Patent Publication Number: US-2010112681-A1

Title: Microchip fluid control mechanism

Description:
TECHNICAL FIELD 
     This invention relates to a microchip fluid control mechanism and, in particular, to a micro-analysis chip used for reacting, mixing, separating or analyzing chemical specimens or for analyzing genes, and having a plurality of reaction vessels and specimen vessels, the reaction vessels and the specimen vessels being connected through microchannels. 
     BACKGROUND ART 
     As described in “Micromachine Technology for Biochemical and Microchemical Analysis Systems” by SHOJI Shuichi (Non-Patent Document 1), and Japanese Laid-Open Patent Publication No. 2002-214241 (Patent Document 2), numerous studies have recently been made on gene analyses performed by reacting samples or liquid specimens on a micro reactor, a micro array, or a single microchip called “Lab-on-a-chip”. Studies also have been made on mechanisms for sequentially transferring extremely small volumes of liquid specimens and on controlling mechanisms. 
     Non-Patent Document 1 discloses in chapter “2. μTAS using micromachine elements” a structure formed on a single base and consisting of “a specimen introduction mechanism, a pump for controlling flows of carrier solution and sample, a mixer-reactor for mixing/reacting the same with a reagent, a component separation portion, and a sensor portion”. This Non-Patent Document 1 also describes “However, there are only few practical applications and experiences of this technology, and micro fluid control elements such as micro valves and micro pumps are important subjects to be studied for practical applications”. 
     Non-Patent Document 1 further discloses a structure in which a large number of complicated transfer means including micro pumps and specimen injectors are mounted on a single base. 
     Patent Document 2 mentioned above describes, “The micro pump 30 is incorporated in the channels 21, 23” (see paragraph [0039]), and transfer means is provided in a microchip. 
     Another conventional technology is disclosed in Japanese Laid-Open Patent Publication No. 2004-226207 (Patent Document 3). Patent Document 3 discloses a transfer mechanism using a diaphragm. Specifically, the transfer mechanism has, in addition to a partition having a possible elasticity, a diaphragm member in contact with the external face of the partition and an incompressible medium for driving the diaphragm member. According to Patent Document 3, the variation in volume of a closed container for “the incompressible medium” is precisely controlled, so that the diaphragm member is driven by the variation in volume and the liquid flow rate is controlled. 
     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention  
     However, according to the conventional technologies described in Non-Patent Document 1 and Patent Document 2, specimen transfer means is provided within or on a microchip, and hence careful cleaning processes must be performed for preventing cross contamination when gene analyses are conducted consecutively. Furthermore, the microchip is increased in size and hence in cost. It has been considered that disposable microchips are desirable for preventing cross contamination. 
     According to the conventional technology disclosed in Patent Document 3, the use of an incompressible medium is indispensable and the use of a compressible medium is not possible. 
     This invention has been made in view of the problems entrained by the conventional technologies as described above, and it is an object of the invention to provide a microchip fluid control mechanism in which transfer means is provided independently from a microchip so that the use of unsophisticated, inexpensive and disposable microchips is made possible, and which makes it possible for devices to realize reduction in size and weight, increase of operating speed, reduction of power consumption, simplification of circuit and device configuration, cost reduction, and improvement in reliability and operability. 
     Means for Solving the Problems  
     In order to achieve the object above, this invention provides a microchip fluid control mechanism having a plurality of specimen vessels each having an open top for receiving specimens, and a plurality of reaction vessels for mixing and reacting the specimens, the specimen vessels and the reaction vessels being mutually linked through a channel to sequentially transfer the specimens by a pressurizing unit so that the specimens are subjected to predetermined processing. The microchip fluid control mechanism is characterized in that a transfer channel from the specimen vessels and transfer channels to the reaction vessels are provided under the specimen vessels and the reaction vessels. 
     Effects of the Invention  
     According to this invention, the need of a valve mechanism conventionally provided in microchips is eliminated to simplify the passage structure, whereby disposable and inexpensive microchip can be provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional perspective view showing a configuration of a microchip transfer mechanism according to a first embodiment of this invention; 
         FIG. 2  is a cross-sectional view showing a configuration of the microchip transfer mechanism according to the first embodiment of this invention; 
         FIG. 3  is a cross-sectional perspective view showing an initial state of the microchip according to the first embodiment of this invention; 
         FIG. 4  is a cross-sectional perspective view showing an operating state of the microchip according to the first embodiment of this invention; 
         FIG. 5  is a cross-sectional perspective view showing an operating state of the microchip according to the first embodiment of this invention; 
         FIG. 6  is a cross-sectional perspective view showing an operating state of the microchip according to the first embodiment of this invention; 
         FIG. 7  is a cross-sectional perspective view showing an operating state of the microchip according to the first embodiment of this invention; 
         FIG. 8  is a cross-sectional perspective view showing an operating state of the microchip according to the first embodiment of this invention; 
         FIG. 9  is a cross-sectional perspective view showing an operating state of the microchip according to the first embodiment of this invention; 
         FIG. 10  is a cross-sectional perspective view showing an operating state of the microchip according to the first embodiment of this invention; 
         FIG. 11  is a cross-sectional perspective view showing an operating state of the microchip according to the first embodiment of this invention; 
         FIG. 12  is a perspective view showing another embodiment of this invention; 
         FIG. 13  is a perspective view showing another embodiment of this invention; 
         FIG. 14  is a perspective view showing another embodiment of this invention; 
         FIG. 15  is a cross-sectional view showing an operating state according to another embodiment of this invention; 
         FIG. 16  is a cross-sectional view showing an operating state according to another embodiment of this invention; and 
         FIG. 17  is a flowchart showing operating states of the microchip according to the first embodiment of this invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Firstly, a first embodiment of this invention will be described in detail. 
