Abstract:
A slide processing apparatus is disclosed. The apparatus comprise a liquid transporter for transporting a staining liquid reserved in a first liquid container and a washing liquid reserved in a second liquid container; a first instruction receiver for receiving a first instruction that instructs to initiate preparation of a slide stained with the staining liquid; a second instruction receiver for receiving a second instruction that instructs to initiate washing of a housing element which accommodates therein a slide to be stained; and a controller. When receiving the first instruction, the controller performs staining of the slide accommodated in the housing element by causing the liquid transporter to transport the staining liquid into the housing element. When receiving the second instruction, the controller performs washing of the housing element by causing the liquid transport to transport the washing liquid into the housing element.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2011-021278 filed on Feb. 3, 2011, the entire content of which is hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a slide processing apparatus for processing a slide within a cassette. 
         [0004]    2. Description of the Related Art 
         [0005]    There are known conventional specimen staining apparatuses for holding a smeared specimen on a slide enclosed in a specimen cassette and automatically performing a staining process on the held specimen (for example, Japanese Laid-Open Patent Publication No. 2006-38781). The specimen staining apparatus disclosed in Japanese Laid-Open Patent Publication No. 2006-38781 stains a specimen by injecting a staining liquid into a specimen cassette which holds the specimen, and after the staining process washes the specimen by injecting water into the specimen cassette. 
         [0006]    In the specimen staining apparatus disclosed in Japanese Laid-Open Patent Publication No. 2006-38781, staining liquid may adhere inside the specimen cassette following repeated use of the specimen cassette. Therefore, in order to repeatedly use the specimen cassette, the user must manually wash the specimen cassette to remove the staining liquid adhered inside the specimen cassette. 
       SUMMARY OF THE INVENTION 
       [0007]    A first aspect of the present invention is a slide processing apparatus comprising: a liquid transporter for transporting a staining liquid reserved in a first liquid container and a washing liquid reserved in a second liquid container; a first instruction receiver for receiving a first instruction that instructs to initiate preparation of a slide stained with the staining liquid; a second instruction receiver for receiving a second instruction that instructs to initiate washing of a housing element which accommodates therein a slide to be stained; and a controller, wherein, when receiving the first instruction, the controller performs staining of the slide accommodated in the housing element by causing the liquid transporter to transport the staining liquid into the housing element; and, when receiving the second instruction, the controller performs washing of the housing element by causing the liquid transport to transport the washing liquid into the housing element. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view showing the structure of an embodiment of a clinical sample processing apparatus; 
           [0009]      FIG. 2  is a plan view showing the structure of an embodiment of a smear preparation apparatus viewed from above; 
           [0010]      FIGS. 3(   a ) and  3 ( b ) are perspective views showing the structure of an embodiment of a cassette; 
           [0011]      FIGS. 4(   a )- 4 ( c ) show the operation of the staining unit of the embodiment; 
           [0012]      FIG. 5  briefly shows a fluid circuit diagram of the smear preparation apparatus of the embodiment; 
           [0013]      FIG. 6  shows the structure of a first methanol chamber of the embodiment; 
           [0014]      FIG. 7  briefly shows the structures of a transport device and the smear preparation apparatus of the embodiment; 
           [0015]      FIG. 8  is a flow chart showing the processes of the smear preparation apparatus of the embodiment; 
           [0016]      FIGS. 9(   a ) and  9 ( b ) show a start setting screen and a shutdown setting screen of the embodiment; 
           [0017]      FIGS. 10(   a ) and  10 ( b ) are flow charts showing the methanol dispensing process in the staining process and smear preparation process of the embodiment; 
           [0018]      FIGS. 11(   a ) and  11 ( b ) show threshold number setting screen and a flow chart of the threshold number setting process of the embodiment; 
           [0019]      FIGS. 12  ( a ) and  12 ( b ) are flow charts of the cassette washing process and a flow chart of the methanol dispensing process in the washing process of the embodiment; 
           [0020]      FIGS. 13(   a ) and  13 ( b ) are flow charts of the methanol collection process and the counting process of the collection counter of the embodiment; 
           [0021]      FIG. 14  is a flow chart of the methanol replacement process of the first methanol chamber of the embodiment; 
           [0022]      FIG. 15  is a flow chart of the methanol supplying process of the first methanol chamber and the second methanol chamber of the embodiment; and 
           [0023]      FIGS. 16(   a )- 16 ( f ) show specific examples of the washing process of the embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    The present embodiment is an application of the invention in a clinical sample processing apparatus for preparing a smear sample from a blood sample. The clinical sample processing apparatus of the present embodiment is provided with a smear preparation apparatus and a transport device. Note that the necessity of preparing a smear sample is usually determined based on blood sample analysis results of a blood analyzer or the like at a previous stage. When preparing a smear sample, a sample rack holding a sample container which contains a sample is placed in the transport device. Subsequently, the sample rack is moved by the transport device and a smear sample is prepared by the smear preparation apparatus. 
         [0025]    The embodiment of the clinical sample processing apparatus is described below with reference to the drawings. 
         [0026]      FIG. 1  is a perspective view showing the structure of a clinical sample processing apparatus  1 . The clinical sample processing apparatus  1  is provided with a smear sample preparation device  2  and a transport device  3 . Note that below the X-axis positive direction is referred to as the left direction, the X-axis negative direction is the right direction, the Y-axis positive direction is the backward direction, the Y-axis negative direction is the forward direction, the Z-axis positive direction is the upward direction, and the Z-axis negative direction is the downward direction. 
         [0027]    The smear sample preparation device  2  is provided with an operation display unit  2   a  configured by a touch panel disposed on the front surface of a cover. openings  2   b  and  2   c  are respectively formed at the top right and top left of the front surface of the cover of the smear sample preparation device  2 . The smear sample preparation device  2  also has a hand unit  41   a  for holding a sample container T through an opening  2   d . The user controls the smear sample preparation device  2  by operating the operation display unit  2   a , sets a cassette  20  in a cassette receiver  47  (refer to  FIG. 2 ; described later) through the opening  2   c , and removes the cassette  20  deposited in the cassette storage unit  51  (refer to  FIG. 2 ; described later) through the opening  2   c.    
         [0028]    Bottle  101  through  105  for containing staining liquid and the like to be used by a staining unit  50  (described later) are connected to the smear sample preparation device  2 . In the present embodiment, the bottles  101  through  105  respectively contain methanol, May-Grünwald solution (staining liquid), Giemsa solution (staining liquid), phosphate buffer solution (diluting liquid), and water for washing samples. Two chambers (a first methanol chamber  111  and a second methanol chamber  112 ) containing methanol are also connected to the smear sample preparation device  2 . 
         [0029]    Note that, in addition to the first methanol chamber  111  and second methanol chamber  112 , the smear sample preparation device  2  is also connected to a first staining liquid chamber  121 , second staining liquid chamber  122 , staining liquid chamber  131 , diluting liquid chamber  143 , first mixing chamber  151 , second mixing chamber  152 , and discard chamber  165 , as shown in  FIG. 5 . 
         [0030]    The transport device  3  is arranged at the front side of the smear sample preparation device  2 , and has a loader  3   a  and an ejector  3   b . The transport device  3  transports a sample rack L that is positioned on the loader  3   a  to the ejector  3   b . When the sample rack L is positioned in front of the hand unit  41   a , the sample rack L is removed therefrom by the hand unit  41   a  and placed within the smear sample preparation device  2 . 
         [0031]      FIG. 2  is a plan view showing the structure of the smear sample preparation device  2  viewed from above. 
         [0032]    The smear sample preparation device  2  is provided with an aspirating/dispensing mechanism  41 , slide glass supplier  42 , slide glass cross-feeder  43 , smearing mechanism  44 , smear drier  45 , printer  46 , cassette receiver  47 , cassette cross-feeder  48 , cassette rotator  49 , staining unit  50 , and cassette storage unit  51 . 
         [0033]    The aspirating/dispensing mechanism  41  has a hand unit  41   a , piercer (aspirating needle)  41   b , and dispensing pipette  41   c . A sample container T that is positioned in front of the hand unit  41   a  is removed from the sample rack L that is gripped by the hand unit  41   a . Then, the blood sample accommodated in the sample container T is aspirated by the piercer  41   b , and dripped by the laterally movable dispensing pipette  41   c  onto a slide glass  10  that is position in front of the smearing mechanism  44 . 
