Flow-controlled magnetic particle manipulation
First Claim
1. A method comprising:
- providing a fluid flow path, the fluid flow path having first and second ends, a fluid flow controller effective to variably impose a positive or negative pressure on the flow path to cause controlled fluid flow through the fluid flow path in a first or second direction at predetermined rates, and a capture zone between the first and second ends, wherein a fixed magnetic field intercepts the fluid flow path in the capture zone;
providing in the fluid flow path a first mixture including a plurality of solid magnetic particles dispersed in a carrier medium;
passing the first mixture through the capture zone at a first predetermined capture rate whereby a major portion of the magnetic particles become trapped in the capture zone by the force of the magnetic field and thereby separated from the carrier medium to form a first magnetic particle isolate;
perfusing the first magnetic particle isolate with a first dispersion medium; and
pulsing the first dispersion medium through the capture zone at a first predetermined dispersion rate effective to dislodge the first magnetic particle isolate from the capture zone, move the magnetic particles from the magnetic field, and suspend the magnetic particles in the first dispersion medium to provide a second mixture.
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Accused Products
Abstract
Inventive methods and apparatus are useful for collecting magnetic materials in one or more magnetic fields and resuspending the particles into a dispersion medium, and optionally repeating collection/resuspension one or more times in the same or a different medium, by controlling the direction and rate of fluid flow through a fluid flow path. The methods provide for contacting derivatized particles with test samples and reagents, removal of excess reagent, washing of magnetic material, and resuspension for analysis, among other uses. The methods are applicable to a wide variety of chemical and biological materials that are susceptible to magnetic labeling, including, for example, cells, viruses, oligonucleotides, proteins, hormones, receptor-ligand complexes, environmental contaminants and the like.
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Citations
59 Claims
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1. A method comprising:
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providing a fluid flow path, the fluid flow path having first and second ends, a fluid flow controller effective to variably impose a positive or negative pressure on the flow path to cause controlled fluid flow through the fluid flow path in a first or second direction at predetermined rates, and a capture zone between the first and second ends, wherein a fixed magnetic field intercepts the fluid flow path in the capture zone;
providing in the fluid flow path a first mixture including a plurality of solid magnetic particles dispersed in a carrier medium;
passing the first mixture through the capture zone at a first predetermined capture rate whereby a major portion of the magnetic particles become trapped in the capture zone by the force of the magnetic field and thereby separated from the carrier medium to form a first magnetic particle isolate;
perfusing the first magnetic particle isolate with a first dispersion medium; and
pulsing the first dispersion medium through the capture zone at a first predetermined dispersion rate effective to dislodge the first magnetic particle isolate from the capture zone, move the magnetic particles from the magnetic field, and suspend the magnetic particles in the first dispersion medium to provide a second mixture. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. An apparatus, comprising:
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a fluid flow path, the fluid flow path having first and second ends and a capture zone between the first and second ends;
a fluid flow controller effective to variably impose a positive or negative pressure on the flow path to cause controlled fluid flow through the fluid flow path in a first or second direction at predetermined rates;
a magnetic field source generating a fixed magnetic field, the source positioned in a fixed relationship to the fluid flow path whereby the field intercepts the fluid flow path in the capture zone; and
a detector positioned to detect a physical or chemical property of a fluid in the flow path. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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55. An apparatus, comprising:
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a fluid flow path, the fluid flow path having first and second ends and a plurality of capture zones between the first and second ends;
a fluid flow controller effective to variably impose a positive or negative pressure on the flow path to cause controlled fluid flow through the fluid flow path in a first or second direction at predetermined rates; and
a plurality of magnetic field sources, each source generating a fixed magnetic field, and each the source positioned in a fixed relationship to the fluid flow path whereby each field intercepts the fluid flow path in a capture zone;
wherein each capture zone is separated from one or more other capture zones by a zone that is substantially free from a magnetic field.
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56. An apparatus, comprising:
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a fluid flow path means having first and second ends and a capture zone between the first and second ends;
means for providing in the fluid flow path a first mixture including a plurality of solid magnetic particles dispersed in a carrier medium;
means for variably imposing a positive or negative pressure on the fluid flow path means to cause controlled fluid flow through the fluid flow path in a first or second direction at predetermined rates; and
means for providing a fixed magnetic field that intercepts the fluid flow path means in the capture zone.
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57. A method comprising:
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passing a mixture including a plurality of solid magnetic particles dispersed in a carrier medium through a conduit extending through a fixed magnetic field at a first predetermined capture rate whereby magnetic particles become trapped in the field and thereby separated from the carrier medium to form a magnetic particle isolate;
passing a dispersion medium into the conduit and into contact with the magnetic particle isolate; and
pulsing the dispersion medium through the conduit at a first predetermined dispersion rate effective to move the magnetic particles from the magnetic field and suspend the magnetic particles in the dispersion medium.
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58. A method comprising:
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passing a first mixture including a plurality of solid magnetic particles dispersed in a carrier medium through a conduit extending through a magnetic field at a first predetermined capture rate whereby magnetic particles become trapped in the field and thereby separated from the carrier medium to form a magnetic particle isolate;
releasing the magnetic particle isolate from the magnetic field by pulsing a dispersion medium through the conduit at a first predetermined dispersion rate effective to move the magnetic particles from the magnetic field and suspend the magnetic particles in the dispersion medium to provide a second mixture; and
recapturing the magnetic particles by passing the second mixture through the magnetic field in a direction opposite said passing of the first mixture, at a second predetermined capture rate whereby magnetic particles become trapped in the field and thereby separated from the carrier medium to form a magnetic particle isolate. - View Dependent Claims (59)
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Specification