BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a solution temperature control device in a cell observation chamber, and specifically to a solution temperature control device in a cell observation chamber adapted to control solutions in the cell observation chamber to be a predetermined temperature in an apparatus used for: for example, determining whether or not cells move in a certain direction by themselves; observing a state where cells move in a certain direction by themselves; measuring the number of cells that have moved in a certain direction by themselves; and isolating cells that move in a certain direction by themselves, that is, an apparatus for detecting cell chemotaxis and for isolating chemotactic cells, and thereby to improve the accuracy of these operations.  
         [0003]     2. Description of the Prior Art  
         [0004]     There have conventionally been proposed and marketed various kinds of apparatuses for detecting cell chemotaxis and for isolating chemotactic cells. In particular, there has been proposed an apparatus, as described in Japanese Patent Laid-Open Publication No. 2002-159287, adapted to be capable of observing and quantitating the self-based movement of cells precisely and easily using a few cell samples to detect the chemotaxis of the cells due to chemotactic factor or the chemotaxis inhibition of the cells due to chemotactic factor inhibitor. In this apparatus, it is also possible to isolate the cells utilizing the chemotaxis of the cells.  
         [0005]     In the apparatus for detecting cell chemotaxis and for isolating chemotactic cells described in the foregoing publication, a cell observation chamber is arranged as follows.  
         [0006]     As shown in  FIG. 16 , the cell observation chamber  00  comprises: a circular shallow dish-shaped bottom support body  01  with a window  01   c  for observing the movement of cells provided in the center of the bottom part thereof, a glass substrate  08  adapted to be placed on the bottom part  01   a  of the bottom support body  01 ; a dish-shaped intermediate support body  02  adapted to be attached to the bottom support body  01  to press and fix the glass substrate  08  from above onto the bottom part  01   a  by connecting a cover  04  to be described hereinafter to the bottom support body  01  with screws; a substrate  07  and a packing member  010  adapted to be fitted into a rectangular opening portion  02   c  that is formed in the center of the bottom part of the intermediate support body  02  to be fixed onto the glass substrate  08 ; a block body  09  adapted to be fitted into the central recessed portion of the intermediate support body  02  to press and fix the substrate  07  onto the glass substrate  08  through the packing member  010  using pressing screws not shown in the figure; and a cover  04  adapted to be attached to the bottom support body  01  through a screw connection to press and fix the block body  09  from above to the intermediate support body  02 . The substrate  07  is made of silicon single-crystal material.  
         [0007]     The connection between the bottom support body  01  and the intermediate support body  02  is to be made by screwing a male thread  02   d  formed in the outer peripheral surface of the body part of the intermediate support body  02  into a female thread  01   d  formed in the inner peripheral surface of the body part of the bottom support body  01  and by a screw connection between the bottom support body  01  and the cover  04 . The screw connection between the bottom support body  01  and the cover  04  is to be made by screwing a male thread  01   e  formed in the outer peripheral surface of the bottom support body  01  into a female thread  04   a  formed in the inner peripheral surface of the sleeve part of the cover  04 . The intermediate support body  02  is to be positioned on the bottom support body  01  by inserting guide pins (not shown in the figure) disposed on the upper surface of the body part of the bottom support body  01  into guide pin receiving holes  02   f  formed in the lower surface of the flange part  02   b  of the intermediate support body  02 . Also, the block body  09  is to be positioned in the intermediate support body  02  by inserting guide pins  013  disposed on the bottom surface of the intermediate support body  02  into guide pin receiving holes  09   a  formed in the bottom surface of the block body  09 .  
         [0008]     Then, in a state where the above components are assembled integrally and used, at least a pair of wells and a flow path for communicating of these wells are to be formed between the substrate  07  and the glass substrate  08 . One of these wells is to be provided with cell suspension, while the other thereof is to be provided with chemotactic factor containing solution, so that cells move from one to the other of the wells through the flow path in response to the chemotactic factor. A microscopic observation is to be carried out through the window  01   c  to observe the state and to measure the number of moving cells.  
         [0009]     The injection of cell suspension and chemotactic factor containing solution into one and the other wells that are formed between the substrate  07  and the glass substrate  08  is to be performed using a micropipette through specialized through holes formed, respectively, in the block body  09 , the packing member  010 , and the substrate  07 . After assembling the bottom support body  01 , the intermediate support body  02 , and the cover  04 , an O-ring  011  is to be interposed between the intermediate support body  02  and the glass substrate  08  so that no solution filling the bottom support body  01  leaks. On the other hand, the packing member  010  is also provided between the substrate  07  and the block body  09  so as to be useful in preventing each solution from leaking from the wells and the flow path for communicating of the wells.  
         [0010]     Meanwhile, in order to observe the state of cells that move from one to the other of the wells through the flow path and to measure the number of moving cells precisely, it is necessary to control the temperature of the cell suspension and the chemotactic factor containing solution or the mixture containing these solutions filling these sections so as to be suitable for the activity of the cells. Also when it is demanded that the reaction of the cells due to temperature change be measured and analyzed more precisely, it is necessary to control the temperature of the solutions. For these reasons, in this apparatus, the cell observation chamber  00  is adapted to be placed on a heating section composed of heating elements not shown in the figure, and a temperature control device is used to heat these solutions indirectly through the wall of the bottom support body  01  to control these solutions to be a desired temperature while controlling the heating section to be a predetermined temperature.  
         [0011]     Since the conventional cell observation chamber is thus arranged in such a manner that the solutions filling the wells and the flow path for communicating of the wells in the cell observation chamber  00  are heated from outside the cell observation chamber  00 , for example, indirectly through the wall of the bottom support body  01 , and that a temperature sensor is installed outside the chamber, it is not easy to keep the solutions at a desired constant temperature, which makes it inadequate to say that the accuracy in controlling the temperature of the solutions is sufficiently given.  
         [0012]     Patent Document 1: Japanese Patent Laid-Open Publication No. 2002-159287  
         [0013]     Patent Document 2: Japanese Patent Laid-Open Publication No. 2003-088357  
       SUMMARY OF THE INVENTION  
       [0014]     The present invention has been made to solve the above-described problems of the solution temperature control device in the conventional cell observation chamber, and an object thereof is to provide a solution temperature control device in a cell observation chamber whereby it is easy to keep solutions in the cell observation chamber at a desired constant temperature as well as it is possible to improve the accuracy in controlling the temperature of the solutions and thereby the accuracy of operations such as detecting and measuring cell chemotaxis and isolating chemotactic cells.  