       FIG. 1  is a cross-sectional perspective view showing a configuration of a device for reacting chemical specimens by using a microchip according to the first embodiment of the invention. 
     A table  3  is provided on a machine casing  1  by means of pillars  2 , and the table  3  is provided with discharging holes  5   a ,  5   b ,  5   c  the peripheries of which are sealed with O-rings  6   a ,  6   b ,  6   c , and tubes  7   a ,  7   b ,  7   c . The discharging holes  5   a ,  5   b ,  5   c  are connected to a waste vessel  8  disposed on the machine casing  1 , through discharging electromagnetic valves  18   a ,  18   b ,  18   c . Pins  10   a ,  10   b  are provided so as to project from the upper surface of the table  3 , for guiding a microchip  50  to a predetermined position. Further, a cover  20  is provided on the table  3  turnably in directions A and B by means of a hinge  9 . The cover  20  has a fastening screw  25  and pressurizing holes  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  the peripheries of which are sealed with O-rings  26  and passing through the cover. Further, a threaded hole  4  is formed at an end of the table  3  at a position corresponding to the fastening screw  25 . 
     On the other hand, the microchip  50  has a plate-like shape and is provided with reaction vessels  51   a ,  51   b ,  51   c  for mixing a plurality of specimens, and specimen vessels  52   a ,  52   b ,  52   c ,  52   d ,  52   e ,  52   f  for containing the specimens. Discharging holes  53   a ,  53   b ,  53   c  are linked to the reaction vessels  51   a ,  51   b ,  51   c  through a channel  56  for discharging the specimens having overflowed from the reaction vessels  51   a ,  51   b ,  51   c . Pin holes  55   a ,  55   b  are opened at the opposite ends of the microchip  50  to guide the microchip to the position where it is mounted on the table  3 . 
     The pressurizing holes  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  formed to pass through the cover  20  are connected to secondary sides of pressurizing electromagnetic valves  16   a ,  16   b ,  16   c ,  16   d ,  16   e ,  16   f  through tubes  17   c ,  17   d ,  17   e ,  17   f . Primary sides of the pressurizing electromagnetic valves  16   a ,  16   b ,  16   c ,  16   d ,  16   e ,  16   f  are connected to an accumulator  11 . The accumulator  11  is connected to a pump  12  driven by a motor  13 , and a pressure sensor  14  for detecting internal pressure. 
     A controller  15  for executing a preinstalled program is connected to the pressurizing electromagnetic valves  16   a ,  16   b ,  16   c ,  16   d ,  16   e ,  16   f  and the discharging electromagnetic valves  18   a ,  18   b ,  18   c  such that operations thereof can be controlled. Further, the controller  15  is connected to the motor  13  for driving the pump  12  such that the pressure within the accumulator  11  can be controlled to a predetermined value, and to a pressure sensor  14  for detecting and feeding back the pressure within the accumulator  11 . The configuration as described above allows the pressure within the accumulator  11  to be held constantly at a predetermined pressure according to a command from the controller  15 . 
       FIG. 2  is a perspective view showing details of the microchip  50 . 
     The microchip  50  is of a three-layer structure consisting of a main plate  50   a , a lower plate  50   b , and an upper plate  50   c , and has specimen vessels  52   a ,  52   b ,  52   c ,  52   d ,  52   e ,  52   f  passing through the main plate  50   a  and upper plate  50   c  and each having a container shape. The microchip  50  further has reaction vessels  51   a ,  51   b ,  51   c  passing through the main plate  50   a  and each having a container hole shape sealed with the lower plate  50   b  and upper plate  50   c , and discharging ports  53   a ,  53   b ,  53   c  passing through the main plate  50   a  and lower plate  50   b . The specimen vessels  52   a ,  52   b  are linked to the reaction vessel  51   a  through micro-channels  56   a ,  56   b ,  56   g  formed on the side of the main plate  50   a  facing the lower plate  50   b . The discharging port  53   a  and the reaction vessel  51   a  are linked to each other through a micro-channel  56   j  formed on the side of the main plate  50   a  facing the upper plate  50   c . Further, filters  58   a ,  58   b ,  58   c  are provided at the upper ends of the discharging ports  53   a ,  53   b ,  53   c  such that circulating liquid passes through the filters. 
     Further, the reaction vessels  51   a ,  51   b  and the specimen vessels  52   c ,  52   d  are mutually linked through channels  56   h ,  56   c ,  56   d  on the side of the main plate  50   a  facing the lower plate  50   b , while the discharging port  53   b  and the reaction vessel  51   b  are linked to each other through a channel  56   k  on the side of the main plate  50   a  facing the upper plate  50   c.    
     Further, the reaction vessels  51   b ,  51   c  are linked to the specimen vessels  52   e ,  52   f  through channels  56   i ,  56   e ,  56   f  on the side of the main plate  50   a  facing the lower plate  50   b , while the discharging port  53   c  and the reaction vessel  51   c  are connected to each other through a channel  56   l  on the side of the main plate  50   a  facing the upper plate  50   c.    
     On the other hand, pin holes  55   a ,  55   b  are provided in the end faces of the microchip  50  to pass through the main plate  50   a , the lower plate  50   b  and the upper plate  50   c  and to function as guide means when the microchip  50  is mounted. 
