Machine for mixing and separating magnetic particles

Abstract

An apparatus for carrying out the affinity separation of a target substance from a test medium by mixing magnetic particles having surface immobilized ligand or receptor within the test medium to promote an affinity binding reaction between the ligand and the target substance. A container with a liquid and magnetic particles therein is positioned between two plates with magnets thereon. The plates are fixed to a common shaft. Either the container or the plates are rotated to impart a relative angular movement of the particles relative to a magnet. The shaft is horizontally orientated and the plates can be hexagonal shaped.

1 . A device for mixing and separating magnetic particles in a liquid, comprising;
 at least one container having a liquid and magnetic particles therein;   means for holding said container;   a first magnet support holding at least one magnet thereon;   a second magnet support offset from the first magnet support to create a gap therebetween; and at least one magnet mounted thereon at an orientation of about 180 degrees from the angular position of said magnet mounted on said first magnet support;   said first and second supports fixed to a common shaft rotatable on a common axis and separated by a sufficiently wide gap to permit the rotation of the two supports without hindrance from said container;   means for repeatedly positioning a magnet on the opposite sides of said container by rotating the said magnet supports, thereby alternately exposing the said magnetic particles to magnetic field from opposite directions;   means for mixing magnetic particles in said liquid by first positioning a magnet on one side of said container by rotating either the first or second magnet support to agglomerate magnetic particles on one side of said container nearest the magnet, then rotating either the first or second magnet support to position the magnet on the opposite side of said container thereby causing the agglomerated particles to breakup, disperse and migrate to the opposite side of said container nearest the magnet, wherein magnetic particles are subjected to repeated breakup, dispersion and migration.   means for stopping the rotation of said magnet supports and positioning one magnet at the outside wall of said container to separate and agglomerate said magnetic particles on the inside wall of said container nearest the magnet.   
     
     
         2 . The device of  claim 1 , wherein said means for rotating is by at least one electric motor operated and controlled by electronic means. 
     
     
         3 . The device of  claim 1 , wherein said rotation is step-wise at an angular acceleration of about 21 radians/sec/sec. or higher with a delay time of about 0.25 seconds or higher between successive positioning of said magnets. 
     
     
         4 . The device of  claim 1 , wherein said first and second supports can be independently rotated on a common axis. 
     
     
         5 . The device of  claim 1 , wherein said device comprises means for oscillating said magnet supports by alternately rotating in clockwise or anticlockwise directions. 
     
     
         6 . The device of  claim 1 , wherein said magnetic particles are non-colloidal paramagnetic or super paramagnetic. 
     
     
         7 . The device of  claim 1 , constructed and arranged to isolate nucleic acid or proteins by affinity binding on magnetic, paramagnetic or super paramagnetic particles and separation of said magnetic particles from liquid by magnets. 
     
     
         8 . The device of  claim 1 , wherein the device is configured to agglomerate magnetic particles, and then breakup and disperse said agglomerated magnetic particles by magnetically induced movement of magnetic particles in said liquid thereby promoting mixing is said liquid. 
     
     
         9 . A device for mixing magnetic particles, comprising;
 at least one container having a liquid and said particles therein;
 said container mounted on a container support; 
   at least two magnet supports fixed to a horizontally orientated rotatable shaft, said magnet supports positioned opposite each other and separated by a sufficient distance to position said container substantially centered therebetween;   each magnet support having at least one magnet mounted thereon, wherein the magnet position on two magnet supports differs by an angular position of about 180 degrees or less;   said device construced and arranged to provide repetitively changing direction of magnetic field by rotating said magnet supports to alternately position said magnets on the opposite sides of said container thereby mixing said magnetic particles in liquid.   
     
     
         10 . The device of  claim 9 , wherein said rotation is step-wise with a sufficient delay time to collect substantially all the migrating magnetic particles in the liquid between each change in the direction of magnetic field. 
     
     
         11 . The device of  claim 10 , wherein said step-wise rotation is at a sufficiently rapid rate to prevent the gravitational settling down of the magnetic particles agglomerated on the inside wall of said container between each change in the direction of magnetic field. 
     
     
         12 . The device of  claim 9 , wherein said magnets are rare earth high energy magnets of rectangular or round shape. 
     
     
         13 . The device of  claim 9 , wherein said magnets repetitively subject one lateral side of said container at a time to magnetic field, thereby subjecting agglomerated magnetic particles at the opposite side of said container to breakup, disperse and migrate to the side of said container nearest said magnet, wherein mixing occurs during magnetically induced repetitive movement of magnetic particles between two sides of said container. 
     
     
         14 . The device of  claim 9 , wherein said container is substantially cylindrical and tapers to a conical shape with a closed end. 
     
     
         15 . The device of  claim 9 , wherein said magnet supports are rotatable on a common axis perpendicular to the longitude of said container. 
     
     
         16 . The device of  claim 9 , wherein said magnet supports are fixed and said container is rotated to position said magnets on opposite sides of said container. 
     
     
         17 . The device of  claim 9 , wherein said container comprises a row of containers spaced apart and mounted in a support, and means for moving one container at a time to a position between said two magnet supports. 
     
     
         18 . A device for mixing and separating magnetic particles, comprising;
 at least one container having a liquid and said particles therein;
 said container mounted on a container support; 
   at least two magnet supports fixed to a shaft;
 each magnet support having at least one magnet mounted thereon; 
   said at least one container positioned between said magnet supports;
 said magnets parallel positioned opposite each other but at a sufficiently different angle to substantially reduce the mixing of two magnetic fields acting on said container; 
   said device constructed and arranged to provide relative angular movement between a magnet and said magnetic particles on rotation of either the container or the magnet supports.   
     
     
         19 . The device of  claim 18 , wherein said opposite magnets are separated by an angular position of about 90 to about 180 degrees. 
     
     
         20 . The device of  claim 18 , where said rotation is step-wise at an acceleration of about 21 radians/sec./sec. or higher with a delay time of about 0.25 seconds or higher between each change in the direction of magnetic field.