         [0015]     In accordance with the present invention, the foregoing object can be achieved with the following solution temperature control device in the cell observation chamber.  
         [0016]     That is, the solution temperature control device in the cell observation chamber is adapted to be used in an apparatus for detecting cell chemotaxis and for isolating chemotactic cells, the chamber comprising: a dish-shaped bottom support body with a window for observing the movement of cells provided in the center of the bottom part thereof, a glass substrate adapted to be placed on the bottom surface of the bottom support body; a dish-shaped intermediate support body with an opening portion formed in the center of the bottom part thereof, the intermediate support body being adapted to be attached to the bottom support body to press and fix the glass substrate from above onto the bottom surface of the bottom support body; a substrate with a plurality of through holes for guiding cell suspension and chemotactic factor containing solution therethrough formed therein in a vertically penetrating manner, the substrate being adapted to be fixed onto the surface in the central part of the glass substrate, in which a concavo-convex shape is formed in the surface facing the glass substrate to form at least a pair of wells and a flow path for communicating of the wells with the glass substrate; a packing member with a plurality of through holes for guiding the cell suspension and the chemotactic factor containing solution therethrough formed therein in a vertically penetrating manner, the packing member being adapted to be fitted into the opening portion that is formed in the center of the bottom part of the intermediate support body to press the substrate from above; a dish-shaped cover block body with a plurality of through holes for guiding the cell suspension and the chemotactic factor containing solution therethrough formed in the center of the bottom part thereof in a vertically penetrating manner, the cover block body being adapted to be attached to the bottom support body with the intermediate support body attached thereto to press and fix the substrate from above onto the glass substrate through the packing member; and the solution temperature control device for controlling the solutions filling the pair of wells and the flow path to be a predetermined temperature, wherein one of the pair of wells is adapted to be provided or given with the cell suspension through each one of the plurality of through holes that are formed, respectively, in the cover block body, the packing member, and the substrate, while the other of the wells is adapted to be provided or given with the chemotactic factor containing solution through each one of the plurality of through holes that are formed, respectively, in the cover block body, the packing member, and the substrate, so that a state where cells move from one to the other of the wells through the flow path can be observed and the number of the cells can be measured through the window provided in the bottom support body while keeping the solutions or the mixture containing the solutions at a predetermined temperature, and wherein the solution temperature control device comprises: a first temperature controller for measuring the temperature of the solutions filling the pair of wells and the flow path and for controlling the solutions to be a predetermined temperature; and a second temperature controller for measuring the temperature of a heating section that heats the cell observation chamber from outside, thereby indirectly heats the solutions filling the pair of wells and the flow path, and for controlling the heating section to be a predetermined preheating temperature.  
         [0017]     The solution temperature control device in the cell observation chamber is arranged as mentioned above and comprises the first temperature controller and the second temperature controller, the first temperature controller being adapted to measure the temperature of the solutions filling the pair of wells and the flow path and to control the solutions to be a predetermined temperature, and the second temperature controller being adapted to measure the temperature of the heating section that heats the cell observation chamber from outside, thereby indirectly heats the solutions filling the pair of wells and the flow path, and to control the heating section to be a predetermined preheating temperature, whereby after placing the cell observation chamber on the heating section that has been controlled to be the predetermined preheating temperature by the second temperature controller, it is possible to control and keep the solutions filling the pair of wells and the flow path in the cell observation chamber at the predetermined temperature while measuring the temperature thereof using the first temperature controller, which therefore makes it possible to shorten the time required to control the solutions in the cell observation chamber to be a desired constant temperature, resulting in a dramatic improvement in the accuracy in controlling the temperature.  
         [0018]     In a preferred embodiment, the first temperature controller comprises a temperature sensor for measuring the temperature of the solutions filling the pair of wells and the flow path, the temperature sensor being attached detachably to the cell observation chamber, and the temperature sensing part thereof being immersed in solution in a liquid storage chamber formed in the cell observation chamber, and the liquid storage chamber is provided in an isolated position where the solution therein can receive the indirect heating by the heating section equally with the solutions filling the pair of wells and the flow path.  
         [0019]     Since this causes the temperature of the solution in the liquid storage chamber to be increased in a similar manner as that of the solutions filling the pair of wells and the flow path, the temperature sensing part of the temperature sensor provided in the first temperature controller can measure the temperature of the solutions containing cells and filling the pair of wells and the flow path precisely without contaminating the solutions. Also, the attachment/detachment of the temperature sensor, which is attached detachably to the cell observation chamber, can be carried out easily, and the sensor cannot get in the way of assembling/disassembling the cell observation chamber if detached therefrom, which makes it possible to carry out the assembling/disassembling operation smoothly.  
         [0020]     In another preferred embodiment, the second temperature controller has a function of preventing the heating section from being overheated. Accordingly, it is possible to prevent cells from being dead and the functions of sample solution such as chemotactic factor containing solution from being damaged as well as to prevent the cell observation chamber from being damaged due to overheating. It is also possible to prevent the heating section from being overheated reliably even if there may poor contact between the heating section and the cell observation chamber.  
