Patent Publication Number: US-2023143259-A1

Title: Automatic analyzing apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2021-184163, filed Nov. 11, 2021, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to an automatic analyzing apparatus. 
     BACKGROUND 
     An automatic analyzing apparatus is employed in a variety of tests including a biochemical test, an immunological test, a blood coagulation test, and so on, where it optically measures color changes, turbidity transitions, etc., caused by a sample reacting with a reagent used for analysis in an individual test item. With an automatic analyzing apparatus, analysis data expressed as concentrations, enzyme activities, or other properties of the respective test-item ingredients contained in samples can be acquired based on measurement results. 
     Such an automatic analyzing apparatus is adapted to dispense a sample and a reagent into a reaction container by use of one or more probes, conduct measurement by irradiating the reaction liquid formed of the sample and the reagent in the reaction container with light, and wash the probes after dispensing operations and the reaction container after measurement so that they are used repeatedly. To wash components of probes and reaction containers which contact a sample and/or a reagent, a washing liquid containing a powerful detergent component is used. For example, in a method that uses such a washing liquid for washing reaction containers, a concentrated liquid containing a high concentration of a detergent component is diluted with a diluent to obtain the washing liquid, and the obtained washing liquid is used for washing. 
     Here, the concentrated liquid and the diluent are fed through different flow paths so as to join together in a given channel, where the concentrated liquid is diluted to provide the washing liquid for use in washing. However, this method does not guarantee a constant concentration of the detergent component for individual washing steps, which could lead to a poor capability to wash reaction containers due to the washing liquid having a reduced detergent component concentration, or to an undesired influence on the reaction of the reaction liquid due to a subtle amount of the detergent component remaining in the reaction container due to the washing liquid having an increased detergent component concentration. Consequently, conducting measurement with a reaction liquid may produce a problem of degraded analysis data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram showing a configuration of an automatic analyzing apparatus according to an embodiment. 
         FIG.  2    is a perspective view showing an exemplary structure of an analyzer section according to the embodiment. 
         FIG.  3    is a diagram showing a configuration of a washer according to the embodiment. 
         FIG.  4    is a diagram showing a configuration of a first washing member according to the embodiment. 
         FIG.  5    is a diagram showing a configuration of a second washing member according to the embodiment. 
         FIG.  6    is a diagram showing an exemplary structure of a mixer unit according to the embodiment. 
         FIG.  7    is a diagram showing another exemplary structure of the mixer unit according to the embodiment. 
         FIG.  8    is a diagram showing a configuration of a third washing member according to the embodiment. 
         FIG.  9    is a diagram showing a configuration of a fourth washing member according to the embodiment. 
         FIG.  10    is a diagram showing a configuration of a drain member according to the embodiment. 
         FIG.  11    is a diagram showing a configuration of another washer according to the embodiment. 
         FIG.  12    is a diagram showing a structure of a washing bath according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to one embodiment, an automatic analyzing apparatus includes a feeder and a mixer unit. The feeder is configured to feed a first liquid and a second liquid. The mixer unit includes an inflow part, an internal space, and an outflow part. The mixer unit is configured so that the first liquid and the second liquid fed from the feeder enter through the inflow part, the first liquid and the second liquid entering through the inflow part flow inside the internal space, and the first liquid and the second liquid flowing inside the internal space exit through the outflow part according to an inflow entering through the inflow part. 
     Embodiments will be described with reference to the drawings. 
     In one embodiment, a feeder and a mixer unit are provided. The mixer unit includes an inflow part, an internal space, and an outflow part. The feeder feeds a first liquid and a second liquid. The first liquid and the second liquid fed from the feeder enter through the inflow part. The first liquid and the second liquid that have entered through the inflow part flow inside the internal space. The first liquid and the second liquid that have flown inside the internal space exit through the outflow part according to an inflow entering through the inflow part. 
       FIG.  1    is a block diagram showing a configuration of an automatic analyzing apparatus according to the embodiment. The description will assume that the automatic analyzing apparatus is intended for biochemical tests, immunological tests, and blood coagulation tests. 
     The automatic analyzing apparatus, denoted by reference number “100”, includes an analyzer section  10  for dispensing a sample such as a standard sample provided for an intended test item or a subject sample, and a reagent for the test item, and analyzing each sample by subjecting a reaction liquid containing the sample and the reagent to measurement operations. The automatic analyzing apparatus  100  also includes a driver section  31  for driving multiple components in the analyzer section  10  to perform dispensing operations, etc. for each sample and each reagent. 
     Also, the automatic analyzing apparatus  100  includes an analysis controller section  32  for controlling the driver section  31  to operate each component in the analyzer section  10 . The automatic analyzing apparatus  100  includes a computer section  33  for preparing a calibration curve for each test item from standard data that has been generated by the analyzer section  10  through measurement of a reaction liquid containing a standard sample provided for the corresponding test item and a reagent for the test item, and for generating analysis data for the test item from subject data that has been generated through measurement of a reaction liquid containing a subject sample and the reagent for the test item. The automatic analyzing apparatus  100  includes a data storage  34  for storing calibration curves, analysis data, etc., obtained at the computer section  33 . 
     The automatic analyzing apparatus  100  includes a display  35  for presenting calibration curves, analysis data, etc., obtained at the computer section  33 . The automatic analyzing apparatus  100  includes an input interface  36  for enabling inputs for setting identification information, test item information, etc. for each sample, and so on. The automatic analyzing apparatus  100  also includes a system controller section  37  which takes total control over the analysis controller section  32 , the computer section  33 , the data storage  34 , and the display  35 . 
       FIG.  2    is a perspective view showing an exemplary structure of the analyzer section  10 . The analyzer section  10  is provided with one or more sample containers  11  each adapted to contain a sample such as a standard sample, a subject sample, or the like, and includes a sample rack  12  capable of holding more than one sample container  11 . The analyzer section  10  is also provided with one or more first reagent containers  13  each adapted to contain a first reagent which is used as a reagent in, for example, a single-reagent system or a dual-reagent system to react with an ingredient in a sample for the intended test item. The analyzer section  10  includes a first reagent rack  14  for holding more than one first reagent container  13  in such a manner that the first reagent containers  13  can move. The analyzer section  10  is further provided with one or more second reagent containers  15  each adapted to contain a second reagent which forms a pair with the first reagent in the dual-reagent system. The analyzer section  10  includes a second reagent rack  16  for holding more than one second reagent container  15  in such a manner that the second reagent containers  15  can move. 
     The analyzer section  10  includes multiple reaction containers  17  circumferentially arranged at equal pitches, and a reaction disk  18  for holding the reaction containers  17  in such a manner that the reaction containers  17  can rotate. The analyzer section  10  includes a sample dispensing probe  19  for performing a dispensing action including aspiration of a sample from each sample container  11  and discharge of this sample into the intended reaction container  17 . The analyzer section  10  includes a sample dispensing arm  20  for supporting the sample dispensing probe  19  in such a manner that the sample dispensing probe  19  can move vertically and also rotate. 
