Device for mixing and separation of magnetic particles

Abstract

An apparatus for mixing and separating magnetic particles in a liquid comprises a holder having a plurality of apertures configured as an array of rows and columns and a plurality of containers capable of receiving liquid containing magnetic particles, each container being sized to be placed in one of the apertures; plural magnets capable of being moved relative to the containers between a first position and a second position to change the position of the magnets and magnetic particles in the container; and a drive mechanism for moving the magnets between positions at a sufficiently high speed that the particles do not settle down due to gravitational forces during motion between the first and second positions.

What is claimed is: 
     
         1 . An apparatus constructed and arranged for mixing and separating magnetic particles in a liquid, the apparatus comprising:
 a rotatable holder configured to hold a plurality of regularly spaced containers in a circular configuration in a horizontal plane;   a plurality of containers, each container being capable of receiving liquid containing magnetic particles;   a plurality of magnets disposed on a rotatable support and arranged relative to the containers so as to produce at least one magnetic field in each container, said magnets or said containers being rotatable between a first position and a second position so as to alternately subject opposite lateral sides of the container to magnetic field thereby changing the relative angular position of the magnets and the magnetic particles in the containers;   a drive mechanism for rotating either the magnets or the containers in a repetitive motion between the first and second positions with a delay between such movements so as to stop the rotation at a first position for a first time interval before moving to the second position, and to stop the rotation at said second position for a second time interval before moving the magnets back to the first position;   means for stopping the rotary motion so as to position a magnet on one lateral side of the container to separate the magnetic particles as a relatively compact mass.   
     
     
         2 . The apparatus of  claim 1 , wherein the plurality of magnets are configured in a circular configuration disposed on one support linked to the drive mechanism for rotating the support. 
     
     
         3 . The apparatus of  claim 2 , wherein the magnets are substantially rectangular or cylindrical and held generally perpendicularly above the support. 
     
     
         4 . The apparatus of  claim 1 , wherein the drive mechanism additionally comprises an electric motor repetitively rotating the magnets or the containers between first and second positions. 
     
     
         5 . The apparatus of  claim 4 , wherein the motion is configured to rotate the magnets or the containers at a sufficiently high speed to prevent the gravitational settling of magnetic particles during motion between the first and second positions. 
     
     
         6 . The apparatus of  claim 1 , wherein the time interval where the magnets or containers are stopped at either the first or second position is substantially longer than the time interval where the magnets or the containers are moving between either the first or second positions. 
     
     
         7 . The apparatus of  claim 6 , wherein the time interval where the magnets or containers are stopped at either the first or second position is at least 0.25 seconds. 
     
     
         8 . The apparatus of  claim 1 , wherein the repetitive motion of either the magnets or containers is rotary in the horizontal plane. 
     
     
         9 . The apparatus of  claim 1 , wherein the magnets or the containers move simultaneously.