         [0021]     In addition, another solution temperature control device in another cell observation chamber is adapted to be used in an apparatus for detecting cell chemotaxis and for isolating chemotactic cells, the chamber comprising the following means, that is: a dish-shaped bottom support body with a window for observing the movement of cells provided in the center of the bottom part thereof, a glass substrate adapted to be placed on the bottom surface of the bottom support body; a dish-shaped intermediate support body with an opening portion formed in the center of the bottom part thereof, the intermediate support body being adapted to be attached to the bottom support body to press and fix the glass substrate from above onto the bottom surface of the bottom support body; a substrate with a plurality of through holes for guiding cell suspension and chemotactic factor containing solution therethrough formed therein in a vertically penetrating manner, the substrate being adapted to be fixed onto the surface in the central part of the glass substrate, in which a concavo-convex shape is formed in the surface facing the glass substrate to form at least a pair of wells and a flow path for communicating of the wells with the glass substrate; a packing member with a plurality of through holes for guiding the cell suspension and the chemotactic factor containing solution therethrough formed therein in a vertically penetrating manner, the packing member being adapted to be fitted into the opening portion that is formed in the center of the bottom part of the intermediate support body to press the substrate from above; a dish-shaped cover block body with a plurality of through holes for guiding the cell suspension and the chemotactic factor containing solution therethrough formed in the center of the bottom part thereof in a vertically penetrating manner, the cover block body being adapted to be attached to the bottom support body with the intermediate support body attached thereto to press and fix the substrate from above onto the glass substrate through the packing member; and the solution temperature control device for controlling the solutions filling the pair of wells and the flow path to be a predetermined temperature. Then, one of the pair of wells is adapted to be provided or given with the cell suspension through each one of the plurality of through holes that are formed, respectively, in the cover block body, the packing member, and the substrate, while the other of the wells is adapted to be provided or given with the chemotactic factor containing solution through each one of the plurality of through holes that are formed, respectively, in the cover block body, the packing member, and the substrate, so that a state where cells move from one to the other of the wells through the flow path can be observed and the number of the cells can be measured through the window provided in the bottom support body while keeping the solutions or the mixture containing the solutions at a predetermined temperature. Further, the solution temperature control device comprises a temperature sensor for measuring the temperature of the solutions filling the pair of wells and the flow path, the temperature sensor being attached detachably to the cell observation chamber, and the temperature sensing part thereof being immersed in solution in a liquid storage chamber formed in the cell observation chamber, and the liquid storage chamber is provided in an isolated position where the solution therein can receive the indirect heating by the heating section equally with the solutions filling the pair of wells and the flow path.  
         [0022]     The another solution temperature control device in the another cell observation chamber is arranged as mentioned above and comprises the temperature sensor for measuring the temperature of the solutions filling the pair of wells and the flow path, the temperature sensor being attached detachably to the cell observation chamber, and the temperature sensing part thereof being immersed in solution in the liquid storage chamber formed in the cell observation chamber, and the liquid storage chamber is provided in an isolated position where the solution therein can receive the indirect heating by the heating section equally with the solutions filling the pair of wells and the flow path, whereby it is possible to increase the temperature of the solution in the liquid storage chamber in a similar manner as that of the solutions filling the pair of wells and the flow path, and the temperature sensing part of the temperature sensor provided in the first temperature controller can measure the temperature of the solutions containing cells and filling the pair of wells and the flow path precisely without contaminating the solutions. Also, the attachment/detachment of the temperature sensor, which is attached detachably to the cell observation chamber, can be carried out easily, and the sensor cannot get in the way of assembling/disassembling the cell observation chamber if detached therefrom, which makes it possible to carry out the assembling/disassembling operation smoothly.  
         [0023]     As described heretofore, in accordance with the present invention, it is possible to shorten the time required to control the solutions in the cell observation chamber to be a desired constant temperature, resulting in a dramatic improvement in the accuracy in controlling the temperature of the solutions. Also, the temperature sensing part of the temperature sensor provided in the first temperature controller can measure the temperature of the solutions containing cells and filling the pair of wells and the flow path precisely without contaminating the solutions. In addition, it is possible to prevent the heating section from being overheated, and therefore it is possible to reliably prevent cells from being dead, the functions of sample solutions (e.g. cell suspension and chemotactic factor containing solution) from being damaged, and the cell observation chamber from being damaged due to overheating of the heating section. Further, the attachment/detachment of the temperature sensor can be carried out easily, and the sensor cannot get in the way of assembling/disassembling the cell observation chamber if detached therefrom, which makes it possible to carry out the assembling/disassembling operation smoothly. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     In order to control the temperature of solutions in a cell observation chamber, it is arranged that a first temperature controller and a second temperature controller are used, the first temperature controller being adapted to measure the temperature of solutions filling a pair of wells and a flow path in the cell observation chamber and to control the solutions to be a predetermined temperature, and the second temperature controller being adapted to measure the temperature of a heating section that heats the cell observation chamber from outside, thereby indirectly heats the solutions filling the pair of wells and the flow path, and to control the heating section to be a predetermined preheating temperature. It is then arranged that a state where cells move from one to the other of the wells through the flow path can be observed and the number of the cells can be measured while keeping the solutions filling the pair of wells and the flow path at the predetermined temperature precisely.  
         [0025]     In addition, it is arranged that a temperature sensing part of a temperature sensor provided in the first temperature controller is attached detachably to the cell observation chamber and immersed in solution in a liquid storage chamber formed in the cell observation chamber to measure the temperature of the solution in the liquid storage chamber. It is also arranged that the liquid storage chamber is provided in an isolated position where the solution therein can receive the indirect heating by the heating section equally with the solutions filling the pair of wells and the flow path. It is further arranged that the second temperature controller has a function of preventing the heating section from being overheated.  
         [0026]     Next will be described an embodiment of the present invention.  
         [0027]     The principle of the operation of an apparatus for detecting cell chemotaxis and for isolating chemotactic cells to which the present invention is applied will first be described. In this apparatus for detecting cell chemotaxis and for isolating chemotactic cells, a plurality of wells are connected and communicate with each other through a flow path, in each well being provided two pipes: one is for injecting or removing samples, and the other is for preventing the pressure in the well from increasing or decreasing due to the operation of injecting or removing the samples. These pipes may be formed by through holes formed in a block. It is here noted that the flow path is a part for communicating of two wells, that is, a channel through which cells pass when moving from one to the other of the wells. In accordance with the apparatus, since the liquid flow toward the opposite wells in the flow path is unlikely to occur when injecting or removing samples, there is no possibility that the liquid in the wells provided on both ends of the flow path intermingles with each other, whereby it is possible to detect the case where cells mainly move based only on the effect of chemotactic factor.  
         [0028]     To describe the principle based on the accompanying drawings, in  FIGS. 1 and 2 , the numeral  1  indicates a flow path, and the numeral  2  indicates wells for storing samples such as cell suspension and specimen solution, consisting of a pair of wells  2 A and  2 B. These samples are provided or removed to/from the wells  2  through the through holes  3  formed in the block body  9  using a micropipette, etc. When one well  2 A of the wells  2  is provided with the cell suspension, cells try to move toward the other well  2 B and pass through the flow path  1  if the specimen solution put in the well  2 B contains chemotactic factor (chemotactic factor containing solution).  