     The analyzer section  10  includes a first reagent dispensing probe  21  for performing a dispensing action including aspiration of the first reagent from each first reagent container  13  and discharge of this first reagent into the intended reaction container  17 . The analyzer section  10  includes a first reagent dispensing arm  22  for supporting the first reagent dispensing probe  21  in such a manner that the first reagent dispensing probe  21  can move vertically and also rotate. The analyzer section  10  also includes a second reagent dispensing probe  23  for performing a dispensing action including aspiration of the second reagent from each second reagent container  15  and discharge of this second reagent into the intended reaction container  17 . The analyzer section  10  includes a second reagent dispensing arm  24  for supporting the second reagent dispensing probe  23  in such a manner that the second reagent dispensing probe  23  can move vertically and also rotate. 
     The analyzer section  10  includes a stirrer  25  for stirring a reaction liquid in each reaction container  17 , which may be a mixture of the sample and the first reagent or a mixture of the sample, the first reagent, and the second reagent. The analyzer section  10  includes a measurer  26  for optically measuring each stirred reaction liquid. The analyzer section  10  includes a washer  27  for washing the reaction containers  17  using one or more types of washing liquids. The analyzer section  10  also includes a washer  28  for washing the sample dispensing probe  19  using one or more types of washing liquids. The analyzer section  10  further includes a washer  29  for washing the first reagent dispensing probe  21  using one or more types of washing liquids, and a washer  30  for washing the second reagent dispensing probe  23  using one or more types of washing liquids. 
     The measurer  26 , by measuring a reaction liquid containing a standard sample and a reagent or reagents, generates standard data which may be expressed as, for example, an absorbency level. The measurer  26  also generates subject data which may be expressed as an absorbency level, by measuring a reaction liquid containing a subject sample and a reagent or reagents. 
     Turning back to  FIG.  1   , the driver section  31  includes a conveyor mechanism and a mechanism for driving the conveyor mechanism to convey the sample rack  12  at the analyzer section  10 . The driver section  31  also includes one or more mechanisms for driving each of the first reagent rack  14  and the second reagent rack  16  so that the first reagent containers  13  and the second reagent containers  15  each rotate. The driver section  31  includes a mechanism for driving the reaction disk  18  so that the reaction containers  17  each rotate. 
     The driver section  31  includes a mechanism for driving the sample dispensing arm  20  so as to rotate the sample dispensing probe  19  between a given position above one or more sample containers  11  and a given position above one or more reaction containers  17 , and to vertically move the sample dispensing probe  19  between the given position above the one or more sample containers  11  and the target sample container  11  and between the given position above the one or more reaction containers  17  and the target reaction container  17 . 
     The driver section  31  also includes a mechanism for driving the first reagent dispensing arm  22  to rotate the first reagent dispensing probe  21  between a given position above one or more first reagent containers  13  and a given position above one or more reaction containers  17 , and to vertically move the first reagent dispensing probe  21  between the given position above the one or more first reagent containers  13  and the target first reagent container  13 . The driver section  31  includes a mechanism for driving the second reagent dispensing arm  24  to rotate the second reagent dispensing probe  23  between a given position above one or more second reagent containers  15  and a given position above one or more reaction containers  17 , and to vertically move the second reagent dispensing probe  23  between the given position above the one or more second reagent containers  15  and the target second reagent container  15 . 
     The driver section  31  includes one or more mechanisms for driving the washers  27  to  30  for conducting the feeding and draining of their washing liquids. 
     The analysis controller section  32  includes a CPU and memory circuitry, and controls the driver section  31  to operate each component in the analyzer section  10  based on inputs given via the input interface  36 . The analysis controller section  32 , in response to an input given via the input interface  36  for starting a calibration for a test item, causes the components of the analyzer section  10  and the driver section  31  to carry out the calibration by conveying the sample rack  12 , moving the first reagent container  13 , the second reagent container  15 , and the reaction container  17 , dispensing the standard sample for the corresponding test item, dispensing the first reagent and/or the second reagent for the test item, stirring the reaction liquid, measuring the reaction liquid, washing the reaction container  17 , the sample dispensing probe  19 , and the first reagent dispensing probe  21  and/or the second reagent dispensing probe  23 , and so on. 
     Also, the analysis controller section  32 , in response to an input given via the input interface  36  for starting a test on a subject sample, causes the components of the analyzer section  10  and the driver section  31  to carry out the test by conveying the sample rack  12 , moving the first reagent container  13 , the second reagent container  15 , and the reaction container  17 , dispensing the subject sample, dispensing the first reagent and/or the second reagent for the test item, stirring the reaction liquid, measuring the reaction liquid, washing the reaction container  17 , the sample dispensing probe  19 , and the first reagent dispensing probe  21  and/or the second reagent dispensing probe  23 , and so on. 
     The computer section  33  includes a CPU and memory circuitry, and generates a calibration curve for each test item based on standard data and a standard value or values. Here, the standard data has been generated by the measurer  26  of the analyzer section  10  through the calibration for the corresponding test item. The standard value indicates a concentration of the ingredient for this test item, set for the standard sample. The computer section  33  also generates, using the calibration curve for each test item, analysis data expressed as an activity value, a concentration, or other properties from subject data for the test item, generated by the measurer  26  through measurement of the subject sample. 
     The data storage  34  includes a storage which may be, for example, a hard disk drive (HDD), etc. The data storage  34  stores various data including identification information and standard values set for the standard samples for the respective test items, data generated by the analyzer section  10  such as the standard data and the subject data for the test items, data prepared and generated by the computer section  33  such as the calibration curves and the analysis data, and so on. 
     The display  35  includes one or more monitors constituted by, for example, a liquid crystal panel. The display  35  displays various setting screens such as a standard sample setting screen for setting identification information, standard values, etc. for standard samples for the respective test items, a subject sample setting screen for setting identification information, test items, etc. for subject samples, and so on. The display  35  also displays various data including the standard data and the subject data generated by the analyzer section  10 , the calibration curves and the analysis data generated by the computer section  33 , and so on. 
     The input interface  36  includes, for example, one or more input devices such as a keyboard, a mouse, buttons, and a touch key panel. The input interface  36  enables inputs to set identification information, standard values, etc. for standard samples for the respective test items. The input interface  36  also enables inputs to start calibrations for the respective test items. The input interface  36  enables inputs to set identification information and test item information for the subject samples. The input interface  36  also enables inputs to start tests on subject samples. 
     The system controller section  37  includes a CPU and memory circuitry, and stores command signals, input information, etc., input via the input interface  36  in the memory circuitry. Based on the input information, the system controller section  37  controls the entire system by performing a total control over the analysis controller section  32 , the computer section  33 , the data storage  34 , and the display  35 . 
