Patent Publication Number: US-2022221378-A1

Title: Sampling device

Description:
TECHNICAL FIELD 
     The present invention relates to a sampling apparatus for sampling a liquid in a container. 
     BACKGROUND ART 
     A technology has been known in which an analysis such as metabolome analysis is performed by culturing cells of microorganisms and plants in a culture medium in a culture vessel, collecting cells from the culture medium, performing pre-processing, and then supplying the cells to a liquid chromatograph mass spectrometer. In this kind of technology, a sampling apparatus for sampling a culture medium containing cells and a pre-processing apparatus for performing pre-processing on the cells contained in the sampled culture medium are used. The sampling of the culture medium is performed under an aseptic condition (refer to, for example, Patent Document 1 below). 
     As a method of sampling the culture medium, a method of feeding the culture medium to a flow path connected to the culture vessel using a liquid feeder, a method of inserting a needle into the culture vessel and sucking a required amount of the culture medium, and the like have been known. In the method of feeding the culture medium in the culture vessel to the flow path by using the liquid feeder, the culture medium is not exposed to the outside air, so that sampling can be performed while keeping the culture medium under an aseptic condition. On the other hand, in the method of inserting the needle into the culture vessel and sucking the culture medium, the needle is inserted into the culture vessel after a lid of the culture vessel is removed. Therefore, the culture medium in the culture vessel is exposed to the outside air, so that it is necessary to perform the sampling in a sterile room. 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: Japanese Patent Laid-Open No. 2012-200239 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     In the method of feeding the culture medium in the culture vessel to the flow path by using the liquid feeder, for example, a tubing pump is used as the liquid feeder. This type of liquid feeder can feed the liquid with a simple configuration by deforming (compressing and relaxing) a flexible tube, but there is a problem that it is difficult to sample the culture medium in an accurate amount. 
     On the other hand, in the method of inserting the needle into the culture vessel and sucking the culture medium, it is possible to perform the sampling by sucking the culture medium into the needle in an accurate amount. However, since it is necessary to provide a sterile room, there is a problem that the equipment becomes large and the configuration for operating the needle becomes complicated. 
     The above-described problems may occur not only in a case of sampling the culture medium but also in a case of sampling various liquids other than the culture medium from the inside of the container. 
     The invention has been made in view of the above circumstances, and an object of the invention is to provide a sampling apparatus capable of sampling an accurate amount of liquid with a simple configuration. 
     Means for Solving the Problems 
     (1) A sampling apparatus according to the invention is a sampling apparatus that samples a liquid in a container, and includes a circulation mechanism and a flow path switching unit. The circulation mechanism circulates the liquid in the container via a circulation flow path by leading out the liquid from the container into the circulation flow path and introducing the liquid from the circulation flow path into the container. The flow path switching unit is provided in the middle of the circulation flow path, and switches a flow path such that the liquid circulated in the circulation flow path flows out to a branch flow path to be sampled. 
     According to such a configuration, with a simple configuration in which the flow path is only switched by using the flow path switching unit while the liquid in the container is circulated in the circulation flow path, sampling can be performed by causing the liquid circulated in the circulation flow path to flow out to the branch flow path. When the flow path is switched by the flow path switching unit for a predetermined time in a state where the liquid is stably circulated in the circulation flow path, an accurate amount of liquid according to the time can be sampled. In addition, sampling can be performed at high speed by repeating the switching of the flow path by the flow path switching unit in a short time. 
     (2) The circulation mechanism may have a flexible tube constituting at least a part of the circulation flow path. In this case, the circulation mechanism may feed the liquid in the tube by deforming the tube. 
     According to such a configuration, the sampling of the liquid can be performed by using a simple configuration in which the flexible tube is deformed to feed the liquid. Further, when the inside of the tube becomes dirty or the like, maintenance can be performed easily and inexpensively simply by replacing the tube. 
     (3) The sampling apparatus may further include a control unit. The control unit controls a sampling amount of the liquid by controlling time for switching the flow path by the flow path switching unit. 