         [0029]     When providing the cell suspension, one sample, to the well  2 A through the through hole  3  using a micropipette, etc., there is a possibility that cells move toward the well  2 B provided on the opposite side through the flow path  1  due to the pressure of the liquid injected. This situation, if occurred, causes confusion about determining whether or not the movement of the cells is due to the chemotactic factor contained in the specimen, and in the case of aiming at isolating cells, causes desired cells to intermingle with other cells, which makes it impossible to achieve the purpose. In order to solve the problem, this apparatus is arranged in such a manner that an injection pressure to be applied to the through hole  3  is released toward the through hole  4  to prevent cells from being flowed forcibly toward the flow path  1 .  
         [0030]     Also, when providing the specimen solution to the well  2 B through the through hole  3  using a micropipette, etc., there is a possibility that the specimen solution enters the well  2 A provided on the opposite side through the flow path  1  due to the pressure of the liquid injected to intermingle with the cell suspension, and therefore the phenomenon that cells pass through the flow path  1  due to the chemotaxis thereof may be confused or disturbed. In order to prevent such a situation from occurring, a through hole  4  is also provided in the well  2 B for storing the specimen.  
         [0031]     Thus providing the through holes  4  that communicate with the through holes  3  for injecting the samples therethrough can minimize the horizontal impact of the liquid pressure and thereby can determine whether or not the specimen solution has chemotaxis more precisely. The effect of reducing pressure difference using the through holes  4  is also effective in reducing pressure reduction when removing samples such as cells from the wells, which therefore makes it easy to remove the samples.  
         [0032]     To describe the case of injecting samples into the wells  2  in this apparatus with reference to  FIG. 1 , the wells  2 A and  2 B and the flow path  1  are preliminarily filled with cell isotonic solution, and then approximately the same quantity of cell suspension and chemotactic factor containing solution is injected, respectively, through the through hole  3  of the well  2 A and the through hole  3  of the well  2 B. This allows the pressure increase when injecting the samples to be reduced by the through holes  4 .  
         [0033]     As shown in FIGS.  3  to  5 , the flow path  1  is composed of one or a plurality of, for example about 100, grooves  5  formed in a barrier  6  along the direction or the opposite direction from the well  2 A toward the well  2 B, the barrier  6  running in the direction perpendicular to the direction or the opposite direction from the well  2 A toward the well  2 B. These grooves  5  are formed at a width in accordance with the diameter of cells or the deformability thereof. Thus providing the grooves  5  makes it possible to observe the cells at individual level and also to isolate the cells into desired classes.  
         [0034]     It is noted that the numeral  7 a in FIGS.  1  to  3  indicates a bank formed between the wells  2 A and  2 B, while the numeral  7   b  in  FIGS. 3 and 4  indicates a terrace formed on the bank  7   a . The terrace  7   b  is a flat portion surrounding the barrier  6 .  
         [0035]     An observation of a state where cells move through the flow path  1  and a measurement of the number of cells that currently pass or have passed through the flow path  1  are to be made by setting a sensing device, for example, a microscope  70  in such a manner that the sensing device faces the flow path  1  through a glass substrate  8  as shown in  FIG. 3 . Also, combining the microscope with a video camera or a CCD camera makes it possible to record the progress of the cell movement automatically.  
         [0036]     Defining such an apparatus as mentioned above, in which the wells  2 A and  2 B with the through holes  3  and  4  provided respectively therein are communicated with each other through the flow path  1 , as one unit and integrating a plurality of units makes it possible to construct an apparatus whereby the movement (chemotaxis) of cells can be detected and chemotactic cells can be isolated at the same time for other kinds of specimens or other kinds of cells. Since the size of such an apparatus is wholly reduced, it is possible to treat samples at a small quantity. In addition, the treatment can be automated easily with a program control system for the injection/removal quantity of the liquid.  
         [0037]     Such a unit as mentioned above, in which the wells  2 A and  2 B with the through holes  3  and  4  provided respectively therein are communicated with each other through the flow path  1 , is actually manufactured as follows.  
         [0038]     The inner shape of the wells  2 A and  2 B and the flow path  1  can be formed by applying a known technique for manufacturing an integrated circuit onto the surface of a substrate  7  made of silicon single-crystal material. Arranging the substrate  7  with a concavo-convex shape obtained by thus transferring the inner shape of the wells  2 A and  2 B and the flow path  1  thereto engraved on the surface thereof to face and overlap the glass substrate  8  causes the wells  2 A and  2 B and the flow path  1  to be formed between the substrates  7  and  8 .  
         [0039]     In the substrate  7 , through holes  3 ′ for guiding cell suspension or chemotactic factor containing solution therethrough are also formed correspondingly to the respective wells  2 A and  2 B in a vertically penetrating manner, and through holes  4 ′ for reducing pressure increase or pressure reduction that occurs when injecting or removing the solutions into/from the wells  2 A and  2 B are formed in pairs with the respective through holes  3 ′ in a vertically penetrating manner. These pairs of through holes  3 ′ and  4 ′ are communicated with each other through the well  2 A or  2 B and communicate with the respective through holes  3  and  4  that are formed in the block body  9  in a vertically penetrating manner. It is noted that there is actually interposed a packing between the substrate  7  and the block body  9  so as to seal the liquid therebetween.  
         [0040]     Next will be described in detail the cell observation chamber according to the present embodiment in which a plurality of such units as mentioned above, in which the wells  2 A and  2 B with the through holes  3  and  4  provided respectively therein are communicated with each other through the flow path  1 , are incorporated.  
         [0041]     The outline of the overall structure of the apparatus for detecting cell chemotaxis and for isolating chemotactic cells to which the cell observation chamber according to the present embodiment is applied will first be described.  
         [0042]     As shown in  FIG. 6 , in the apparatus  10  for detecting cell chemotaxis and for isolating chemotactic cells to which the cell observation chamber  30  according to the present embodiment is applied, the cell observation chamber  30  is housed in such a manner as to be partially exposed on the upper surface of a relatively low casing  20  having a rectangular parallelepiped shape. Also, a laptop computer  50  is placed on the upper surface of the casing  20 , and the laptop computer  50  is adapted to operate to, for example, give instructions to a temperature control section for solutions containing cell suspension, etc. and analyze, record, and monitor temperature data and/or cell observation data. The monitoring includes displaying an image of an actual cell movement.  