     The specimen vessels  52   a ,  52   b ,  52   c ,  52   d ,  52   e ,  52   f  are preliminarily filed with predetermined volumes of specimens  57   a ,  57   b ,  57   c ,  57   d ,  57   e ,  57   f . In general, the specimen  57   a  is a sample liquid containing chemical specimens such as genes to be analyzed, and the specimens  57   b ,  57   c ,  57   d ,  57   e ,  57   f  are specimen liquids to be sequentially reacted with the sample specimen  57   a  to extract specific genes. The specimens  52   a ,  52   b ,  52   c ,  52   d ,  52   e ,  52   f  will not leak out since they are transferred to the micro-channels  56   a ,  56   b ,  56   c ,  56   d ,  56   e ,  56   f  which are fine enough to prevent the specimens from flowing out by surface tension. 
     Next, operation of the first embodiment of this invention will be described with reference to  FIGS. 1 to 11  and  FIG. 17 . 
     The first stage of operation is shown in  FIG. 1  (step  1701  in  FIG. 17 ). 
     The microchip  50  is mounted on the table  3  by inserting the pins  10   a ,  10   b  into the pin holes  55   a ,  55   b . The cover  20  is turned in the direction B so that the fastening screw  25  is engaged in and fastened to the threaded hole  4 . When the microchip  50  is mounted on the table  3 , the specimen vessels  52   a ,  52   b ,  52   c ,  52   d ,  52   e ,  52   f  on the microchip  50  and the pressurizing holes  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  in the cover  20  are both sealed with the O-rings  26  and located at positions corresponding to each other. The discharging ports  53   a ,  53   b ,  53   c ,  53   d ,  53   e ,  53   f  are sealed on the table  3  by the O-rings  6   a ,  6   b , and  6   c  and fixed at the positions corresponding to those of the discharging holes  5   a ,  5   b , and  5   c.    
     The second stage of the operation is shown in  FIG. 3  (step  1701  in  FIG. 17 ). 
       FIG. 3  shows an initial state in which the microchip  50  is mounted on the table  3 . The pressurizing electromagnetic valves  16   a ,  16   b ,  16   c ,  16   d ,  16   e ,  16   f  are in deenergized state to turn off the pressure in the accumulator  11  shown in  FIG. 1 . The discharging electromagnetic valves  18   a ,  18   b ,  18   c  are also in deenergized state to turn off the tubes  7   a ,  7   b ,  7   c  extending from the discharging ports  53   a ,  53   b ,  53   c  to the waste vessel  8 . The specimen vessels  52   a ,  52   b ,  52   c ,  52   d ,  52   e ,  52   f  are filled with the specimens  57   a ,  57   b ,  57   c ,  57   d ,  57   e ,  57   d , while the reaction vessels  51   a ,  51   b ,  51   c  are vacant. 
     The third stage of the operation is shown in  FIG. 4  (steps  1702  and  1703  in  FIG. 17 ). 
     When the pressurizing electromagnetic valve  16   a  and the discharging electromagnetic valve  18   a  are energized, the pressure in the accumulator  11  shown in  FIG. 1  is introduced into the pressurizing hole  22   a  via the pressurizing electromagnetic valve  16   a  and the tube  17   a . On the other hand, as for the pressurizing holes  22   b ,  22   c ,  22   d ,  22   e ,  22   f , since the pressurizing electromagnetic valve  16   b ,  16   c ,  16   d ,  16   e ,  16   f  are deenergized, the connecting tubes  17   b ,  17   c ,  17   d ,  17   e ,  17   f  are turned off. Further, the discharging electromagnetic valves  18   b ,  18   c  are deenergized and thus the connecting tubes  7   b ,  7   c  including in the same circuits as the discharging electromagnetic valves  18   b ,  18   c  are turned off. Since the tube  7   a  is the only path open to the waste vessel  8 , the specimen  57   a  in the specimen vessel  52   a  is introduced into the waste vessel  8  through the channels  56   a ,  56   g  and via the reaction vessel  51   a , the discharging hole  53   a , the filter  58   a , the tube  7   a , and the discharging electromagnetic valve  18   a . When this is done, the channels  56   a ,  56   g  are located under the reaction vessel  52   a . The channel  56   j  functions as an outlet from above the reaction vessel  51   a . After introducing the specimen  57   a  into the reaction vessel  52   a , the channel  56   j  introduces only pressurized gas to the waste vessel  8  via the channel  56   j , the discharging hole  53   a , the filter  58   a , the tube  7   a , and the discharging electromagnetic valve  18   a , while leaving the specimen  52   a  in the reaction vessel  51   a  due to passing resistance occurring at the filter  58   a . This means that the specimen  57   a  contained in the specimen vessel  52   a  is transferred in a direction C to the reaction vessel  51   a . After that, the pressurizing electromagnetic valve  16   a  and the discharging electromagnetic valve  18   a  are deenergized by a preinstalled program controlled by the controller  15  shown in  FIG. 1 , whereby the relevant circuit is turned off. 
     The fourth stage of the operation is shown in  FIG. 5  (steps  1704  and  1705  in  FIG. 17 ). 