         [0034]    The slide glass supplier  42  holds a plurality of new slide glasses  10 , and sequentially moves new slide glasses  10  up to the slide glass cross-feeder  43 . The slide glass cross-feeder  43  moves the new slide glass  10  supplied from the slide glass supplier  42  in a leftward direction to position the slide glass  10  in front of the smearing mechanism  44 . 
         [0035]    The smearing mechanism  44  smears the blood sample when the blood sample is dripped onto the slide glass  10  positioned in front of the smearing mechanism  44 . The slide glasses  10  bearing the smeared blood samples are moved in the rightward direction by the slide glass cross-feeder  43  and positioned directly below the printer  46  and in front of the smear drier  45 . The smear drier  45  dries the blood sample smeared on the slide glass  10  positioned in front of the smear drier  45  via a fan (not shown in the drawing). The printer  46  is a printer (not shown in the drawing) that prints the sample number, day, receipt number, name and the like on the end of the slide glass  10 . 
         [0036]    The cassette receiver  47  has a belt  47   a  that is movable in a forward direction, and transmission type sensors  47   s  configured by a light emitter and a light receiver disposed near the front end and the back end of the belt  47   a . The user can place an empty cassette  20  on the belt  47   a  through the opening  2   b  (refer to  FIG. 1 ). The empty cassette  20  placed on the belt  47   a  is transported by the moving belt  47   a  in a forward direction. The sensors  47   s  detect whether a cassette  20  is placed on the belt  47   a.    
         [0037]      FIGS. 3(   a ) and ( b ) are perspective views showing the structure of the cassette  20 . Note that  FIGS. 3(   a ) and ( b ) show the coordinate axes of  FIG. 2  when the cassette  20  is placed on the belt  47   a.    
         [0038]    Referring to  FIG. 3(   a ), the cassette  20  is formed of resin, and has a thickness in the Y-axis direction so as to accommodate a slide glass  10  in a receiver  20   e . Receiving holes  20   a  and  20   b , which are laterally partitioned by a partition  20   c , are formed on the top part of the cassette  20 . The receiver  20   e  is formed within the cassette  20  with a partition  20   d  arranged in the downward direction of the partition  20   c . Flanges  20   f  and  20   g  are formed on the lateral sides of the cassette  20 , and the bottom surface of the flanges  20   f  and  20   g  are disposed on the belt  47   a  of  FIG. 2  and maintained thus by the bottom surface of the flanges  20   f  and  20   g . A bottom part  20   h  is formed below the cassette  20 . The slide glass  20  can be inserted from the top side through the receiving hole  20   a.    
         [0039]      FIG. 3(   b ) is a perspective view showing the slide glass  10  accommodated in the cassette  20 , as shown in  FIG. 3(   b ), when the slide glass  10  is accommodated, there is a gap in the region on the right side of the partitions  20   c  and  20   d  in the receiver  20   e . This gap allows the insertion of a pipette through the receiving hole  20   b  even when a slide glass  10  is accommodated in the cassette  20 . 
         [0040]    Returning to  FIG. 2 , the cassette cross-feeder  48  has a cassette support  48   a , a laterally movable belt  48   b , and transmission type sensors  48   s  configured by a light emitter and a light receiver. The cassette support  48   a  is attached to the belt  48   b  so as to support the bottom part  20   h  of the cassette  20  in an upward direction. An empty cassette  20  which is positioned in front of the cassette receiver  47  is supported by the cassette support  48   a  and transported leftward to in front of the cassette rotator  49 . The sensors  48   s  are positioned in front of the cassette rotator  49  to detect whether a slide glass  10  is accommodated in the cassette  20  that is positioned in front of the cassette rotator  49  supported on the cassette support  48   a.    
         [0041]    The cassette rotator  49  has a flat surface  49   a . The flat surface  49   a  is configured so as to rotate while maintaining parallel to the X-Y plane and parallel to the X-Z plane. The cassette rotator  49  receives the empty cassette  20  positioned in front of the cassette rotator  49 , and the slide glass  10  is pushed from the printer  46  into the cassette  20 . Then, the cassette  20 , which contains the slide glass  10  on the flat surface  49   a , is moved to the cassette support  48   a  of the cassette cross-feeder  48 . Subsequently, the cassette  20  is transported leftward by the cassette cross-feeder  48  and positioned in front of the staining unit  50 . 
         [0042]    The staining unit  50  has a feed unit  50   a , belt  50   b  that is movable in a backward direction, methanol processing unit M, stain processing units D 1  through D 3 , wash processing unit W, and feed unit  50   c . Each processing unit includes dispensing pipettes Ma, D 1   a , D 2   a , D 3   a , and Wa, collecting pipettes D 1   b , D 2   b &lt;D 3   b , and Wb, and sensors Ms, D 1   s , D 2   s , D 3   s , and Ws. 
         [0043]    The sensor Ms is a transmission type sensor configured by a light emitter and light receiver to detect when a cassette  20  is positioned at a position Mp (left end position of the cassette cross-feeder  48 ) for processing by the methanol processing unit M. The sensors D 1   s , D 2   s , D 3   s , and Ws are contact type sensors for detecting a cassette  20  respectively positioned at the stain processing units D 1 , D 2 , D 3 , and positions D 1   p , D 2   p , D 3   p , and Wp for processing by the wash processing unit W. 
         [0044]    When the cassette  20  is detected by the sensor Ms, methanol is dispensed from the receiving hole  20   b  of the cassette  20  into the receiver  20   e  via the dispensing pipette Ma of the methanol processing unit M. At this time, the cassette  20  is supported by the cassette support  48   a  of the cassette cross-feeder  48 . Thereafter, the cassette  20  is fed onto the belt  50   b  by the feeding unit  50   a.    
         [0045]    The cassette  20  which has been fed onto the belt  50   b  by the feeding unit  50   a  is supported by the flanges  20   f  and  20   g . In this state, the cassette  20  is transported backward by the moving belt  50   b.    
         [0046]    When the cassette  20  is detected by the sensor D 1   s , the methanol inside the receiver  20   e  is recovered (aspirated) from the receiving hole  20   b  of the cassette  20  via the recovery pipette D 1   b  of the stain processing unit D 1 . The smear sample on the slide glass  10  is then dried by a fan not shown in the drawing. The fixing (adhesion) of the smear sample by methanol then ends. Subsequently, May-Grünewald solution is dispensed (discharged) into the receiver  20   e  of the receiving hole  20   b  of the cassette  20  via the dispensing pipette D 1   a . The cassette  20  is then transported backward by the belt  50   b.    
         [0047]    When the cassette  20  is detected by the sensor D 2   s , the May-Grünewald solution inside the receiver  20   e  is recovered (aspirated) from the receiving hole  20   b  of the cassette  20  via the recovery pipette D 2   b  of the stain processing unit D 2 . Subsequently, May-Grünewald diluting liquid is dispensed (discharged) into the receiver  20   e  of the receiving hole  20   b  of the cassette  20  via the dispensing pipette D 2   a . The cassette  20  is thereafter transported backward by the belt  50   b . Note that the May-Grünewald diluting liquid is a mixture of the May-Grünewald solution of bottle  102  and diluting liquid of bottle  104 . 
         [0048]    When the cassette  20  is detected by the sensor D 3   s , the May-Grünewald solution inside the receiver  20   e  is recovered (aspirated) from the receiving hole  20   b  of the cassette  20  via the recovery pipette D 3   b  of the stain processing unit D 3 . Then, Giemsa diluting liquid is dispensed (discharged) into the receiver  20   e  of the receiving hole  20   b  of the cassette  20  via the dispensing pipette D 3   a . The cassette  20  is thereafter transported backward by the belt  50   b . Note that the Giemsa diluting liquid is a mixture of the Giemsa solution of bottle  103  and diluting liquid of bottle  104 . 
         [0049]    When the cassette  20  is detected by the sensor Ws, the Giemsa liquid inside the receiver  20   e  is recovered (aspirated) from the receiving hole  20   b  of the cassette  20  via the recovery pipette Wb of the wash processing unit W. Then, water used for sample washing is dispensed (discharged) into the receiver  20   e  of the receiving hole  20   b  of the cassette  20  via the dispensing pipette Wa. The water used for sample washing is then recovered (aspirated) from inside the receiver  20   e  of the cassette  20  by the recovery pipette Wb. The cassette  20  is thereafter transported backward by the belt  50   b.    
         [0050]    The cassette  20  which has been moved backward by the belt  50   b  is then sent leftward by the feed unit  50   c . The cassette  20  is therefore positioned at the back of the cassette storage unit  51 . 
