Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C1/00—Magnetic separation
  • B03C1/02—Magnetic separation acting directly on the substance being separated
  • B03C1/035—Open gradient magnetic separators, i.e. separators in which the gap is unobstructed, characterised by the configuration of the gap
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C1/00—Magnetic separation
  • B03C1/02—Magnetic separation acting directly on the substance being separated
  • B03C1/025—High gradient magnetic separators
  • B03C1/031—Component parts; Auxiliary operations
  • B03C1/033—Component parts; Auxiliary operations characterised by the magnetic circuit
  • B03C1/0332—Component parts; Auxiliary operations characterised by the magnetic circuit using permanent magnets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C1/00—Magnetic separation
  • B03C1/02—Magnetic separation acting directly on the substance being separated
  • B03C1/28—Magnetic plugs and dipsticks
  • B03C1/288—Magnetic plugs and dipsticks disposed at the outer circumference of a recipient
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/02—Permanent magnets [PM]
  • H01F7/0273—Magnetic circuits with PM for magnetic field generation
  • H01F7/0278—Magnetic circuits with PM for magnetic field generation for generating uniform fields, focusing, deflecting electrically charged particles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C2201/00—Details of magnetic or electrostatic separation
  • B03C2201/18—Magnetic separation whereby the particles are suspended in a liquid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C2201/00—Details of magnetic or electrostatic separation
  • B03C2201/22—Details of magnetic or electrostatic separation characterised by the magnetic field, e.g. its shape or generation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C2201/00—Details of magnetic or electrostatic separation
  • B03C2201/26—Details of magnetic or electrostatic separation for use in medical or biological applications