     Once the pressurizing electromagnetic valve  16   b  and the discharging electromagnetic valve  18   a  are energized by a signal from the controller  15  shown in  FIG. 1 , the pressurized gas is introduced into the reaction vessel  52   b  via the pressurizing electromagnetic valve  16   b , the tube  17   b  and the pressurizing hole  22   b  to push out the specimen  57   b . Since the pressurizing electromagnetic valves  16   a ,  16   c ,  16   d ,  16   e ,  16   f  and the discharging electromagnetic valves  18   b ,  18   c  are closed, the specimen  57   b  flows out into the waste vessel  8 , passing through the sole open path, namely through the channels  56   b ,  56   g , the reaction vessel  51   a , the channel  56   j , the discharging port  53   a , the filter  58   a , the tube  7   a , and the discharging electromagnetic valve  18   a , like the operation as described above. However, since the reaction vessel  51   a  has already been filled with the specimen  57   a  transferred by the previous operation described above, the specimen  57   a  is mixed with the newly transferred specimen  57   b  to form a specimen mixture  57   ab.  A volume of the specimen mixture  57   ab  exceeding the capacity of the reaction vessel  51   a  and compressed gas additionally supplied are fed in a direction D to be discharged into the waste vessel  8  via the channel  56   j , the discharging port  53   a , the filter  58   a , the tube  7   a , and the discharging electromagnetic valve  18   a . The pressurizing electromagnetic valve  16   b  and the discharging electromagnetic valve  18   a  are then deenergized by the preinstalled program, whereby the relevant circuit is blocked. As a result, the reaction vessel  51   a  is filled with the specimen mixture  57   ab  and the specimens react with each other. 
     The fifth stage of the operation is shown in  FIG. 6  (steps  1706  and  1707  in  FIG. 17 ). 
     Once the pressurizing electromagnetic valve  16   b  and the discharging electromagnetic valve  18   b  are then energized by the preinstalled program, the specimen vessel  52   b  is pressurized via the pressurizing electromagnetic valve  16   b  and the tube  17   b . Since the pressurizing electromagnetic valve  16   a  for the specimen vessel  52   a  is closed, the pressurized gas is fed to the reaction vessel  51   a  through the channels  56   b ,  56   g . On the other hand, since the discharging electromagnetic valve  18   a  is closed, the channel  56   j , the discharging port  53   a , and the tube  7   a  form a closed circuit. Therefore, the pressurized gas introduced into the reaction vessel  51   a  stays in the upper part of the reaction vessel  51   a  and pressurizes the specimen mixture  57   ab  previously present in the reaction vessel  51   a . The specimen vessel  52   c  and the specimen layer  52   d  are closed by the closed pressurizing electromagnetic valves  16   c ,  16   d , and the specimen vessels  52   e ,  52   f  located upstream of the reaction vessel  51   b  are also closed by the closed pressurizing electromagnetic valves  16   e ,  16   f . Further, the channel  56   l , the discharging port  53   c , and the tube  7   c  for the reaction vessel  51   c  are closed by the closed discharging electromagnetic valve  18   c . As a result, the specimen mixture  57   ab  in the reaction vessel  51   a  is fed in a direction E. Specifically, the specimen mixture  57   ab  is fed into the waste vessel  8  by way of the discharging electromagnetic valve  18   b , that is the only valve opened, via the channel  56   h , the reaction vessel  51   b , the channel  56   k , the discharging port  53   b , the filter  58   b , and the tube  7   b . Further, the specimen mixture  57   ab  fed to the reaction vessel  51   b  is flows into the reaction vessel  51   b  from below. Since the channel  56   k  is located above the reaction vessel  51   b  and passing resistance occurs at the filter  58   b , the specimen mixture  57   ab  stays in the reaction vessel  51   b , while only the pressurized gas is discharged into the waste vessel  8  through the channel  56   k , the discharging port  53   b , the filter  58   b , the tube  7   b , and the discharging electromagnetic valve  18   b . As a result, the specimen mixture  57   ab  contained in the reaction vessel  51   a  is transferred to the reaction vessel  51   b . The pressurizing electromagnetic valve  16   b  and the discharging electromagnetic valve  18   b  are then deenergized by the preinstalled program. 
     The sixth stage of the operation is shown in  FIG. 7  (steps  1708  and  1709  in  FIG. 17 ). 
     Once the pressurizing electromagnetic valve  16   c  and the discharging electromagnetic valve  18   b  are energized, the specimen  57   c  contained in the specimen vessel  52   c  is pressurized through the tube  17   c , and fed to the only path opened to a direction F, namely through the channels  56   c ,  56   h , the reaction vessel  51   b , the channel  56   k , the discharging port  53   b , the filter  58   b , the tube  7   b , the discharging electromagnetic valve  18   b , and introduced into the waste vessel  8 . The specimen  57   c  flows, through the channel  56   h , into the reaction layer  51   b  that has already been filled with the specimen mixture  57   ab . Since the channel  56   k  to which the specimen flows out is disposed above the reaction vessel  51   b , the specimen  57   c  is further mixed with the specimen mixture  57   ab  contained in the reaction vessel  52   b  to produce a specimen mixture  57   abc,  and the overflowing specimen mixture  57   abc  is discharged, together with compressed gas further supplied, into the waste vessel  8  via the channel  56   k , the discharging port  53   b , the filter  58   b , the tube  7   b , and the discharging electromagnetic valve  18   b . As a result, some of the specimen mixture  57   abc  remains in the reaction vessel  51   b.  The pressurizing electromagnetic valve  16   c  and the discharging electromagnetic valve  18   b  are then deenergized by the preinstalled program. 
     The seventh stage of the operation is shown in  FIG. 8  (steps  1710  and  1711  in  FIG. 17 ). 