         [0051]    The cassette storage unit  51  has a feeding unit  51   a  and a belt  51   b  which is movable in a forward direction. The cassette  20  which has been sent from the feed unit  50   c  is moved onto the belt  51   b  by the feeding unit  51   a . The cassette  20  which has been sent onto the belt  51   b  is transported forward by the moving belt  51   b . The cassette  20  positioned in front of the belt  51   b  is removed by the user through the opening  2   c  (refer to  FIG. 1 ). The smear sample preparation therefore ends. Note that the cassette  20  which has been recovered in the cassette storage unit  51  and removed by the user through the opening  2   c  (refer to  FIG. 1 ), is thereafter again placed in the cassette receiver  47  through the opening  2   b  (refer to  FIG. 1 . 
         [0052]    The operation of the staining unit  50  (methanol processing unit M, stain processing units D 1  through D 3 , and wash processing unit W) is described next, referring to  FIG. 4 . Note that the operation of the methanol processing unit M, stain processing units D 1  through D 3 , and wash processing unit W is identical to that of the stain processing unit D 1 . 
         [0053]      FIGS. 4(   a ) through ( c ) are side views of the stain processing unit D 1  viewed in the Y-axis positive direction. The stain processing unit D 1  has, in addition to the dispensing pipette D 1   a  and recovery pipette D 1   b  shown in  FIG. 2 , a substrate D 11 , stopper D 12 , support member D 13 , and holder D 14 . 
         [0054]    Referring to  FIG. 4(   a ), the substrate D 11  is attached within the smear sample preparation device  2 . The stopper D 12  is a metal plate which is vertically movable (Z-axis direction) relative to the substrate D 11 , and the sensor D 1   s  is provided on the front surface (surface on the side in the Y-axis negative direction) of the stopper D 12 . The dispensing pipette D 1   a , recovery pipette D 1   b , and holder D 14  are integrated with the support member D 13  so as to be vertically movable. 
         [0055]    In the state shown in  FIG. 4(   a ), the backside surface of the cassette  20 , which has been transported backward supported on the belt  50   b , abuts the stopper D 12  and is stopped. At this time, the cassette  20  is positioned at position D 1   p  of  FIG. 2 , and the arrival of the cassette  20  is detected by the sensor D 1   s . In this state, the support member D 13  moves downward and the tips of the dispensing pipette D 1   a  and recovery pipette D 1   b  are positioned within the receiver  20   e  of the cassette  20  as shown in  FIG. 4(   b ). 
         [0056]    In the state shown in  FIG. 4(   b ), the methanol within the cassette  20  is recovered by the recovery pipette D 1   b . The slide glass  10  in the cassette  20  is then gripped by the holder D 14  and lifted upward from the cassette  20 . In this condition, the slide glass  10  is dried by a fan not shown in the drawing, and thereafter the slide glass  10  is returned into the cassette  20 . May-Grünwald solution is then dispensed into the cassette  20  from the dispensing pipette Dla. The support member D 13  and the stopper D 12  then move upward and in the state shown in  FIG. 4(   c ) the cassette  20  is transported backward by the belt  50   b.    
         [0057]    Note that the methanol processing unit M has a configuration wherein the stopper D 12  of  FIG. 4  corresponds to the recovery pipette D 1   b . In the methanol processing unit M, the slide glass  10 , which is accommodated in the cassette  20  positioned at position Mp (refer to  FIG. 2 ), is raised upward by the holder corresponding to the holder D 14  of  FIG. 4 , and thereafter methanol is dispensed to the cassette  20  via the dispensing pipette Ma. The raised slide glass  10  is then returned into the cassette  20 . Thereafter, the cassette  20  is fed onto the belt  50   b  by the feeding unit  50   a.    
         [0058]    The stain processing unit D 2 , stain processing unit D 3 , and wash processing unit W have a structure corresponding to the holder D 14  of  FIG. 4 . In the stain processing unit D 2 , stain processing unit D 3 , and wash processing unit W, staining liquid and the like is dispensed and recovered while the slide glass  10  is housed in the cassette  20  respectively positioned at position D 2   p , D 3   p , and Wp. 
         [0059]    The cassette  20  stored in the cassette storage unit  51  is again placed in the cassette receiver  47 . Therefore, when the cassette  20  is used repeatedly, the staining liquid adheres to the cassette  20 . In the smear sample preparation device  2  of the present embodiment, the interior of the cassette  20  is washed by dispensing methanol into the cassette  20  in a process separate from the staining process. 
         [0060]    In this case, the empty cassette  20  housed in the cassette receiver  47  is transported to the staining unit  50 . At position Mp, methanol is dispensed into the cassette  20  by the dispensing pipette Ma, and at position D 1   p  the methanol in the cassette  20  is recovered by the recovery pipette D 1   p . Hence, the staining liquid adhered within the cassette  20  is washed therefrom. 
         [0061]    Note that in the washing process for the interior of the cassette  20  only dispensing of the methanol by the dispensing pipette Ma and the recovery of the methanol by the recovery pipette Dlb are performed. That is, the cassette  20  is moved backward without being stopped by the stopper at positions D 2   p , D 3   p , and Wp. 
         [0062]    In the washing process of the cassette  20 , the liquid surface of the methanol dispensed into the cassette  20  by the dispensing pipette Ma is the same height as the liquid surface of the methanol dispensed into the cassette  20  by the dispensing pipette Ma in the staining process. That is, the amount of methanol dispensed for the washing process of the interior of the cassette  20  is a volume just sufficiently greater for the immersion of the slide glass  10  than the amount of methanol dispensed into the cassette  20  in the staining process. Hence, washing is reliably performed since the methanol is in contact with the staining liquid adhering to the interior of the cassette  20  while washing the cassette  20 . 
         [0063]      FIG. 5  briefly shows a fluid circuit diagram of the smear sample preparation device  2 . 
         [0064]    The smear sample preparation device  2  has flow passes formed so as to connect the first staining liquid chamber  121 , second staining liquid chamber  122 , staining liquid chamber  131 , diluting liquid chamber  143 , first mixing chamber  151 , second mixing chamber  152 , and discard chamber  165  in addition to the bottles  101  through  104 , first methanol chamber  111  and second methanol chamber  112  shown in  FIG. 1 . Note that although the wash water bottle  105 , dispensing pipette Wa, recovery pipette Wb and their corresponding flow passes are illustrated, they are omitted in  FIG. 5  for convenience. 
         [0065]    As shown in the drawing, valves v 11  through v 17 , v 18   a , v 18   b , v 19 , v 20  through v 28 , v 20   a , v 29   b , v 30   a , v 30   b , v 31  through v 34 , v 35   a , v 35   b , v 41   a  through v 43   a , v 41   b  through v 43   b , v 51   a , v 51   b , v 52   a , v 52   b , and v 53  through v 56  are connected to the flow pass. The staining liquid and the like is allowed to flow or is blocked via the valves which are set to either an open state or a closed state. Pressure regulators  113  through  115 ,  123  through  125 ,  127 ,  132 ,  133 ,  141 ,  146 ,  161 ,  163 ,  166  for regulating pressure, and diaphragm pumps  116 ,  126 ,  128 ,  134 ,  142 ,  145 ,  147 ,  162 , and  164  which function to aspirate or discharge a set amount of staining liquid or the like are connected to the flow pass as shown in the drawing. 
         [0066]    Referring to  FIG. 6 , the first methanol chamber  111  is configured by a tank  111   b  provided with an internal float switch  111   a . The float switch  111   a  is configured by a float member  111   c , and a support rod  111   d  for supporting the float member  111   c  so as to be movable in vertical directions. A magnet  111   e  is embedded within the float member  111   c . The float member  111   c  moves vertically according to the liquid surface within the tank  111   b , and the magnet  111   e  is positioned at the height of the liquid surface. A magnetic sensor type reed switch  111   f  is embedded at a predetermined position (hereinafter referred to as “standard position”) in the vertical direction of the support rod  111   d.    
         [0067]    The reed switch is turned on when the surface of the liquid within the tank  111   b  is positioned at the standard position. The reed switch is turned off when the surface of the liquid in the tank  111   b  is not at the standard position. Hence, it is possible to determine whether a predetermined amount of methanol is retained in the first methanol tank  111 . 