Definitions

• cells tagged with micron sized (0.1 ⁇ m) magnetic or magnetized particles can be removed or separated from mixtures using magnetic devices that either repel or attract the tagged cells.
• desired cells i.e., cells which provide valuable information
• the desired cell population is magnetized and removed from the complex liquid mixture (positive separation).
• the undesirable cells i.e., cells that may prevent or alter the results of a particular procedure, are magnetized and subsequently removed with a magnetic device (negative separation).
• the magnetic force of attraction between these smaller particles and the separating magnet is directly related to the size (volume and surface area) of the particle.
• Small magnetic particles are weak magnets.
• the magnetic gradient of the separating magnetic device must increase to provide sufficient force to pull the labeled cells toward the device.
• the magnetic pole device of the present invention has four polar magnets and any number of interpolar magnets adjacent to and in between said polar magnets.
• the interpolar magnets are positioned to progressively rotate towards the orientation of the four polar magnets.
• Such a magnetic device creates a high flux density gradient within the liquid sample and causes radial movement of magnetized particles toward the inner wall of the surrounding magnets.
• the present invention relates to a method of separating non- magnetized cells from magnetized cells using the magnetic device of the present invention.
• Figure 1 is an illustration of a top view (cross-section) of one version of the magnetic device of the present invention showing eight adjacent magnet segments with four (4) polar magnets and four (4) interpolar magnets.
• Figure 2 is an illustration of another embodiment of the present invention showing the top of a rod-shaped magnet that is positioned in the center of the cylindrical space defined by the magnetic device of the present invention.
• the magnetic pole device of the present invention has four polar magnets and any number of interpolar magnets adjacent to and in between said polar magnets.
• the interpolar magnets are positioned to progressively rotate towards the orientation of the four polar magnets to form a cylinder.
• Such a magnetic device would create an even flux within a liquid sample and cause the efficient radial movement of magnetized particles toward the inner wall of the surrounding magnets.
• north polar magnet refers to a magnet positioned so that its north pole is positioned toward the interior of the magnetic device.
• South polar magnet refers to a magnet oriented so that its south pole faced the interior of the device.
• interpolar magnets refer to the magnets positioned in between the north polar and south polar magnets and oriented so that an imagined line between the interpolar magnet's north and south poles is approximately perpendicular to the center of the device, i.e., the inte ⁇ olar magnet vectors are between the unlike interior poles of the polar magnets. Therefore, the polarity of the inte ⁇ olar magnets is such that like poles abut toward the interior of the device. Supe ⁇ osition of the magnetic fields from all magnets results in a high gradient internal magnetic field. Abutting unlike poles on the exterior of the device results in a low reluctance outer return path with minimal external flux leakage.
• cylinder as used herein is intended to include what is conventionally understood to mean a cylinder, a tube, a ring, a pipe or a roll and intended to include a cylinder that defines any shape between an octagon (such as would be found with the device depicted in Figure 1) and a circle.
• the dimensions (i.e. length and diameter) of the defined cylinder needs to be sufficiently large enough to accommodate the insertion of any test tube containing the liquid sample.
• Magnets of the present invention can be constructed of iron, nickel, cobalt and generally rare earth metals such as cerium, praseodymium, neodymium and samarium. Acceptable magnets can be constructed of mixtures of the above listed metals (i.e. alloys) such as samarium cobalt or neodymium iron boron. Ceramic, or any other high coercivity material with intrinsic coercivity greater than the flux density produced by supe ⁇ osition where like magnetic poles abut materials, may be used as well.
• the magnetic device comprises eight (8) magnets arranged at 45° intervals. Inward polarity of these magnets is illustrated in Figure 1. The magnets with two designations (i.e., N-S, S-N) are arranged such that the poles are pe ⁇ endicular to the center sample volume. Magnetic flux is directed between the closest opposite poles.
• the magnetic device further comprises a rod-shaped magnet that is positioned in the center of the cylindrical space defined by the magnetic device (see Figure 2). It is believed that such a rod-shaped magnet would contribute to cause the migration of magnetized substances toward the inner walls of the magnetic device of the present invention.
• the rod-shaped magnet could be attached to the inside of a test tube cap or stopper. The rod-shaped magnet would be inserted into the test tube and the attached test tube cap would seal the top of the test tube. The test tube would then be paled into the magnetic device of the present invention for the incubation step to separate the magnetized substances from the non-magnetized substances.
• the tube was then centrifuged at 200g (900-1000 RPM on Sorvall 6000B) for 10 minutes at room temperature. The supernatant was aspirated and the pellet was dispersed with 1 ml of dilution buffer containing 0.5% bovine serum albumin (BSA) (Sigma, St. Louis, Mo.) in phosphate buffered saline (PBS) (BSA/PBS dilution buffer).
• BSA bovine serum albumin
• PBS phosphate buffered saline
• FLMC fetal liver mononuclear cells
• Mouse anti-CD45 (a leukocyte common antigen) (100 ⁇ g/ml) was diluted to 1 ⁇ g/ml by adding 2 ⁇ l of the antibody to 198 ⁇ l of the BSA/PBS dilution buffer.
• Goat anti- mouse antibody, tagged with magnetic particles purchased from Immunicon (Huntington Valley, PA) was diluted from a concentration of 500 ⁇ g/ml to 15 ⁇ g/ml by adding 30 ⁇ l of the tagged antibody (ferrofluid) to 970 ⁇ l of a dilution buffer provided by Immunicon (ferrofluid dilution buffer).
• Resuspended debulked and spiked cells debulked by the method described above, in 750 ⁇ l in the BSA/PBS dilution buffer in 2 ml tube. 200 ⁇ l of the diluted mouse anti- CD45 antibody was added to the resuspended cells. The cells and antibody were incubated at room temperature for 15 minutes.
• a 2 ml tube for each sample was placed into two magnetic devices, one being an eight (8) poled magnetic device shown in Figure 2 and one purchased from Immunicon (a four-poled magnetic device) and allowed to separate for 5 minutes at room temperature.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Apparatus Associated With Microorganisms And Enzymes (AREA)
• Investigating Or Analysing Biological Materials (AREA)
• Micro-Organisms Or Cultivation Processes Thereof (AREA)
• Centrifugal Separators (AREA)
• Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
• Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (8)

Cited By (2)

Families Citing this family (55)

Citations (2)

Family Cites Families (4)

• 1997
  • 1997-06-04 US US08/868,598 patent/US6451207B1/en not_active Expired - Lifetime
• 1998
  • 1998-06-04 JP JP50303499A patent/JP4444377B2/ja not_active Expired - Lifetime
  • 1998-06-04 DE DE69825890T patent/DE69825890T2/de not_active Expired - Lifetime
  • 1998-06-04 AT AT98928931T patent/ATE274376T1/de not_active IP Right Cessation
  • 1998-06-04 WO PCT/US1998/011816 patent/WO1998055236A1/en not_active Ceased
  • 1998-06-04 CA CA002292631A patent/CA2292631C/en not_active Expired - Lifetime
  • 1998-06-04 AU AU80616/98A patent/AU753848B2/en not_active Expired
  • 1998-06-04 EP EP98928931A patent/EP0986436B1/en not_active Expired - Lifetime
• 2002
  • 2002-09-13 US US10/244,126 patent/US6572778B2/en not_active Expired - Lifetime

Patent Citations (2)

Non-Patent Citations (2)

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