     According to such a configuration, the sampling amount of the liquid can be accurately controlled by accurately controlling the time for switching the flow path by the flow path switching unit, using the control unit. 
     (4) The control unit may collect the liquid into the container by causing the liquid in the circulation flow path to flow back after the liquid is sampled. 
     According to such a configuration, the liquid remaining in the circulation flow path can be collected into the container by causing the liquid in the circulation flow path to flow back after the liquid is sampled. Therefore, the amount of the liquid used in the container can be suppressed as compared with a case where the liquid remaining in the circulation flow path is drained as it is. 
     (5) The control unit may introduce a cleaning liquid into at least a part of the circulation flow path and drain the cleaning liquid after the liquid in the circulation flow path is collected into the container. 
     According to such a configuration, the liquid remaining in the circulation flow path is collected into the container after the liquid is sampled, and then the inside of the circulation flow path can be cleaned with the cleaning liquid. As a result, it is possible to reliably prevent the next sampling from being performed with the liquid remaining in the circulation flow path. 
     (6) The liquid in the container may be a culture medium containing cells. 
     According to such a configuration, it is possible to sample an accurate amount of culture medium with a simple configuration when sampling the culture medium containing cells. 
     Effects of the Invention 
     According to the invention, when the flow path is switched by the flow path switching unit for a predetermined time in a state where the liquid is stably circulated in the circulation flow path with a simple configuration in which the flow path is only switched by using the flow path switching unit while the liquid in the container is circulated in the circulation flow path, an accurate amount of liquid according to the time can be sampled. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a schematic configuration of an automatic pre-processing system including a sampling apparatus according to an embodiment of the invention. 
         FIG. 2  is a flow path diagram illustrating a flow path configuration of the sampling apparatus. 
         FIG. 3  is a block diagram illustrating an electrical configuration of the sampling apparatus. 
         FIG. 4A  is a flow path diagram for describing an operation of the sampling apparatus. 
         FIG. 4B  is a flow path diagram for describing the operation of the sampling apparatus. 
         FIG. 4C  is a flow path diagram for describing the operation of the sampling apparatus. 
         FIG. 4D  is a flow path diagram for describing the operation of the sampling apparatus. 
         FIG. 4E  is a flow path diagram for describing the operation of the sampling apparatus. 
         FIG. 4F  is a flow path diagram for describing the operation of the sampling apparatus. 
         FIG. 4G  is a flow path diagram for describing the operation of the sampling apparatus. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     1. Schematic Configuration of Automatic Pre-Processing System 
       FIG. 1  is a block diagram illustrating a schematic configuration of an automatic pre-processing system  10  including a sampling apparatus  1  according to an embodiment of the invention. The automatic pre-processing system  10  is a device for automatically performing pre-processing on an analysis target. In the present embodiment, the analysis target is, for example, a cultured cell, and more specifically, a bacterial cell. 
     The automatic pre-processing system  10  includes the sampling apparatus  1  and a pre-processing apparatus  2 . The metabolites of the cells are extracted from the cells after the pre-processing is performed by the automatic pre-processing system  10 , and are supplied to a liquid chromatograph mass spectrometer  3 . The liquid chromatograph mass spectrometer  3  is only an example of an analysis device for analyzing an analysis target, and it is also possible to perform an analysis by using another analysis device. 
     The sampling apparatus  1  is a apparatus for sampling a liquid from a container (culture container). For example, the cells of microorganisms and plants are cultured in a culture medium in a container called a bioreactor, and the culture medium containing the cells in the bioreactor is sampled by the sampling apparatus  1 . In the bioreactor, for example, a stirring member that is rotated by using magnetic force, an oxygen concentration sensor for detecting the concentration of dissolved oxygen, and the like are provided, and the cells are cultured in the sampling apparatus  1  by adjusting the dissolved oxygen concentration while stirring the culture medium in the bioreactor. 