         [0068]    Note that the second methanol chamber  112 , first staining liquid chamber  121 , second staining liquid chamber  122 , staining liquid chamber  131 , diluting liquid chamber  143 , and discard chamber  165  have the same structure as the first methanol chamber  111 , and are provided with an internal float switch. The standard amount of liquid retained in each chamber, is set individually, and the standard position at which the reed switch is in the turned on state is set individually in accordance therewith. 
         [0069]    Returning to  FIG. 5 , when supplying methanol from the bottle  101  to the first methane chamber  111 , the valves v 12  through v 16  are closed and valve v 11  is open. In this state, a vacuum is created within the first methanol chamber  111  by the pressure regulator  113 . Hence, the methanol retained in the bottle  101  is supplied into the first methane chamber  111 . 
         [0070]    When supplying methanol from the bottle  101  to the second methanol chamber  112 , the valves v 11 , v 13 , v 17 , and v 19  are closed and valve v 12  is opened. In this state, there is a vacuum created within the second methanol chamber  112  by the pressure regulator  114 . Hence, the methanol retained in the bottle  101  is supplied into the second methane chamber  112 . 
         [0071]    When the methanol retained in the first methanol chamber  111  is dispensed from the dispensing pipette Ma to the cassette  20 , valves v 11 , v 14 , v 15 , v 17 , and v 18   b  are closed and valves v 16  and v 18   a  are opened. In this state, there is a vacuum created within the diaphragm pump  116  by the pressure regulator  115 . Hence, a fixed amount of the methanol retained in the first methanol chamber  111  is aspirated into the diaphragm pump  116 . Then, the valve v 18   a  is closed and the valve  18   b  is opened. In this state, a positive pressure is created within the diaphragm pump  116  by the pressure regulator  115 . Hence, the methanol within the diaphragm pump  116  is dispensed from the dispensing pipette Ma to the cassette  20 . 
         [0072]    When the methanol retained in the second methanol chamber  112  is dispensed from the dispensing pipette Ma to the cassette  20 , valves v 12 , v 16 , v 18   b , and v 19  are closed and valves v 17  and v 18   a  are opened. In this state, there is a vacuum created within the diaphragm pump  116  by the pressure regulator  115 . Hence, a fixed amount of the methanol retained in the second methanol chamber  112  is aspirated into the diaphragm pump  116 . The methanol in the diaphragm pump  116  is then dispensed from the dispensing pipette Ma to the cassette  20  in the same way as the case of the first methanol chamber  111 . 
         [0073]    When recovering the methanol retained in the cassette  20  in the first methanol chamber  111  via the recovery pipette D 1   b , the valves v 11 , v 14 , v 16  are closed and the valve  15  is opened. In this state, a vacuum is created within the first methanol chamber  111  by the pressure regulator  113 . Hence, the methanol aspirated from the recovery pipette D 1   b  is recovered in the first methanol chamber  111 . 
         [0074]    When discharging the methanol retained in the first methanol chamber  111 , the valves v 11 , v 15 , v 16  are closed and the valve v 14  is opened. In this state, the pressure is increased within the first methanol chamber  111  by the pressure regulator  113 . Hence, the methanol retained in the first methanol chamber  111  is discharged therefrom. 
         [0075]    Next, when supplying the May-Grünewald solution as a staining liquid from the bottle  102  to the first staining liquid chamber  121 , the valves v 22  through v 24 , v 26 , and v 27  are closed and the valves v 20  and v 21  are opened. In this state, a vacuum is created within the first staining liquid chamber  121  by the pressure regulator  123 . Hence, the May-Grünewald solution retained within the bottle  102  is supplied to the first staining liquid chamber  121 . 
         [0076]    When supplying May-Grünewald solution from the bottle  102  to the second staining liquid chamber  122 , the valves v 21 , v 23 , v 25 , and v 28  are closed and the valves v 20  and v 22  are opened. In this state, a vacuum is created within the second staining liquid chamber  122  by the pressure regulator  124 . Hence, the May-Grünewald solution retained within the bottle  102  is supplied to the second staining liquid chamber  122 . 
         [0077]    When the May-Grünwald solution retained in the first staining liquid chamber  121  is dispensed from the dispensing pipette D 1   a  to the cassette  20 , the valves v 21 , v 24 , v 26 , v 28 , v 29   b , and v 30   a  are closed and the valves v 27  and v 29   a  are opened. In this state, there is a vacuum created within the diaphragm pump  126  by the pressure regulator  125 . Hence, a fixed amount of the May-Grünewald solution retained in the first staining liquid chamber  121  is aspirated into the diaphragm pump  126 . Then, the valve v 29   a  is closed and the valve v 29   b  is opened. In this state, pressure is increased within the diaphragm pump  126  by the pressure regulator  125 . Hence, the May-Grünewald solution within the diaphragm pump  126  is dispensed from the dispensing pipette D 1   a  to the cassette  20 . 
         [0078]    When the May-Grünewald solution retained in the second staining liquid chamber  122  is dispensed from the dispensing pipette D 1   a  to the cassette  20 , the valves v 22 , v 25 , v 27 , v 28 , v 29   b , and v 30   a  are closed and the valves v 28  and v 29   a  are opened. In this state, there is a vacuum created within the diaphragm pump  126  by the pressure regulator  125 . Hence, a fixed amount of the May-Grünewald solution retained in the second staining liquid chamber  122  is aspirated into the diaphragm pump  126 . The May-Grünewald solution in the diaphragm pump  126  is then dispensed from the dispensing pipette D 1   a  to the cassette  20  in the same way as the case of the first staining liquid chamber  121 . 
         [0079]    When recovering the May-Grünewald solution retained in the cassette  20  in the first staining liquid Chamber  121  via the recovery pipette D 2   b , the valves v 21 , v 24 , v 27  are closed and the valve v 26  is opened. In this state, a vacuum is created within the first staining liquid chamber  121  by the pressure regulator  123 . Hence, the May-Grünewald solution aspirated from the recovery pipette D 2   b  is recovered in the first staining liquid chamber  121 . 
         [0080]    When supplying the May-Grünewald solution retained in the first staining liquid chamber  121  to the first mixing chamber  151 , the valves v 21 , v 24 , v 26 , v 28 , v 29   a , and v 30   b  are closed and the valves v 27  and v 30   a  are opened. In this state, there is a vacuum created within the diaphragm pump  128  by the pressure regulator  127 . Hence, a fixed amount of the May-Grünewald solution retained in the first staining liquid chamber  121  is aspirated into the diaphragm pump  128 . Then, the valve v 30   a  is closed and the valve v 30   b  is opened. In this state, pressure is increased within the diaphragm pump  128  by the pressure regulator  127 . In this way the May-Grünewald solution within the diaphragm pump  128  is supplied to the first mixing chamber  151 . Note that an opening is provided in the first mixing chamber  151  to equalize the pressure within the chamber with the ambient pressure outside. 
         [0081]    When supplying the May-Grünewald solution retained in the second staining liquid chamber  122  to the first mixing chamber  151 , the valves v 22 , v 25 , v 27 , v 29   a , and v 30   b  are closed and the valves v 28  and v 30   a  are opened. In this state, there is a vacuum created within the diaphragm pump  128  by the pressure regulator  127 . Hence, a fixed amount of the May-Grünewald solution retained in the second staining liquid chamber  122  is aspirated into the diaphragm pump  128 . The May-Grünewald solution in the diaphragm pump  128  is then supplied to the first mixing chamber  151  in the same way as the case of the first staining liquid chamber  121 . 
         [0082]    When discharging the May-Grünewald solution retained in the first staining liquid chamber  121 , the valves v 21 , and v 25  through v 27  are closed and the valve v 24  is opened. In this state, the pressure is increased within the first staining liquid chamber  121  by the pressure regulator  123 . Hence, the May-Grünewald solution retained in the first staining liquid chamber  121  is discharged. 
         [0083]    When discharging the May-Grünewald solution retained in the second staining liquid chamber  122 , the valves v 22 , v 24  and v 28  are closed and the valve v 25  is opened. In this state, the pressure is increased within the second staining liquid chamber  122  by the pressure regulator  124 . Hence, the May-Grünewald solution retained in the second staining liquid chamber  122  is discharged. 
         [0084]    Similarly, by controlling the corresponding valves, pressure regulator and diaphragm pump, the Giemsa solution (staining liquid) is supplied from the bottle  103  to the staining solution chamber  131  Giemsa solution retained in the staining liquid chamber  131  is supplied to the second staining chamber  152 , phosphate buffer solution (diluting liquid) is supplied from the bottle  104  to the diluting liquid chamber  143 , diluting liquid retained in the diluting liquid chamber  143  is supplied to the first mixing chamber  151 , and diluting liquid retained in the diluting liquid chamber  143  is supplied to the second mixing chamber  152 . 
