Abstract:
An automatic analysis device and method having a BF separation process, wherein the width in a container conveyance direction of a surface facing a reaction container of a magnet for preliminary magnetic collection of a first magnetic generation part ( 32   p ) is set to have a length including a region for housing a liquid sample of the reaction container conveyed to a magnetic collection position of the first magnetic generation part. An end in the container conveyance direction of a surface facing the reaction container of a magnet for regular magnetic collection of a second magnetic generation part ( 32   m ) is designed to be close to the center of the region for housing the liquid sample of the reaction container conveyed to a magnetic collection position of the second magnetic generation part.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an automatic analysis device, particularly, an automatic analysis device including solid-phase magnetic particles and a separation and washing method. 
       BACKGROUND ART 
       [0002]    Automatic analysis devices are used for tests in various different fields, such as for an immunological test, a biochemical test, or a blood transfusion test to analyze many samples. Automatic analysis devices quickly and highly accurately analyze an intended substance among many components contained in each sample. 
         [0003]    Automatic analysis devices include an immune analysis device that quantitatively or qualitatively detects, through immunoreaction, an intended substance (such as antigen or antibody) contained in a sample (such as serum, blood plasma, or urine). An immune analysis device includes a system for bound-free (BF) separation performed to separate an intended substance in the sample, which is to be analyzed, from a reaction solution and wash the intended substance using a reagent in which an antigen or an antibody that reacts on the intended substance in the sample is combined with a solid phase (such as a magnetic particle). 
         [0004]    For BF separation, a nozzle of an automatic analysis device that uses magnetic particles is inserted into a reaction solution in a reaction vessel and caused to suck the reaction solution in the reaction vessel. At this time, the reaction solution is sucked while the magnetic particles are temporarily attracted to (magnetically collected on) an inner wall surface of the reaction vessel by magnets disposed outside the reaction vessel so that the magnetic particles that form immune complexes contained in the reaction solution are not sucked. Thus, only magnetic particles that are bound to an intended substance to form immune complexes are left in the reaction vessel and other unreacted sample-derived components or the like are removed through the sucked solution. Thereafter, a washing liquid is discharged and sucked through the nozzle to and from the reaction vessel, so that the magnetic particles in the reaction vessel are washed. The number of times the BF separation operation is performed is determined depending on the conditions of an analysis of an intended substance. 
         [0005]    Various different types of BF separation mechanism for an automatic analysis device have been developed to efficiently perform the BF separation. A disclosed example of a device performs two steps of magnetic collection on a reaction vessel using one magnet disposed on one side surface of the reaction vessel (see, for example, PTL 1). In addition, a disclosed example of a device that is equipped with a BF separation mechanism performs two steps of magnetic collection using first magnetic means and second magnetic means before performing BF separation (see, for example, PTL 2). 
       CITATION LIST 
     Patent Literature 
       [0006]    PTL 1: Japanese Unexamined Patent Application Publication No. 4-58157 
         [0007]    PTL 2: Japanese Unexamined Patent Application Publication No. 2003-227838 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0008]    The magnetic particles in an automatic analysis device are particles having a diameter of approximately 1 μm to 10 μm. The magnetic particles form immune complexes and float while being suspended in the reaction solution. A BF separation operation involves a time lag from when a magnet approaches a reaction vessel until when magnetic particles are completely attracted to the inner wall surface of the reaction vessel. This time lag differs depending on factors such as the particle diameter of particles, the magnetic force of the magnet, or the shape of the reaction vessel but falls within a range of approximately several seconds to approximately ten-odd seconds. The magnetic particles that have not yet been attracted to the inner wall surface of the reaction vessel may thus be sucked together with the reaction solution if the nozzle is inserted into the reaction vessel immediately after the magnetic collection and performs a suction operation of the reaction solution before the magnetic collection is completely performed. 
         [0009]    To address this situation, a preliminary magnetic collection step, in which the magnetic particles contained in the reaction solution are attracted to the inner wall surface of the reaction vessel in advance, is provided as a preliminary step for transition to an actual BF washing step. This step allows the magnetic particles to be preliminarily attracted to the inner wall surface of the reaction vessel in a sufficiently long period of the preliminary magnetic collection step before transition to an actual BF washing step (main magnetic collection). In the BF washing step, the magnetic particles magnetically collected in advance are held and an additional magnetic collection is performed. Thus, the washing step, for which the BF washing step is intended, can take a sufficiently long time without the need of waiting until the magnetic particles are magnetically collected. 
         [0010]    Existing automatic analysis devices take following measures to magnetically collect magnetic particles in a reaction vessel during BF separation and washing. PTL 1 discloses a method including two steps of magnetic collection using a single magnet and a method including preliminary magnetic collection and main magnetic collection using two magnets of the same shape. PTL 2 discloses an analysis device including a BF separation mechanism in which multiple magnets are disposed on the side surface of the reaction vessel at different levels lowered stepwise. These devices fail to fully collect magnetic particles in the reaction solution within a predetermined time required for magnetic collection. These devices thus allow some amount of magnetic particles to flow out of the reaction vessel during a washing operation and cause problems of varying analysis results and reducing analytical sensitivity. Specifically, the shapes of magnets included in existing devices are appropriate for neither preliminary magnetic collection nor main magnetic collection. 
         [0011]    The present invention was made in consideration of the above-described circumstances and aims to provide a device that reduces the amount of magnetic particles flowing out during a washing operation in a BF separation step involving preliminary magnetic collection and main magnetic collection. 
       Solution to Problem 
       [0012]    To solve the above-described problem, an aspect of an automatic analysis device according to the invention is an automatic analysis device that analyzes an intended substance contained in a sample using a reagent containing magnetic particles. The automatic analysis device includes a vessel transport portion, a first magnetic generation part, a second magnetic generation part, and a separation and washing portion. 
         [0013]    In the vessel transport portion, vessels holding a liquid sample containing the sample and the reagent containing the magnetic particles are disposed. The vessel transport portion transports the vessels along a path. 
         [0014]    The first magnetic generation part is disposed on the path and includes at least one preliminary-magnetic-collection magnet that magnetically collects the magnetic particles in the liquid sample inside each of the vessels that has been transported to a magnetic collection position of the first magnetic generation part. 
         [0015]    The second magnetic generation part is disposed on the path downstream from the first magnetic generation part. The second magnetic generation part includes at least one main-magnetic-collection magnet that magnetically collects the magnetic particles in the liquid sample that have been magnetically collected by the first magnetic generation part. The liquid sample is held inside each vessel that has been transported to a magnetic collection position of the second magnetic generation part. 
         [0016]    The separation and washing portion separates a component other than the magnetic particles and washes an inside of each vessel while the magnetic particles are magnetically collected inside the vessel by the second magnetic generation part. 
         [0017]    A surface of the preliminary-magnetic-collection magnet of the first magnetic generation part facing the vessels has a width in a vessel transport direction that is as long as to cover an effective area of each vessel that has been transported to the magnetic collection position of the first magnetic generation part. A surface of the main-magnetic-collection magnet of the second magnetic generation part facing the vessels has an end portion in the vessel transport direction that is located adjacent to a center of the effective area of each vessel that has been transported to the magnetic collection position of the second magnetic generation part. 
         [0018]    An aspect of a separation and washing method according to the invention is a separation and washing method for separating and washing a component containing magnetic particles with an automatic analysis device that analyzes an intended substance contained in a sample using a reagent containing magnetic particles. 
         [0019]    In the separation and washing method, vessels each holding a liquid sample containing the sample and the reagent containing the magnetic particles are transported along a path using a vessel transport portion in which the vessels are disposed. 
         [0020]    In addition, the magnetic particles in the liquid sample inside each of the vessels that has been transported to a magnetic collection position of a first magnetic generation part, disposed on the path and including a preliminary-magnetic-collection magnet, are magnetically collected by the first magnetic generation part. 
         [0021]    In addition, the magnetic particles in the liquid sample that have been magnetically collected by the first magnetic generation part inside each of the vessels that has been transported to a magnetic collection position of a second magnetic generation part are magnetically collected by the second magnetic generation part, the second magnetic generation part being disposed on the path downstream from the first magnetic generation part, the second magnetic generation part including a main-magnetic-collection magnet. 
         [0022]    A component containing the magnetic particles is separated and an inside of each vessel is washed using a separation and washing portion while the magnetic particles are magnetically collected inside the vessel by the second magnetic generation part. 
         [0023]    A surface of the preliminary-magnetic-collection magnet of the first magnetic generation part facing the vessels has a width in a vessel transport direction that is as long as to cover an area of each vessel that has been transported to the magnetic collection position of the first magnetic generation part, the area holding the liquid sample. 
         [0024]    A surface of the main-magnetic-collection magnet of the second magnetic generation part facing the vessels has an end portion in the vessel transport direction that is located adjacent to a center of the area of each vessel that has been transported to the magnetic collection position of the second magnetic generation part, the area holding the liquid sample. 
       Advantageous Effects of Invention 
       [0025]    At least one aspect of the present invention is capable of reducing the amount of magnetic particles flowing out through a washing operation in a BF separation step involving preliminary magnetic collection and main magnetic collection. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0026]      FIG. 1  is a schematic diagram of a configuration of an automatic analysis device according to a first embodiment of the invention. 
           [0027]      FIG. 2  is a schematic perspective view of the automatic analysis device illustrated in  FIG. 1  from which an upper layer of a turntable of an immuno-enzyme reaction unit is removed. 
           [0028]      FIG. 3  is a configuration diagram of a control system of the automatic analysis device illustrated in  FIG. 1 . 
           [0029]      FIG. 4  is a flowchart showing a BF separation step. 
           [0030]      FIG. 5  is a timing chart of the BF separation step. 
           [0031]      FIG. 6  illustrates, in a schematic perspective view, the positional relationship between reaction vessels and magnetic generation parts during the BF separation step. 
           [0032]      FIG. 7  illustrates, in a schematic top view and a schematic sectional view, the positional relationship between the reaction vessels and the magnetic generation parts during the BF separation step. 