     A description will be given of an exemplary configuration of the washers  27  to  30  in the analyzer section  10 , and an exemplary washing operation performed with them. 
     First,  FIGS.  1  to  3    will be referred to for describing an exemplary configuration of the washer  27 . In one example, this washer  27  uses first to third washing liquids to wash the reaction containers  17 . The first washing liquid may be, for example, pure water. The second washing liquid is constituted by a first liquid and a second liquid. The first liquid may be the first washing liquid and serves as a diluent. The second liquid is, for example, a concentrated alkaline liquid containing a high concentration of a detergent component, which provides a higher detergency than the first washing liquid. In the second washing liquid, the second liquid is diluted with the first liquid. The third washing liquid is constituted by the first liquid and a third liquid. The third liquid is, for example, a concentrated acidic liquid containing a high concentration of a detergent component, which provides a higher detergency than the first washing liquid. In the third washing liquid, the third liquid is diluted with the first liquid. 
       FIG.  3    shows a configuration of the washer  27 . The washer  27  includes first to fourth washing members  40 ,  50 ,  60 , and  70  for washing the respective reaction containers  17  stopped at first to fourth washing positions W 1  to W 4  for every one cycle time, using the first liquid retained in a first reservoir  82 . 
     The first washing member  40  discharges the first washing liquid into the reaction container  17  stopped at the first washing position W 1 . The second washing member  50  discharges the second washing liquid into the reaction container  17  stopped at the second washing position W 2 . The third washing member  60  discharges the third washing liquid into the reaction container  17  stopped at the third washing position W 3 . The fourth washing member  70  discharges the first washing liquid into the reaction container  17  stopped at the fourth washing position W 4 . 
     The washer  27  also includes a drain member  80  for draining liquids in the reaction containers  17 , including: the reaction liquid present within the reaction container  17  stopped at the first washing position W 1 ; the first washing liquid discharged at the first washing position W 1  and then present within the reaction container  17  stopped at the second washing position W 2 ; the second washing liquid discharged at the second washing position W 2  and then present within the reaction container  17  stopped at the third washing position W 3 ; the third washing liquid discharged at the third washing position W 3  and then present within the reaction container  17  stopped at the fourth washing position W 4 ; and the first washing liquid discharged at the fourth washing position W 4  and then present within the reaction container  17  stopped at a fifth washing position W 5 . 
     The washer  27  includes one or more holders  81  adapted to hold given components of the first to fourth washing members  40 ,  50 ,  60 , and  70  and the drain member  80  in such a manner that these components can be moved up and down. 
     Next,  FIG.  4    will be referred to for describing a configuration of the first washing member  40 . 
       FIG.  4    shows an exemplary configuration of the first washing member  40 . The first washing member  40  includes a first feeding unit  41  for feeding the first washing liquid, and a first discharge nozzle  42  for discharging the first washing liquid fed from the first feeding unit  41 . 
     The first feeding unit  41  includes a first feeding pump  401  and a first valve  402  with first to third ports. The first feeding unit  41  includes a tube  411  forming a first-liquid channel between the first feeding pump  401  and the first port of the first valve  402 , a tube  412  forming another first-liquid channel between the second port of the first valve  402  and the first reservoir  82 , and a tube  413  forming a further first-liquid channel between the third port of the first valve  402  and the first discharge nozzle  42 . 
     The first feeding pump  401  is constituted by, for example, a syringe, a plunger, etc. The first feeding pump  401  is driven by the driver section  31  to perform a sucking action where the plunger slides in the direction of arrow L 1  and an ejecting action where the plunger slides in the direction of arrow L 2 . 
     The first valve  402  is, for example, a three-way solenoid valve, which may be driven by the driver section  31  to open the flow path between the first port and the second port while closing the flow path between the first port and the third port. Also, the first valve  402  may be adapted to open the flow path between the first port and the third port while closing the flow path between the first port and the second port, during the suspension of driving. 
     The first discharge nozzle  42  has a discharge hole at its lower end. The first discharge nozzle  42  is provided so that it can enter the reaction container  17  arranged at the first washing position W 1  upon the holder  81  making a vertical movement according to the driving of the driver section  31 . While the reaction containers  17  are rotating, the first discharge nozzle  42  is kept stationary at an upper stop position above the rotation trajectory of the reaction containers  17 . While the rotation of the reaction containers  17  is halted, the first discharge nozzle  42  descends and reaches a lower stop position where its lower end comes close to the bottom of the reaction container  17  placed at the first washing position W 1 . 
     Next,  FIGS.  3  and  4    will be referred to for describing a washing operation conducted with the first washing member  40 . 
     Here, the first feeding pump  401 , the first valve  402 , the tubes  411  to  413 , and the first discharge nozzle  42  are all filled with the first liquid. Under the condition that the first valve  402  opens the flow path between the first port and the second port while closing the flow path between the first port and the third port, the first feeding pump  401  performs a sucking action to draw the first liquid from the first reservoir  82 . In response to the first feeding pump  401  finishing the sucking action, the first valve  402  closes the flow path between the first port and the second port and opens the flow path between the first port and the third port. 
     In response to the measurer  26  finishing the measurement and the reaction container  17  being stopped at the first washing position W 1 , the first discharge nozzle  42  descends and stays at the lower stop position. After the reaction liquid is removed from the reaction container  17  by a draining action of the drain member  80 , the first feeding pump  401  performs an ejecting action to feed, as the first washing liquid, the first liquid to the first discharge nozzle  42  in an amount greater than the amount of the reaction liquid that has been present in the reaction container  17  and removed therefrom. The first discharge nozzle  42  discharges the first washing liquid to the inside of the reaction container  17  according to the ejecting action of the first feeding pump  401 . 
     Next,  FIGS.  5  to  6    will be referred to for describing a configuration of the second washing member  50 . 
       FIG.  5    shows an exemplary configuration of the second washing member  50 . The second washing member  50  includes a second feeding unit  51  for feeding the second washing liquid, and a second discharge nozzle  52  for discharging the second washing liquid fed from the second feeding unit  51 . 
     The second feeding unit  51  is constituted by a feeder  53  for feeding the first liquid and the second liquid, and a mixer unit  54  for mixing the first liquid and the second liquid fed from the feeder  53  to prepare a mixture, namely, the second washing liquid. The second feeding unit  51  also includes a tube  55  having one end connected to the mixer unit  54  and the other end connected to the second discharge nozzle  52 . 
     The feeder  53  includes first and second feeding pumps  501  and  502 , and first and second valves  503  and  504  each with first to third ports. The feeder  53  includes a three-way branch pipe  505  with first to third ports, and a second reservoir  506  which retains the second liquid. The feeder  53  includes a tube  511  forming a first-liquid channel between the first feeding pump  501  and the first port of the first valve  503 , and a tube  512  forming another first-liquid channel between the second port of the first valve  503  and the first reservoir  82 . 