         [0085]    In the first mixing chamber  151 , the May-Grünewald solution supplied from the first staining liquid chamber  121  or the second staining liquid chamber  122  is mixed with the diluting liquid supplied from the diluting liquid chamber  143 . Hence, a May-Grünwald dilute solution is produced within the first mixing chamber  151 . In the second mixing chamber  152 , the Giemsa solution supplied from the staining liquid chamber is mixed with the diluting liquid supplied from the diluting liquid chamber  143 . Hence, a Giemsa dilute solution is produced within the second mixing chamber  152 . 
         [0086]    By controlling the corresponding valves, pressure regulator and diaphragm pump, the Giemsa solution retained in the staining liquid chamber  131  is dispensed from the dispensing pipette D 2   a  to the cassette  20 , and Giemsa dilute solution retained in the second mixing chamber  152  is dispensed from the dispensing pipette D 3   a  to the cassette  20 . The May-Grünewald dilute solution retained in the cassette  20  is recovered in the discard chamber  165  via the recovery pipette D 3   b , the May-Grünewald dilute solution retained in the first mixing chamber  151  is supplied to the discard chamber  165 , and the Giemsa dilute solution retained in the second mixing chamber  152  is supplied to the discard chamber  165 . The staining solution and the like retained in the discard chamber  165  is discharged therefrom by controlling the valves v 53  through v 56  and the pressure regulator  166 . 
         [0087]    Note that the Giemsa dilute solution retained in the cassette  20  is recovered similar to the above through the recovery pipette Wb via chamber, diaphragm pump, and valves not shown in the drawings. The washing water retained in the bottle  105  is similarly dispensed to the cassette  20  through the dispensing pipette Wa and recovered through the recovery pipette Wb via chamber, diaphragm pump, and valves not shown in the drawing. 
         [0088]    Thus, the staining liquid and the like accommodated in the bottles  101  through  105  can be dispensed to the cassette  20  through the flow pass by the dispensing pipettes Ma, D 1   a  through D 3   a , and Wa. The staining liquid and the like aspirated by the recovery pipettes Wb and D 1   b  through D 3   b  can be recovered in the corresponding chambers through the flow pass. The staining liquid and the like retained in each chamber also can be discharged through the flow pass. 
         [0089]      FIG. 7  briefly shows a the structures of the smear sample preparation device  2  and the transport device  3 . 
         [0090]    The smear sample preparation device  2  is provided with a controller  201 , memory unit  202 , drive unit  203 , sensor unit  204 , fluid transporter  205 , communication unit  206 , and operation display unit  2   a.    
         [0091]    The controller  201  controls the parts of the smear sample preparation device  2  by executing a computer program stored in the memory unit  202 . The memory unit  202  is a memory device such as a hard disk and the like, and stores a computer program for operating the smear sample preparation device  2 . 
         [0092]    The memory unit  202  stores a reuse counter Rk for indicating the frequency of methanol reuse, a threshold frequency R 0  for indicating the upper limit reuse frequency, a recovery counter Ck for indicating the methanol recovery frequency, and a threshold frequency C 0  for indicating the upper limit of the recovery frequency, which will be described later. These frequencies are described later with reference to  FIGS. 10(   b ),  12 ( b ), and  14 . 
         [0093]    The drive unit  203  includes an aspirating/dispensing mechanism  41 , slide glass supplier  42 , slide glass cross-feeder  43 , smearing mechanism  44 , smear drier  45 , printer  46 , cassette receiver  47 , cassette cross-feeder  48 , cassette rotator  49 , staining unit  50 , and cassette storage unit  51 , and a mechanism for driving each part within the smear sample preparation device  2 , and is controlled by the controller  201 . 
         [0094]    The sensor unit  204  includes a sensor Ms for the methanol processing unit M, sensors D 1   s  through D 3   s  for the stain processing units D 1  through D 3 , and sensor Ws for the wash processing unit W. The sensor unit  204  includes a reed switch  111   f  for the first methanol chamber  111 , and similar reed switches disposed in the other chambers. Each sensor included in the sensor unit  204  is controlled by the controller  201 , and the detection signals of the sensor unit  204  are output to the controller  201 . 
         [0095]    The liquid transporter  205  includes pressure regulators  113  through  115 ,  123  through  125 ,  127 ,  132 ,  133 ,  141 ,  144 ,  146 ,  161 ,  163 ,  166 , and valves v 11  through v 17 , vl 8   a , v 18   b , v 10 , v 20  through v 28 , v 29   a , v 29   b , v 30   a , v 30   b , v 31  through v 34 , v 35   a , v 35   b , v 41   a  through v 43   a , v 41   b  through v 43   b , v 51   a , v 51   b , v 52   a , v 53   b , v 53  through v 56 . The parts included in the liquid transporter  205  are controlled by the controller  201 . 
         [0096]    The operation display unit  2   a  is a touch panel with integrated input and display functions, as shown in  FIG. 1 . When the user operates the operation display unit  2   a , a signal indicting the operation content is output to the controller  201 . The controller  201  displays each type of information on the operation display unit  2   a . The communication unit  206  performs data communication with the communication unit  304  of the transport device  3 . 
         [0097]    The transport device  3  is provided with a controller  301 , drive unit  302 , sensor unit  303 , and communication unit  304 . The controller  301  controls the parts within the transport device  3 . The drive unit  302  includes mechanism for driving each part in the transport device  3 , and is controlled by the controller  301 . The sensor unit  303  includes sensors in the transport device  3 , is controlled by the controller  301 , and the detection signal of the sensor unit  303  is output to the controller  301 . The communication unit  304  performs data communication with the communication unit  206  of the smear sample preparation device  2 . 
         [0098]      FIG. 8  is a flow chart showing the processes of the smear sample preparation device  2 . 
         [0099]    The controller  201  executes processes corresponding to the pressed button when the user presses any of the buttons including the smear sample preparation start button  401 , cassette washing start button  402 , or shutdown start button  501 . 
         [0100]      FIG. 9(   a ) shows the start setting screen  400  displayed on the operation display  2   a . The smear sample preparation start button  401  and the cassette washing start button  402  are displayed on the start setting screen  400 .  FIG. 9(   b ) shows the shutdown setting screen  500  displayed on the operation display  2   a . The shutdown start button  501  is displayed on the shutdown start setting screen  500 . Note that the user can suitably display the start setting screen  400  and the shutdown setting screen  500  by operating the operation display unit  2   a.    
         [0101]    Returning to  FIG. 8 , when the controller  201  determines that the smear sample preparation start button  401  has been pressed (step S 11 : YES), the smear sample preparation process is executed (S 12 ). When the controller  201  determines that the cassette washing start button  402  has been pressed (step S 12 : N 0 , S 13 : YES), the cassette washing process is executed (S 12 ). When the controller  201  determines that the shutdown start button  501  has been pressed (S 11 : N 0 , S 13 : N 0 , S 15 : YES), the shutdown process is executed for the smear sample preparation device  2 . The smear sample preparation process and the cassette washing process are described below referring to  FIGS. 10(   a ) and  12 ( a ). Note that the controller  201  displays the message “Smear sample preparation process is executing” is displayed on the operation display unit  2   a  while the smear sample preparation process (S 12 ) is being performed. On the other hand, that the controller  201  displays the message “Cassette washing process is executing” is displayed on the operation display unit  2   a  while the cassette washing process (S 14 ) is being performed. Hence, the operator and others can readily comprehend whether the device is currently performing a process by confirming the indication on the operation display unit  2   a  of the smear sample preparation device  2 . 
         [0102]    Selection of the cassette wash start button  402  is disabled while the smear sample preparation process (S 12 ) is being performed after selecting the smear sample preparation start button  401 . On the other hand, selection of the smear sample preparation start button  401  is disabled while the cassette washing process (S 14 ) is being performed after selecting the cassette wash start button  402 . Thus, mixing of washed cassettes  20  and cassettes  20  with adhered staining liquid in the cassette storage unit  51  can be prevented by not interrupting an ongoing process with another process. Suspending a process through operation error also is prevented. 
         [0103]      FIG. 10(   a ) is a flow chart showing the smear sample preparation process. 