           [0033]      FIG. 8  illustrates, in a side view, the positional relationship between a reaction vessel and a magnetic generation part. 
           [0034]      FIG. 9  is a perspective view of a first magnetic generation part used for preliminary magnetic collection. 
           [0035]      FIG. 10  is a top view of the first magnetic generation part illustrated in  FIG. 9 . 
           [0036]      FIG. 11  is a side view of the first magnetic generation part illustrated in  FIG. 9 . 
           [0037]      FIGS. 12A and 12B  are schematic diagrams of lines of the magnetic force exerted by the first magnetic generation part, where  FIG. 12A  shows lines of the magnetic force viewed from above the first magnetic generation part and  FIG. 12B  shows lines of the magnetic force viewed from a side of the first magnetic generation part. 
           [0038]      FIG. 13  illustrates the positional relationship between the reaction vessels and the first magnetic generation part. 
           [0039]      FIG. 14  is a perspective view of a second magnetic generation part used for main magnetic collection. 
           [0040]      FIG. 15  is a top view of the second magnetic generation part illustrated in  FIG. 14 . 
           [0041]      FIG. 16  is a side view of the second magnetic generation part illustrated in  FIG. 14 . 
           [0042]      FIG. 17  illustrates the positional relationship between reaction vessels and the second magnetic generation part. 
           [0043]      FIG. 18  illustrates an example of measurement data showing the ratio of how many magnetic particles remain in the reaction vessel after a typical BF separation step is performed. 
           [0044]      FIG. 19  illustrates an example of measurement data showing the ratio of how many magnetic particles remain in the reaction vessel after a BF separation step according to a first embodiment is performed. 
           [0045]      FIGS. 20A, 20B, and 20C  illustrate images of magnetically collected magnetic particles remaining in the reaction vessel depending on different magnetic shapes, where  FIG. 20A  illustrates an image of magnetically collected magnetic particles remaining when only the first magnetic generation part is used,  FIG. 20B  illustrates an image of magnetically collected magnetic particles remaining when only the second magnetic generation part is used, and  FIG. 20C  illustrates an image of magnetically collected magnetic particles remaining when the first magnetic generation part and the second magnetic generation part are used. 
           [0046]      FIG. 21  illustrates first magnetic generation parts and a second magnetic generation part according to a second embodiment of the present invention. 
           [0047]      FIG. 22  illustrates first magnetic generation parts and second magnetic generation parts according to a third embodiment of the present invention. 
           [0048]      FIG. 23  illustrates a first magnetic generation part according to a fourth embodiment. 
           [0049]      FIG. 24  is a schematic diagram of a configuration of an automatic analysis device according to a fifth embodiment. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0050]    Referring now to the attached drawings, examples of forms in which the present invention is embodied are described below. Throughout the drawings, the same components are denoted with the same reference symbols and are not described redundantly. 
         [0051]    Embodiments described below each exemplarily disclose an immune analysis device, but the present invention is not limited to an immune analysis device. The present invention is also applicable to, for example, a nucleic acid detecting/measuring device that solidifies and attaches a nucleic acid probe to a magnetic particle and captures nucleic acid (DNA or RNA) in the sample. The present invention is applicable to all the automatic analysis devices including a BF separation mechanism using magnetic particles. 
       1. First Embodiment 
     [Summary of Automatic Analysis Device] 
       [0052]      FIG. 1  is a schematic diagram of a configuration of an automatic analysis device according to a first embodiment of the present invention. 
         [0053]    An automatic analysis device  1  illustrated in  FIG. 1  is a form obtained by applying the present invention to an immune analysis device that detects or measures objects such as an antigen or an antibody in the sample through an immune analysis. The automatic analysis device  1  includes a measuring device  2  and a controlling device  60 , which controls the entirety of the automatic analysis device  1  including the measuring device  2  and analyzes measurement data output from the measuring device  2 . 
         [0054]    The automatic analysis device  1 , which is an immune analysis device, performs highly sensitive measurement by, for example, chemiluminescent enzyme immunoassay (CLEIA). CLEIA includes, as main steps, a reaction step, in which an intended substance (antigen or antibody) in the sample is caused to react with a reagent in a reaction vessel, a separation step (BF separation), in which a reacted (bound) substance and an unreacted (free) substance in the reaction vessel are separated from each other, and a light measurement step in which an amount of light resulting from a reaction between a chemiluminescent substrate and an immune complex is measured, the immune complex being produced from a reaction between each reagent and the intended substance in the sample. 
       [Measurement System of Automatic Analysis Device] 
       [0055]    The measuring device  2  mainly includes a reaction vessel supply unit  3 , a sample stand unit  4 , a reaction vessel transport unit  5 , a sample pipetting unit  6 , a reagent cooling unit  7 , a first reagent pipetting unit  8 , a second reagent pipetting unit  9 , an immuno-enzyme reaction unit  10 , a first BF separation unit  11 , a second BF separation unit  12 , a substrate liquid cooling device  14 , a vessel transfer arm  15 , and a luminescence measurement unit  16 . 
         [0056]    The reaction vessel supply unit  3  houses multiple reaction vessels (cuvettes)  3   a  and provides the multiple reaction vessels  3   a  one by one to a transfer position. Each of the reaction vessels  3   a  provided to the transfer position is transported to the immuno-enzyme reaction unit  10  by the reaction vessel transport unit  5 . A sample and a predetermined reagent are fed to each of the reaction vessels  3   a  transported to the immuno-enzyme reaction unit  10 . 
         [0057]    The reaction vessel transport unit  5  includes an arm, which rises and lowers vertically and freely rotates around a vertical line that passes through its base end portion, and a holding portion, disposed at a far end portion of the arm. The reaction vessel transport unit  5  holds each reaction vessel  3   a  fed to a feed position of the reaction vessel supply unit  3  using the holding portion and rotates the arm to transport the reaction vessel  3   a  to a predetermined position of the immuno-enzyme reaction unit  10  at a predetermined timing. 
         [0058]    The sample stand unit  4  includes a turntable having a shape of a substantially cylindrical tubular vessel having one end in the axial direction open. The sample stand unit  4  houses multiple sample vessels  4   a . Each sample vessel  4   a  holds a sample, such as blood or urine, taken from a subject. The multiple sample vessels  4   a  are arranged at predetermined intervals in the circumferential direction of the sample stand unit  4 . The sample stand unit  4  is supported by a driving mechanism, not illustrated, so as to be rotatable in the circumferential direction. The sample stand unit  4  is rotated by the driving mechanism, not illustrated, in the circumferential direction at each predetermined angle range at a predetermined speed. In the example illustrated in  FIG. 1 , the sample vessels  4   a  are arranged in the circumferential direction of the sample stand unit  4  in two rows, which are spaced apart from each other at a predetermined distance in the radial direction of the sample stand unit  4 . Examples usable as a sample may include a sample diluted by a predetermined dilution. 
         [0059]    The sample pipetting unit  6  includes an arm and a probe. The arm rises and lowers vertically and freely rotates around a vertical line passing through its base end portion. The probe is disposed at a far end portion of the arm. The sample pipetting unit  6  sucks, through the probe, the sample inside each sample vessel  4   a  shifted to a predetermined position of the sample stand unit  4  and rotates the arm to pipette the sample into a reaction vessel  3   a  positioned at a predetermined position of the immuno-enzyme reaction unit  10  at a predetermined timing. 
         [0060]    Similarly to the sample stand unit  4 , the reagent cooling unit  7  also includes a turntable having a shape of a substantially cylindrical tubular vessel having one end in the axial direction open. The reagent cooling unit  7  is supported by a driving mechanism, not illustrated, so as to be rotatable in the circumferential direction. The reagent cooling unit  7  is rotated by the driving mechanism, not illustrated, forward or backward in the circumferential direction by each predetermined angle range at a predetermined speed. 
         [0061]    The reagent cooling unit  7  houses first reagent vessels  7   a  and second reagent vessels  7   b . The first reagent vessels  7   a  and the second reagent vessels  7   b  are arranged on the reagent cooling unit  7  in the circumferential direction at predetermined intervals. Each first reagent vessel  7   a  holds a first reagent, an example of which is a magnetic reagent containing magnetic particles that react with an intended substance (for example, antigen) in the sample. Each second reagent vessel  7   b  holds a second reagent, an example of which is a labeling reagent (enzyme antibody) that reacts with a reacted product in which the magnetic reagent is bound with an intended substance (for example, antigen) in the sample. The inside of the reagent cooling unit  7  is kept at a predetermined temperature by a cooling system, not illustrated. Thus, the first reagent (magnetic reagent) held in each first reagent vessel  7   a  and the second reagent (labeling reagent) held in each second reagent vessel  7   b  are cooled at the predetermined temperature. 
         [0062]    The first reagent pipetting unit  8  includes an arm and a probe. The arm rises and lowers vertically and freely rotates around a vertical line passing through its base end portion. The probe is disposed at a far end portion of the arm. The first reagent pipetting unit  8  sucks, through the probe, the first reagent (magnetic reagent) inside each first reagent vessel  7   a  shifted to a predetermined position of the reagent cooling unit  7  and rotates the arm to pipette the first reagent into the reaction vessel  3   a  positioned at a predetermined position of the immuno-enzyme reaction unit  10  at a predetermined timing. 
         [0063]    The second reagent pipetting unit  9  has a similar configuration as that of the first reagent pipetting unit  8 . The second reagent pipetting unit  9  sucks, through the probe, the second reagent (labeling reagent) inside each second reagent vessel  7   b  shifted to a predetermined position of the reagent cooling unit  7  and rotates the arm to pipette the second reagent into the reaction vessel  3   a  positioned at a predetermined position of the immuno-enzyme reaction unit  10  at a predetermined timing. 