     The pre-processing apparatus  2  performs pre-processing on the cells contained in the culture medium sampled from the bioreactor. In the sampling apparatus  1 , the culture medium containing the cells is housed in a test tube as a container (sampling container). The pre-processing apparatus  2  is provided with a centrifugation mechanism  4 , a liquid removal mechanism  5 , a reagent supply mechanism  6 , a stirring mechanism  7 , an extraction mechanism  8 , and the like, and by each of these mechanisms, the pre-processing is sequentially performed on the cells contained in the culture medium in the test tube. 
     The centrifugation mechanism  4  centrifuges the test tube in which the culture medium containing the cells is housed. As a result, centrifugal force is applied to the culture medium in the test tube, and the cells (solid) and the liquid other than the cells are separated. Then, the liquid other than the cells centrifuged in the test tube by the centrifugation mechanism  4  is removed by using the liquid removal mechanism  5 , and thereby the cells are collected. 
     The reagent is supplied by the reagent supply mechanism  6 , to the test tube after the liquid is removed by the liquid removal mechanism  5 . As a result, the reagent is mixed with the cells in the test tube, and a mixed solution is generated. Then, the mixed solution generated by the reagent supply mechanism  6  is stirred by the stirring mechanism  7 . 
     The reagent used in the present embodiment is a reagent for extracting metabolites in the cells, and a suspension in which the metabolites are extracted from the cells is obtained by stirring the mixed solution in which the reagent is mixed with the cells. Apart of the suspension obtained in this manner is extracted as an extraction liquid by the extraction mechanism  8 , and is supplied to the liquid chromatograph mass spectrometer  3 . 
     2. Flow Path Configuration of Sampling Apparatus 
       FIG. 2  is a flow path diagram illustrating a flow path configuration of the sampling apparatus  1 . In the sampling apparatus  1 , the culture medium containing the cells in the bioreactor  11  is sampled. A stirring member  111  that is rotated by using magnetic force is provided in the bioreactor  11 . 
     The bioreactor  11  is held by a holding unit  12  provided in the sampling apparatus  1 . In the present embodiment, one holding unit  12  can hold three bioreactors  11 , and a plurality of such holding units  12  are provided. However, a configuration in which one holding unit  12  is provided may be adopted, or a configuration in which one holding unit  12  can hold two or less or four or more bioreactors  11  may be adopted. 
     The bioreactor  11  can carry out the culture in a state of being heated by a heater (not illustrated) provided in the holding unit  12 . Further, a motor  13  for rotating a magnet (not illustrated) is connected to the holding unit  12 . The magnet is rotated by rotating the motor  13 , and the stirring member  111  in each bioreactor  11  can be rotated by the magnetic force thereof. 
     In the present embodiment, the culture medium can be stirred by the stirring member  111  to carry out the culture while controlling the temperature of the culture medium in the bioreactor  11 . Then, in the sampling apparatus  1 , the culture medium containing the cultured cells can be sampled in a test tube  14  at an arbitrary timing. 
     The sampling apparatus  1  is provided with a culture medium sampling mechanism  20  for sampling the culture medium in the test tube  14 , and a reagent sampling mechanism  30  for sampling the reagent in the test tube  14 . The test tube  14  houses the mixed solution in which the culture medium and the reagent are mixed with each other, is sealed by a cap (not illustrated), and is transferred to the pre-processing apparatus  2 . 
     The culture medium sampling mechanism  20  includes a pump  21  and a plurality of valves  22  and  23 . The valve  23  has, for example, one pair of common ports and five pairs of selection ports (10 selection ports in total), and any one pair of selection ports is arbitrarily selected to be connected to the one pair of common ports, so that the flow path can be switched. 
     The pump  21  and the valve  22  are provided in a flow path  41  connecting the one pair of common ports. The valve  22  constitutes a flow path switching unit (first flow path switching unit) for switching whether or not to guide the liquid in the flow path  41  to a branch flow path  42  that branches with respect to the flow path  41 . That is, the valve  22  can switch between a state in which the liquid flows between the one pair of common ports via the flow path  41  and a state in which the liquid in the flow path  41  is guided to the branch flow path  42 . 