     Also, the feeder  53  includes a tube  513  forming a further first-liquid channel between the third port of the first valve  503  and the first port of the three-way branch pipe  505 , and a tube  514  forming a second-liquid channel between the second feeding pump  502  and the first port of the second valve  504 . The feeder  53  includes a tube  515  forming another second-liquid channel between the second port of the second valve  504  and the second reservoir  506 , and a tube  516  forming a further second-liquid channel between the third port of the second valve  504  and the second port of the three-way branch pipe  505 . The feeder  53  further includes a tube  517  forming a multi-liquid channel between the third port of the three-way branch pipe  505  and the mixer unit  54  and having a constant diameter throughout from one end to the other end. 
     The first and second feeding pumps  501  and  502  are each constituted by, for example, a syringe, a plunger, etc. The first feeding pump  501  is driven by the driver section  31  to perform a sucking action where the plunger slides in the direction of arrow L 1  for sucking the first liquid from the first reservoir  82 , and to perform an ejecting action where the plunger slides in the direction of arrow L 2  for ejecting the first liquid in a first amount. The second feeding pump  502  is driven by the driver section  31  to perform a sucking action where the plunger slides in the L 1  direction for sucking the second liquid from the second reservoir  506 , and to perform an ejecting action where the plunger slides in the L 2  direction for ejecting the second liquid in a second amount smaller than the first amount. 
     Each of the first and second valves  503  and  504  is, for example, a three-way solenoid valve which may be driven by the driver section  31  to open the flow path between the first port and the second port while closing the flow path between the first port and the third port. The first and second valves  503  and  504  may each be adapted to open the flow path between the first port and the third port while closing the flow path between the first port and the second port, during the suspension of driving by the driver section  31 . 
     The feeder  53  intermittently feeds the first liquid and the second liquid to the mixer unit  54  for every one cycle time. The feeder  53 , in response to the reaction container  17  stopped at the second washing position W 2 , performs the sucking action and the ejecting action with each of the first and second feeding pumps  501  and  02  so that the first liquid and the second liquid are fed to the mixer unit  54  one time. 
       FIG.  6    is a diagram showing an exemplary structure of the mixer unit  54 . Here,  FIG.  6 ( a )  is a planar view of the mixer unit  54 , and  FIG.  6 ( b )  is a cross-section along the line A-A viewed in the arrow direction. The description of the mixer unit  54  will assume that an X axis extends in a horizontal direction, a Y axis extends in another horizontal direction orthogonal to the X axis, and a Z axis extends in a direction orthogonal to both the X axis and the Y axis. However, the mixer unit  54  may be arranged in any orientation, etc. 
     The mixer unit  54  includes an inflow part  521 , a main part  522 , and an outflow part  523 . The first liquid and the second liquid fed from the feeder  53  enter through the inflow part  521 . The main part  522  has a shape of, for example, a rectangular parallelepiped or a cuboid and includes an internal space  5221  in which the first liquid and the second liquid that have entered through the inflow part  521  flow. The first liquid and the second liquid that have flown inside the internal space  5221  of the main part  522  exit through the outflow part  523 . 
     The inflow part  521  is provided at or near the lower central portion of one side surface of the main part  522 , and has one end connected to the tube  517  of the feeder  53  and the other end joined to the main part  522 . The inflow part  521  includes a channel that has been formed so that a cross-sectional area on the side of said other end has a size smaller than a cross-sectional area on the side of said one end, with a line  5224  extending through them as a central axis parallel to the X axis. Here, the channel of the inflow part  521  is designed so that its cross-sectional area on the side of said other end is smaller than the cross-sectional area of the tube  517  serving as a multi-liquid channel. 
     The main part  522  includes the internal space  5221 , and also an inlet  5222  and an outlet  5223 . The internal space  5221  is formed so that its cross-sectional area normal to the line  5224  is larger than the cross-sectional area of the tube  517  serving as a multi-liquid channel. The internal space  5221  defines a shape of, for example, a die or a cuboid having portions where its surfaces cross at right angles rounded. The internal space  5221  is tightly sealed except at the inlet  5222  and the outlet  5223 . Assuming that the sum of an amount of the first liquid, i.e., the first amount, and an amount of the second liquid, i.e., the second amount, ejected from the respective first and second feeding pumps  501  and  502  is a third amount, the internal space  5221  has a volumetric capacity capable of containing more than the third amount, for example, an amount equal to or greater than double the third amount. 
     The inlet  5222  is formed at the side surface of the main part  522  and penetrates through the main part  522  between the outside and the inside. The inlet  5222  is plugged by the inflow part  521 . The outlet  5223  is formed at a position of the top surface of the main part  522 , which is a position distant from the inlet  5222  among positions of the top surface, and penetrates through the main part  522  between the outside and the inside. The outlet  5223  is plugged by the outflow part  523 . 
     The outflow part  523  is provided at a position of the top surface of the main part  522 , which is a position distant in the X-axis direction from the inflow part  521  and located at the center in the Y-axis direction among positions of the top surface. The outflow part  523  includes a channel having a central axis parallel to the Z axis. Here, the outflow part  523  is arranged so that the extension of this central axis orthogonally crosses the extension of the line  5224 . The outflow part  523  has one end connected to the tube  55  and the other end joined to the main part  522 . The channel of the outflow part  523  has been formed so that a cross-sectional area on the side of said other end has a size smaller than a cross-sectional area on the side of said one end. 
     Note that the embodiment is not limited to the mixer unit  54 . For example, a mixer unit  54   a  as shown in  FIG.  7    may be employed. 
       FIG.  7    is a diagram showing a structure of the mixer unit  54   a . The description of the mixer unit  54   a  will assume that an X axis extends in a horizontal direction, a Y axis extends in another horizontal direction orthogonal to the X axis, and a Z axis extends in a direction orthogonal to both the X axis and the Y axis. However, the mixer unit  54   a  may be arranged in any orientation, etc. 
     The mixer unit  54   a  differs from the mixer unit  54  shown in  FIG.  6    in the locations of the inflow part and the outflow part with respect to the main part. 
     The mixer unit  54   a  includes an inflow part  521   a , a main part  522   a , and an outflow part  523   a . The first liquid and the second liquid enter through the inflow part  521   a . The main part  522   a  has a shape of a rectangular parallelepiped or a cuboid and includes an internal space  5221   a  in which the first liquid and the second liquid that have entered through the inflow part  521   a  flow. The first liquid and the second liquid that have flown inside the internal space  5221   a  of the main part  522   a  exit through the outflow part  523   a.    
     The inflow part  521   a  is provided at or near the lower central portion of one side surface of the main part  522   a , and has one end connected to the tube  517  and the other end joined to the main part  522   a . The inflow part  521   a  includes a channel that has been formed so that a cross-sectional area on the side of said other end has a size smaller than a cross-sectional area on the side of said one end, with a line  5224   a  extending through them as a central axis parallel to the X axis. The channel of the inflow part  521   a  is designed so that its cross-sectional area on the side of said other end is smaller than the cross-sectional area of the tube  517  serving as a multi-liquid channel. 