         [0104]    The controller  201  aspirates the sample positioned in front of the hand unit  41   a  (refer to  FIG. 1 ) and performs the smear process (S 121 ). That is, the controller  201  prepares a smear sample from the aspirated sample, houses the smear sample in the cassette  20 , and positions the cassette  20  at the position Mp. The controller  201  then performs the staining process on the cassette  20  positioned at the position Mp via the staining unit  50 , and transports the cassette  20  to the cassette storage unit  51 . 
         [0105]    The controller  201  then determines whether the smear preparation (S 121 , S 122 ) has been completed for all samples (S 123 ). When smear preparation of all samples is not complete (S 123 : NO), the controller  201  returns the process to S 121 , and sequentially performs smear preparation for subsequent samples. When smear preparation for all samples is completed (S 123 : YES), the smear sample preparation process ends. 
         [0106]    In the staining process of the present embodiment, methanol, which has been dispensed from the first methanol chamber  111  to the cassette  20  through the dispensing pipette Ma, is then recovered in the first methanol chamber  111  through the recovery pipette D 1   b , and reused for dispensing through the dispensing pipette Ma. 
         [0107]      FIG. 10(   b ) is a flow chart showing the methanol dispensing process in the staining process of the present embodiment. 
         [0108]    When the dispensing process starts, the controller  201  awaits the arrival of the cassette  20  at the position Mp. When the cassette  20  arrives at the position Mp (S 201 : YES), the controller  201  dispenses methanol from the first methanol chamber  111  to the cassette  20  (S 202 ), and adds [1] to the reuse counter Rk (S 203 ). The reuse counter Rk is stored in the memory unit  202  and is reset during initial startup of the smear sample preparation device  2 . The controller  201  then determines whether the reuse counter Rk has attained a preset threshold frequency R 0  (S 204 ). The threshold frequency R 0  is stored in the memory unit  202 . 
         [0109]    Note that the methanol dispensed to the cassette  20  is recovered from the cassette  20  to the first methanol chamber  111  at the position D 1   p . Therefore, as the dispensing process progresses, the methanol in the first methanol chamber  111  is gradually degraded. The methanol recovery process is described below referring to  FIG. 13(   a ). 
         [0110]    When the reuse counter Rk has not attained the threshold frequency R 0  (S 204 : NO), the controller  201  returns the process to S 201 , and the process of S 201  and subsequent steps are repeated. Therefore, the methanol is dispensed from the first methanol chamber  111  to the cassette  20  until the reuse counter Rk reaches the threshold frequency R 0 . In the present embodiment, the threshold frequency R 0  is user settable. The threshold frequency R 0  is an indicator to replace the methanol in the first methanol chamber  111  with fresh methanol. 
         [0111]      FIG. 11(   a ) is a flow chart showing the process for setting the threshold frequency R 0 . 
         [0112]    When the controller  201  receives a display instruction of the threshold frequency setting screen  600  from the user (S 301 : YES), the controller  201  displays the threshold frequency setting screen  600  on the operation display unit  2   a  (S 302 ) (refer to  FIG. 1 ). 
         [0113]      FIG. 11(   b ) shows the threshold frequency setting screen  600  displayed on the operation display unit  2   a . The threshold frequency setting screen  600  has an input field  601 , OK button  602 , and cancel button  603 . The input field  601  is an area capable of receiving numbers 1 to 20 input by the user. The input field  601  includes up and down buttons; when the user presses the up button, the number in the input field  601  is incremented, whereas the number in the input field  601  is decremented when the down button is pressed. Note that the number  20  is set as the default value in the threshold frequency R 0 . 
         [0114]    When the user presses the OK button  602  (S 303 : YES), the controller  201  writes the numerical value entered in the input field  601  in the threshold frequency R 0  stored in the memory unit  202  (S 304 ) and the threshold frequency setting screen  600  closes; when the cancel button  603  is pressed (S 303 : NO, S 305 : YES), the value entered in the input field  601  is deleted and the threshold frequency setting screen  600  closes. 
         [0115]    Returning to  FIG. 10(   b ), when the reuse counter Rk attains the threshold frequency R 0  (S 204 : YES), the controller  201  starts, in parallel with the dispensing process, a process for replacing the methanol in the first methanol chamber  111  with fresh methanol (S 205 ). When the replacement process of the first methanol chamber  111  ends, the controller  201  resets the reuse counter Rk (S 206 ) and returns the process to S 201 . Thus, a new dispensing process starts after the methanol replacement. 
         [0116]      FIG. 12(   a ) is a flow chart showing the cassette washing process. 
         [0117]    When the cassette wash start button  402  of  FIG. 9  is pressed, the controller  201  transports the cassette  20  held in the cassette receiver  47  toward the cassette storage unit  51  (S 141 ). At this time, the cassette  20  held in the cassette receiver  47  is transported forward by the belt  47   a  and supported by the cassette support  48   a  of the cassette cross-feeder  48 . The cassette  20  supported on the cassette support  48   a  is positioned in front of the cassette rotator  49 . Here, the controller  201  determines whether a slide glass  10  is accommodated in the cassette  20  via the sensor  48   s  (S 142 ). 
         [0118]    When the cassette  20  does not contain a slide glass  10  (S 142 : YES), the controller  201  performs the washing process on the cassette  20  (S 143 ). That is, methanol is dispensed by the dispensing pipette Ma to the cassette  20  positioned at position Mp, and methanol is recovered by the recovery pipette D 1   b  from the cassette  20  positioned at the position D 1   p  as previously described. After the washing process ends, the washed cassette  20  is transported to the cassette storage unit  51 . When the cassette  20  contains a slide glass  10  (S 142 : NO), the washing process is not performed, and the cassette  20  is moved backward by the belt  50   b  of the staining unit  50  to the cassette storage unit  51 . 
         [0119]    The controller  201  then determines whether washing (S 141  through S 143 ) has been completed for all cassettes  20  (S 144 ). This determination is YES if a cassette  20  is detected by the sensor  47 , and this determination is NO is a cassette  20  is not detected. When washing of all cassettes  20  is not complete (S 144 : NO), the controller  201  returns the process to S 141 , and sequentially performs washing for subsequent cassettes  20 . When washing of all cassettes  20  is completed (S 144 : YES), the cassette washing process ends. 
         [0120]    In the washing process of the present embodiment, methanol, which has been dispensed from the first methanol chamber  111  to the cassette  20  through the dispensing pipette Ma, is then recovered in the first methanol chamber  111  through the recovery pipette D 1   b , and reused for dispensing through the dispensing pipette Ma similar to the smear sample preparation process. 
         [0121]      FIG. 12(   b ) is a flow chart showing the methanol dispensing process in the washing process of the present embodiment. 
         [0122]    When the dispensing process starts, the controller  201  awaits the arrival of the cassette  20  at the position Mp. When the cassette  20  arrives at the position Mp (S 401 : YES), the controller  201  dispenses methanol from the first methanol chamber  111  to the cassette  20  (S 402 ), and adds [1] to the reuse counter Rk (S 403 ). Note that when the cassette  20  washing operation started after the staining operation, the incrementation by S 403  was made on the reuse counter Rk incremented in S 403  of  FIG. 10   b ). The controller  201  then determines whether the reuse counter Rk has attained a preset threshold frequency R 0  (S 204 ). The reuse counter Rk and the threshold frequency R 0  are the same as the Rk and R 0  used in the dispensing process of the staining process of  FIG. 10(   b ). 
         [0123]    Note that, in this case also, the methanol dispensed to the cassette  20  is recovered from the cassette  20  to the first methanol chamber  111  at the position D 1   p . Therefore, as the dispensing process progresses, the methanol in the first methanol chamber  111  is gradually degraded. Recovery of the methanol is performed according to the recovery process of  FIG. 13(   a ). 
         [0124]    When the reuse counter Rk has not attained the threshold frequency R 0  (S 404 : NO), the controller  201  returns the process to S 401 , and the process of S 401  and subsequent steps are repeated. Therefore, the methanol is dispensed from the first methanol chamber  111  to the cassette  20  until the reuse counter Rk reaches the threshold frequency R 0 . 
         [0125]    When the reuse counter Rk attains the threshold frequency R 0  (S 404 : YES), the controller  201  starts, in parallel with the dispensing process, a process for replacing the methanol in the first methanol chamber  111  with fresh methanol (S 405 ), and starts the count of the recovery counter Ck (S 406 ). The recovery counter Ck is stored in the memory unit  202 . The methanol recovery process is described below referring to  FIG. 14 . The counting process of the recovery counter Ck is described below referring to  FIG. 13(   b ). 