     Once the pressurizing electromagnetic valve  16   d  and the discharging electromagnetic valve  18   b  are energized, the specimen  57   d  contained in the specimen vessel  52   d  is pressurized through the tube  17   d , and is fed to the only path opened to a direction G, specifically through the channels  56   d ,  56   h , the reaction vessel  51   b,  the channel  56   k , the discharging port  53   b , the filter  58   b , the tube  7   b , the discharging electromagnetic valve  18   b , and introduced into the waste vessel  8 . The specimen  57   d  flows, through the channel  56   d , into the reaction vessel  51   b  already filled with the specimen mixture  57   abc,  and a specimen mixture  57   abcd  is produced. Since the channel  56   k  is disposed above the reaction vessel  51   b , the overflowing specimen mixture  57   abcd  and the compressed gas further supplied are discharged into the waste vessel  8  via the channel  56   k , the discharging port  53   b , the filter  58   b , the tube  7   b , and the discharging electromagnetic valve  18   b . As a result, the specimen mixture  57   abcd  remains and is stored in the reaction vessel  51   b.  After that, the pressurizing electromagnetic valve  16   b  and the discharging electromagnetic valve  18   b  are deenergized by the preinstalled program. 
     The eighth stage of the operation is shown in  FIG. 9  (steps  1712  and  1713  in  FIG. 17 ). 
     Once the pressurizing electromagnetic valve  16   d  and the discharging electromagnetic valve  18   c  are energized, the specimen vessel  52   d  to which the specimen  57   d  has already been transferred is pressurized through the pressurizing electromagnetic valve  16   d  and the tube  17   d . Since the pressurizing electromagnetic valves  16   a ,  16   b ,  16   d ,  16   e ,  16   f,  and the discharging electromagnetic valve  18   a ,  18   b  are closed, the compressed gas pressurizing the specimen vessel  52   d  is fed to the only path opened to a direction H, namely through the channel  56   d , the reaction vessel  51   b , the channel  56   i , the reaction vessel  51   c , the channel  56   l , the discharging port  53   c , the filter  58   c , the tube  7   c , the discharging electromagnetic valve  18   c , and into the waste vessel  8 . While the reaction vessel  51   b  has already been filled with the specimen mixture  57   abcd,  the compressed gas flowing into the reaction vessel  51   b  from the channel  56   h  is contained in the upper part of the reaction vessel  51   b  to push out the specimen mixture  57   abcd  and feed the same to the channel  56   i , and causes the specimen mixture  57   abcd  to flow into the reaction vessel  51   c . Since the channel  56   l  serving as a discharge path is disposed above the reaction vessel  51   c , and passing resistance occurs at the filter  58   c , the compressed gas which has pushed out is fed into the waste vessel  8  through the channel  56   l  via the discharging hole  53   c , the filter  58   c , the tube  7   c , the discharging electromagnetic valve  18   c , while leaving the specimen mixture  57   abcd  in the reaction vessel  51   c . As a result, the specimen mixture  57   abcd  contained in the reaction vessel  51   b  is transferred to the reaction vessel  51   c . After that, the pressurizing electromagnetic valve  16   d  and the discharging electromagnetic valve  18   c  are deenergized by the preinstalled program. 
     The ninth stage of the operation is shown in  FIG. 10  (steps  1714  and  1715  in  FIG. 17 ). 
     The pressurizing electromagnetic valve  16   e  and the discharging electromagnetic valve  18   c  are energized. When the specimen vessel  52   e  filled with the specimen  57   e  is pressurized through the pressurizing electromagnetic valve  16   e  and the tube  17   e , the specimen  57   e  is fed to the only path opened to a direction I, namely through the channels  56   e ,  56   i , the reaction vessel  51   c , the channel  56   l , the discharging port  53   c , the filter  58   c , the tube  7   c , the discharging electromagnetic valve  18   c  and into the waste vessel  8 , since the pressurizing electromagnetic valves  16   a ,  16   b ,  16   c ,  16   d ,  16   f  and the discharging electromagnetic valves  18   a ,  18   b  are closed. The specimen  52   e  thus pushed out flows into the reaction vessel  51   c  from the channel  56   i  linked to the lower side of the reaction vessel  51   c  which has already been filled with the specimen mixture  57   abcd  in the previous step, and reacts with the specimen mixture  57   abcd  to produce a specimen mixture  57   abcde.  Further, the overflowing specimen mixture  57   abcde  and the compressed gas further supplied are discharged from the channel  56   l  disposed above the reaction vessel  51   c  into the waste vessel  8  via the discharging port  53   c , the filter  58   c , the tube  7   c , and the discharging electromagnetic valve  18   c . As a result, the reaction vessel  51   c  is filled with the specimen mixture  57   abcde.  After that, the pressurizing electromagnetic valve  16   e  and the discharging electromagnetic valve  18   c  are deenergized. 
     The tenth stage of the operation is shown in  FIG. 11  (steps  1716  and  1717  in  FIG. 17 ). 
     The pressurizing electromagnetic valve  16   f  and the discharging electromagnetic valve  18   c  are energized. When the specimen vessel  52   f  is pressurized through the pressurizing electromagnetic valve  16   f  and the tube  17   f , the specimen  57   f  is fed to the only path opened to a direction J, namely through the channels  56   f ,  56   i , the reaction vessel  51   c , the channel  56   l , the discharging port  53   c , the filter  58   c , the tube  7   c , and the discharging electromagnetic valve  18   c , and into the waste vessel  8 , since the pressurizing electromagnetic valves  16   a ,  16   b ,  16   c ,  16   d ,  16   e  and the discharging electromagnetic valves  18   a ,  18   b  are closed. While the reaction vessel  51   c  has already been filled with the specimen mixture  57   abcde  in the previous step, the specimen  57   f  is additionally fed into the reaction vessel  51   c  from the channel  56   i  linked to the lower side of the reaction vessel  51   c , and a specimen mixture  57   abcdef  is produced. The overflowing specimen mixture  57   abcdef  and the compressed gas further supplied are discharged from the channel  56   l  provided above the reaction vessel  51   c  into the waste vessel  8  via the discharging port  53   c , the filter  58   c , the tube  7   c , and the discharging electromagnetic valve  18   c . As a result, some specimen mixture  57   abcdef  is left and contained in the reaction vessel  51   c . After that, the pressurizing electromagnetic valve  16   f  and the discharging electromagnetic valve  18   c  are deenergized. 