         [0064]    In the immuno-enzyme reaction unit  10 , each of the reaction vessels  3   a  arranged in the circumferential direction allows the sample and a predetermined reagent corresponding to an intended analysis category to cause an immunoreaction and an immune complex resulting from this immunoreaction and a chemiluminescent substrate to cause an enzyme reaction. The immuno-enzyme reaction unit  10  also serves as a thermostat that keeps the temperature of the reaction vessel  3   a  constant. 
         [0065]    Similarly to the sample stand unit  4 , the immuno-enzyme reaction unit  10  (an example of a vessel transport portion) includes a turntable having a shape of a substantially cylindrical tubular vessel having one end in the axial direction open. The immuno-enzyme reaction unit  10  is supported by a driving mechanism, not illustrated, so as to be rotatable in the circumferential direction. The immuno-enzyme reaction unit  10  is rotated by the driving mechanism, not illustrated, in the circumferential direction by each predetermined angle range at a predetermined speed. An example used as the mechanism that drives the turntable to rotate is a stepping motor. Here, the immuno-enzyme reaction unit  10  rotates counterclockwise (in the direction of arrow). In the example illustrated in  FIG. 1 , the reaction vessels  3   a  are arranged in the circumferential direction of the immuno-enzyme reaction unit  10  in a single row at a predetermined interval. Alternatively, a row of reaction vessels  3   a  for the first reagent, described below, and a row of reaction vessels  3   a  for the second reagent, described below, may be disposed at a predetermined distance away from each other in the radial direction (see  FIG. 24 ). 
         [0066]    When the first reagent pipetting unit  8  pipettes a magnetic reagent into each reaction vessel  3   a  holding the sample, the immuno-enzyme reaction unit  10  stirs a liquid mixture (liquid sample) containing the magnetic reagent and the sample using a stirring system, not illustrated, and allows the magnetic reagent and the intended substance (for example, antigen) in the sample to cause immunoreactions for a predetermined time period (primary immunoreaction). Subsequently, the immuno-enzyme reaction unit  10  moves the reaction vessel  3   a  to a first magnetic collection mechanism (first-half magnetic collection mechanism  31  and second-half magnetic collection mechanism  33 ) to magnetically collect a reacted product, in which the intended substance and the magnetic reagent are bound, using a magnetic force. In this state, the inside of the reaction vessel  3   a  is washed and an unreacted substance that has not reacted with the magnetic reagent is removed (primary BF separation). 
         [0067]    The first magnetic collection mechanism is fixed at a position corresponding to the first BF separation unit  11 , disposed near the outer circumferential portion of the immuno-enzyme reaction unit  10 . The first magnetic collection mechanism includes a first-half magnetic collection mechanism  31  and a second-half magnetic collection mechanism  33 . The first-half magnetic collection mechanism  31  includes a first magnetic generation part  32   p  and a second magnetic generation part  32   m , disposed downstream from the first magnetic generation part  32   p  in a vessel transport direction. The second-half magnetic collection mechanism  33  includes a first magnetic generation part  34   p  and a second magnetic generation part  34   m , disposed downstream from the first magnetic generation part  34   p  in the vessel transport direction. A stirring system  39 - 1  is disposed between the first-half magnetic collection mechanism  31  and the second-half magnetic collection mechanism  33 . The magnetic generation parts and the stirring system  39 - 1  are arranged in the circumferential direction at predetermined intervals corresponding to the pitch at which the reaction vessels  3   a  are transported. 
         [0068]    Referring now to  FIG. 2 , the turntable of the immuno-enzyme reaction unit  10  is described. 
         [0069]      FIG. 2  is a schematic perspective view of the automatic analysis device  1  illustrated in  FIG. 1  from which the upper layer of the turntable of the immuno-enzyme reaction unit  10  is removed. 
         [0070]    The turntable of the immuno-enzyme reaction unit  10  includes two layers, that is, a fixed lower layer  10   b  and a rotatable upper layer (not illustrated). As illustrated in  FIG. 2 , the first-half magnetic collection mechanism  31  and the second-half magnetic collection mechanism  33  of the first magnetic collection mechanism are disposed on the lower layer  10   b  of the turntable. The reaction vessels  3   a  (see  FIG. 1 ) are disposed on the upper layer of the turntable. The lower layer  10   b  of the turntable of the immuno-enzyme reaction unit  10  has an annular groove  49   d  extending in the circumferential direction, on the path along which the reaction vessels  3   a  pass. The lower layer  10   b  of the turntable of the immuno-enzyme reaction unit  10  also has storage grooves  41 ,  42 ,  43 , and  44 , extending perpendicularly to the groove  49   d.    
         [0071]    The first magnetic generation part  32   p  and the second magnetic generation part  32   m  of the first-half magnetic collection mechanism  31  are respectively fitted into (held in) the storage groove  41  and the storage groove  42  and disposed on the path of the reaction vessels  3   a . Similarly, the first magnetic generation part  34   p  and the second magnetic generation part  34   m  of the second-half magnetic collection mechanism  33  are respectively fitted into (held in) the storage groove  43  and the storage groove  44  and disposed on the path of the reaction vessels  3   a . As illustrated in  FIG. 7 , described below, for example, each of the first and second magnetic generation parts  32   p ,  32   m ,  34   p , and  34   m  has a through hole  85  (see  FIG. 10 , described below). A male screw  45  is screwed onto a female screw, formed in the lower layer  10   b  of the turntable, through the through hole  85  of each magnetic generation part. Each magnetic generation part is thus fixed to the lower layer  10   b  of the turntable. The first and second magnetic generation parts  32   p ,  32   m ,  34   p , and  34   m  of the first-half magnetic collection mechanism  31  and the second-half magnetic collection mechanism  33  each produce magnetism to magnetically collect magnetic particles and reacted products containing the magnetic particles inside each reaction vessel  3   a  that has been transported thereto along the path. 
         [0072]    As described below, the first magnetic generation parts  32   p  and  34   p  are used for preliminary magnetic collection and the second magnetic generation parts  32   m  and  34   m  are used for main magnetic collection during BF washing. The first magnetic generation parts  32   p  and  34   p  and the second magnetic generation parts  32   m  and  34   m  have different dimensions in the cross direction, which is parallel to the tangential direction of the immuno-enzyme reaction unit  10 . The reason for this will be described below. In the following description of BF separation, magnetic particles and reacted products containing the magnetic particles are collectively referred to as “magnetic particles” in some cases. 
         [0073]      FIG. 1  is described again. The first BF separation unit  11  (an example of a separation and washing portion) includes an arm  25 , a nozzle  21  attached to the arm  25 , and a washing bath  24 . The arm  25  rises and lowers vertically and freely rotates around a vertical line passing through its base end portion. The arm  25  moves the nozzle  21  between the reaction vessel  3   a  positioned at a primary BF separation position of the immuno-enzyme reaction unit  10  and the washing bath  24  positioned at a nozzle washing position near the first BF separation unit  11 . In this embodiment, the primary BF separation is divided into first-half and second-half processes. The first-half process is performed by the first-half magnetic collection mechanism  31  and the second-half process is performed by the second-half magnetic collection mechanism  33 . The nozzle  21  discharges a washing liquid into the reaction vessel  3   a  holding the sample and the magnetic reagent at the primary BF separation position and sucks the washing liquid from the reaction vessel  3   a  to wash the reaction vessel  3   a  and remove an unreacted substance that did not react with the magnetic reagent (BF washing). 
         [0074]    When each reaction vessel  3   a  is transported to the primary BF separation position, the first BF separation unit  11  performs primary BF separation. In the primary BF separation and the BF washing, a reacted product, in which an intended substance in the sample and the magnetic reagent are bound, is magnetically collected in the reaction vessel  3   a . When the primary BF separation is finished, the arm  25  moves the nozzle  21  to the nozzle washing position at which the washing bath  24  is disposed. In the example illustrated in  FIG. 1 , the first BF separation unit  11  moves each reaction vessel  3   a  to the primary BF separation position or the nozzle washing position using the single arm  25 . However, arms may be individually provided for the first-half magnetic collection mechanism  31  and the second-half magnetic collection mechanism  33 . 
         [0075]    After the primary BF separation, the second reagent pipetting unit  9  pipettes a labeling reagent into the reaction vessel  3   a  in which a reacted product remains. Then, the immuno-enzyme reaction unit  10  stirs a liquid mixture (liquid sample), containing the labeling reagent and the reacted product, using a stirring system, not illustrated, and allows the reacted product and the labeling reagent to cause an immunoreaction (secondary immunoreaction) for a predetermined time period. Subsequently, the immuno-enzyme reaction unit  10  moves the reaction vessel  3   a  to the second magnetic collection mechanism to magnetically collect an immune complex, in which the reacted product and the labeling reagent are bound, using a magnetic force. In this state, the inside of the reaction vessel  3   a  is washed and the unreacted substance that has not reacted with the labeling reagent is removed (secondary BF separation). 
         [0076]    The second magnetic collection mechanism has a configuration similar to that of the first magnetic collection mechanism. The second magnetic collection mechanism is fixed in a position corresponding to the second BF separation unit  12 , disposed near the outer circumferential portion of the immuno-enzyme reaction unit  10 . Similarly to the first magnetic collection mechanism, the second magnetic collection mechanism includes a first-half magnetic collection mechanism  35  and a second-half magnetic collection mechanism  37 . The first-half magnetic collection mechanism  35  includes a first magnetic generation part  36   p  and a second magnetic generation part  36   m , disposed downstream from the first magnetic generation part  36   p  in the vessel transport direction. The second-half magnetic collection mechanism  37  includes a first magnetic generation part  38   p  and a second magnetic generation part  38   m , disposed downstream from the first magnetic generation part  38   p  in the vessel transport direction. A stirring system  39 - 2  is disposed between the first-half magnetic collection mechanism  35  and the second-half magnetic collection mechanism  37 . The magnetic generation parts and the stirring system  39 - 2  are arranged in the circumferential direction at predetermined intervals corresponding to the pitch at which the reaction vessels  3   a  are transported. 