     Among the five pairs of selection ports, one pair of selection ports is connected to a lead-out path  43  and an introduction path  44  that communicate with one bioreactor  11 , respectively. The lead-out path  43  is a flow path for leading out the culture medium in the bioreactor  11 . On the other hand, the introduction path  44  is a flow path for introducing the culture medium, which has been led out from the bioreactor  11  via the lead-out path  43  and has been circulated through the flow path  41 , into the bioreactor  11  again. Further, another pair of selection ports is connected to a lead-out path  45  and an introduction path  46  that communicate with another bioreactor  11 , respectively. Still another pair of selection ports is connected to a lead-out path  47  and an introduction path  48  that communicate with still another bioreactor  11 . 
     In the present embodiment, one of the lead-out paths  43 ,  45 , and  47  and the corresponding one of the introduction paths  44 ,  46 , and  48  are caused to communicate with each other via the flow path  41 , and the pump  21  is driven in that state, so that the culture medium in each bioreactor  11  can be circulated. That is, the flow path  41 , each of the lead-out paths  43 ,  45 , and  47 , and each of the introduction paths  44 ,  46 , and  48  constitute a circulation flow path (first circulation flow path) for circulating the culture medium in each bioreactor  11 . The pump  21  constitutes a circulation mechanism (first circulation mechanism) for circulating the culture medium in each bioreactor  11  via the first circulation flow path by leading out the culture medium from each bioreactor  11  into the first circulation flow path and also introducing the culture medium into each bioreactor  11  from the first circulation flow path. 
     The tip end of each of the lead-out paths  43 ,  45 , and  47  is immersed in the culture medium in the corresponding bioreactor  11 . On the other hand, the tip end of each of the introduction paths  44 ,  46 , and  48  is located at a position separated upward from the culture medium in the corresponding bioreactor  11 . Therefore, the culture medium that is led out from the bioreactor  11  via each of the lead-out paths  43 ,  45 , and  47  and is circulated through the flow path  41  falls from the tip end of each of the introduction paths  44 ,  46 , and  48  to be introduced into the bioreactor  11 . 
     In the present embodiment, in the flow path  41  connecting the one pair of common ports, at least a portion where the pump  21  is provided is composed of a flexible tube. The pump  21  is, for example, a tubing pump, and can feed the liquid in the flexible tube by deforming (compressing and relaxing) the tube. 
     When the valve  22  as the first flow path switching unit provided in the middle of the flow path  41  is switched, the culture medium circulated in each bioreactor  11  via the flow path  41  can flow out to the branch flow path  42 . At this time, the tip end of the branch flow path  42  is arranged in the test tube  14 , and the culture medium is sampled in the test tube  14  via the branch flow path  42 . 
     Of the two pairs of selection ports other than the three pairs of selection ports to which the lead-out paths  43 ,  45 , and  47  and the introduction paths  44 ,  46 , and  48  are connected, one pair of selection ports is connected to a cleaning liquid tank  26  and a waste liquid tank  27 . Further, the remaining one pair of selection ports is connected to a filter  25  and the waste liquid tank  27 , respectively. A cleaning liquid for cleaning the flow path for the culture medium is housed in the cleaning liquid tank  26 . 
     After the culture medium is sampled in the test tube  14  from any of the bioreactors  11 , when the valve  23  is switched to connect the cleaning liquid tank  26  and the waste liquid tank  27  to the flow path  41  and the pump  21  is driven in that state, the cleaning liquid in the cleaning liquid tank  26  is drained into the waste liquid tank  27  via the flow path  41 . As a result, the flow path  41 , the valve  22  provided in the flow path  41 , and the like can be cleaned with the cleaning liquid. 
     Further, after the cleaning with the cleaning liquid, when the valve  23  is switched to connect the filter  25  and the waste liquid tank  27  to the flow path  41  and the pump  21  is driven in that state, air is introduced into the flow path  41  through the filter  25 , and is discharged into the waste liquid tank  27  together with the water remaining in the flow path  41 . As a result, water can be removed from the flow path  41 , the valve  22  provided in the flow path  41 , and the like. 
