Abstract:
The present invention is directed to provide a preparation chip system having a simpler configuration and improved reliability while addressing the case where a plurality of reagents have to be fed as in a preparation of extracting DNA from a sample solution. The preparation chip system includes a sample chamber, a dissolving solution chamber, a cleaning solution chamber, an eluting solution chamber, a mixing passage connected to the sample chamber and the dissolving solution chamber and mixing the sample and the dissolving solution with each other, a carrier part connected to the mixing passage, a waste chamber connected to the carrier part via a holding passage, a collection chamber holding the eluting solution passed through the carrier part, and a plurality of resistive materials forming a passage resistor disposed in a first passage connecting the cleaning solution chamber with both the mixing passage and the carrier part. The eluting solution is passed through the carrier part by pressure from a pressure source.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a preparation chip for extracting DNA from a sample solution as a biological material for conducting a gene test and to a preparation chip system using the same. 
         [0003]    2. Description of the Related Art 
         [0004]    To test a living body with a DNA sequencer, a DNA chip, and the like at a gene level, it is necessary to extract DNA from a biological material. A method is known, to separate a desired analyte from a fluid sample, of using a chamber, a storage chamber, and a cartridge obtained by assembling a detecting process region or the like on a fine fluid chip and leading the flow, particularly, the diversion of a sample solution, a reagent, a waste solution, and the like by using a diverter including a capillary or a hydrophobic film. Such a method is described in, for example, Japanese Patent Application National Publication Laid-Open No. 2001-527220. 
         [0005]    In the conventional technique, to divert a waste solution, a diverter for passing a solution simply in the case where limit back pressure is generated is used. In the case of applying the conventional technique to the case where the number of branches is large such as a case of sequentially passing a plurality of regents, a plurality of limit back pressures have to be set and it is difficult to reliably pass the regents. 
       SUMMARY OF THE INVENTION 
       [0006]    An object of the present invention is to provide a biological material preparation chip and a preparation chip system with a simpler configuration, realizing reliable flow of solutions, with improved reliability, and realizing prompt processing also in the case where a plurality of reagents have to be fed like in a preparation of extracting DNA from a sample solution. 
         [0007]    To solve the problem of the conventional technique, the present invention provides a preparation chip system, in order to extract DNA from a biological material, for injecting a sample solution into a preparation chip, mixing the sample solution with a dissolving solution to expose DNA, passing the dissolved sample solution through a carrier part to adsorb the DNA on the surface of a carrier, passing a cleaning solution through the carrier part to wash away the sample solution remaining on the surface, passing an eluting solution through the carrier part to elute the adsorbed DNA, and taking out the eluting solution containing the DNA. The system includes: a sample chamber in which the sample is injected; a dissolving solution chamber containing the dissolving solution; a cleaning solution chamber containing the cleaning solution; an eluting solution chamber containing the eluting solution; a mixing passage connected to the sample chamber and the dissolving solution chamber and mixing the sample and the dissolving solution with each other; a carrier part connected to the mixing passage; a waste chamber connected to the carrier part via a holding passage; a collection chamber connected to the waste chamber and holding the eluting solution passed through the carrier part; and a plurality of resistive materials forming a passage resistor disposed in a first passage connecting the cleaning solution chamber with both the mixing passage and the carrier part. The eluting solution is passed through the carrier part by pressure from a pressure source. 
         [0008]    According to the invention, the passage for passing the cleaning solution and the eluting solution is ramified while a passage resistor being set by using a plurality of resistive materials. Therefore, also in the case where a plurality of reagents have to be fed like in a preparation of extracting DNA from a sample solution, a simpler configuration, reliable flow of the solutions, and improved reliability can be realized. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a top view of a preparation chip according to an embodiment of the invention; 
           [0010]      FIG. 2  is a perspective view showing the details of a resistance part in  FIG. 1 ; 
           [0011]      FIG. 3  is a flowchart showing a preparation process according to an embodiment; and 
           [0012]      FIG. 4  is a perspective view showing an outline of a preparation chip apparatus according to an embodiment. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0013]    Referring to  FIG. 1 , the structure of a preparation chip for extracting DNA from a sample solution as an embodiment will be described. 
         [0014]    A preparation chip  100  has a sample chamber  110  in which a sample containing a biological material is injected, a dissolving solution chamber  111  containing a dissolving solution, cleaning solution chambers  112  and  113  containing cleaning solution, an eluting solution chamber  114  containing an eluting solution, a passage  120  for mixing the sample with the eluting solution, a carrier part  130  made of a plurality of carriers as substances for adsorbing DNA in the sample thereon and effectively performing chemical/physical operation of a small amount of an element and compound, a holding passage  121  for temporarily holding the sample, the dissolving solution, the cleaning solution, and the eluting solution passed through the carrier part  130 , a waste chamber  115  for holding the sample, the dissolving solution, and the cleaning solution passed through the carrier part  130 , and a collection chamber  116  for holding the eluting solution passed through the carrier part  130 . 
         [0015]    The chambers  110  to  116  are connected to ports  190  to  196  via port passages  180  to  186 , respectively. Further, between the both of the mixing passage  120  and the carrier part  130  and the group consisting of the first and second cleaning solution chambers  112 ,  113  and the eluting solution chamber  114 , resistance parts  160  to  164  made from a plurality of resistive materials  169  are provided, with connection passages being interposed among them. 
         [0016]    The resistance part  162  is disposed in a first passage connecting the first cleaning solution chamber  112  with both the mixing passage  120  and the carrier part  130 . The resistance part  163  is disposed in a second passage connecting the carrier part side of the first passage and the second cleaning solution chamber  113 . 
         [0017]    The resistance part  164  is disposed between the eluting solution chamber  114  and the carrier part  130 , the resistance part  161  is disposed between the resistance parts  163 ,  164  and the carrier part  130 , and the resistance part  160  is disposed between the resistance parts  161 ,  162  and the both of the passage  120  and the carrier part  130 . A suitable carrier has the surface made of a glass material such as glass beads, glass wool, glass sintered body, porous glass, since such material efficiently adsorbs DNA. 
         [0018]    The magnitude relations of the passage resistances between the passage  120 , the carrier part  130 , and the resistance parts  160  to  164  are as follows. 
         [0000]    Passage  120 &lt;carrier part  130 &lt;resistance part  160 
 