         [0077]    Similarly to the first magnetic collection mechanism, the first-half magnetic collection mechanism  35  and the second-half magnetic collection mechanism  37  of the second magnetic collection mechanism are disposed on the lower layer  10   b  (see  FIG. 2 ) of the turntable. Although not illustrated, the lower layer  10   b  of the turntable of the immuno-enzyme reaction unit  10  has other four storage grooves  41  to  44 , each extending perpendicularly to the groove  49   d , as in the case of the first magnetic collection mechanism. The first magnetic generation part  36   p  and the second magnetic generation part  36   m  of the first-half magnetic collection mechanism  35  are respectively fitted into (held in) the storage groove  41  and the storage groove  42  and disposed on the path of the reaction vessels  3   a . Similarly, the first magnetic generation part  38   p  and the second magnetic generation part  38   m  of the second-half magnetic collection mechanism  37  are respectively fitted into (held in) the storage groove  43  and the storage groove  44  and disposed on the path of the reaction vessels  3   a . The magnetic generation parts of the first-half magnetic collection mechanism  35  and the second-half magnetic collection mechanism  37  each produce magnetism to magnetically collect magnetic particles and reacted products containing the magnetic particles inside each reaction vessel  3   a  that has been transported thereto along the path. 
         [0078]      FIG. 1  is described again. The second BF separation unit  12  (an example of a separation and washing portion) has a similar configuration as that of the first BF separation unit  11 . The second BF separation unit  12  is disposed at a predetermined distance away from the first BF separation unit  11  in the circumferential direction. The arm  25  rises and lowers vertically and freely rotates around a vertical line that passes through its base end portion. The arm  25  moves the nozzle  21  between the reaction vessel  3   a  positioned at a secondary BF separation position of the immuno-enzyme reaction unit  10  and the washing bath  24 , positioned at a nozzle washing position near the second BF separation unit  12 . In this embodiment, the secondary BF separation is divided into first-half and second-half processes. The first-half process is performed by the first-half magnetic collection mechanism  35  and the second-half process is performed by the second-half magnetic collection mechanism  37 . The nozzle  21  discharges a washing liquid into the reaction vessel  3   a  holding the labeling reagent at the secondary BF separation position and sucks the washing liquid from the reaction vessel  3   a  to wash the reaction vessel  3   a  and remove a remnant unreacted substance that did not react with the labeling reagent (BF washing). 
         [0079]    The second BF separation unit  12  performs secondary BF separation when each reaction vessel  3   a  is transported to the secondary BF separation position. During the secondary BF separation and the BF washing, an immune complex in which the labeling reagent and the reacted product, consisting of an intended substance in the sample and the magnetic reagent, are bound is magnetically collected in the reaction vessel  3   a . When the secondary BF separation is finished, the arm  25  moves the nozzle  21  to the nozzle washing position at which the washing bath  24  is disposed. Similarly to the first BF separation unit  11 , the second BF separation unit  12  moves the reaction vessel  3   a  using the single arm  25  between the secondary BF separation position and the nozzle washing position. However, arms may be individually provided for the first-half magnetic collection mechanism  35  and the second-half magnetic collection mechanism  37 . 
         [0080]    Here, the nozzle  21  and the washing bath  24  are described. The first BF separation unit  11  and the second BF separation unit  12  are described collectively. 
         [0081]    The nozzle  21  includes, for example, a discharge nozzle (example of discharge unit), which discharges a washing liquid, and a suction nozzle (example of suction unit), which sucks the washing liquid. The discharge nozzle and the suction nozzle are disposed so as touch each other in a direction parallel to the axial direction. The discharge nozzle has a tubular shape and has an opening (discharge port) at its lower end. The suction nozzle has a tubular shape that is longer than the discharge nozzle in the axial direction. The suction nozzle has an opening (suction port) at its lower end. The lower end of the nozzle  21  is a portion from which the nozzle  21  enters the reaction vessel  3   a  or the washing bath  24 . 
         [0082]    The washing bath  24  has a substantially quadrangular prism or cylinder shape having an opening at its top portion. The washing bath  24  is capable of storing the washing liquid discharged from the nozzle  21  inserted thereinto from its top portion during the nozzle washing. The washing bath  24  has an exhaust port in it bottom surface. The stored washing liquid is discharged through the exhaust port. 
         [0083]      FIG. 1  is described again. A substrate solution pipetting unit  26  is also attached to the arm  25  of the second BF separation unit  12 . The substrate solution pipetting unit  26  is disposed at a position further from the rotation shaft of the arm  25  than is the position of the nozzle  21 . The substrate solution pipetting unit  26  is connected to the substrate liquid cooling device  14 , which holds and cools a substrate solution, with a tube, not illustrated, interposed therebetween. The substrate solution pipetting unit  26  pipettes, into each reaction vessel  3   a  that has been subjected to the secondary BF separation, a substrate solution containing a chemiluminescent substrate that specifically reacts with a labeling reagent (enzyme antibody) in an immune complex in which the labeling reagent is bounded with a magnetic reagent and an intended substance such as an antigen. Each reaction vessel  3   a  holding the substrate solution is transported to a predetermined position by a rotation of the immuno-enzyme reaction unit  10 . The reaction vessel  3   a  that has been transported to the predetermined position is shifted to the luminescence measurement unit  16  by the vessel transfer arm  15 . 
         [0084]    The luminescence measurement unit  16  is a photometer portion that includes a photomultiplier (PMT)  16   a  for use as a detector. The luminescence measurement unit  16  measures, using photon counting, light emission phenomena caused by an immune complex and a chemiluminescent substrate. Specifically, the luminescence measurement unit  16  measures the amount of light emitted. A light measurement signal corresponding to a light beam (amount of light emitted) detected by the luminescence measurement unit  16  is digitized by an analog-digital converter, not illustrated. The digitized light measurement signal is then input to the controlling device  60  through components such as a serial interface and is then subjected to an analysis. 
         [0085]    Each unit of the above-described measuring device  2  operates in accordance with a command from the controlling device  60 . 
       [Control System of Automatic Analysis Device] 
       [0086]    Referring now to  FIG. 3 , a control system of the automatic analysis device  1  is described.  FIG. 3  illustrates a configuration of the control system of the automatic analysis device  1 , particularly, a portion for controlling the separation step in an immune analysis. 
         [0087]    As illustrated in  FIG. 3 , the measuring device  2  of the automatic analysis device  1  includes a control portion  51 , a turntable rotation driving circuit  52 , a first-reagent arm driving circuit  53 , a second-reagent arm driving circuit  54 , and a communication interface  55  (expressed as “communication I/F” in  FIG. 3 ). The measuring device  2  also includes a primary-BF-separation arm driving circuit  11   a  and a primary-BF-separation nozzle driving circuit  11   b  of the first BF separation unit  11  and a secondary-BF-separation arm driving circuit  12   a  and a secondary-BF-separation nozzle driving circuit  12   b  of the second BF separation unit  12 . 
         [0088]    The control portion  51  includes, for example, a central processing unit (CPU), a read only memory (ROM), not illustrated, which stores a program, and a random access memory (RAM), used as a working area of the CPU. The control portion  51  is electrically connected to each driving circuit and the communication interface  55  with a system bus, not illustrated, interposed therebetween. The CPU of the control portion  51  is controlled by a control portion  61  of the controlling device  60  to control the process or the operation of each component in the measuring device  2 . 
         [0089]    The turntable rotation driving circuit  52  generates, on the basis of a control signal fed from the control portion  51 , a driving signal for rotating the reagent cooling unit  7  and the immuno-enzyme reaction unit  10  and feeds the driving signal to a driving mechanism, not illustrated. The first-reagent arm driving circuit  53  and the second-reagent arm driving circuit  54  each generate, on the basis of a control signal fed from the control portion  51 , a driving signal for driving the arm and the probe of the corresponding one of the first reagent pipetting unit  8  and the second reagent pipetting unit  9  and feed the driving signal to a driving mechanism, not illustrated. 
         [0090]    The primary-BF-separation arm driving circuit  11   a  and the primary-BF-separation nozzle driving circuit  11   b  of the first BF separation unit  11  each generate, on the basis of a control signal fed from the control portion  51 , a driving signal for driving the corresponding one of the arm  25  and the nozzle  21  of the first BF separation unit  11  and feed the driving signal to a driving mechanism, not illustrated. The secondary-BF-separation arm driving circuit  12   a  and the secondary-BF-separation nozzle driving circuit  12   b  of the second BF separation unit  12  each generate, on the basis of a control signal fed from the control portion  51 , a driving signal for driving the corresponding one of the arm  25  and the nozzle  21  of the second BF separation unit  12  and feed the driving signal to a driving mechanism, not illustrated. 
         [0091]    The communication interface  55  is an interface that transmits and receives information in a predetermined form between itself and the controlling device  60  with a communication network, not illustrated, interposed therebetween. An example used as the communication interface  55  is a serial interface. 
         [0092]    As illustrated in  FIG. 3 , the controlling device  60  includes the control portion  61 , an input portion  62 , an analysis portion  63 , a storage portion  64 , an output portion  65 , and a communication interface (expressed as “communication I/F” in  FIG. 3 )  66 . 
         [0093]    The control portion  61  includes, for example, a CPU, a ROM, not illustrated, which stores a program, and a RAM, used as a working area of the CPU. The CPU of the control portion  61  retrieves the program stored in the ROM to the RAM and controls the process and the operation of each component of the automatic analysis device  1  in accordance with this program. The control portion  61  is electrically connected to the input portion  62 , the analysis portion  63 , the storage portion  64 , the output portion  65 , and a communication interface  66  with a system bus, not illustrated, interposed therebetween. The controlling device  60  controls a reaction step, a separation step (BF separation), and a light measurement step in an immune analysis using various programs related to the processes of the automatic analysis device  1 . 
         [0094]    The input portion  62  is a portion through which measurement categories and the like are input to the control portion  61 . Examples used as the input portion  62  include a keyboard and a mouse. 