         [0043]     Since a level  21  is additionally attached to the upper surface of the casing  20 , it is possible to monitor the evenness of the apparatus  10  constantly. Further, a brightness (light intensity) adjustment knob  22  for a cell observation image in the microscope, a position adjustment knob  23  for the microscope, and a focal point adjustment lever  24 , etc. are attached to the front surface of the casing  20  in this order from the lower right to the upper left in  FIG. 6 . Since an optical axis, not shown in the figure, in the optical system of the microscope is arranged horizontally in the casing  20 , it is possible to reduce the height of the casing  20  and therefore the apparatus  10 , which makes it possible to perform the operation of detecting cell chemotaxis, isolating chemotactic cells, and measuring the number of cells in a sitting posture using the apparatus  10  placed on a desk, resulting in a significant improvement in operationality.  
         [0044]     The cell observation chamber  30  is arranged as follows.  
         [0045]     As shown in FIGS.  7  to  10 ,  13 , and  14 , the arrangement of the cell observation chamber  30  will be understood as follows based on the appearance thereof and a partially disassembled state achieved by a simple rotational operation of cam control levers  36  and  37  to be described hereinafter. That is, onto a circular dish-shaped bottom support body  31  that is arranged in the lowest part is attached an intermediate support body  32  having also a circular dish shape; onto the intermediate support body  32  is attached a cover block body  33  having also a circular dish shape with the relatively thick bottom part  33   a  and the relatively wide outer peripheral flange part  33   b ; onto the cover block body  33  is attached a guide block body  34  across the central recessed portion  33   c  of the cover block body  33  in such a manner that the central enlarged portion  34   a  thereof is sunk into the central recessed portion  33   c ; and on the upper surface of the cover block body  33  is seated a pedestal part  35 a of a temperature sensor  35 .  
         [0046]     Then, rotating the cam control lever  36  causes the cover block body  33  to be brought into pressurized contact with the intermediate support body  32  from above, which causes the intermediate support body  32  to be brought into pressurized contact with the bottom support body  31  from above, so that the cover block body  33  is finally to be attached to the bottom support body  31 . Also, rotating the cam control lever  37  causes the intermediate support body  32  to be brought into pressurized contact with the bottom support body  31  from above and to be attached thereto. It is noted that in an actual attachment order, the intermediate support body  32  is first attached to the bottom support body  31 , and the cover block body  33  is then attached to the bottom support body  31 . In the case of a disassembling operation, the operation is to be performed in the reverse order. The cover block body  33  corresponds to one obtained by combining the block body  09  and the cover  04  in the conventional cell observation chamber  00  (refer to  FIG. 16 ).  
         [0047]     The cam control levers  36  and  37  each have a U shape when viewed from above, and the end portions  36   a  and  37   a  of the both leg parts thereof exist on the outer peripheral surface of the body part  31   b  of the circular dish-shaped bottom support body  31  to be supported rotatably around a pair of support shafts  38  that are implanted symmetrically with respect to the axial center of the body part. Also, the end portions  36   a  and  37   a  of the both leg parts are enlarged into a rectangular shape when viewed from front, in the inner surface of which being formed curved cam grooves  36   b  and  37   b , respectively, for the cam control levers  36  and  37  (refer to  FIGS. 13 and 14 ).  
         [0048]     On the outer peripheral surface of the outer peripheral flange part  33   b  of the circular dish-shaped cover block body  33 , there are implanted pins  40  symmetrically with respect to the axial center of the flange part (refer to  FIGS. 14 and 11 ). The pins  40  are fitted into the cam grooves  36   b  of the cam control lever  36  so as to move within the cam grooves  36   b  in a sliding manner when the cam control lever  36  is rotated. This causes the lower surface of the outer peripheral flange part  33   b  of the cover block body  33  to come close to and to be brought into contact with the upper surface of the outer peripheral flange part  32   b  of the intermediate support body  32  from above, and then to be attached to the bottom support body  31 . Also, rotating the cam control lever  36  reversely causes the cover block body  33  to be detached from the bottom support body  31 . Between the outer peripheral flange part  33   b  of the cover block body  33  and the outer peripheral flange part  32   b  of the intermediate support body  32 , there is interposed an O-ring  42  for preventing medium from leaking from an inner space to be formed between the cover block body  33  and the intermediate support body  32  when the cover block body  33  is attached to the intermediate support body  32 .  
         [0049]     Similarly, on the outer peripheral surface of the outer peripheral flange part  32   b  of the circular dish-shaped intermediate support body  32 , there are implanted pins  41  symmetrically with respect to the axial center of the flange part (refer to  FIG. 11 ). The pins  41  are fitted into the cam grooves  37   b  of the cam control lever  37  so as to move within the cam grooves  37   b  in a sliding manner when the cam control lever  37  is rotated. This causes the lower surface of the outer peripheral flange part  32   b  of the intermediate support body  32  to come close to and to be brought into contact with the upper surface of the body part  31   b  of the bottom support body  31  from above, and to be attached to the bottom support body  31  firmly. Also, rotating the cam control lever  37  reversely causes the intermediate support body  32  to be detached from the bottom support body  31 .  
         [0050]     In the central enlarged portion  34   a  of the guide block body  34 , there are formed six narrow through holes  34 c in a vertically penetrating manner aligned in the longitudinal direction of the guide block body  34 . When an operator inserts or withdraws the needlepoint of a micropipette (not shown in the figure) carrying a sample such as cell suspension or specimen solution into/from the chamber  30 , these through holes  34   c  are useful in guiding the needlepoint of the micropipette and in guiding the solution discharged from the micropipette to the well to be described hereinafter (this well is identical with one of the foregoing pair of wells  2 A and  2 B ( FIG. 1 )). The position where the six through holes  34   c  are aligned is displaced slightly toward one side of a centerline “a” dividing the guide block body  34  into two sections in the width direction when viewed from above (refer to  FIG. 8 ).  
         [0051]     The guide block body  34  is positioned and attached onto the flange part  33   b  detachably with pins  39  penetrating through arm parts  34   b  and  34   b  on either side of the central enlarged portion  34   a  and the flange part  33   b  of the cover block body  33 . Therefore, after the guide block body  34  is detached from the cover block body  33  and rotated by 180 degrees so that the positions of the arm parts  34   b  and  34   b  on either side are switched with each other, the guide block body  34  can be attached again onto the flange part  33   b  of the cover block body  33  detachably by being positioned using the pins  39  similarly before the switching. In this case, the position where the six through holes  34   c  are aligned is symmetrical to the alignment position before the switching with respect to the centerline “a”.  