     As seen from the description above, the specimens  57   a  and  57   b  are mixed together and caused to react for a certain period of time in the reaction vessel  51   a , and the mixture product is transferred to the reaction vessel  51   b . The specimens  57   c  and  57   d  are additionally fed into the reaction vessel  51   b  where they are caused to react for a certain period of time, and then the product is transferred into the reaction vessel  51   c . Further, the specimens  57   e  and  57   f  are added and caused to react, whereby the final product is obtained in the reaction vessel  51   c , and a series of transfer processing steps is terminated (step  1718  in  FIG. 17 ). 
     Other Exemplary Embodiments of the Invention 
     Another exemplary embodiment of this invention is shown in  FIG. 12 . 
     There is provided on a microchip  150  a reaction line  151  composed of the reaction vessels  51   a ,  51   b ,  51   c , the specimen vessels  52   a ,  52   b ,  52   c ,  52   d ,  52   e ,  52   f , the discharging holes  53   a ,  53   b ,  53   c , and the channel  56  shown in  FIG. 1 . Further, reaction lines  152 ,  153  having a similar mechanism configuration to that of the reaction line  151  are additionally provided. A cover  220  is provided with pressurizing hole groups  251 ,  252 ,  253  each composed of the pressurizing holes  22   a ,  22   b ,  22   c ,  22   d ,  22   e ,  22   f  and the O-rings  26  shown in  FIG. 1 . Further, there are provided, on a table  303 , discharging hole groups  351 ,  352 ,  353  each composed of the discharging holes  5   a ,  5   b ,  5   c  and the O-rings  6   a ,  6   b ,  6   c  shown in  FIG. 1 . 
     The pressurizing hole groups  251 ,  252 ,  253  on the cover  220  are engaged with paths branched from the tubes  17   a ,  17   b ,  17   c ,  17   d ,  17   e ,  17   f  in the same manner as the paths shown in  FIG. 1 . The tubes  7   a ,  7   b ,  7   c  connected to and extending from the discharging electromagnetic valves  18   a ,  18   b ,  18   c  are branched and connected to the discharging hole groups  351 ,  352 ,  353  in the same manner as shown in  FIG. 1 . It is made possible, by providing the configuration described above and transferring each of the specimens as described above, to drive a plurality of reaction lines  151 ,  152 ,  153  simultaneously. Furthermore, this embodiment provides an advantage that a greater number of reaction processes can be performed at the same time since the discharging electromagnetic valves  18   a ,  18   b ,  18   c  and the pressurizing electromagnetic valves  16   a ,  16   b ,  16   c ,  16   d ,  16   e ,  16   f  shown in  FIG. 1 , which serve as drive means, can be used in common. Although the description above has been made in terms of a case in which there are three reaction lines, an equivalent result can be obtained even if more reaction lines are provided. 
     While the description has been made above on the first to tenth stages of the operation, it is obvious that the same result can be obtained eve if the filters  58   a ,  58   b ,  58   c  provided on the discharging channels are omitted depending on the characteristics (such as viscosity) of the specimens  57   a ,  57   b ,  57   c ,  57   d ,  57   e ,  57   f.    
     Still another embodiment of this invention is shown in  FIG. 13 . 
     The waste vessel  8  has a sealed structure, and is provided with a negative pressure pump  412  for establishing a negative pressure in the inside of the waste vessel  8 , and with a drive motor  413 . Further, a pressure sensor  414  is further connected to the waste vessel  8  for detecting and feeding back the pressure in the waste vessel  8 . The motor  413  and the pressure sensor  414  are connected to a controller  15  so that the pressure in the waste vessel  8  is controlled to a predetermined negative value. The configuration as described above makes it possible that specimens and compressed gas can be discharged into the waste vessel  8  more reliably than when the inside of the waste vessel  8  is maintained at the atmospheric pressure, and thus the time required for discharging is shortened and the productivity is improved. 
     Still another embodiment of this invention is shown in  FIG. 14 , 
     Specimen vessels  52   a ,  52   b  provided in a microchip  50  are filled with specimens  57   a ,  57   b , and a stretchable film  59  is disposed on the top of the specimen vessels.  FIG. 15  is a cross-sectional view showing a configuration including the specimen  57   a  contained in the specimen vessel  52   a , the cover  20 , the pressurizing hole  22   a , the O-ring  26 , the channel  56   a , and the film  59  described above. 
     Operation of this embodiment will be described with reference to  FIG. 16 . 
     Since the film  59  is sealed with the O-ring  26 , compressed gas supplied through the pressurizing hole  22   a  formed in the cover  20  causes the film  50  to bulge downward in the specimen vessel  52   a . The specimen  57   a  in the specimen vessel  52   a  is thereby pressurized and pushed out to the direction of the channel  56   a . This makes it possible to prevent supply of excessive gas and to improve the accuracy in quantity of transferred specimens without the need of using an expensive micro pump having high flow control accuracy. The quantity of transferred specimens can be controlled by changing the combination of the size of the specimen vessel  52   a , the material of the film  59 , and the pressure of the compressed gas to be supplied. 