     The main part  522   a  includes the internal space  5221   a , and also a non-illustrated inlet plugged by the inflow part  521   a  and a non-illustrated outlet plugged by the outflow part  523   a . The internal space  5221   a  has the same shape and the same volumetric capacity as those of the internal space  5221  shown in  FIG.  6   , and its cross-sectional area normal to the line  5224   a  parallel to the X axis is larger than the cross-sectional area of the tube  517  serving as the multi-liquid channel. 
     The outflow part  523   a  is provided at or near the upper central portion of one side surface of the main part  522   a  which is opposite to the side surface where the inflow part  521   a  is provided. The outflow part  523   a  has one end connected to the tube  55  and the other end joined to the main part  522   a . The outflow part  523   a  includes a channel formed so that a cross-sectional area on the side of said other end has a size smaller than a cross-sectional area on the side of said one end, with a central axis parallel to the line  5224   a  extending through them. 
     Note that it is also possible to arrange the inflow part  521   a  at the center of one side surface of the main part  522   a  while arranging the outflow part  523   a  at the center of the opposing side surface of the main part  522   a . Further, it is likewise possible to arrange the inflow part  521   a  at a position of one side surface of the main part  522   a , which is a position in the lower part of the side surface and close to one edge in the Y-axis direction, while arranging the outflow part  523   a  at a position of the opposing side surface of the main part  522   a , which is a position in the upper part of this opposing side surface and close to the opposing edge in the Y-axis direction. 
     Next,  FIGS.  3 ,  5 , and  6    will be referred to for describing a washing operation conducted with the second washing member  50 . 
     Components in the feeder  53 , namely, the first feeding pump  501 , the first valve  503 , the first port of the three-way branch pipe  505 , and the tubes  511  to  513  serving as the first-liquid channels are all filled with the first liquid attributable to sucking and ejecting actions of the first feeding pump  501 . Also, the second feeding pump  502 , the second valve  504 , the second port of the three-way branch pipe  505 , and the tubes  514  to  516  serving as the second-liquid channels are all filled with the second liquid attributable to sucking and ejecting actions of the second feeding pump  502 . The first and second valves  503  and  504  are each in the state where the flow path between the first port and the third port is open and the flow path between the first port and the second port is closed. Also, the tube  517  serving as a multi-liquid channel, the mixer unit  54 , the tube  55 , and the second discharge nozzle  52  are all filled with a mixture of the first liquid and the second liquid attributable to sucking and ejecting actions of the first and second feeding pumps  501  and  502 . 
     Under the condition that the first and second valves  503  and  504  each close the flow path between the first port and the third port and open the flow path between the first port and the second port, the first feeding pump  501  performs a sucking action to draw the first amount of the first liquid from the first reservoir  82  and the second feeding pump  502  performs a sucking action to draw the second amount of the second liquid from the second reservoir  506 . In response to the first and second feeding pumps  501  and  502  finishing their respective sucking actions, the first and second valves  503  and  504  each close the flow path between the first port and the second port and open the flow path between the first port and the third port. 
     In response to the reaction container  17  that has been subjected to the discharge of the first washing liquid being stopped at the second washing position W 2  next to the first washing position W 1  upon elapse of n cycle times (where n is a positive integer) since this reaction container  17  made a stop at the first washing position W 1 , the second discharge nozzle  52  descends and stays at the lower stop position. After the first washing liquid is removed from the reaction container  17  by a draining action of the drain member  80 , the first and second feeding pumps  501  and  502  substantially simultaneously perform their ejecting actions to feed the first liquid and the second liquid, which together amount to the third amount. 
     Note that the second feeding pump  502  here is intended to eject an amount smaller than the amount ejected by the first feeding pump  501 . Thus, a configuration of driving the second feeding pump  502  to perform its ejecting action while the first feeding pump  501  is performing the ejecting action may be adopted. 
     The ejecting action of the first feeding pump  501  causes the first liquid in the tubes  511  and  513  to flow toward the three-way branch pipe  505  as shown by the corresponding arrows. Also, the ejecting action of the second feeding pump  502  causes the second liquid in the tubes  514  and  516  to flow toward the three-way branch pipe  505  as shown by the corresponding arrows. Then, attributable to the ejecting actions of the first and second feeding pumps  501  and  502 , the first liquid flown through the first port of the three-way branch pipe  505  and the second liquid flown through the second port of the three-way branch pipe  505  are joined together at the third port of the three-way branch pipe  505  and caused to flow in the tube  517  toward the mixer unit  54  as shown by the corresponding arrow. 
     In this manner, the first liquid and the second liquid are caused to join together in the three-way branch pipe  505  and then flow within the tube  517 , so that the first liquid and the second liquid can be mingled together in the tube  517 . 
     The first liquid and the second liquid enter the inflow part  521  of the mixer unit  54  according to the ejecting actions of the first and second feeding pumps  501  and  502 , and further flow into the internal space  5221  in a radial fashion around the line  5224  from the opening at the other end of the channel in the inflow part  521  and at a higher velocity than the velocity of the flow within the tube  517 . See the arrows shown in  FIG.  6 ( b ) . The first liquid and the second liquid already present in the internal space  5221  are mixed by the first liquid and the second liquid entering from the inflow part  521 , and the former first and second liquids and the latter first and second liquids are together caused to flow toward the outflow part  523  as an integral current. 
     According to the inflow of the first liquid and the second liquid into the internal space  5221 , the third amount of a mixture of the first liquid and the second liquid among the first liquid and the second liquid within the internal space  5221  is caused to flow out from the outflow part  523 , and then flow in the tube  55  toward the second discharge nozzle  52  as the second washing liquid. The second discharge nozzle  52  discharges the third amount of the second washing liquid to the inside of the reaction container  17  according to the ejecting actions of the first and second feeding pumps  501  and  502 . 
     As described above, a mixture of the first liquid and the second liquid is caused to flow into the internal space  5221  from the opening at the other end of the channel in the inflow part  521 . Here, the cross-sectional area of the internal space  5221 , which is normal to the central axis of the channel in the inflow part  521 , is larger than the cross-sectional area of the tube  517  serving as a multi-liquid channel. Also, the other end of the channel in the inflow part  521  (i.e., the opening at the other end) has a cross-sectional area smaller than the cross-sectional area of the tube  517  serving as a multi-liquid channel. Accordingly, the mixture of the first liquid and the second liquid flows through the channel in the inflow part  521  at a higher velocity than the velocity of the flow within the tube  517  and enters the internal space  5221  in a radial fashion. 