         [0052]     In order to position the cover block body  33  and the intermediate support body  32  relatively in the circumferential direction, a pair of positioning pins  46   a  and  46   b  penetrate through holes formed respectively therefor across the cover block body  33  and the intermediate support body  32 . Similarly, in order to position the intermediate support body  32  and the bottom support body  31  relatively in the circumferential direction, a pair of positioning pins  47   a  and  47   b  penetrate through holes formed respectively therefor across the intermediate support body  32  and the bottom support body  31 . The pins  46   a  and  46   b  and the pins  47   a  and  47   b  have their respective different diameters to fulfill a function of preventing an assembling error in an assembling operation from occurring.  
         [0053]     Next will be described the internal structure of the cell observation chamber  30  in detail.  
         [0054]     In the center of the bottom part  31   a  of the bottom support body  31 , there is provided a window  31   c  for observing the movement of cells. Also, the transparent glass substrate  8  is placed on the bottom surface of the body. When the intermediate support body  32  is attached to the bottom support body  31 , the glass substrate  8  is pressed firmly against and fixed to the bottom part  31   a  by the bottom part  32   a  of the intermediate support body  32 . Between the bottom part  32   a  and the glass substrate  8  and on the outer peripheral side thereof, there is interposed an O-ring  43  to prevent medium from leaking from an inner space to be formed therebetween.  
         [0055]     The substrate  7  is placed on the surface in the central part of the glass substrate  8 . The glass substrate  8  and the substrate  7  are identical with the foregoing glass substrate  8  and substrate  7  in  FIG. 1  having basically the same structure. Therefore, on the surface of the substrate  7  facing the glass substrate  8 , there are engraved six units of concavo-convex shapes obtained by transferring the inner shape of the pair of wells  2 A and  2 B and the flow path  1  for communicating of the wells thereto, and in a state where the shapes are arranged to face and overlap the glass substrate  8 , six units of combination structures of the wells  2 A and  2 B and the flow path  1  are formed between the substrates  7  and  8 .  
         [0056]     In the substrate  7 , the through holes  3 ′ for guiding cell suspension or chemotactic factor containing solution therethrough are also formed correspondingly to the respective wells  2 A and  2 B in a vertically penetrating manner, and the through holes  4 ′ for reducing pressure increase or pressure reduction that occurs when injecting or removing the solutions into/from the wells  2 A and  2 B are formed in pairs with the respective through holes  3 ′ in a vertically penetrating manner. These pairs of through holes  3 ′ and  4 ′ are communicated with each other through the well  2 A or  2 B.  
         [0057]     The opening portion  32   c  is formed in the central part of the bottom part  32   a  of the intermediate support body  32 , and the packing member  44  having a thickness slightly greater than that of the bottom part  32   a  is fitted into the opening portion  32   c  in such a manner as to protrude therefrom to press the substrate  7  placed on the glass substrate  8  from above against the glass substrate  8 .  
         [0058]     The substrate  7 , which has a very small thickness, is represented as a heavy solid line segment sandwiched between the glass substrate  8  and the packing member  44  in  FIGS. 11 and 12 . The shape of the through holes  3 ′ and  4 ′, the wells  2 A and  2 B, and the flow path  1  formed in the substrate  7  is not shown in the figures.  
         [0059]     In the packing member  44 , there are formed the same number of through holes  3 - 1  and  4 - 1  that communicate, respectively, with the through holes  3 ′ and  4 ′ formed in the substrate  7  in a penetrating manner as the total number of the through holes  3 ′ and  4 ′ in a vertically penetrating manner. Since the through holes  3 ′ and  4 ′ are formed in each of the wells  2 A and  2 B in a pair, a total of four through holes are to be formed in one unit, and integrating six units causes a total of  24  through holes (groups of through holes  3 - 1  and  4 - 1 ) to be formed and aligned lengthwise and crosswise. The through holes  3 - 1 , which exist deeply and on the near side in the direction perpendicular to the space in  FIG. 11 , are not shown in the figure.  
         [0060]     It is noted that the through holes  3 - 1  and  4 - 1  to be formed in the packing member  44  in a penetrating manner are not necessarily formed separately, and the through holes  3 - 1  may be combined with the respective through holes  4 - 1 . This cannot cause, for example, falling solution and rising gas to be intermingled with each other, and since the gas passes through the falling solution to be discharged through a through hole  4 - 2  above, there is no interference with the function of reducing pressure increase in the wells. In  FIG. 12  is shown the structure of thus arranged packing member  44 . Also, for that purpose, if the lower end portions of through holes  3 - 2  and  4 - 2  to be formed in the cover block body  33  are cut off by a small length to form small blank spaces therein, it is possible to retain the function of reducing pressure increase and pressure reduction further reliably (refer to the two left and right small blank spaces directly below the through holes  3 - 2  and  4 - 2  in  FIG. 12 ).  
         [0061]     When the cover block body  33  is attached to the bottom support body  31 , the lower surface of the bottom part  33   a  of the cover block body  33  is brought into contact with the upper surface of the packing member  44  and presses the surface. Therefore, the substrate  7  is consequently to be pressed by the cover block body  33  through the packing member  44  to be fixed onto the glass substrate  8 .  
         [0062]     In one part nearer the peripheral edge of the bottom part  33   a  of the cover block body  33 , there is formed a relatively large-diameter through hole  33   d  in a vertically penetrating manner through which mixture in the chamber  30  is adapted to go in and out of the central recessed portion  33   c . Also, in the central part of the bottom part  33   a , there are formed the same number of through holes  3 - 2  and  4 - 2  that communicate, respectively, with the through holes  3 - 1  and  4 - 1  formed in the packing member  44  in a penetrating manner as the total number of the through holes  3 - 1  and  4 - 1  in a vertically penetrating manner. Among these groups of through holes formed in the central part of the bottom part  33   a , six units of the through holes  4 - 2  belonging to the well  2 A side, that is, six aligned through holes  4 - 2  belonging to the well  2 A side correspond one-on-one to the six through holes  34   c  in the guide block body  34  that is attached to the cover block body  33  in the posture as shown in  FIG. 8  to share the centerline thereof.  