         [0095]    The analysis portion  63  is connected to the luminescence measurement unit  16  with the control portion  61  interposed therebetween. The analysis portion  63  analyzes, for example, a component density among the measurement categories of the sample on the basis of the amount of light received by the luminescence measurement unit  16  and outputs the analysis result to the control portion  61 . 
         [0096]    The storage portion  64  is a nonvolatile mass storage device. The storage portion  64  stores various types of information including, for example, measurement conditions for each measurement category of the sample or analysis results of each measurement category of the sample. Examples used as the storage portion  64  include a storage device such as a solid state drive (SSD) or a magnetism disk. The storage portion  64  may include an auxiliary storage device capable of retrieving information stored in a storage medium such as an optical disk, a magneto-optical disk, an IC card, or a SD card. 
         [0097]    The output portion  65  includes, for example, a display (display portion), a speaker, and a printer. The output portion  65  outputs various types of information related to an analysis of the sample under the control of the control portion  61 . The display displays the contents of or warnings about an analysis of the sample. The input portion  62  and the display portion may be embodied by a touch screen. 
         [0098]    The communication interface  66  is an interface that transmits and receives information in a predetermined form between itself and the measuring device  2  with a communication network, not illustrated, interposed therebetween. An example used as the communication interface  66  is a serial interface. 
         [0099]    The control portion  61  outputs a command on each driving circuit of the measuring device  2  through the communication interface  66  to control the separation step in the immune analysis. The measuring device  2  and the controlling device  60  communicate with each other through the communication interface  55  and the communication interface  66 . In the following description, however, communications between the measuring device  2  and the controlling device  60  are described without the intervention of the communication interfaces  55  and  66 . 
       [BF Separation Step] 
       [0100]    Now, the flow of the BF separation step performed by the first BF separation unit  11  and the second BF separation unit  12  of the measuring device  2  is described. 
         [0101]      FIG. 4  is a flowchart of the BF separation step performed by the first BF separation unit  11  and the second BF separation unit  12  of the measuring device  2 . 
         [0102]    The basic flow of the BF separation step performed by the first BF separation unit  11  and that performed by the second BF separation unit  12  are the same, so that the flow of the BF separation step (primary BF separation) performed by the first BF separation unit  11  is described here. 
         [0103]    In the BF separation step, the first magnetic generation part  32   p  of the first-half magnetic collection mechanism  31  firstly performs preliminary magnetic collection (step S 1 ) on a reaction vessel  3   a  that has been transported thereto in a first half of the primary BF separation. Thus, the magnetic particles contained in the liquid sample held in the reaction vessel  3   a  are roughly magnetically collected at (attracted to) the inner wall surface of the reaction vessel  3   a.    
         [0104]    Subsequently, the second magnetic generation part  32   m  of the first-half magnetic collection mechanism  31  performs main magnetic collection and BF washing to magnetically collect the magnetic particles roughly magnetically collected during the preliminary magnetic collection and to hold the magnetic particles on the inner wall surface of the reaction vessel  3   a  (step S 2 ). This main magnetic collection allows a lump of the magnetic particles magnetically collected on the inner wall surface of the reaction vessel  3   a  during the preliminary magnetic collection to be magnetically collected (sucked) to a further localized portion of the inner wall surface of the reaction vessel  3   a.    
         [0105]    Thereafter, the sample in the reaction vessel  3   a  is stirred by the stirring system  39 - 1  (step S 3 ). This stirring disperses magnetic particles or components not containing the magnetic particles confined in the lump of the magnetic particles magnetically collected on the inner wall surface of the reaction vessel  3   a  by the first-half magnetic collection mechanism  31 . 
         [0106]    Subsequently, the first magnetic generation part  34   p  of the second-half magnetic collection mechanism  33  performs preliminary magnetic collection (step S 4 ) in a second half of the primary BF separation on a reaction vessel  3   a  that has been transported thereto. Thus, the magnetic particles contained in the liquid sample in the reaction vessel  3   a  are roughly magnetically collected (sucked) again on the inner wall surface of the reaction vessel  3   a.    
         [0107]    Subsequently, the second magnetic generation part  34   m  of the second-half magnetic collection mechanism  33  performs main magnetic collection and BF washing to magnetically collect the magnetic particles roughly magnetically collected again during the preliminary magnetic collection and to hold the magnetic particles on the inner wall surface of the reaction vessel  3   a  (step S 5 ). This main magnetic collection allows a lump of the magnetic particles magnetically collected on the inner wall surface of the reaction vessel  3   a  during the preliminary magnetic collection to be magnetically collected (sucked) to a further localized portion of the inner wall surface of the reaction vessel  3   a . When the BF washing is complete, the BF separation step is finished. 
         [0108]    Similarly, in the second BF separation unit  12 , the first-half magnetic collection mechanism  35  and the second-half magnetic collection mechanism  37  perform the steps illustrated in  FIG. 4 . 
         [0109]    The automatic analysis device  1  operates in a cycle of, for example,  15  seconds. The turntable of the immuno-enzyme reaction unit  10  rotates in a  15 -second cycle.  FIG. 5  illustrates a timing chart of the BF separation step performed on one reaction vessel  3   a . When the automatic analysis device  1  operates in a  15 -second cycle and performs magnetic collection on two reaction vessels  3   a  at a time, the reaction vessels  3   a  are transported to the magnetic collection position, two cycles of a first half of the preliminary magnetic collection are then performed, and two cycles of BF washing (main magnetic collection) are then performed. Thereafter, one cycle of stirring is performed on the reaction vessels  3   a  and the reaction vessels  3   a  are left on standby for a period corresponding to one cycle. Thereafter, two cycles of a second half of the preliminary magnetic collection are performed and then two cycles of BF washing (main magnetic collection) are performed. The time length required from the start of the first half of the preliminary magnetic collection to the completion of the second half of the BF washing (main magnetic collection) is 150 sec. 
         [0110]    The invention is not limited to the embodiment in which each process is performed per two cycles. Each process may be performed by one cycle at a time as long as a sufficiently large magnetic collection effect can be obtained through the cycle or each process may be performed by three cycles or more at a time if the effect is not sufficient. Embodiments of a first-half magnetic collection mechanism (first magnetic generation part and second magnetic generation part) and a second-half magnetic collection mechanism (first magnetic generation part and second magnetic generation part) used for performing a process by one cycle and three cycles at a time are described below. 
         [0111]    Thereafter, the positional relationship during the BF separation step between the reaction vessels  3   a  and the first and second magnetic generation parts  32   p ,  32   m ,  34   p , and  34   m  (see  FIG. 1  and  FIG. 2 ) is described. 
         [0112]      FIG. 6  illustrates, in a schematic perspective view, the positional relationship during the BF separation step between the reaction vessels  3   a  and the first and second magnetic generation parts  32   p ,  32   m ,  34   p , and  34   m.    
         [0113]      FIG. 7  illustrates, in a schematic diagram, the positional relationship during the BF separation step between the reaction vessels  3   a  and the first and second magnetic generation parts  32   p ,  32   m ,  34   p , and  34   m , where an upper part of  FIG. 7  is a top view and a lower part of  FIG. 7  is a sectional view taken along line A-A. For the simplicity of illustration, however, the upper part of  FIG. 7  excludes an illustration of the lower layer  10   b  of the turntable and the lower part of  FIG. 7  excludes an illustration of sections of the reaction vessels  3   a.    
         [0114]      FIG. 6  and  FIG. 7  clearly illustrate the positional relationship during the BF separation step between the reaction vessels  3   a  and the first and second magnetic generation parts  32   p ,  32   m ,  34   p , and  34   m  while the first and second magnetic generation parts  32   p ,  32   m ,  34   p , and  34   m  arranged in the circumferential direction are illustrated as being arranged linearly along the BF separation step. One BF separation step (primary BF separation) flows from the near side on the left to the far side on the right in  FIG. 6  and from the left to the right in  FIG. 7 . The positional relationship between the reaction vessels  3   a  and the first and second magnetic generation parts  36   p ,  36   m ,  38   p , and  38   m  remains the same also in the secondary BF separation. The two-directional arrow Dc denotes an effective diameter (inner diameter) of a body portion of each reaction vessel  3   a.    
         [0115]    The numbers of the positions of the reaction vessels  3   a  illustrated in  FIG. 6  and  FIG. 7  represent the following positions: 
         [0116]    positions (1) and (2) denote first-half preliminary magnetic collection positions; 
         [0117]    positions (3) and (4) denote first-half BF washing positions (main magnetic collection positions); 
         [0118]    position (5) denotes a stirring position; 
         [0119]    position (6) denotes a standby position; 
         [0120]    positions (7) and (8) denote second-half preliminary magnetic collection positions; and 
         [0121]    positions (9) and (10) denote second-half BF washing positions (main magnetic collection positions). 
         [0122]      FIG. 8  is a side view of the positional relationship between a reaction vessel  3   a  and a magnetic generation part.  FIG. 8  illustrates the first magnetic generation part  32   p  as an example of the magnetic generation part. 
         [0123]    In areas MB in the reaction vessel  3   a  illustrated in  FIG. 8  or the vicinity of the areas MB, magnetic particles contained in the liquid sample in the reaction vessel  3   a  are attracted to the inner wall surface of the reaction vessel  3   a  by the effect of magnets  71 ,  72 ,  75 , and  76  of the first magnetic generation part  32   p . The reason why the magnetic particles are magnetically collected at two separate points is because the magnetic fields are produced on the left and right side of each reaction vessel  3   a  that has been transported to the first magnetic generation part  32   p . The detailed configuration of each magnetic generation part and the detailed positional relationship between each reaction vessel  3   a  and the corresponding magnetic generation part are separately described below. 
       [Structure of Magnetic Generation Part for Preliminary Magnetic Collection] 
       [0124]    Referring now to  FIG. 9  and  FIG. 11 , the structure of each of the first magnetic generation parts  32   p ,  34   p ,  36   p , and  38   p  used for preliminary magnetic collection is described in detail. The first magnetic generation parts  32   p ,  34   p ,  36   p , and  38   p , however, have the same structure and thus, only the first magnetic generation part  32   p  is described below. 
