US4473452A
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Electrophoresis using alternating transverse electric fields
Assignee: Columbia University
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Filing: 1982-11-18
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Granted: 1984-09-25
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Expires: 2002-11-18
Abstract
Abstract Disclosed are an apparatus for and a method of electrophoretically separating particles by electric fields which are transverse to each other, which alternate between respective high and low intensities out of phase with each other at a frequency related to the mass of the particles and which move the particles in an overall direction transverse to the respective directions of the fields. For separating large macromolecules, at least one of the fields preferably has an intensity gradient in a direction transverse to its own. The new arrangement makes it possible to: (1) separate particles (molecules) larger in size than those able to be separated with previously known techniques, (2) carry out separation at higher speed and at better resolution than is possible with previously known techniques, and (3) concurrently separate particles which differ greatly in mass (molecular weight).
Inventors
- 👤 Charles R. Cantor
- 👤 David C. Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:34
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44756; G01N27/44773
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
83 words
An analytical electrophoresis method of separating particles which is capable of separating at least large DNA molecules and comprises subjecting said particles in a suitable medium to at least two electric fields varying with time and having generally co-planar overall directions which are transverse to each other, to move the particles in an overall direction generally co-planar with but transverse to the respective overall directions of said fields to achieve high resolution analytical electrophoresis separation of said particles into a pattern of bands.
Claim 2
Dependent Claim
83 words
An analytical electrophoresis method of separating particles which is capable of separating at least large DNA molecules and comprises subjecting said particles in a suitable medium to at least two electric fields varying with time and having generally co-planar overall directions which are transverse to each other, to move the particles in an overall direction generally co-planar with but transverse to the respective overall directions of said fields to achieve high resolution analytical electrophoresis separation of said particles into a pattern of bands.
Claim 3
Dependent Claim
43 words
A method as in claim 1 in which at least one of the fields has an intensity gradient in a direction transverse to and generally co-planar with its overall direction for at least a portion of the time it acts on the particles.
Claim 4
Dependent Claim
30 words
A method as in claim 1 or 2 in which said at least two fields vary by alternating between respective low and high intensities out of phase with each other.
Claim 5
Dependent Claim
24 words
A method as in claim 3 in which the timing of said alternating is related to the mass of the particles to be separated.
Claim 6
Dependent Claim
38 words
A method as in claim 1 in which said fields acting on the particles to cause them to move vary with time as a function of the mass of the particles raised to the power of about 1.5.
Claim 7
Dependent Claim
13 words
A method as in claim 1 in which the particles are polypeptide molecules.
Claim 8
Dependent Claim
16 words
A method as in claim 1 in which the particles are myosin or hyaluronic acid molecules.
Claim 9
Dependent Claim
14 words
A method as in claim 1 in which the particles are nucleic acid molecules.
Claim 10
Dependent Claim
15 words
A method as in claim 8 in which the nucleic acid molecules are DNA molecules.
Claim 11
Dependent Claim
12 words
A method as in claim 1 in which the particles are chromosomes.
Claim 12
Dependent Claim
15 words
A method as in claim 10 in which said chromosomes are derived from a eucaryote.
Claim 13
Dependent Claim
13 words
A method as in claim 1 in which the particles are human chromosomes.
Claim 14
Dependent Claim
13 words
A method as in claim 1 in which the particles are animal chromosomes.
Claim 15
Dependent Claim
13 words
A method as in claim 1 in which the particles are plant chromosomes.
Claim 16
Dependent Claim
13 words
A method as in claim 1 in which the particles are yeast chromosomes.
Claim 17
Dependent Claim
27 words
A method as in claim 1 in which the particles move in a gel medium having an effective pore size less than the size of the particles.
Claim 18
Dependent Claim
59 words
A method as in claim 16 in which the particles being separated are obtained by lysing whole cells or spheroplasts in an insert of the same or a compatible gel which is thereafter placed in said gel medium and in which said electrophoretic separation is carried out without first separating said particles from the lysed whole cells of spheroplasts.
Claim 19
Dependent Claim
91 words
A method as in claim 1 in which said medium is a layer of gel and including the step of suspending whole cells or spheroplasts in the same or compatible gel material and solidifying the suspension into a solid insert, lysing the cells or spheroplasts without removing them from the solidified gel insert, and thereafter placing the lysed insert into a matching well in said layer of gel and subjecting it to said electric fields, and wherein at least one of said fields has an intensity gradient along the gel layer.
Claim 20
Dependent Claim
45 words
A method as in claim 1 in which said medium has a pore size less than the particle size and the action of said electric field on the particles repeatedly changes the molecular configuration of the particles to cause them to move through said medium.