         [0126]    Thereafter, the controller  201  awaits the arrival of the cassette  20  at the position Mp (S 407 ). When the cassette  20  arrives at the position Mp (S 407 : YES), the controller  201  dispenses methanol to the cassette  20  from the second methanol chamber  112  rather than from the first methanol chamber  111 . Hence, when the methanol replacement process starts, the methanol chamber used to dispense methanol to the cassette  20  is switched from the first methanol chamber  111  to the second methanol chamber  112 . 
         [0127]    It is then determined whether the methanol replacement in the first methanol chamber  111  is complete (S 409 ). When the methanol replacement in the first methanol chamber  111  is not complete (S 409 : NO), the controller  201  returns the process to S 407 . Hence, the methanol is dispensed from the second methanol chamber  112  to the cassette  20  until the methanol replacement in the first methanol chamber  111  is completed. Note that the recovery process of  FIG. 13(   a ) is performed and the methanol from the cassette  20  is recovered to the first methanol chamber  111  even when methanol is dispensed from the second methanol chamber  112 . When the methanol replacement in the first methanol chamber  111  is completed (S 409 : YES), the controller  201  resets the reuse counter Rk (S 410 ), and returns the process to S 401 . Thus, a new dispensing process starts after the methanol replacement. 
         [0128]      FIG. 13(   a ) is a flow chart showing the methanol recovery process. 
         [0129]    The controller  201  awaits the arrival of the cassette  20  at the position D 1   p  (S 501 ). When the cassette  20  arrives at the position D 1   p  (S 501 : YES), the controller  201  recovers the methanol from the cassette  20  to the first methanol chamber  111  (S 502 ). Then, the controller  201  determines whether the liquid surface of the first methanol chamber exceeds the standard position (S 503 ); when the liquid surface exceeds the standard position (S 503 : YES), the methanol is discharged from the first methanol chamber  111  until the liquid surface in the first methanol chamber  111  is at the standard position (S 504 ). Thereafter, the controller  201  returns to S 501  and awaits the arrival of the next cassette  20  at the position Dp 1 . Hence, methanol dispensed to the cassette  20  is recovered in the first methanol chamber  111 . The methanol in the second methanol chamber  112  is therefore maintained in a fresh unused condition. 
         [0130]      FIG. 13(   b ) is a flow chart showing the count process of the recover counter Ck. 
         [0131]    When the recovery counter Ck count process starts in S 406  of  FIG. 12(   b ), the controller  201  resets the recovery counter Ck (S 511 ). When recovering the methanol from the cassette  20  in the first methanol chamber  111  via the process of  FIG. 13(   a ), the controller  201  adds [1] to the recovery counter Ck (S 513 ). The counting process is performed until the recovery counter Ck count process is canceled. Cancellation of the recovery counter Ck counting process is performed in S 602  of  FIG. 14 . 
         [0132]      FIG. 14  is a flow chart showing the methanol replacement process of the first methanol chamber  111 . 
         [0133]    When the methanol replacement process starts in S 405  of  FIG. 12 , the controller  201  waits for the recovery counter Ck to attain the threshold frequency C 0  (S 601 ). The threshold frequency C 0  is a value pre-stored in the memory unit  202 . When the recovery counter Ck attains the threshold frequency C 0  (S 601 : YES), the controller  201  cancels the count of the recovery counter Ck (S 602 ), discharges all methanol in the first methanol chamber  111  (S 603 ), and thereafter replenishes fresh methanol from the bottle  101  to the first methanol chamber  111  (S 604 ). Hence, the replacement process ends when the methanol is replenished in the first methanol chamber  111  until the liquid surface attains the standard position (S 605 : YES). The determination of S 409  of  FIG. 12(   b ) is therefore YES. 
         [0134]    On the other hand, when the methanol is not replenished in the first methanol chamber  111  until the liquid surface reaches the standard position (S 605 : NO), the controller  201  alerts the user to replace the bottle  101  by a methanol replenishment error (S 606 ). This alert is accomplished, for example, by displaying an alert screen on the operation display unit  2   a  (refer to  FIG. 1 ). When a replenishment error is detected, transporting of the cassette  20  and dispensing of methanol to the cassette  20  are suspended. 
         [0135]    Thereafter, the controller  201  awaits the replacement of the bottle  101  (S 607 ). When the error alert is received the user replaces the bottle  101  with a fresh bottle  101  and thereafter, when, for example, replacement completed input is entered from the screen of the operation display  2   a  (S 607 : YES), the controller  201  replenishes the first methanol chamber  111  with fresh methanol from the new bottle  101  (S 608 ). Methanol replenishment is thus started. 
         [0136]    When the methanol is not replenished in the first methanol chamber  111  until the liquid surface reaches the standard position (S 609 : NO), the controller  201  alerts the user of a bottle replacement error (S 611 ), and the controller  201  awaits proper installation of the new bottle  101  (S 607 ). On the other hand, when the methanol is replenished in the first methanol chamber  111  until the liquid surface reaches the standard position (S 609 : YES), the controller  201  cancels the replenishment error (S 610 ), and the replacement process ends. When a replenishment error is canceled, transporting of the cassette  20  and dispensing of methanol to the cassette  20  are restarted. 
         [0137]    Note that in the replacement process of  FIG. 14 , the methanol is discharged from the first methanol chamber  111  after the recovery counter Ck has attained the threshold frequency C 0  in S 601  without immediately discharging the methanol from the first methanol chamber  111  even when the methanol replacement process has started in S 405  of  FIG. 12(   b ). This is done to prevent recovery of repeatedly used methanol in the first methanol chamber  111  after the replacement with fresh methanol. That is, a plurality of cassettes  20  are usually present from the position Mp to the position D 1   p  with the timing of starting the methanol replacement process in S 405  of  FIG. 12(   b ). The methanol degraded through repeated use is dispensed from the first methanol chamber  111  to these cassettes  20 . Therefore, it is not desirable to recover methanol to the first methanol chamber  111  after replacing the methanol from the cassettes  20 . 
         [0138]    In the present embodiment, discharge and replenishment of the methanol is not performed for the first methanol chamber  111  immediately until the recovery counter Ck has attained the threshold frequency C 0  even though the methanol replacement process starts. The threshold frequency C 0  is set so that the cassette  20  that has been dispensed unused methanol from the second methanol chamber  112  in S 408  of  FIG. 12(   b ) reaches the position D 1   p  with the timing of the completion of the methanol replacement. 
         [0139]    Note that the threshold frequency C 0  is preset based on the time (immersion time) from the dispensing of the methanol to the cassette  20  at position Mp to the recovery of the methanol from the cassette  20  at position D 1   p . Therefore, recovery of pre-replacement degraded methanol in the first methanol chamber  111  immediately after methanol replacement is prevented by providing a time lag based on the threshold frequency C 0  until the methanol replacement process is performed for the first methanol chamber  111 . 
         [0140]      FIG. 15  is a flow chart showing the methanol replenishment process of the first methanol chamber  111  and second methanol chamber  112 . The replenishment process is performed every time methanol is dispensed from the first methanol chamber  111  or second methanol chamber  112  to the cassette  20 . Note that the description of the methanol replenishment process for the first methanol chamber  111  is identical to the methanol replenishment process for the second methanol chamber  112 . 
         [0141]    When the liquid surface in the first methanol chamber  111  falls below the standard position (S 701 : YES), the controller  201  supplies fresh methanol to the first methanol chamber  111  from the bottle  101  (S 702 ). Methanol replenishment is thus started. 
         [0142]    When the methanol is replenished in the first methanol chamber  111  until the liquid surface attains the standard position (S 703 : YES), the replenishment process ends. On the other hand, when the methanol is not replenished in the first methanol chamber  111  until the liquid surface reaches the standard position (S 703 : NO), the controller  201  alerts the user to replace the bottle  101  by a methanol replenishment error (S 704 ). When a replenishment error is detected while washing a cassette, transporting of the cassette  20  and dispensing of methanol to the cassette  20  are suspended. 