     The first liquid and the second liquid already present in the internal space  5221  are mixed by the first liquid and the second liquid introduced from the inflow part  521 . The first liquid and the second liquid already present in the internal space  5221  are thus caused to flow together with the introduced first and second liquids as an integral current, within the internal space  5221  and toward the outflow part  523 . Therefore, the first liquid and the second liquid are more strongly mixed with each other than in the case of being mixed only within the tube  517 . This allows for the preparation of the second washing liquid with a constant concentration of the detergent component provided from the second liquid. 
     This second washing liquid prepared through the step of strongly mixing the first liquid and the second liquid with the mixer unit  54  is discharged from the second discharge nozzle  52 . Therefore, it is possible to avoid the degradation of analysis data that could result from a poor capability to wash the reaction container  17  due to the washing liquid having a reduced detergent component concentration, or the degradation of analysis data that could result from the detergent component remaining in the reaction container  17  due to the washing liquid having an increased detergent component concentration. 
     Additionally, in the configuration where the mixer unit  54   a  shown in  FIG.  7    is adopted, the first liquid and the second liquid flow through the channel in the inflow part  521   a  at a higher velocity than the velocity of the flow within the tube  517  and enter the internal space  5221   a  along the line  5224   a . This causes the first liquid and the second liquid already present in the internal space  5221   a  to be mixed by the first liquid and the second liquid introduced along the line  5224   a  from the inflow part  521   a , in such a manner that they swirl in the arrow direction shown in  FIG.  7    at the curved face in the internal space  5221   a  where the extension of the line  5224   a  crosses, so that the former first and second liquids and the latter first and second liquids are caused to flow together as an integral current within the internal space  5221   a  and exit from the outflow part  523   a . Therefore, the first liquid and the second liquid are more strongly mixed with each other than in the case of being mixed only within the tube  517 . This allows for the preparation of the second washing liquid with a constant concentration of the detergent component provided from the second liquid. 
     Next,  FIGS.  5 ,  6 , and  8    will be referred to for describing a configuration of the third washing member  60 . 
       FIG.  8    shows an exemplary configuration of the third washing member  60 . Note that, for the components of the third washing member  60  which are substantially the same as the components of the second washing member  50  shown in  FIG.  5   , the description will use the same reference numbers or symbols as those of the second washing member  50  and omit their explanations. 
     The third washing member  60  includes a third feeding unit  61  for feeding the third washing liquid, and a third discharge nozzle  62  for discharging the third washing liquid fed from the third feeding unit  61 . 
     The third feeding unit  61  is constituted by a feeder  63  for feeding the first liquid and the third liquid, and a mixer unit  54  for mixing the first liquid and the third liquid fed from the feeder  63  to prepare a mixture, namely, the third washing liquid. The third feeding unit  61  also includes a tube  55  having one end connected to the mixer unit  54  and the other end connected to the third discharge nozzle  62 . 
     The feeder  63  differs from the feeder  53  shown in  FIG.  5    in that the second reservoir  506  is replaced with a third reservoir  606  retaining the third liquid. The tube  515  here has its one end connected to the second port of the second valve  504  and the other end connected to the third reservoir  606 . 
     The third discharge nozzle  62  has a discharge hole at its lower end, and is held by the holder  81 . The third discharge nozzle  62  is provided so that it can enter the reaction container  17  arranged at the third washing position W 3  upon the holder  81  making a vertical movement according to the driving of the driver section  31 . While the reaction containers  17  are rotating, the third discharge nozzle  62  is kept stationary at an upper stop position above the rotation trajectory of the reaction containers  17 . While the rotation of the reaction containers  17  is halted, the third discharge nozzle  62  descends and reaches a lower stop position where its lower end comes close to the bottom of the reaction container  17  placed at the third washing position W 3  next to the second washing position W 2 . 
       FIGS.  3 ,  6 , and  8    will be referred to for describing a washing operation conducted with the third washing member  60 . 
     Components in the feeder  63  of the third feeding unit  61 , namely, the first feeding pump  501 , the first valve  503 , the first port of the three-way branch pipe  505 , and the tubes  511  to  513  are all filled with the first liquid. Also, the second feeding pump  502 , the second valve  504 , the second port of the three-way branch pipe  505 , and the tubes  514  to  516  are all filled with the third liquid. The tube  517 , the mixer unit  54 , the tube  55 , and the third discharge nozzle  62  are all filled with a mixture of the first liquid and the third liquid. The first and second valves  503  and  504  are each in the state where the flow path between the first port and the third port is open and the flow path between the first port and the second port is closed. The tube  517 , the mixer unit  54 , the tube  55 , and the third discharge nozzle  62  are filled with a mixture of the first liquid and the third liquid. 
     Under the condition that the first and second valves  503  and  504  each close the flow path between the first port and the third port and open the flow path between the first port and the second port, the first feeding pump  501  performs a sucking action to draw the first amount of the first liquid from the first reservoir  82  and the second feeding pump  502  performs a sucking action to draw the second amount of the third liquid from the third reservoir  606 . In response to the first and second feeding pumps  501  and  502  finishing their respective sucking actions, the first and second valves  503  and  504  each close the flow path between the first port and the second port and open the flow path between the first port and the third port. 
     In response to the reaction container  17  that has been subjected to the discharge of the second washing liquid being stopped at the third washing position W 3  next to the second washing position W 2  upon elapse of n cycle times since this reaction container  17  made a stop at the second washing position W 2 , the third discharge nozzle  62  descends and stays at the lower stop position. After the second washing liquid is removed from the reaction container  17  by a draining action of the drain member  80 , the first and second feeding pumps  501  and  502  substantially simultaneously perform their ejecting actions to feed the first liquid and the third liquid, which together amount to the third amount. 
     The ejecting action of the first feeding pump  501  causes the first liquid in the tubes  511  and  513  to flow toward the three-way branch pipe  505 , and the ejecting action of the second feeding pump  502  causes the third liquid in the tubes  514  and  516  to flow toward the three-way branch pipe  505 . Then, attributable to the ejecting actions of the first and second feeding pumps  501  and  502 , the first liquid flown through the first port of the three-way branch pipe  505  and the third liquid flown through the second port of the three-way branch pipe  505  are joined together at the third port of the three-way branch pipe  505  and caused to flow in the tube  517  toward the mixer unit  54 . 
     In this manner, the first liquid and the third liquid are caused to join together in the three-way branch pipe  505  and then flow within the tube  517 , so that the first liquid and the third liquid can be mingled together in the tube  517 . 
     The first liquid and the third liquid enter the inflow part  521  of the mixer unit  54  according to the ejecting actions of the first and second feeding pumps  501  and  502 , and further flow into the internal space  5221  in a radial fashion around the line  5224  from the opening at the other end of the channel in the inflow part  521  and at a higher velocity than the velocity of the flow within the tube  517 . The first liquid and the third liquid introduced into the internal space  5221  flow toward the outflow part 
     According to the inflow of the first liquid and the third liquid into the internal space  5221 , the third amount of a mixture of the first liquid and the third liquid among the first liquid and the third liquid that fill the internal space  5221  is caused to flow out from the outflow part  523 , and then flow in the tube  55  toward the third discharge nozzle  62  as the third washing liquid. The third discharge nozzle  62  discharges the third amount of the third washing liquid to the inside of the reaction container  17  according to the ejecting actions of the first and second feeding pumps  501  and  502 . 