Claim 21
Dependent Claim
22 words
A method as in claim 1 including controlling said field for selective sharpening of a selected part of said pattern of bands.
Claim 22
Independent Claim
111 words
A method of detecting or diagnosing genetic phenomena correlated with variations in the molecular weight of chromosomes, nucleic acids or proteins comprising separating the chromosomes, nucleic acids or proteins into an analytical electrophoresis band pattern by subjecting them to electric fields which have overall directions transverse to and generally co-planar with each other, at least one of which has a field intensity gradient transverse to and generally co-planar with its overall direction, and wherein the respective intensities of the fields are varied over time periods which are out of phase as between respective fields and are related to the molecular weight of the chromosomes, nucleic acids or proteins to be separated.
Claim 23
Independent Claim
111 words
A method of detecting or diagnosing genetic phenomena correlated with variations in the molecular weight of chromosomes, nucleic acids or proteins comprising separating the chromosomes, nucleic acids or proteins into an analytical electrophoresis band pattern by subjecting them to electric fields which have overall directions transverse to and generally co-planar with each other, at least one of which has a field intensity gradient transverse to and generally co-planar with its overall direction, and wherein the respective intensities of the fields are varied over time periods which are out of phase as between respective fields and are related to the molecular weight of the chromosomes, nucleic acids or proteins to be separated.
Claim 24
Independent Claim
141 words
An apparatus for analytical electrophoresis comprising: a support for a medium in which one or more samples of particles to be separated can be placed; means for generating electric fields which act on the particles along respective different overall directions transverse to and generally co-planar with each other and for causing at least one of the fields to have an intensity gradient transverse to and generally co-planar with its overall direction; and means for repetitively varying selected characteristics of the respective fields over time periods which are out of phase as between different fields and are related to the mass of the particles to be separated, to move the particles in an overall direction transverse to and generally co-planar with the respective overall direction of each of two varying fields and thereby separate said particles into an analytical electrophoresis band pattern.
Claim 25
Independent Claim
141 words
An apparatus for analytical electrophoresis comprising: a support for a medium in which one or more samples of particles to be separated can be placed; means for generating electric fields which act on the particles along respective different overall directions transverse to and generally co-planar with each other and for causing at least one of the fields to have an intensity gradient transverse to and generally co-planar with its overall direction; and means for repetitively varying selected characteristics of the respective fields over time periods which are out of phase as between different fields and are related to the mass of the particles to be separated, to move the particles in an overall direction transverse to and generally co-planar with the respective overall direction of each of two varying fields and thereby separate said particles into an analytical electrophoresis band pattern.
Claim 26
Dependent Claim
40 words
Electrophoresis apparatus as in claim 22 in which the field generating means comprise at least three discrete electrodes spaced apart from each other and means for maintaining the respective electrodes at respective independently selectable potentials for respective selected time periods.
Claim 27
Independent Claim
86 words
An apparatus for analytical electrophoresis comprising: a support for a layer of medium in which one or more samples of particles can be placed for separation into an analytical electrophoresis band pattern along the plane of the layer; at least three electrodes spaced from each other and arranged at selected positions to contact the medium; and means for maintaining the respective electrodes at respective independently selectable electrical potentials for respective selected time periods to effect said separation of the particles into an analytical electrophoresis band pattern.
Claim 28
Independent Claim
86 words
An apparatus for analytical electrophoresis comprising: a support for a layer of medium in which one or more samples of particles can be placed for separation into an analytical electrophoresis band pattern along the plane of the layer; at least three electrodes spaced from each other and arranged at selected positions to contact the medium; and means for maintaining the respective electrodes at respective independently selectable electrical potentials for respective selected time periods to effect said separation of the particles into an analytical electrophoresis band pattern.
Claim 29
Dependent Claim
85 words
An electrophoresis apparatus as in claim 24 in which the means for maintaining the electrodes at respective potentials comprise means for causing the electrodes to generate at least two electrical fields having a selected characteristic varying out of phase as between the two fields, said fields having overall directions transverse to each other in the layer plane and causing the particles to move in a third overall direction which is along the layer plane and is transverse to the respective overall directions of said fields.
Claim 30
Dependent Claim
54 words
An apparatus as in claim 25 in which the means for causing the electrodes to generate said at least two electric fields comprise diode connections between the at least three electrodes which are switchable to selectively energize selectable combinations or subcombinations of electrodes to thereby control the intensity, uniformity and/or gradients of said fields.
References Cited (Backward Citations)
US4148703A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-25 | 1988-03-26 | 1988-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-25 | 1992-03-26 | 1992-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-25 | 1996-03-26 | 1996-09-25 | $7700.00 | Window Closed / Lapsed |