Magnetic material for collecting magnetic particles and utilization thereof

Abstract

For collecting magnetic particles, there is used a magnetic material including a plurality of magnets that are arranged in contact one with another in parallel to a direction of magnetization in such a manner that south and north poles of adjacent magnets are reversed alternately or a magnetic material having at least one peak of a magnetic force in a magnetic pole surface, and the peak magnetic force is 600 gausses or more.

1 . A magnetic material for collecting magnetic particles, comprising a plurality of magnets that are arranged in contact one with another in parallel to a direction of magnetization in such a manner that south and north poles of adjacent magnets are reversed alternately.  
     
     
         2 . A magnetic material for collecting magnetic particles, having at least one peak of a magnetic force in a magnetic pole surface, wherein the peak magnetic force is 600 gausses or more.  
     
     
         3 . A method of collecting magnetic particles by adsorbing and holding magnetic particles in a liquid on a wall surface by a magnetic force and then making the magnetic particles unaffected by the magnetic force to release the magnetic particles, comprising the step of generating the magnetic force from a magnetic material for collecting the magnetic particles, wherein the magnetic material includes a plurality of magnets that are arranged in contact one with another in parallel to a direction of magnetization in such a manner that south and north poles of adjacent magnets are reversed alternately.  
     
     
         4 . The method according to  claim 3 , wherein the wall surface is an inner wall surface of a liquid suction line of a dispenser that sucks a liquid from a vessel and discharges the liquid.  
     
     
         5 . The method according to  claim 3 , wherein the magnetic particles are used for performing an immunoassay.  
     
     
         6 . A method of collecting magnetic particles by adsorbing and holding magnetic particles in a liquid on a wall surface by a magnetic force and then making the magnetic particles unaffected by the magnetic force to release the magnetic particles, comprising the step of generating the magnetic force from a magnetic material for collecting the magnetic particles, wherein the magnetic material has at least one peak of a magnetic force in a magnetic pole surface, and the peak magnetic force is 600 gausses or more.  
     
     
         7 . The method according to  claim 6 , wherein the wall surface is an inner wall surface of a liquid suction line of a dispenser that sucks a liquid from a vessel and discharges the liquid.  
     
     
         8 . The method according to  claim 6 , wherein the magnetic particles are used for performing an immunoassay.  
     
     
         9 . A method of an immunoassay for a substance to be tested which is present in a sample, comprising: 
 (a) a first reaction step of adding, to a sample, magnetic particles having carried thereon a first substance capable of specifically binding to the substance to be tested and contained in the sample to cause reaction,    (b) a first separation step of separating a first reaction product formed in the first reaction step from the reaction system,    (c) a second reaction step of adding a second substance capable of specifically binding to the separated first reaction product to cause reaction to form a second reaction product in the reaction system,    (d) a second separation step of separating the second reaction product formed in the second reaction step from the reaction system, and    (e) a measuring step of measuring an amount of the separated second reaction product,    wherein the separation of the first and second reaction products from the reaction system is performed by using a magnetic material for collecting magnetic particles, the magnetic material comprising a plurality of magnets that are arranged in contact one with another in parallel to a direction of magnetization in such a manner that south and north poles of adjacent magnets are reversed alternately.    
     
     
         10 . The method according to  claim 9 , wherein the measurement of the amount of the second reaction product is performed by a chemiluminescent method or a fluorescent method.  
     
     
         11 . A method of immunoassay for a substance to be tested which is present in a sample, comprising: 
 (a) a first reaction step of adding, to a sample, magnetic particles having carried thereon a first substance capable of specifically binding to a substance to be tested contained in the sample to cause reaction,    (b) a first separation step of separating a first reaction product formed in the first reaction step from the reaction system,    (c) a second reaction step of adding a second substance capable of specifically binding to the separated first reaction product to cause reaction to form a second reaction product in the reaction system,    (d) a second separation step of separating the second reaction product formed in the second reaction step from the reaction system, and    (e) a measuring step of measuring an amount of the separated second reaction product,    wherein the separation of the first and second reaction products from the reaction system is performed by using a magnetic material having at least one peak of a magnetic force in a magnetic pole surface, the peak magnetic force being at 600 gausses or more.    
     
     
         12 . The method according to  claim 11 , wherein the measurement of the amount of the second reaction product is performed by a chemiluminescent method or a fluorescent method.  
     
     
         13 . An apparatus comprising: 
 a dispenser having a liquid suction line that sucks a liquid from a vessel and discharges the liquid; and    a magnetic material provided in the liquid suction line,    wherein the apparatus is configured to be controlled in such a manner that magnetic particles in the liquid sucked by the liquid suction line are adsorbed and held on an inner wall surface of the liquid suction line by a magnetic force of the magnetic material, and then the magnetic particles are made unaffected by the magnetic force of the magnetic material to release the magnetic particles from the liquid suction line and discharged together with the liquid to outside the liquid suction line, and wherein the magnetic material comprises a plurality of magnets that are arranged in contact one with another in parallel to a direction of magnetization in such a manner that south and north poles of adjacent magnets are reversed alternately.    
     
     
         14 . An apparatus comprising: 
 a dispenser having a liquid suction line that sucks a liquid from a vessel and discharges the liquid; and    a magnetic material provided in the liquid suction line,    wherein the apparatus is configured to be controlled in such a manner that magnetic particles in the liquid sucked by the liquid suction line are adsorbed and held on an inner wall surface of the liquid suction line by a magnetic force of the magnetic material, and then the magnetic particles are made unaffected by the magnetic force of the magnetic material to release the magnetic particles from the liquid suction line and discharged together with the liquid to outside the liquid suction line, and wherein the magnetic material has at least one peak of the magnetic force in a magnetic pole surface and the peak magnetic force is 600 gausses or more.