     As described above, a mixture of the first liquid and the third liquid is caused to flow into the internal space  5221  from the opening at the other end of the channel in the inflow part  521 . Here, the cross-sectional area of the internal space  5221 , which is normal to the central axis of the channel in the inflow part  521 , is larger than the cross-sectional area of the tube  517  serving as a multi-liquid channel. Also, the other end of the channel in the inflow part  521  (i.e., the opening at the other end) has a cross-sectional area smaller than the cross-sectional area of the tube  517  serving as a multi-liquid channel. Accordingly, the mixture of the first liquid and the third liquid flows through the channel in the inflow part  521  at a higher velocity than the velocity of the flow within the tube  517  and enters the internal space  5221  in a radial fashion. 
     The first liquid and the third liquid already present in the internal space  5221  are mixed by the first liquid and the third liquid introduced from the inflow part  521 . The first liquid and the third liquid already present in the internal space  5221  are thus caused to flow together with the introduced first and third liquids as an integral current, within the internal space  5221  and toward the outflow part  523 . Therefore, the first liquid and the third liquid are more strongly mixed with each other than in the case of being mixed only within the tube  517 . This allows for the preparation of the third washing liquid with a constant concentration of the detergent component provided from the third liquid. 
     The third washing liquid prepared through the step of strongly mixing the first liquid and the third liquid with the mixer unit  54  is discharged from the third discharge nozzle  62 . Therefore, it is possible to avoid the degradation of analysis data that could result from a poor capability to wash the reaction container  17  due to the washing liquid having a reduced detergent component concentration, or the degradation of analysis data that could result from the detergent component remaining in the reaction container  17  due to the washing liquid having an increased detergent component concentration. 
     Next,  FIGS.  4  and  9    will be referred to for describing a configuration of the fourth washing member  70 . 
       FIG.  9    shows an exemplary configuration of the fourth washing member  70 . The fourth washing member  70  differs from the first washing member  40  shown in  FIG.  4    in that the first discharge nozzle  42  of the first washing member  40  is replaced with a fourth discharge nozzle  72 . The fourth washing member  70  includes a first feeding unit  41 , and this fourth discharge nozzle  72  for discharging the first washing liquid fed from the first feeding unit  41 . The tube  413  of the first feeding unit  41  here has its one end connected to the third port of the first valve  402  and the other end connected to the fourth discharge nozzle  72 . 
     The fourth discharge nozzle  72  has a discharge hole at its lower end. The fourth discharge nozzle  72  is provided so that it can enter the reaction container  17  arranged at the fourth washing position W 4  upon the holder  81  making a vertical movement according to the driving of the driver section  31 . The fourth discharge nozzle  72  is connected to the tube  413  of the first feeding unit  41 . While the reaction containers  17  are rotating, the fourth discharge nozzle  72  is kept stationary at an upper stop position above the rotation trajectory of the reaction containers  17 . While the rotation of the reaction containers  17  is halted, the fourth discharge nozzle  72  descends and reaches a lower stop position where its lower end comes close to the bottom of the reaction container  17  placed at the fourth washing position W 4 . 
     Next,  FIGS.  3  and  9    will be referred to for describing a washing operation conducted with the fourth washing member  70 . The fourth washing member  70  may perform the washing operation for the reaction container  17  placed at the fourth washing position W 4 , at the same timing as the first washing member  40  performing its washing operation. 
     The first feeding pump  401  of the first feeding unit  41 , and also the first valve  402 , the tubes  411  to  413 , and the fourth discharge nozzle  72  are filled with the first liquid. Under the condition that the first valve  402  opens the flow path between the first port and the second port while closing the flow path between the first port and the third port, the first feeding pump  401  performs a sucking action to draw the first liquid from the first reservoir  82 . In response to the first feeding pump  401  finishing the sucking action, the first valve  402  closes the flow path between the first port and the second port and opens the flow path between the first port and the third port. 
     In response to the reaction container  17  that has been subjected to the discharge of the third washing liquid being stopped at the fourth washing position W 4  next to the third washing position W 3  upon elapse of n cycle times since this reaction container  17  made a stop at the third washing position W 3 , the fourth discharge nozzle  72  descends and stays at the lower stop position. After the third washing liquid is removed from the reaction container  17  by a draining action of the drain member  80 , the first feeding pump  401  performs an ejecting action to feed, as the first washing liquid, the first liquid to the fourth discharge nozzle  72 . The fourth discharge nozzle  72  discharges the first washing liquid fed according to the ejecting action of the first feeding pump  401 , to the inside of the reaction container  17 . 
     Next,  FIGS.  3  and  10    will be referred to for describing a configuration of the drain member  80  and a washing operation conducted with the drain member  80 . 
       FIG.  10    shows an exemplary configuration of the drain member  80 . The drain member  80  includes first to fifth suction nozzles  801  to  805 , and a draining pump  806  connected with each of the first to fifth suction nozzles  801  to  805  via respective tubes. 
     The first to fifth suction nozzles  801  to  805  each have a suction hole at the lower end, and are held by the holder  81 . The first to fifth suction nozzles  801  to  805  are provided so that they can enter the respective reaction containers  17  arranged at the first to fifth washing positions W 1  to W 5  upon the holder  81  making a vertical movement according to the driving of the driver section  31 . 
     While the reaction containers  17  are rotating, the first to fifth suction nozzles  801  to  805  are kept stationary at their respective upper stop positions above the rotation trajectory of the reaction containers  17 . While the rotation of the reaction containers  17  is halted, the first to fifth suction nozzles  801  to  805  descend and reach their respective lower stop positions where the lower end comes close to the bottom of the corresponding one of the reaction containers  17  placed at the first to fifth washing positions W 1  to W 5 . Here, with the action of the draining pump  806 , the first to fourth suction nozzles  801  to  804  suck and drain the reaction liquid in the reaction container  17  at the first washing position W 1 , the first washing liquid in the reaction container  17  at the second washing position W 2 , the second washing liquid in the reaction container  17  at the third washing position W 3 , and the third washing liquid in the reaction container  17  at the fourth washing position W 4 . 
     Also, the fifth suction nozzle  805  sucks and drains the first washing liquid in the reaction container  17  stopped at the fifth washing position W 5  next to the fourth washing position W 4  upon elapse of n cycle times since this reaction container  17  made a stop at the fourth washing position W 4 . 
       FIGS.  4 ,  5 ,  6 , and  11    will be referred to for describing a configuration of the washer  28  and a washing operation conducted with the washer  28 . As the washers  29  and  30  each have substantially the same configuration as the washer  28 , the description will omit their explanation. 