         [0125]      FIG. 9  is a perspective view of the first magnetic generation part  32   p  used for preliminary magnetic collection. 
         [0126]      FIG. 10  is a top view of the first magnetic generation part  32   p.    
         [0127]      FIG. 11  is a side view of the first magnetic generation part  32   p.    
         [0128]    The first magnetic generation part  32   p  includes four magnets  71 ,  72 ,  75 , and  76  having the same rectangular parallelepiped shape (see  FIG. 9 ). The magnet  71  (first magnet) and the magnet  72  (second magnet) are arranged vertically so that different magnetic poles face each other. Specifically, each of the magnet  71  and the magnet  72  has a first magnetic pole (for example, north pole) and a second magnetic pole (for example, south pole) arranged in a direction that is horizontal and that is perpendicular to the vessel transport direction (see  FIG. 11 ). An arrangement of the magnetic poles of the magnet  71  in a direction that is horizontal and that is perpendicular to the vessel transport direction is opposite to an arrangement of the magnetic poles of the magnet  72  in the direction that is horizontal and that is perpendicular to the vessel transport direction, that is, the magnetic poles of opposing surfaces of the magnet  71  and the magnet  72  are opposite to each other. A nonmagnetic member  73  (such as aluminium sheet) is disposed between the magnet  71  and the magnet  72 . 
         [0129]    Similarly to the magnet  71  and the magnet  72 , the magnet  75  (third magnet) and the magnet  76  (fourth magnet) are also arranged vertically so that different magnetic poles face each other. A nonmagnetic member  77  (such as aluminium sheet) is disposed between the magnet  75  and the magnet  76 . The pair of magnets  71  and  72  and the pair of magnets  75  and  76  are disposed so as to face each other across the path (groove  49   d ). The opposing surfaces of the magnet  71  and the magnet  75  have a south pole and the opposing surfaces of the magnet  72  and the magnet  76  have a north pole (see  FIG. 11 ). The first magnetic generation part  32   p  includes a set of these four magnets  71 ,  72 ,  75 , and  76 . 
         [0130]    Examples used as the four magnets  71 ,  72 ,  75 , and  76  for preliminary magnetic collection are permanent magnets according to, for example, Japan Industrial Standard (JIS C 2502). Japan Industrial Standard classifies permanent magnets into three types, that is, hard magnetic alloys, hard magnetic ceramics, and bonded magnets. Examples well known as a permanent magnet include a permanent magnet containing a rare earth exemplified by, for example, neodymium. 
         [0131]    The magnets  71 ,  72 ,  75 , and  76  are fixed to a yoke  80  made of a ferromagnetic substance (such as an iron material). The yoke  80  has a letter U shape. The yoke  80  has a bottom board portion  81 , with which the lower surfaces of the magnets  72  and  76  come into contact. The yoke  80  also has a left wall  82 L, with which side surfaces of the magnets  71  and  72  come into contact, and a right wall  82 R, with which side surfaces of the magnets  75  and  76  come into contact. Male screws  84  are screwed in female screws formed at upper end portions of the left wall  82 L, so that a fastening plate  83 L is pressed against the upper surface of the magnet  71 . Similarly, male screws  84  are screwed in female screws formed at upper end portions of the right wall  82 R, so that a fastening plate  83 R is pressed against the upper surface of the magnet  75 . Attaching the magnets  71 ,  72 ,  75 , and  76  to the yoke  80  can form a magnetic circuit and prevent a leakage of the magnetic field to the outside. In addition, the first magnetic generation part  32   p  including the four magnets  71 ,  72 ,  75 , and  76  can be easily fixed to the lower layer  10   b  of the turntable. 
         [0132]      FIGS. 12A and 12B  are schematic diagrams of lines of the magnetic force output by the first magnetic generation part  32   p , where  FIG. 12A  illustrates lines of the magnetic force viewed from above the first magnetic generation part  32   p  and  FIG. 12B  illustrates lines of the magnetic force viewed from the side of the first magnetic generation part  32   p.    
         [0133]    The first magnetic generation part  32   p  having the above-described configuration forms a closed magnetic circuit using the magnets  71  and  72  and the yoke  80 , as illustrated in  FIG. 12B . The first magnetic generation part  32   p  also forms a closed magnetic circuit using the magnets  75  and  76  and the yoke  80 . It is known that magnets have high magnetic collection ability at their corners. In the example illustrated in  FIG. 12A , lines of the magnetic force are crowded and the magnetic flux density is high at both end portions (corner portions) of the surface of the magnet  71  ( 72 ) facing the magnet  75  ( 76 ). In the example illustrated in  FIG. 12B , lines of the magnetic force are crowded and the magnetic flux density is high at both end portions (corner portions) of the surfaces of the magnet  71  and the magnet  72  facing each other. Similarly, lines of the magnetic force are crowded and the magnetic flux density is high at both end portions (corner portions) of the surfaces of the magnet  75  and the magnet  76  facing each other. 
         [0134]      FIG. 13  illustrates the positional relationship between the reaction vessels  3   a  and the first magnetic generation part  32   p.    
         [0135]    The surface of each magnet of the first magnetic generation part  32   p  used for preliminary magnetic collection facing the reaction vessels  3   a  has a width Wp in the vessel transport direction that is as long as to cover effective areas of two reaction vessels  3   a  transported to the magnetic collection position of the first magnetic generation part  32   p  and spaced a predetermined arrangement pitch (distance) apart from each other. Here, each effective area is an area (space) that holds, for example, the sample in the body portion of the reaction vessel  3   a . The dimension of the area in the vessel transport direction, that is, the inner diameter of the body portion is referred to as an effective diameter. 
         [0136]    When the effective diameter (inner diameter) of the body portion of each reaction vessel  3   a  is denoted with Dc and the arrangement pitch at which the reaction vessels  3   a  are arranged (arranged in the circumferential direction in an actual immuno-enzyme reaction unit  10 ) is denoted with Pc, the width Wp of the first magnetic generation part  32   p  can be determined using the following formula: 
         [0000]        Wp≧Dc+Pc   (1).
 
         [0137]    In the preliminary magnetic collection, disposing each reaction vessel  3   a  at a portion located inward from both end portions of the magnet  71  ( 72 ,  75 , or  76 ) is important. To this end, the magnet  71  ( 72 ,  75 , or  76 ) having a large width Wp is suitable. In other words, preferably, the effective area of each reaction vessel  3   a  is located within an area interposed between two imaginary lines, which are straight lines imaginarily drawn from both ends of the magnet  71  ( 72 ,  75 , or  76 ) so as to be perpendicular to the vessel transport direction. A gap We between the opposing magnets  71  ( 72 ) and  75  ( 76 ) is determined to be a minimum possible distance that does not hinder the reaction vessels  3   a  to pass therethrough. 
         [0138]    The positional relationship between each reaction vessel  3   a  and the magnet  71  ( 72 ,  75 , or  76 ) that satisfies the formula ( 1 ) is not suitable for collecting the magnetic particles in the liquid sample inside the reaction vessel  3   a  at one point. In this case, however, the magnetic force of the magnet  71  ( 72 ,  75 , or  76 ) is exerted on the entirety of the liquid sample inside the reaction vessel  3   a . Such a positional relationship is thus effective for roughly collecting the magnetic particles widely dispersed inside the liquid sample at one point. 
       [Structure of Magnetic Generation Part for Main Magnetic Collection] 
       [0139]    Referring now to  FIG. 14  to  FIG. 16 , the structure of the second magnetic generation parts  32   m ,  34   m ,  36   m , and  38   m  used for main magnetic collection is described in detail. Since the second magnetic generation parts  32   m ,  34   m ,  36   m , and  38   m , however, have the same structure, only the structure of the second magnetic generation part  32   m  is described below. 
         [0140]      FIG. 14  is a perspective view of the second magnetic generation part  32   m  used for the main magnetic collection. 
         [0141]      FIG. 15  is a top view of the second magnetic generation part  32   m.    
         [0142]      FIG. 16  is a side view of the second magnetic generation part  32   m.    
         [0143]    The basic structure of the second magnetic generation part  32   m  is the same as that of the first magnetic generation part  32   p  for preliminary magnetic collection. However, the way how the width Wm of the second magnetic generation part  32   m  in the vessel transport direction is determined is significantly different from that in the case of the first magnetic generation part  32   p.    
         [0144]    The second magnetic generation part  32   m  includes four magnets  91 ,  92 ,  95 , and  96  having the same rectangular parallelepiped shape (see  FIG. 14 ). The magnets  91 ,  92 ,  95 , and  96  are assembled in the same manner as are the magnets  71 ,  72 ,  75 , and  76  of the first magnetic generation part  32   p  ( 34   p ,  36   p , or  38   p ). Here, the width of the magnets  91 ,  92 ,  95 , and  96  in the vessel transport direction is shorter than the width of the magnets  71 ,  72 ,  75 , and  76  of the first magnetic generation part  32   p  ( 34   p ,  36   p , or  38   p ). The magnet  91  (first magnet) and the magnet  92  (second magnet) are arranged vertically so that different magnetic poles face each other. Specifically, each the magnet  91  and the magnet  92  has a first magnetic pole (for example, north pole) and a second magnetic pole (for example, south pole) arranged in a direction that is horizontal and that is perpendicular to the vessel transport direction and the magnet  91  and the magnet  92  are disposed so that their opposing magnetic poles are opposite to each other (see  FIG. 16 ). A nonmagnetic member  93  (such as aluminium sheet) is disposed between the magnet  91  and the magnet  92 . 