     When this device is operated in the atmospheric air or the like, gas such as air will exist around the pressurizing hole  22   a  formed in the cover  20  if the specimen vessel  52   a  in the microchip  50  is filled with a specimen, the stretchable film  59  is disposed thereon, and then the cover  20  is placed to cover the same. However, since compressed gas is supplied through the pressurizing hole  22   a  formed in the cover  20 , the air (gas) existing around the pressurizing hole  22   a  will not be mixed in and will not pose any problem. This detachable construction of the cover makes it possible to replace the microchip  50  for every analysis, and to prevent the contamination possibly caused by mixture of specimens to be tested. As a result, the device can be simplified in configuration, while the fault tolerance and reliability can be improved. 
     Since the cover  20  is detachable, as described above, the stretchable film  59  to be disposed on the top of the specimen vessel  52   a  in the microchip  50  also can be made detachable. This makes it possible to introduce a specimen into the specimen vessel  52   a  from the top of the microchip  50 . In addition, since the channel  56   a  is disposed under the specimen vessel  52   a , part of the specimen introduced into the lower part of the specimen vessel  52   a  is first pushed out into the channel  56   a , even if the specimen has not been introduced completely into the specimen vessel  52   a  and some gas is brought into the upper part of the specimen vessel  52   a . It is made possibly, by changing the combination of the size of the specimen vessel  52   a , the material of the film  59 , and the pressure of the compressed gas to be supplied, to transfer only the specimen while leaving the gas, which might be mixed into the specimen, in the upper part of the specimen vessel  52   a . As a result, the handling of the device is simplified and the fault tolerance is improved. 
     Using a transfer mechanism according to an aspect of this invention, a plurality of chemical specimens can be sequentially transferred to a plurality of reaction vessels in a microchip by simple configuration and control, so that they can be reacted to efficiently produce a product required for gene analysis. Further, the size reduction of the device makes it possible to reduce the weight, to increase the operating speed, and reduce the power consumption. 
     Specimens according to an aspect of the invention may be any substance of any form as long as it can be transferred by the transfer mechanism. Specifically, the chemical specimens that can be transferred in the microchip may assume the form of liquid, gas, gel, powder, or the like. Taking this function into consideration, it will be understood that this invention is applicable to analysis of gas containing bacteria or the like. 
     Further, using this microchip transfer mechanism, the need is eliminated of providing drive means for the transfer purpose within the microchip, and it is made possible to provide disposable, inexpensive and small-sized microchips. Thus, the washing process conventionally required before every reuse of the microchip can be omitted, making it possible to perform gene analyses at a low cost and yet to improve the analysis reliability. 
     Further, this microchip transfer mechanism allows a large number of reaction lines to operate simultaneously with the use of a single drive means for the transfer purpose, resulting in significant improvement in working efficiency, in reliability, and in operability. 
     As described above, this invention provides a microchip fluid control mechanism having a plurality of specimen vessels each having an open top for receiving specimens, and a plurality of reaction vessels for mixing and reacting the specimens, the specimen vessels and the reaction vessels being mutually linked through channels so that the specimens are sequentially transferred with the use of pressurizing means and subjected to predetermined processing. The microchip fluid control mechanism of the invention is characterized in that transfer channels extending from the specimen vessels and transfer channels to the reaction vessels are provided under the specimen vessels and the reaction vessels. 
     The predetermined processing is processing to react, mix, separate, or analyze the specimens, or processing to extract, react, or analyze genes. 
     Preferably, compressed gas is supplied under pressure by the pressurizing means from an opening provided at the top of each of the specimen vessels, so that the specimens are transferred, together with the compressed gas, to the reaction vessels. 
     Preferably, the transfer channels extending from the reaction vessels are provided on and above the reaction vessels while the transfer channels are opened to below the microchip. 
     When the transfer channel extending from each of the specimen vessels and the transfer channel extending to each the reaction vessels are formed as a single reaction line, it is preferred that the reaction line be provided in plurality on the microchip, and a single pressurizing means be branched to drive the plurality of reaction lines. 
     Preferably, the microchip transfer mechanism further has negative pressure generation means and a discharging vessel for collecting the pressurized gas and the specimens discharged thereto, and a negative pressure is established in the inside of the discharging vessel by driving the transfer channels extending from the reaction vessels by the negative pressure generation means. 
     It is also preferred that a filter be provided in each of the transfer channels extending from the reaction vessels so as to leave the specimens in the reaction vessels. 
     Preferably, a stretchable film is provided on the top face of each specimen vessel, and when the specimen is transferred, the specimen vessel is pressurized through the stretchable film to feed out the specimen. The stretchable film is preferably provided detachable. 
     Further, this invention provides a microchip fluid control mechanism having a plurality of specimen vessels each having an open top for receiving specimens, and a plurality of reaction vessels for mixing and reacting the specimens, the specimen vessels and the reaction vessels being mutually linked through channels so that the specimens are sequentially transferred with the use of pressurizing means and subjected to predetermined processing, and characterized in that: the specimens are transferred by supplying compressed gas from above the specimen vessels; transfer channels to the reaction vessels are provided under the microchip, while transfer channels extending from the reaction vessels are provided on the microchip; and pressurizing means for supplying compressed gas from a member holding the microchip is provided outside the microchip. 
     The predetermined processing is processing to react, mix, or analyze the specimens, or processing to extract, react, or analyze genes. 
     Further, this invention provides a microchip fluid control mechanism having a plurality of specimen vessels each having an open top for receiving specimens, and a plurality of reaction vessels for mixing and reacting the specimens, the specimen vessels and the reaction vessels being mutually linked through channels so that the specimens are sequentially transferred with the use of pressurizing means and subjected to predetermined processing, the microchip fluid control mechanism being characterized in that: the microchip is composed of a lower plate, an upper plate, and a main plate interposed between the lower plate and the upper plate; the specimen vessels have a container shape passing through the main plate and the upper plate; the reaction vessels have a container hole shape passing through the main plate and sealed with the lower plate and the upper plate; a plurality of discharging ports are formed to pass through the main plate and the lower plate; the specimen vessels and the reaction vessels are linked to each other through a first channel provided on the side of the main plate facing the lower plate; and the discharging ports and the reaction vessels are linked to each other through a second channel provided on the side of the main plate facing the upper plate. 