       FIG.  11    shows an exemplary configuration of the washer  28 . For the components of the washer  28  which are substantially the same as the respective components of the first feeding unit  41  shown in  FIG.  4    and the second feeding unit  51  shown in  FIG.  5   , the description will use the same reference numbers or symbols and omit their explanations. 
     The washer  28  includes its first feeding unit  41  and second feeding unit  51 , and also a washing bath  90  in which the sample dispensing probe  19  is washed using the first washing liquid and the second washing liquid fed from the first feeding unit  41  and the second feeding unit  51 . 
       FIG.  12    shows an exemplary configuration of the washing bath  90 .  FIG.  12 ( a )  is a side view of the washing bath  90 , and  FIG.  12 ( b )  is a planar view of the washing bath  90 . The washing bath  90  is constituted by two discharge pipes  91  for discharging the first washing liquid fed from the first feeding unit  41 , a tub  92  for pooling the second washing liquid fed from the second feeding unit  51 , and a bath main part  93  for supporting each of the discharge pipes  91  and the tub  92 . 
     The two discharge pipes  91  lie down and face each other with a trajectory Ob of the sample dispensing probe  19  interposed between them. Along this trajectory Ob, the sample dispensing probe  19  makes a horizontal movement between a given position above the sample container  11  held by the sample rack  12  and a given position above the reaction container  17  held by the reaction disk  18 . 
     While not illustrated in the drawing, the washing bath  90  includes a three-way branch pipe and two tubes. The first port of this three-way branch pipe is connected to the tube  413  of the first feeding unit  41 . In the washing bath  90 , the second port of the three-way branch pipe is connected to one of the discharge pipes  91 , and the third port of the three-way branch pipe is connected to the other one of the discharge pipes  91 . 
     The tub  92  is located below the trajectory Ob, and includes a liquid receiving portion  921  into which the second washing liquid fed from the second feeding unit  51  is introduced, and a liquid receiving chamber  922  where the second washing liquid overflown from the liquid receiving portion  921  is kept. 
     The bath main part  93  includes a drain pipe  931  for draining the first washing liquid and the second washing liquid that have been used for washing the sample dispensing probe  19 . 
     The two discharge pipes  91  each discharge the first washing liquid fed from the first feeding unit  41 , toward the sample dispensing probe  19  stopped at a washing position WS set between the discharge pipes  91 . The discharge of the first washing liquid here may aim at the portion of the sample dispensing probe  19  which contacted the sample. In this manner, the outer part of the sample dispensing probe  19  that was in contact with the sample is washed. 
     To undergo washing with the second washing liquid, the sample dispensing probe  19  is moved along the trajectory Ob to a position above the tub  92 , before aspirating a sample from the sample container  11  or after discharging a sample to the reaction container  17 . The sample dispensing probe  19  is caused to descend to a level where its outer part for contacting the sample reaches the second washing liquid in the liquid receiving chamber  922 . The sample dispensing probe  19  aspirates the second washing liquid. Subsequently, the sample dispensing probe  19  is caused to ascend and is moved to the washing position WS, where it discards the second washing liquid aspirated from the tub  92 . After the sample dispensing probe  19  discards the second washing liquid, the discharge pipes  91  each discharge the first washing liquid toward the sample dispensing probe  19  at the washing position WS. The discharge of the first washing liquid here may aim at the outer part of the sample dispensing probe  19  which contacted the second washing liquid in the tub  92 . In this manner, the second washing liquid attached to the outer part of the sample dispensing probe  19  is washed out, and the washing of the sample dispensing probe  19  with the second washing liquid comes to an end. 
     The washer  29  is adapted to wash the first reagent dispensing probe  21  in a similar manner to the washer  28  washing the sample dispensing probe  19 , and therefore, the explanation of the washer  29  will be omitted. Also, the washer  30  is adapted to wash the second reagent dispensing probe  23  in a similar manner to the washer  28  washing the sample dispensing probe  19 , and therefore, the explanation of the washer  30  will be omitted. 
     Note that the washer  28 , etc. are not limited to the configurations described above for the exemplary embodiments. For example, the washer  28  may further include the third feeding unit  61  and the washing bath  90  may additionally include a tub for pooling the third washing liquid fed from the third feeding unit  61 , so that the sample dispensing probe  19  undergoes washing steps with the respective first to third washing liquids. 
     Providing the mixer unit  54  here enables strong mixing of the first liquid and the second liquid, which allows for preparation of the second washing liquid with a constant concentration of the detergent component. Moreover, feeding the second washing liquid prepared at the mixer unit  54  to the tub  92  can realize avoiding the degradation of analysis data that could result from a poor capability to wash the sample dispensing probe  19  due to the washing liquid having a reduced detergent component concentration, or the degradation of analysis data that could result from the detergent component remaining on the sample dispensing probe  19  due to the washing liquid having an increased detergent component concentration. 
     According to the foregoing embodiments, the mixer unit  54  is provided between the feeder  53  and the second discharge nozzle  52 . The mixer unit  54  is constituted by the inflow part  521 , the main part  522  with the internal space  5221 , and the outflow part  523 . A mixture of the first liquid and the second liquid is caused to flow into the internal space  5221  from the opening at the end of the channel in the inflow part  521 . Here, the cross-sectional area of the internal space  5221 , which is normal to the central axis of the channel in the inflow part  521 , is larger than the cross-sectional area of the tube  517  serving as a multi-liquid channel. Also, said end of the channel in the inflow part  521  (i.e., the opening at said end) has a cross-sectional area smaller than the cross-sectional area of the tube  517  serving as a multi-liquid channel. Accordingly, the mixture of the first liquid and the second liquid flows through the channel in the inflow part  521  at a higher velocity than the velocity of the flow within the tube  517  and enters the internal space  5221  in a radial fashion. 
     The first liquid and the second liquid already present in the internal space  5221  are mixed by the first liquid and the second liquid introduced from the inflow part  521 . The first liquid and the second liquid already present in the internal space  5221  are thus caused to flow together with the introduced first and second liquids as an integral current, within the internal space  5221  and toward the outflow part  523 . Therefore, the first liquid and the second liquid are more strongly mixed with each other than in the case of being mixed only within the tube  517 . This allows for the preparation of the second washing liquid with a constant concentration of the detergent component provided from the second liquid. 
     The second washing liquid prepared through the step of strongly mixing the first liquid and the second liquid with the mixer unit  54  is then discharged from the second discharge nozzle  52 . Therefore, it is possible to avoid the degradation of analysis data that could result from a poor capability to wash the reaction container  17  due to the washing liquid having a reduced detergent component concentration, or the degradation of analysis data that could result from the detergent component remaining in the reaction container  17  due to the washing liquid having an increased detergent component concentration. 
     While certain embodiments have been described, they have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and changes in the form of the embodiments may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.