     The reagent sampling mechanism  30  includes a pump  31  and a plurality of valves  32  and  33 . The valve  33  has, for example, one common port and a plurality of selection ports, and any one of the selection ports is arbitrarily selected to be connected to the common port, so that the flow path can be switched. 
     The pump  31  and the valve  32  are provided in a flow path  49  of which both ends communicate with a reagent tank  34 . A reagent to be mixed with the sampled culture medium in the test tube  14  is housed in the reagent tank  34 . The flow path  49  constitutes a circulation flow path (second circulation flow path) for circulating the reagent in the reagent tank  34 . The pump  31  constitutes a circulation mechanism (second circulation mechanism) for circulating the reagent in the reagent tank  34  via the second circulation flow path by leading out the reagent from the reagent tank  34  into the second circulation flow path and also introducing the reagent into the reagent tank  34  from the second circulation flow path. 
     In the present embodiment, in the flow path  49  of which the both ends are connected to the reagent tank  34 , at least a portion where the pump  31  is provided is composed of a flexible tube. The pump  31  is, for example, a tubing pump, and can feed the reagent in the flexible tube by deforming (compressing and relaxing) the tube. 
     The valve  32  constitutes a flow path switching unit (second flow path switching unit) for switching whether or not to guide the liquid in the flow path  49  to a branch flow path  50  that branches with respect to the flow path  49 . That is, the valve  32  can switch between a state in which the reagent in the reagent tank  34  is circulated via the flow path  49  and a state in which the reagent in the flow path  49  is guided to the branch flow path  50 . 
     In this way, when the valve  32  as the second flow path switching unit provided in the middle of the flow path  49  is switched, the reagent circulated in the reagent tank  34  via the flow path  49  can flow out to the branch flow path  50 . The branch flow path  50  is connected to the common port of the valve  33 , and one of the selection ports of the valve  33  is connected to the inside of the test tube  14 . Therefore, when the selection port connected to the inside of the test tube  14  is caused to communicate with the common port, the reagent flowing out from the flow path  49  to the branch flow path  50  can be sampled in the test tube  14 . 
     3. Electrical Configuration of Sampling Apparatus 
       FIG. 3  is a block diagram illustrating an electrical configuration of the sampling apparatus  1 . The sampling apparatus  1  includes a control unit  60 , a storage unit  70 , and the like in addition to the motor  13 , the pumps  21  and  31 , and the valves  22 ,  23 ,  32 , and  33  described above. 
     The control unit  60  includes, for example, a central processing unit (CPU), and the CPU executes a control program to control the operation of the motor  13 , the pumps  21  and  31 , the valves  22 ,  23 ,  32 , and  33 , and the like. The storage unit  70  is composed of, for example, a read only memory (ROM) and a random access memory (RAM), and can store various kinds of data in addition to the above-described control program. 
     The control unit  60  can circulate the culture medium in any of the bioreactors  11  by driving the pump  21  at a constant liquid feeding speed in a state where one of the lead-out paths  43 ,  45 , and  47  and the corresponding one of the introduction paths  44 ,  46 , and  48  communicate with each other via the flow path  41 . The control unit  60  samples the culture medium in the flow path  41 , in the test tube  14  by switching the valve  22  for a predetermined time based on the control program to cause the flow path  41  to communicate with the branch flow path  42 . 
     At this time, the control unit  60  can control the sampling amount of the culture medium by controlling the time for switching the flow path by the valve  22 . That is, when the liquid feeding speed of the pump  21  is known in advance, a desired amount of culture medium can be accurately sampled in the test tube  14  by adjusting the time for which the flow path  41  communicates with the branch flow path  42 . 