         [0063]     When the guide block body  34  is rotated by 180 degrees from the posture as shown in  FIG. 8  to switch the positions of the arm parts  34   b  and  34   b  on either side with each other, six aligned through holes  4 - 2  belonging to the well  2 B side then correspond one-on-one to the six through holes  34   c  in the guide block body  34 . Thus switching the posture of the guide block body  34  can be employed when the injection of the cell suspension into the well  2 A using a micropipette is followed by the injection of the chemotactic factor containing solution into the well  2 B using a micropipette.  
         [0064]     As is clear from the description above, the through holes  3 ′ and  4 ′ formed in the substrate  7  in a penetrating manner, the through holes  3 - 1  and  4 - 1  formed in the packing member  44  in a penetrating manner, and the through holes  3 - 2  and  4 - 2  formed in the bottom part  33   a  of the cover block body  33  in a penetrating manner are communicated with each other, and six units of through hole assemblies that are formed by the through holes  4 ′,  4 - 1 , and  4 - 2  thus communicating with each other correspond one-on-one to the six through holes  34   c  formed in the guide block body  34  that is attached to the cover block body  33  in the posture as shown in  FIG. 8  to share the centerline thereof (refer to  FIGS. 11 and 12 ). It is noted that the through holes  3 ′ and  4 ′ formed in the substrate  7  in a penetrating manner, which have very small sizes, are not shown in  FIGS. 1l and 12 . The through hole assemblies composed of the through holes  4 - 1  and  4 - 2  correspond to the through holes  4  in  FIG. 1 .  
         [0065]     Accordingly, assuming here that the wells  2 A and  2 B and the flow path  1  are filled with cell isotonic solution and that the well  2 B is provided with chemotactic factor containing solution, when trying to inject cell suspension into the well  2 A using a micropipette, after the needlepoint of the micropipette is inserted into one of the through holes  34   c  that communicates with the well  2 A in a unit to be used and is carried while being guided by the hole until reaching a required depth to discharge the cell suspension there, the discharged cell suspension then falls down through the through holes  4 - 2 ,  4 - 1 , and  4 ′ in this order to reach the well  2 A. In this case, the pressure increase in the well  2 A can be released outside through the through holes  3 ′,  3 - 1 , and  3 - 2 , which can minimize the impact of pressure fluctuation on the chemotaxis of cells that are to react with the chemotactic factor containing solution.  
         [0066]     The same procedure applies also when trying to inject the chemotactic factor containing solution into the well  2 B using a micropipette, and in this case, the chemotactic factor containing solution discharged from the micropipette can fall down through the through holes  4 - 2 ,  4 - 1 , and  4 ′ belonging to the well  2 B side in this order to reach the well  2 B.  
         [0067]     Cells in the cell suspension provided to the well  2 A move from the well  2 A to  2 B through the flow path  1  after reacting with the chemotactic factor containing solution in the well  2 B. It is possible to observe the state and measure the number of cells at the cell level through the window  31   c  using the microscope.  
         [0068]     In order to thus perform the operation of, for example, detecting the chemotaxis of the cells that move from the well  2 A to  2 B through the flow path  1  and isolating the cells utilizing the characteristics thereof, it is necessary to control the temperature of the mixture filling these sections so as to be suitable for the activity of the cells. Also when it is demanded that the reaction of the cells due to temperature change be measured and analyzed more precisely, it is necessary to control the temperature of the mixture. It is noted that the mixture filling these sections here means the mixture of the cell isotonic solution and the cell suspension and the mixture of the cell isotonic solution and the chemotactic factor containing solution, where the both mixture has approximately the same temperature.  
         [0069]     For the foregoing purpose, the present embodiment employs two temperature controllers  62  and  63  as shown in  FIG. 15 , where the first temperature controller  62  is adapted to use the temperature sensor  35  to measure the temperature of the mixture directly and to control the temperature of a heating section  64  to be heated by a heater with the chamber  30  being set thereon to increase the accuracy of the temperature control. Also, the second temperature controller  63  is adapted to heat the heating section  64  preliminarily so that the time required to control the temperature of the mixture to be a desired temperature can be shortened. The temperature controller  63  also has a function of preventing the heating section  64  from being overheated.  
         [0070]     In order to measure the temperature of the mixture directly using the temperature sensor  35 , a temperature sensing part  35   b  of the temperature sensor  35  extends downward from the pedestal part  35   a , as shown in  FIG. 12 , to be directly sunk into a liquid storage chamber  45  filled with solution equivalent to the mixture. The solution in the liquid storage chamber  45  can receive the indirect heating by the heating section  64  equally with the solutions filing the pair of wells  2 A and  2 B and the flow path  1  to increase the temperature to be the same as that of the solutions, whereby the temperature sensor  35  can measure approximately the same temperature as that of the solutions filling the pair of wells  2 A and  2 B and the flow path  1 . The liquid level of the solution in the liquid storage chamber  45  is approximately the same as the liquid level L of the mixture in the cover block body  33 .  
         [0071]     The liquid storage chamber  45  is formed with a recessed portion formed by partially and vertically chipping the outer peripheral wall of the body part of the cover block body  33  being surrounded by the inner peripheral wall of the intermediate support body  32 . It is preferable that the liquid storage chamber  45  be provided separately from the wells  2 A and  2 B, the flow path  1 , and the sections communicating with these portions. For this reason, there is interposed a packing (not shown in the figures) at the lower part of the liquid storage chamber  45  where the liquid storage chamber  45  is connected to the wells  2 A and  2 B, the flow path  1 , and the sections communicating with these portions. This allows the temperature sensing part  35   b  of the first temperature controller  62  to measure the temperature of the solutions containing cells and filling the pair of wells  2 A and  2 B and the flow path  1  precisely without contaminating the solutions.  
         [0072]     To describe the in-chamber mixture temperature control system  60  in more detail with reference to the block diagram shown in  FIG. 15 , when a temperature control switch  66  is first turned ON and a changeover switch  67  is turned ON for preheating, a preheating operation for the heating section  64  is started under the control of the temperature controller  63 . The preheating operation is to be performed while measuring the temperature of the heating section  64  using a sensor  65  and feeding back the measured value. The preheating temperature is to be specified by a computer  61 . The computer  61  is incorporated in the laptop computer  50 . The numeral  69  indicates a solid-state relay (SSR).  
