magnetic particles.
Claim 13
Independent Claim
79 words
A method for separating a substance that is dispersed in a liquid medium from said medium where said substance is caused to bind to magnetic particles, said magnetic particles are caused to aggregate and said medium is subjected to a magnetic field gradient to separate said aggregated mag netic particles from said medium, characterised in that the method comprises causing the magnetic particles to aggregate by inclusion in said medium of chemical means for non-specifically aggregating said magnetic particles.
Claim 14
Dependent Claim
28 words
The method of claim 11 wherein said medium is aqueous, said magnetic particles are charged, and said chemical means is for aggregating said magnetic particles by charge interactions.
Claim 15
Dependent Claim
29 words
The method of claim 12 wherein said chemical means is selected from low ionic strength buffer and a polyionic reagent of charge opposite to that of said magnetic particles.
Claim 16
Dependent Claim
44 words
A composition comprising an aggregate of (a) non-magnetic particles to which are bound a member of a specific binding paid (sbp) consisting of ligand and its complementary receptor non-specifically electrostatically bound to (b) magnetic particles or an aggregate of magnetic particles non-specifically bound together.
Claim 17
Dependent Claim
44 words
A composition comprising an aggregate of (a) non-magnetic particles to which are bound a member of a specific binding paid (sbp) consisting of ligand and its complementary receptor non-specifically electrostatically bound to (b) magnetic particles or an aggregate of magnetic particles non-specifically bound together.
Claim 18
Dependent Claim
97 words
A kit for conducting an assay for determining an analyte in a sample suspected of containing said analyte, said analyte being a member of a specific binding pair consisting of ligand and its complementary receptor, said kit comprising (a) an sbp member complementary to said analyte, (b) an sbp member bound to a charged particle if neither said analyte nor said complementary sbp member is bound to a charged particle, (c) charged magnetic particles where said charged particle is not magnetic, and (d) a non-specific chemical binding agent for coagglutinating said charged particles and charged magnetic particles.
Claim 19
Dependent Claim
97 words
A kit for conducting an assay for determining an analyte in a sample suspected of containing said analyte, said analyte being a member of a specific binding pair consisting of ligand and its complementary receptor, said kit comprising (a) an sbp member complementary to said analyte, (b) an sbp member bound to a charged particle if neither said analyte nor said complementary sbp member is bound to a charged particle, (c) charged magnetic particles where said charged particle is not magnetic, and (d) a non-specific chemical binding agent for coagglutinating said charged particles and charged magnetic particles.
References Cited (Backward Citations)
US2232295A
Cited
DE2037646A1
Cited
US3853987A
Cited
US3933997A
Cited
US4001197A
Cited
US3970518A
Cited
US4018886A
Cited
US4019994A
Cited
US4241176A
Cited
US4070246A
Cited
US4115534A
Cited
US4115535A
Cited
US4318980A
Cited
GB2019378A
Cited
US4275149A
Cited
US4318707A
Cited
EP0127906A1
Cited
US4299916A
Cited
US4285819A
Cited
US4413070A
Cited
WO1983001398A1
Cited
US4454234A
Cited
US4452773A
Cited
US4564598A
Cited
US4526681A
Cited
GB2152664A
Cited
US4523996A
Cited
EP0162819A1
Cited
JPS61210516A
Cited
AU6236586A
Cited
EP0214847A2
Cited
US4806488A
Cited
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