         [0143]    Thereafter, the controller  201  awaits the replacement of the bottle  101  (S 705 ). When the error alert is received the user replaces the bottle  101  with a fresh bottle  101  and thereafter, when, for example, replacement completed input is entered from the screen of the operation display  2   a  (S 705 : YES), the controller  201  replenishes the first methanol chamber  111  with fresh methanol from the new bottle  101  (S 706 ). When the methanol is not replenished in the first methanol chamber  111  until the liquid surface reaches the standard position (S 707 : NO), the controller  201  alerts the user of a bottle replacement error (S 709 ), and the controller  201  awaits proper installation of the new bottle  101  (S 705 ). On the other hand, when the methanol is replenished in the first methanol chamber  111  until the liquid surface reaches the standard position (S 707 : YES), the controller  201  cancels the replenishment error (S 708 ), the process returns to S 701  and the next replenishment timing is awaited. When a replenishment error is canceled, transporting of the cassette  20  and dispensing of methanol to the cassette  20  are restarted. 
         [0144]      FIG. 16  shows an example of the washing process. 
         [0145]    As shown in  FIG. 16(   a ), while the methanol is being reused, the methanol is dispensed from the first methanol chamber  111  to the cassette  20  at position Mp, and methanol is recovered from the cassette  20  to the first methanol chamber  111  at position D 1   p . When the reuse counter Rk attains the threshold frequency R 0 , processes are started during replacement and methanol is dispensed from the second methanol chamber  112  to the cassette  20  at position Mp, and methanol is recovered from the cassette  20  to the first methanol chamber  111  at position D 1   p , as shown in  FIG. 16(   b ). At this time the is at most dl individual cassettes  20  present between the position Mp and the position D 1   p . This process is repeated until the recovery counter Ck attains the threshold frequency C 0 . During this time, when the methanol retained in the first methanol chamber  111  exceeds the standard position, the methanol is discharged from the first methanol chamber  111  as shown in  FIG. 16(   c ). 
         [0146]    Thereafter, when the recovery counter Ck attains the threshold frequency C 0 , the methanol is discharged from the first methanol chamber  111  as shown in  FIG. 16(   d ). At this time methanol from the second methanol chamber  112  is dispensed to the cassette  20  at position Mp. Thereafter, when methanol is replenished to the first methanol chamber  111  to the standard position as shown in  FIG. 16(   e ), the process is switched during reuse and the process using the first methanol chamber is restarted as shown in  FIG. 16(   f ). 
         [0147]    According to the present embodiment described above, washing of all cassettes  20  placed in the cassette receiver  47  is performed automatically by pressing the cassette wash start button  402  when the empty cassette  20  has been placed in the cassette receiver  47 . Therefore, the labor required to wash the cassette  20  is greatly reduced. 
         [0148]    According to the present embodiment, the cassette  20  washing process is skipped when a slide glass  10  is detected in the cassette  20  via the sensor  48   s  during the cassette washing process. Therefore, washing a cassette  20  without removing the slide glass after preparing the smear sample can be avoided even when the cassette  20  is placed in error in the cassette receiver  47 . 
         [0149]    According to the present embodiment, during the washing process the methanol dispensed to the cassette  20  is recovered through the recovery pipette D 1   b  and the methanol of the first methanol chamber  111  is reused. Thus, the consumption of methanol is reduce compared to when methanol is discarded with each washing. This also reduces the environmental burden. 
         [0150]    Although described in terms of the present embodiments, the present invention is not limited to these embodiments. 
         [0151]    For example, although a single slide glass  10  (smear sample) is accommodated in a single cassette  20  in the above embodiment, the present invention is not limited to this arrangement inasmuch as a plurality of slide glasses  10  (smear samples) also may be accommodated. 
         [0152]    Although another process cannot be performed while one of the smear sample preparation process (S 12 ) and cassette washing process (S 14 ) is being performed in the present embodiments, the present invention is not limited to this configuration inasmuch as another process may be performed through an interrupt while performing one process. For example, the smear sample preparation process may be performed through an interrupt even during an ongoing cassette washing process. In this case, a sample can be rapidly prepared when an urgent sample preparation is required during an ongoing cassette washing process. 
         [0153]    In the above embodiments, the process of replacing the first methanol chamber  111  is started when the methanol reuse frequency (reuse counter Rk) attains a preset frequency (threshold frequency R 0 ) while methanol is reused (S 107  of  FIG. 8 ). When the liquid surface of the first methanol chamber  111  is below a standard position while methanol is being reused, methanol is resupplied to the first methanol chamber  111  until the liquid surface attains the standard level (S 402  of  FIG. 12 ). However, the present invention is not limited to this configuration inasmuch as methanol replenishment need not be performed when the liquid surface of the first methanol chamber  111  is below the standard position while methanol is being reused. In this case, the process for replacing the first methanol chamber  111  may be performed based on the amount of remaining methanol in the first methanol chamber  111  and need not be performed in accordance with the methanol reuse frequency (reuse counter Rk). 
         [0154]    Although the connection of the flow passes shown in  FIG. 5  are switched by valves in the above embodiments, the present invention is not limited to this configuration inasmuch as syringe pumps may be respectively provided to the flow passes to switch the connections of the flow passes by switching the actuation of the syringe pumps. 
         [0155]    Although the methanol recovered from the cassette  20  through the recovery pipette D 1   b  is moved to the first methanol chamber  111  in the above embodiments, the present invention is not limited to this configuration inasmuch as the recovered methanol also may be moved to a chamber other than the first methanol chamber  111 . In this case, the methanol moved to another chamber also may be reused. The recovered methanol also may be recovered in the discard chamber  165  so as to be discharged from the smear sample preparation device  2 . 
         [0156]    Although dispensing and recovery of the methanol to/from the cassette  20  is performed once each in the cassette washing process of the above embodiments, the present invention is not limited to this configuration inasmuch as dispensing and recovery may be performed a plurality of times. The cassette  20  containing the methanol also may be shaken in the cassette washing process. Shaking the cassette  20  may be performed by, for example, moving the belt  50   b  forward and back, or changing the lateral height of the belt  50   b  via another mechanism. Methanol in the cassette  20  also may be caused to flow in the cassette washing process. The flow of the methanol may be induced by, for example, repeatedly dispensing and discharging the methanol in the cassette  20  via the recovery pipette D 1   b  at position D 1   p . This operation reliably washes the cassette  20 . 
         [0157]    Although methanol is used to fix the sample when washing the cassette  20  in the above embodiments, the present invention is not limited to this configuration inasmuch as a washing liquid other than methanol (for example, water) also may be used. Note that when was is used as the washing liquid, it is preferable to perform a process to dry the interior of the cassette  20  after the water is recovered from the cassette  20 . 
         [0158]    Although the cassette  20  is moved to the positions Mp and D 1   p  by the belt  50   b  in the above embodiments, the present invention is not limited to this configuration inasmuch as the dispensing and recovery of methanol also may be performed while the cassette  20  is positioned at a predetermined position. In this case, for example, a pipette for dispensing methanol and a pipette for recovering methanol may be moved to the position of the cassette  20  and dispensing and discharge of the methanol may be performed at that position. 
         [0159]    Although the same threshold frequency R 0  is used in the staining process and the washing process in the above embodiments, the present invention is not limited to this configuration inasmuch as different threshold frequencies also may be used. In this case, tolerance ranges can be set relative to the degrading of the reused methanol for both the staining process and the washing process, respectively. For example, a lower threshold frequency may be set for the washing process than for the staining process. In this case, the washing process is performed with less degraded methanol. 
         [0160]    Note that, in the above embodiments, when the washing operation is started after the staining operation, the incrementation by S 403  was made on the reuse counter Rk incremented in S 403  of  FIG. 10   b ). However, the present invention is not limited to this configuration inasmuch as the washing operation may be started after the methanol in the first methanol chamber  11  has been replaced with fresh methanol and the reuse counter Rk has been reset. 
         [0161]    Although the smear sample preparation process is performed when a user presses the sample preparation start button  401  ( FIG. 9(   a )) in the above embodiments, the present invention is not limited to this configuration inasmuch as the process also may be performed when the smear sample preparation device  2  receives a smear sample preparation instruction. For example, the clinical sample processing apparatus  1  of the above embodiment may be used as part of a sample processing system that includes a plurality of analyzers and a transport controller for controlling transport. In this case, the smear sample preparation process also may be performed when the controller  201  of the smear sample preparation device  2  receives a smear sample preparation instruction from the transport controller, or when the controller  201  receives a smear preparation instruction sent from the transport controller via the transport device  3 . 
         [0162]    Although the above embodiments are configured to display a sample preparation start button and a cassette wash start button as software keys on the display unit, these buttons also may be implemented as hardware keys on the device. 
         [0163]    The embodiments of the present invention may be variously and appropriately modified insofar as such modification is within the scope of the meaning expressed in the claims.