         [0073]     When the temperature of the heating section  64  reaches a predetermined preheating temperature and the cell observation chamber  30  is placed on the heating section  64 , the changeover switch  67  is turned ON for heating to start a heating operation for the heating section  64  under the control of the temperature controller  62 . This heating operation, which is aiming at heating the mixture in the chamber to be a predetermined temperature, is to be performed while measuring the temperature of the mixture in the chamber using the sensor  35  and feeding back the measured value. The heating temperature is to be specified by the computer  61 . Since the heating section  64  has been heated to be the predetermined temperature through the foregoing preheating operation, this heating operation can heat the mixture in the chamber to be the predetermined temperature in a short time.  
         [0074]     When the temperature of the mixture in the chamber reaches the predetermined temperature, the temperature controller  62  performs heating control for the heating section  64  to keep the temperature. If the temperature of the heating section  64  increases abnormally (e.g. 43° C.) for some reasons, for example, that the chamber  30  is not in contact with the heating section  64 , the temperature controller  63  operates the relay  68  to shut off the circuit. It is noted that the temperature controller  62  is also adapted to operate the relay  68  to shut off the circuit if the temperature of the mixture in the chamber increases abnormally (e.g. 38 to 40° C.).  
         [0075]     The computer  61  is adapted to monitor and display the temperature of the heating section  64  and the mixture in the chamber, the state of the sensors  35  and  65 , etc. constantly, and to specify a heating temperature and a preheating temperature, respectively, for the temperature controllers  62  and  63 .  
         [0076]     Here will be described in detail an actual procedure for assembling the cell observation chamber  30  according to the present embodiment.  
         [0077]     The glass substrate  8  is first attached to the bottom support body  31 . Then, the intermediate support body  32  is fitted into the bottom support body  31 , and the cam control lever  37  is rotated to bring the intermediate support body  32  into pressurized contact with the bottom support body  31  from above through the O-ring  43  and to attach the intermediate support body  32  to the bottom support body  31 . This can prevent medium from leaking to give the assembly composed of these components a function as a container. Next, the substrate  7  is placed on the glass substrate  8  while being guided by the opening portion  32   c  formed in the central part of the bottom part  32   a  of the intermediate support body  32 , and the cover block body  33  with the packing member  44  attached to the bottom surface thereof is fitted into the intermediate support body  32 , and then the cam control lever  36  is rotated to bring the packing member  44  into pressurized contact with the substrate  7  from above and to bring the substrate  7  into pressurized contact with the glass substrate  8 . At the same time, the cover block body  33  is brought into pressurized contact with the intermediate support body  32  through the O-ring  42  so that it is possible to prevent the medium from leaking to give the general assembly (cell observation chamber  30 ) composed of these components also a function as a container.  
         [0078]     The cell observation chamber  30  according to the present embodiment, which is thus arranged, can exhibit the following effects.  
         [0079]     The solution temperature control device in the cell observation chamber  30  comprises the first temperature controller  62  and the second temperature controller  63 , the first temperature controller  62  being adapted to measure the temperature of the solutions filling the pair of wells  2 A and  2 B and the flow path  1  and to control the solutions to be a predetermined temperature, and the second temperature controller  63  being adapted to measure the temperature of the heating section  64  that heats the cell observation chamber  30  from outside, thereby indirectly heats the solutions filling the pair of wells  2 A and  2 B and the flow path  1 , and to control the heating section  64  to be a predetermined preheating temperature, whereby after placing the cell observation chamber  30  on the heating section  64  that has been controlled to be the predetermined preheating temperature by the second temperature controller  63 , it is possible to control and keep the solutions filling the pair of wells  2 A and  2 B and the flow path  1  in the cell observation chamber  30  at the predetermined temperature while measuring the temperature thereof using the first temperature controller  62 , which therefore makes it possible to shorten the time required to control the solutions in the cell observation chamber  30  to be a desired constant temperature, resulting in a dramatic improvement in the accuracy in controlling the temperature.  
         [0080]     In addition, the temperature sensing part  35   b  of the temperature sensor  35  provided in the first temperature controller  62  is attached detachably to the cell observation chamber  30  and immersed in solution in the liquid storage chamber  45  formed in the cell observation chamber  30 , and the liquid storage chamber  45  is provided in an isolated position where the solution therein can receive the indirect heating by the heating section  64  equally with the solutions filling the pair of wells  2 A and  2 B and the flow path  1  to increase the temperature to be the same as that of the solutions, whereby the temperature sensing part  35   b  can measure the temperature of the solutions containing cells and fling the pair of wells  2 A and  2 B and the flow path  1  precisely without contaminating the solutions.  
         [0081]     Further, the attachment/detachment of the temperature sensor  35 , which is attached detachably to the cell observation chamber  30 , can be carried out easily, and the sensor cannot get in the way of assembling/disassembling the cell observation chamber  30  if detached therefrom, which makes it possible to carry out the assembling/disassembling operation smoothly.  
         [0082]     Also, since the second temperature controller  63  has a function of preventing the heating section  64  from being overheated, it is possible to prevent cells from being dead and the functions of sample solutions (e.g. cell suspension and chemotactic factor containing solution) from being damaged as well as to prevent the cell observation chamber  30  from being damaged due to overheating. Since the second temperature controller  63  is provided with the function of preventing overheating, it is also possible to prevent the heating section  64  from being overheated reliably even if there may be poor contact between the heating section  64  and the cell observation chamber  30 , though it is impossible to prevent the heating section  64  from being overheated if the first temperature controller  62  is provided with the function of preventing overheating.  
         [0083]     It is possible to additionally exhibit various kinds of such effects as mentioned above.  
         [0084]     It is noted that the present invention is not restricted to the above-described embodiment, and various modifications may be made without departing from the gist thereof.
A solution temperature control device in a biological cell observing chamber ( 30) used for the detection of chemotaxis and chemotactic cell separator, comprising a first temperature controller ( 62) and a second temperature controller ( 63). The first temperature controller ( 62) measures the temperature of a solution filled in a pair of wells and a flow passage in the chamber and controls the temperature to a specified temperature, and the second temperature controller ( 63) measures the temperature of a heating part ( 64) which heats the chamber ( 30) from the outside to indirectly heat the solution filled in the pair of wells and the flow passage and controls the temperature to a specified preheat temperature. Since the state and quantity of cells moving from one well to the other through the flow passage while holding the temperature of the solution at a specified temperature can be accurately observed and measured, accuracy for controlling the temperature of the solution can be remarkably increased.