     The control unit  60  can circulate the reagent in the reagent tank  34  by driving the pump  31  at a constant liquid feeding speed in a state where one end of the flow path  49  communicates with the other end thereof. The control unit  60  samples the reagent in the flow path  49  in the test tube  14  by switching the valve  32  for a predetermined time based on the control program to cause the flow path  49  to communicate with the branch flow path  50  and switching the valve  33  to cause the branch flow path  50  to communicate with the test tube  14 . 
     At this time, the control unit  60  can control the sampling amount of the reagent by controlling the time for switching the flow path by the valve  32 . That is, when the liquid feeding speed of the pump  31  is known in advance, a desired amount of reagent can be accurately sampled in the test tube  14  by adjusting the time for which the flow path  49  communicates with the branch flow path  50 . 
     4. Operation of Sampling Apparatus 
       FIGS. 4A to 4G  are flow path diagrams for describing the operation of the sampling apparatus  1 . In  FIGS. 4A to 4G , the flow path illustrated by the solid line illustrates a state in which liquid (culture medium, cleaning liquid, or reagent), gas (air), or the like is flowing, and the flow path illustrated by the broken line illustrates a state in which liquid or gas is not flowing. 
     In the state illustrated in  FIG. 4A , the lead-out path  43  and the introduction path  44  that communicate with one bioreactor  11  communicate with each other via the flow path  41 . By driving the pump  21  in this state, the culture medium in the bioreactor  11  is circulated. At this time, one end of the flow path  49  for the reagent communicates with the other end thereof, and the pump  31  is driven, so that the reagent in the reagent tank  34  is circulated. 
     In a case where the valve  23  is switched as illustrated in  FIG. 4B , the lead-out path  45  and the introduction path  46  that communicate with another bioreactor  11  communicate with each other via the flow path  41 , and the pump  21  is driven in this state to circulate the culture medium in the corresponding bioreactor  11 . In a case where the valve  23  is switched as illustrated in  FIG. 4C , the lead-out path  47  and the introduction path  48  that communicate with still another bioreactor  11  communicate with each other via the flow path  41 , and the pump  21  is driven in this state to circulate the culture medium in the corresponding bioreactor  11 . 
     When the valve  22  is switched from any of the states illustrated in  FIGS. 4A to 4C  to connect the flow path  41  and the branch flow path  42 , the culture medium circulated in the flow path  41  flows out to the branch flow path  42  to be sampled in the test tube  14 . For example, as illustrated in  FIG. 4D , when the valve  22  is switched from the state illustrated in  FIG. 4A , the culture medium circulated through the lead-out path  43 , the flow path  41 , and the introduction path  44  is sampled in the test tube  14  via the branch flow path  42 . 
     At this time, as illustrated in  FIG. 4D , the valves  32  and  33  are also switched so that the flow path  49  communicates with the test tube  14  via the branch flow path  50 . As a result, the reagent circulated in the flow path  49  can be sampled in the test tube  14  in which the culture medium is sampled. 
     When the sampling of the culture medium and the reagent is completed, as illustrated in  FIG. 4E , the valve  22  is switched to return to the state in which the lead-out path  43  and the introduction path  44  communicate with each other through the flow path  41 . Further, the valve  32  is switched to return to the state in which the one end of the flow path  49  for the reagent communicates with the other end thereof. In this state, the pump  21  is driven to cause the liquid in the flow path  41  to flow back. As a result, the culture medium remaining in the flow path  41 , the lead-out path  43 , and the introduction path  44  flows back and is collected in the bioreactor  11 . 
     After that, as illustrated in  FIG. 4F , the valve  23  is switched so that the cleaning liquid tank  26  and the waste liquid tank  27  communicate with each other via the flow path  41 . When the pump  21  is driven in this state, the cleaning liquid in the cleaning liquid tank  26  is introduced into the flow path  41  and is drained into the waste liquid tank  27 . 
     After that, as illustrated in  FIG. 4G , the valve  23  is switched so that the filter  25  and the waste liquid tank  27  communicate with each other via the flow path  41 . When the pump  21  is driven in this state, air is introduced into the flow path  41  via the filter  25 , and is discharged to the waste liquid tank  27  together with the water remaining in the flow path  41 . 