     The predetermined processing is processing to react, mix, separate, or analyze the specimens, or processing to extract, react, or analyze genes. 
     It is preferred that the pressurizing means be provided outside the microchip. 
     Furthermore, according to another preferred aspect of the invention, there is provided, on the bottom side of a microchip with respect to a thickness direction thereof, a channel for discharging from a plurality of specimen container holes and for injecting into specimen reaction container holes, and there is further provided, near the top face of the microchip, a channel for discharging specimens overflowing from a plurality of specimen reaction containers which specimens are injected into. This configuration allows a predetermined volume of specimens to remain in the specimen reaction containers. 
     According to another preferred aspect of the invention, the tops of the specimen container holes provided in the microchip are opened, and a presser cover for holding the microchip from above is provided with compressed gas applying holes at positions corresponding to the opened specimen containers, so that the specimens contained in the specimen containers are pushed out by the compressed gas. 
     According to another preferred aspect of the invention, in order to prevent a necessary volume of specimens from being discharged when the specimens, which have been transferred from a plurality of specimen containers and supplied to reaction vessels, overflow from the reaction vessels, a discharging channel port is provided in each of reaction vessel to be oriented downward from the top, while discharging channels are provided in a table for holding the microchip in cooperation with the cover at positions corresponding to the discharging channel ports, so that a necessary volume of the specimen pushed by the compressed gas remains in the reaction vessel while only excessive specimen is discharged. 
     According to another preferred aspect of the invention, a single transfer drive means is branched to drive a plurality of pairs of specimen reaction channels at the same time for improving the productivity. 
     According to another preferred aspect of the invention, the discharging channel provided in the table is further provided with suction means for sucking the specimens with negative pressure in order to reliably isolate the overflowing specimens to be discharged from the microchip, and a single transfer drive means is branched to drive a plurality of pairs of specimen reaction channels at the same time in order to improve the productivity. 
     According to another preferred aspect of the invention, in order to fill the reaction vessels with specimens efficiently, a filter is provided on the channel extending out from each reaction vessel so as to generate a difference between gas-passing resistance and liquid-passing resistance. 
     According to another preferred aspect of the invention, in order to enable transfer of stable volumes of specimens and to prevent excessive supply of gas for certain specimens, a stretchable film is provided on the top of each specimen vessel, and the specimen vessel is pressurized through the film to transfer the specimen by variation in capacity of the specimen vessel caused by bulging of the film. 
     According to this invention, disposable and inexpensive microchips can be provided by omitting valve mechanisms conventionally provided in microchips and thus simplifying the channel structure. 
     According to a preferred aspect of this invention, valve mechanisms conventionally provided in microchips are omitted and, instead, specimens are transferred by compressed gas supplied from a member holding a microchip. Therefore, this invention can provide disposable and inexpensive microchips. 
     The use of compressible medium (gas) here provides advantageous effects as described below. The device is surrounded by abundant air (gas). In the case of using incompressible medium (see Patent Document 3), care is required to prevent bubbles (of gas such as air) from being mixed into the incompressible medium. In order to prevent this, several measures must be taken. In contrast, in the case of using compressible medium (gas) as in this invention, operation is possible even if air (gas) in the surroundings is mixed into when the air (gas) is supplied from pressurizing holes. This consequently allows simplification of the device and improves the fault tolerance thereof. 
     According a preferred aspect of this invention, the size of the device can be reduced and discharged specimens can be collected reliably. Thus, expensive specimens can be analyzed by using a minimum volume. Furthermore, when performing analyses repeatedly, it is possible to effectively prevent cross contamination with a specimen used in previous analysis. 
     According a preferred aspect of this invention, it is possible to drive a plurality of pairs of specimen reaction channels by using simple transfer drive means. This makes it possible to realize transfer with improved productivity with the use of an inexpensive and miniaturized mechanism. 
     According a preferred aspect of this invention, specimens discharged after use can be collected completely, whereby it is made possible, when analyses are performed repeatedly, to prevent cross contamination with specimens used in previous analyses. 
     According a preferred aspect of this invention, a plurality of pairs of specimen reaction channels can be driven simultaneously by using simple transfer drive means, and thus transfer with improved productivity can be realized by using an inexpensive and miniaturized mechanism. 
     According a preferred aspect of this invention, a stretchable film is provided on the top of a specimen vessel in a microchip, the specimen vessel being filled with a specimen, so that the specimen is transferred by being pressurized through the bulging film. This makes it possible to improve the accuracy of flow rate and to prevent the supply of excessive gas. 
     Although this invention has been described specifically based on its exemplary preferred embodiments, this invention is not limited to these embodiments. It will be understood that various modifications may be made without departing from the scope and spirit of the invention, and such modifications are obviously covered by the scope of this invention. 
     INDUSTRIAL APPLICABILITY 
     According to this invention, specimens and liquid reagents are caused to react on a single chip. Therefore, the invention is applicable to medical diagnosis tools, bioresearch tools, food inspection systems, environmental inspection systems and so on by means of chemical refining, production and analysis, gene analysis, or cell proliferation. 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2007 54041, filed Mar. 5, 2007, the disclosure of which is incorporated herein in its entirety by reference.