         [0145]    Similarly to the magnet  91  and the magnet  92 , the magnet  95  (third magnet) and the magnet  96  (fourth magnet) are also arranged vertically so that different magnetic poles face each other. A nonmagnetic member  97  (such as aluminium sheet) is disposed between the magnet  95  and the magnet  96 . The pair of magnets  91  and  92  and the pair of magnets  95  and  96  are disposed so as to face each other across the path (groove  49   d ). The opposing surfaces of the magnet  91  and the magnet  95  have a south pole and the opposing surfaces of the magnet  92  and the magnet  96  have a north pole (see  FIG. 16 ). The second magnetic generation part  32   m  includes a set of these four magnets  91 ,  92 ,  95 , and  96 . 
         [0146]    Examples used as the four magnets  91 ,  92 ,  95 , and  96  for main magnetic collection include permanent magnets, as in the case of the magnets  71 ,  72 ,  75 , and  76  for preliminary magnetic collection. 
         [0147]    The magnets  91 ,  92 ,  95 , and  96  are fixed to a yoke  100 , made of a ferromagnetic substance (such as an iron material). The width of the yoke  100  in the vessel transport direction is smaller than that of the first magnetic generation part  32   p  so as to correspond to the width of the magnets  91 ,  92 ,  95 , and  96 . The yoke  100  has a letter U shape. The yoke  100  has a bottom board portion  101 , with which the lower surfaces of the magnets  92  and  96  come into contact. The yoke  100  also has a left wall  102 L, with which the side surfaces of the magnets  91  and  92  come into contact, and a right wall  102 R, with which the side surfaces of the magnets  95  and  96  come into contact. Male screws  84  are screwed in female screws formed at upper end portions of the left wall  102 L, so that a fastening plate  83 L is pressed against the upper surface of the magnet  91 . Similarly, male screws  84  are screwed in female screws formed at upper end portions of the right wall  102 R, so that a fastening plate  83 R is pressed against the upper surface of the magnet  95 . 
         [0148]    The second magnetic generation part  32   m  having this configuration forms substantially the same magnetic fields as does the first magnetic generation part  32   p  (see  FIG. 12 ). Specifically, lines of the magnetic force are crowded and the magnetic flux density is high at both end portions (corner portions) of the surface of the magnet  91  ( 92 ) facing the magnet  95  ( 96 ). In addition, lines of the magnetic force are crowded and the magnetic flux density is high at both end portions (corner portions) of the surfaces of the magnet  91  and the magnet  92  facing each other. Similarly, lines of the magnetic force are crowded and the magnetic flux density is high at both end portions (corner portions) of the surfaces of the magnet  95  and the magnet  96  facing each other. 
         [0149]      FIG. 17  illustrates the positional relationship between the reaction vessels  3   a  and the second magnetic generation part  32   m  ( 34   m ,  36   m , or  38   m ). 
         [0150]    The surface of each magnet of the second magnetic generation part  32   m  for main magnetic collection facing the reaction vessels  3   a  has end portions in the vessel transport direction that are located adjacent to the centers of the inner diameters of the reaction vessels  3   a  transported to the magnetic collection position of the second magnetic generation part  32   m . Specifically, the width Wm of each magnet of the second magnetic generation part  32   m  in the vessel transport direction is approximately the same as the arrangement pitch (distance) between two reaction vessels  3   a  that have been transported to the magnetic collection position of the second magnetic generation part  32   m.    
         [0151]    Here, the width Wm of each magnet of the second magnetic generation part  32   m  can be determined using the following formula, where the effective diameter (inner diameter) of the body portion of each reaction vessel  3   a  is denoted with Dc and the arrangement pitch at which the reaction vessels  3   a  are arranged (arranged in the circumferential direction in an actual immuno-enzyme reaction unit  10 ) is denoted with Pc: 
         [0000]      Wm≈Pc  (2).
 
         [0152]    In the main magnetic collection, it is important to hold the magnetic particles magnetically collected during the preliminary magnetic collection on the inner wall surface of each reaction vessel  3   a  so that the magnetic particles are not carried away by the flow of the washing liquid. Preferably, approximately center positions of the reaction vessels  3   a  are roughly aligned with the positions of both end portions of the magnet  91  ( 92 ,  95 , or  96 ) in the vessel transport direction. In other words, preferably, the center position of each reaction vessel  3   a  is located on or substantially on either one of two imaginary lines, which are straight lines imaginarily drawn from both ends of the magnet  91  ( 92 ,  95 , or  96 ) in a direction perpendicular to the vessel transport direction. 
         [0153]    The positional relationship between the reaction vessels  3   a  and the magnet  91  ( 92 ,  95 , or  96 ) that satisfies the formula ( 2 ) is effective in terms that strong magnetic fields produced at both end portions of each magnet  91  ( 92 ,  95 , or  96 ) are capable of magnetically locally collecting magnetic particles contained in the liquid sample in the reaction vessels  3   a  at a point. 
       [Example of Measurement Data] 
       [0154]      FIG. 18  illustrates an example of measurement data of the ratio of how many magnetic particles remain in each reaction vessel  3   a  after the sample is subjected to a typical BF separation step. 
         [0155]      FIG. 19  illustrates an example of measurement data of the ratio of how many magnetic particles remain in each reaction vessel  3   a  after the sample is subjected to a BF separation step according to the first embodiment. 
         [0156]    The BF separation step was performed five times and the ratio (%) of how many magnetic particles remain was measured every time. In  FIG. 18  and  FIG. 19 , “CV” denotes a coefficient of variation. 
         [0157]    The ratio (%) of how many magnetic particles remain is an indicator that shows how may magnetic particles originally contained in the liquid sample inside each reaction vessel  3   a  remain in the reaction vessel  3   a  after the sample is subjected to the B/F separation step. Before employing this embodiment, the average of the ratios of how many magnetic particles remain measured after five times of the BF separation step is approximately 74% (73.6%) (see  FIG. 18 ). However, the average of the ratios measured after five times of the BF separation step is found to have been improved up to approximately 91% as a result of improving the efficiency of preliminary magnetic collection using this embodiment (see  FIG. 19 ). 
       [Examples of Magnetically Collected Magnetic Particle Image] 
       [0158]    For reference,  FIG. 20  illustrates examples of magnetically collected magnetic particle images formed differently depending on magnet shapes. 
         [0159]    The example illustrated in  FIG. 20A  is a magnetically collected magnetic particle image MB 1  obtained using only the first magnetic generation part  32   p . The magnetic particles are magnetically collected to form a lump (dotted form) having a certain size. The diameter of the lump is found to be large. 
         [0160]    The example illustrated in  FIG. 20B  is a magnetically collected magnetic particle image MB 2  obtained using only the second magnetic generation part  32   m . This is a result obtained by imitatively performing an existing method that does not involve preliminary magnetic collection and this method is not directly applicable to this embodiment. Since the second magnetic generation part  32   m  performs magnetic collection using end portions of the magnets, the magnetic particles are magnetically collected by a strong suction force but fail to form in a dotted form. The image MB 2  shows the state where the magnetic particles are magnetically collected linearly extending along the axial direction of the reaction vessel  3   a.    
         [0161]    The example illustrated in  FIG. 20C  is a magnetically collected magnetic particle image MB 3  obtained by the first embodiment. Specifically, this is a magnetically collected magnetic particle image obtained after performing preliminary magnetic collection using the first magnetic generation part  32   p  and then further performing magnetic collection using the second magnetic generation part  32   m . Compared with the magnetically collected magnetic particle image MB 1  illustrated in  FIG. 20A  obtained by performing magnetic collection using only the first magnetic generation part  32   p , the image MB 3  shows the state where the magnetic particles are condensed in smaller dots. 
         [0162]    As described above in the first embodiment, the surface of each of the magnets  71 ,  72 ,  75 , and  76  for preliminary magnetic collection of the first magnetic generation part  32   p  ( 34   p ,  36   p , or  38   p ) facing the reaction vessels  3   a  has the width Wp in the vessel transport direction that is designed to be as long as to cover the effective areas Dc of the reaction vessels  3   a  that have been transported to the magnetic collection position of the first magnetic generation part  32   p  ( 34   p ,  36   p , or  38   p ). In addition, the surface of each of the magnets  91 ,  92 ,  95 , and  96  for main magnetic collection of the second magnetic generation part  32   m  ( 34   m ,  36   m , or  38   m ) facing the reaction vessels  3   a  has end portions in the vessel transport direction that are designed to be located adjacent to the centers of the effective areas Dc of the reaction vessels  3   a  that have been transported to the magnetic collection position of the second magnetic generation part  32   m  ( 34   m ,  36   m , or  38   m ). 
         [0163]    This configuration allows each of the magnets  71 ,  72 ,  75 , and  76  of the first magnetic generation part  32   p  ( 34   p ,  36   p , or  38   p ) to exert its magnetic force over the entirety of the liquid sample inside the reaction vessel  3   a . Thus, the magnetic particles widely dispersed in the liquid sample are roughly collected at a single point during the preliminary magnetic collection. In addition, the magnetic particles in the liquid sample inside the reaction vessel  3   a  that have been preliminarily magnetically collected are magnetically and locally collected and held at a point in the main magnetic collection using strong magnetic forces produced at both end portions of each of the magnets  91 ,  92 ,  95 , and  96  of the second magnetic generation part  32   m  ( 34   m ,  36   m , or  38   m ). This configuration is thus capable of reducing the amount of magnetic particles that are carried away through the washing operation during the BF separation step involving the preliminary magnetic collection and main magnetic collection. 
         [0164]    Specifically, this embodiment is capable of improving the preliminary magnetic collection efficiency and improving the suction force exerted during the main magnetic collection as a result of differing the shape of the magnets used for preliminary magnetic collection in the BF separation step from the shape of the magnets used for the main magnetic collection in the BF separation step so that the shapes are appropriate for their purposes. Thus, the automatic analysis device can perform an immune analysis with improved higher detection sensitivity. 
       Second Embodiment 
       [0165]      FIG. 21  illustrates a first magnetic generation part and a second magnetic generation part according to a second embodiment of the invention. The first magnetic generation part  32   p  according to the first embodiment performs preliminary magnetic collection on two reaction vessels  3   a  at a time. The first magnetic generation part according to the second embodiment, on the other hand, performs preliminary magnetic collection on one reaction vessel  3   a  at a time. The second magnetic generation part for main magnetic collection has a structure the same as that of the second magnetic generation part  32   m  according to the first embodiment. 