     5. Effects 
     (1) In the present embodiment, with a simple configuration in which the flow path is only switched by using the valves  22  and  32  while the culture medium in the bioreactor  11  and the reagent in the reagent tank  34  are circulated in the flow paths  41  and  49 , sampling can be performed by causing the liquid (culture medium or reagent) circulated in the flow paths  41  and  49  to flow out to the branch flow paths  42  and  50 . When the flow paths are switched by the valves  22  and  32  for a predetermined time in a state where the liquid is stably circulated in the flow paths  41  and  49 , an accurate amount of liquid according to the time can be sampled. In addition, sampling can be performed at high speed by repeating the switching of the flow paths by the valves  22  and  32  in a short time. 
     (2) In the present embodiment, the liquid (culture medium or reagent) can be sampled by using the pumps  21  and  31  with a simple configuration in which flexible tubes constituting at least a part of the flow paths  41  and  49  are deformed to feed the liquid. Further, when the inside of the tube becomes dirty or the like, maintenance can be performed easily and inexpensively simply by replacing the tube. 
     (3) In the present embodiment, the sampling amount of the liquid (culture medium or reagent) can be accurately controlled by accurately controlling the time for switching the flow paths by the valves  22  and  32 , using the control unit  60 . 
     (4) In the present embodiment, as illustrated in  FIG. 4E , the culture medium remaining in the flow path  41  can be collected into the bioreactor  11  by causing the culture medium in the flow path  41  to flow back after the culture medium is sampled. Therefore, the amount of the culture medium used in the bioreactor  11  can be suppressed as compared with a case where the culture medium remaining in the flow path  41  is drained as it is. 
     (5) In the present embodiment, the culture medium remaining in the flow path  41  is collected into the bioreactor  11  after the culture medium is sampled, and then the inside of the flow path  41  can be cleaned with the cleaning liquid as illustrated in  FIG. 4F . As a result, it is possible to reliably prevent the next sampling from being performed with the culture medium remaining in the flow path  41 . 
     6. Modification Example 
     In the above embodiment, the case where the liquid sampled by the sampling apparatus  1  is a culture medium or a reagent has been described. However, without being limited to such a configuration, the sampling apparatus  1  according to the invention can be applied when any other liquid is sampled. 
     Further, the valves  22 ,  23 ,  32 , and  33  are not limited to the configuration in which the valves  22 ,  23 ,  32 , and  33  are automatically switched by the control unit  60 , and may be configured to be manually switched by an operator. Similarly, the pumps  21  and  31  are not limited to the configuration in which the operation thereof is automatically started by the control unit  60 , and may be configured such that the operation thereof is started based on an operation of the operator. 
     The circulation mechanism for circulating the liquid is not limited to the tubing pump such as the pumps  21  and  31  in the present embodiment, and the liquid can be circulated by using any other pump. Further, as long as the liquid can be circulated continuously and stably, without being limited to the configuration using the pump, a configuration using any other member may be adopted. 
     The sampling apparatus  1  is not limited to the configuration in which cells are cultured in the bioreactor  11  installed inside the sampling apparatus  1 , and may be configured such that cells cultured externally are set in the sampling apparatus  1 . 
     DESCRIPTION OF REFERENCE SIGNS 
     
         
           1  sampling apparatus 
           2  pre-processing apparatus 
           3  liquid chromatograph mass spectrometer 
           4  centrifugation mechanism 
           5  liquid removal mechanism 
           6  reagent supply mechanism 
           7  stirring mechanism 
           8  extraction mechanism 
           10  automatic pre-processing system 
           11  bioreactor 
           14  test tube 
           20  culture medium sampling mechanism 
           21  pump 
           22  valve 
           23  valve 
           25  filter 
           30  reagent sampling mechanism 
           31  pump 
           32  valve 
           33  valve 
           34  reagent tank 
           41  flow path 
           42  branch flow path 
           49  flow path 
           50  branch flow path