         [0166]    As illustrated in  FIG. 21 , two first magnetic generation parts  131   p  for preliminary magnetic collection are arranged in the vessel transport direction. The way how magnets in each first magnetic generation part  131   p  are assembled together is basically the same as that in the case of the first magnetic generation part  32   p . Specifically, the first magnetic generation part  131   p  includes four magnets, but  FIG. 21  illustrates only two magnets  111  and  112  on the upper side. These magnets  111  and  112  correspond to the magnets  71  and  75  of the first magnetic generation part  32   p . Similarly to the first magnetic generation part  32   p , the first magnetic generation part  131   p  includes a nonmagnetic member and a yoke (not illustrated). 
         [0167]    The surface of each of the magnets  111  and  112  of the first magnetic generation part  131   p  facing the reaction vessel  3   a  has a width Wp&#39; in the vessel transport direction that is as long as to cover the effective area (see  FIG. 7 ) of the reaction vessel  3   a  that has been transported to the magnetic collection position of the first magnetic generation part  131   p . Thus, the four magnets of the first magnetic generation part  131   p , including the magnets  111  and  112 , exert their magnetic forces over the entirety of the liquid sample inside the reaction vessel  3   a . The magnetic particles widely dispersed in the liquid sample are thus roughly collected to one point, as in the case of the first embodiment. These two first magnetic generation parts  131   p  arranged side by side can replace the first magnetic generation part  32   p  that performs preliminary magnetic collection on two reaction vessels  3   a  at a time. 
       Third Embodiment 
       [0168]      FIG. 22  illustrates a first magnetic generation part and a second magnetic generation part according to a third embodiment of the present invention. In the third embodiment, main magnetic collection is performed in accordance with the second embodiment but on two reaction vessels  3   a  at a time. 
         [0169]    As illustrated in  FIG. 22 , two second magnetic generation parts  131   m  for main magnetic collection are arranged in the vessel transport direction. The way how magnets in the second magnetic generation part  131   m  are assembled together is basically the same as that in the case of the second magnetic generation part  32   m . Specifically, the second magnetic generation part  131   m  includes four magnets, but  FIG. 22  illustrates only two magnets  113  and  114  on the upper side. These magnets  113  and  114  correspond to the magnets  91  and  95  of the second magnetic generation part  32   m . Similarly to the second magnetic generation part  32   m , the second magnetic generation part  131   m  includes a nonmagnetic member and a yoke (not illustrated). 
         [0170]    The surface of each of the magnets  113  and  114  of each second magnetic generation part  131   m  facing the reaction vessel  3   a  has one of end portions in the vessel transport direction (on the upstream side in the vessel transport direction in  FIG. 22 ) that is located adjacent to the center of the effective area of the reaction vessel  3   a  that has been transported to the magnetic collection position of the second magnetic generation part  131   m . Thus, the magnetic particles contained in the liquid sample inside the reaction vessel  3   a  that have been preliminarily magnetically collected are magnetically and locally collected and held at a point in the main magnetic collection using strong magnetic forces produced at the end portions of each of the four magnets of the second magnetic generation part  131   m , including the magnets  113  and  114 . These two second magnetic generation parts  131   m  arranged side by side can replace the second magnetic generation part  32   m  that performs main magnetic collection on two reaction vessels  3   a  at a time. 
         [0171]    Here, the second magnetic generation part  32   m  (see  FIG. 7 ) according to the first embodiment may be replaced with two second magnetic generation parts  131   m.    
         [0172]    Instead of the configuration illustrated in  FIG. 22 , one first magnetic generation part  131   p  and one second magnetic generation part  131   m  may be provided. In this case, each of the preliminary magnetic collection and the main magnetic collection is performed in one cycle, which increases the analysis processing speed. 
       Fourth Embodiment 
       [0173]      FIG. 23  illustrates a first magnetic generation part according to a fourth embodiment. 
         [0174]    In the fourth embodiment, preliminary magnetic collection is performed on three reaction vessels  3   a  at a time. 
         [0175]    Similarly to the first magnetic generation part  32   p  according to the first embodiment, a first magnetic generation part  133   p  includes four magnets. The way how the four magnets in the first magnetic generation part  133   p  are assembled together is basically the same as that in the case of the first magnetic generation part  32   p .  FIG. 23  illustrates only two magnets  115  and  116  on the upper side. These magnets  115  and  116  correspond to the magnets  71  and  75  of the first magnetic generation part  32   p . Similarly to the first magnetic generation part  32   p , the first magnetic generation part  131   p  includes a nonmagnetic member and a yoke (not illustrated). 
         [0176]    The surface of each of the magnets  115  and  116  of the first magnetic generation part  133   p  facing the reaction vessels  3   a  has a width Wm″ in the vessel transport direction that is as long as to cover effective areas of three reaction vessels  3   a  transported to the magnetic collection position of the first magnetic generation part  133   p . Specifically, the width Wm″ of each of the magnets  115  and  116  of the first magnetic generation part  133   p  is longer than or equal to the length obtained by adding the inner diameter of two reaction vessels  3   a  to the length equivalent to twice the arrangement pitch between three reaction vessels  3   a  transported to the magnetic collection position of the first magnetic generation part  133   p . This configuration allows each of magnets of the first magnetic generation part  133   p , including the magnets  115  and  116 , to exert its magnetic force over the entirety of the liquid sample inside the three reaction vessels  3   a . The magnetic particles widely dispersed in the liquid sample inside each reaction vessel  3   a  are thus roughly collected at a single point, as in the case of the first embodiment. In addition, three cycles of magnetic collection are performed on one reaction vessel  3   a , so that a sufficiently large magnetic collection effect can be obtained. 
         [0177]    Similarly to the first magnetic generation part  133   p , the second magnetic generation part used for main magnetic collection may perform magnetic collection on three reaction vessels  3   a  at a time. In this case, the centers of the effective areas of both end reaction vessels among the three reaction vessels  3   a  are located adjacent to both end portions of the magnets, so that the effects the same as those in the case of the first embodiment can be obtained. 
       Fifth Embodiment 
       [0178]      FIG. 24  is a schematic configuration diagram of an automatic analysis device  1 A according to a fifth embodiment. 
         [0179]    The automatic analysis device  1 A includes a measuring device  2 A including an immuno-enzyme reaction unit  10 A. The immuno-enzyme reaction unit  10 A includes an outer turntable  10   c  and an inner turntable  10   i , disposed on the inner side of the outer turntable  10   c . As in the case of the first embodiment, a first magnetic generation part and a second magnetic generation part for a BF separation step are disposed on the lower layer of the outer turntable  10   c . The inner turntable  10   i  may include a stirring mechanism. The measuring device  2 A having this configuration performs a primary immunoreaction operation at the inner turntable  10   i . Each reaction vessel  3   a  that has been subjected to the primary immunoreaction operation is shifted to a predetermined position of the outer turntable  10   c  by an arm (reaction vessel shifting mechanism). The measuring device  2 A then performs a primary BF separation operation, a secondary immunoreaction operation, a secondary BF separation operation, and an enzyme reaction operation at the outer turntable  10   c.    
         [0180]    Thus far, embodiments of the present invention have been described, but the present invention is not limited to the above-described embodiments. The present invention includes other embodiments and application examples within a scope not departing from the spirit of the invention described in the scope of the appended claim. 
         [0181]    For example, the above-described embodiments specifically describe the configurations of devices and systems in detail for easy understanding of the present invention. The present invention is thus not necessarily limited to embodiments including all the components described above. At least one of the components in a certain embodiment is replaceable with another component. Alternatively, another component may be added to a configuration of a certain embodiment. 
         [0182]    For example, the diameter or other parameters of the immuno-enzyme reaction unit  10  or  10 A varies depending on the device configuration (particularly, reaction time or processing speed) according to each embodiment described above. Thus, the arrangement of the magnets in each magnetic generation part or the flow of the reaction vessels is not necessarily limited to any of these examples. 
         [0183]    Each embodiment described above includes permanent magnets for use as the magnets  71 ,  72 ,  75 , and  76  for preliminary magnetic collection and the magnets  91 ,  92 ,  95 , and  96  for main magnetic collection. Instead, electromagnets may be used. The measuring device  2  includes, for example, a current source, which is not illustrated and which produces electric currents fed to the magnets  71 ,  72 ,  75 , and  76  and the magnets  91 ,  92 ,  95 , and  96  formed of electromagnets. The current source feeds electric currents to the magnets  71 ,  72 ,  75 , and  76  and the magnets  91 ,  92 ,  95 , and  96  under the control of the control portion  51  ( FIG. 3 ). This configuration is capable of controlling whether each of the magnets  71 ,  72 ,  75 , and  76  and the magnets  91 ,  92 ,  95 , and  96  is to produce a magnetic field. 
       REFERENCE SIGNS LIST 
       [0184]      1  automatic analysis device 
         [0185]      2  measuring device 
         [0186]      3   a  reaction vessel 
         [0187]      10  immuno-enzyme reaction unit 
         [0188]      11  first BF separation unit 
         [0189]      12  second BF separation unit 
         [0190]      21  nozzle 
         [0191]      24  washing bath 
         [0192]      31 ,  35  first-half magnetic collection mechanism 
         [0193]      33 ,  37  second-half magnetic collection mechanism 
         [0194]      32   p ,  34   p ,  36   p ,  38   p  first magnetic generation part (for preliminary magnetic collection) 
         [0195]      32   m ,  34   m ,  36   m ,  38   m  second magnetic generation part (for main magnetic collection) 
         [0196]      49   d  groove 
         [0197]      71 ,  72 ,  75 ,  76  magnet 
         [0198]      91 ,  92 ,  95 ,  96  magnet 
         [0199]      60  controlling device 
         [0200]      61  control portion