Resistance part  160 &lt;resistance part  161 
 
Resistance part  160 &lt;resistance part  162 
 
Resistance part  160 +resistance part  161 &lt;resistance part  163 
 
Resistance part  160 +resistance part  161 &lt;resistance part  164 
 
         [0019]      FIG. 2  is a perspective view showing the details of the resistance part  160 . In the resistance part  160 , two resistive materials  169   a  and  169   b  are connected in series via a connection passage  168   c . Connection passages  168   a  and  168   b  are connected to the resistive material  169   a , and connection passages  168   d  and  168   e  are connected to the resistive material  169   b . The passage  120  is positioned at the end of the connection passage  168   a . The carrier part  130  is positioned at the end of the connection passage  168   b . The resistance part  162  is positioned at the end of the connection passage  168   d . The resistance part  161  is positioned at the end of the connection passage  168   e.    
         [0020]    As the resistive material, it is preferable to use the same material as that of the carrier. Accordingly, to set the passage resistance to a proper value, it is sufficient to set the number of carriers. As compared with the case of setting passage resistance and the like by a single resistive material, not only the value itself but variations of the quality and the like are smaller. Thus, it is easier to assure reliability. 
         [0021]    Outline of the preparing procedure will be described with reference to  FIG. 3 . The preparation corresponds to the range of up to extracting DNA from a biological material and consists of four processes of (1) dissolution, (2) adsorption, (3) cleaning, and (4) elution. 
         [0022]    First, a sample solution is injected into the chip and mixed with a dissolving solution in the chip to dissolve the biological material and expose DNA (dissolving process). Next, the dissolved sample solution is passed through the carrier part where the DNA is adsorbed on the surface of the carrier (adsorbing process). 
         [0023]    A cleaning solution is passed through the carrier part to wash away the sample solution remaining on the surface of the carrier (cleaning process). An eluting solution is passed through the carrier part to elute the DNA adsorbed on the surface of the carrier (eluting process). Finally, the eluting solution containing the DNA is taken out. 
         [0024]    The procedure of performing the above-described preparing process in the chip will be described. 
         [0025]    In the initial state, reagents are contained in the chip. Specifically, the dissolving solution chamber  111  is filled with the dissolving solution, the cleaning solution chamber  112  is filled with a cleaning solution, the cleaning solution chamber  113  is filled with another cleaning solution, and the eluting solution chamber  114  is filled with the eluting solution. 
         [0026]    A sample solution is injected from the port  190  into the chip in the initial state to fill the sample chamber  110 . At this time, the ports  191 ,  192 ,  193 , and  194  are closed. At least one of the ports  195  and  196  is open to inject the sample solution from the port  190 . 
         [0027]    The sample solution in the sample chamber  110  and the dissolving solution in the dissolving solution chamber  111  are fed to the passage  120  where they are mixed. In this instance, the ports  192 ,  193 , and  194  are closed, at least one of the ports  195  and  196  is opened, and air is injected from the ports  190  and  191 . As necessary, the mixture of the sample and the dissolving solution may be heated in the chip. 
         [0028]    The mixture of the sample solution and the eluting solution is fed from the passage  120  via the carrier part  130  to the passage  121 . In this instance, the ports  192 ,  193 , and  194  are closed, at least one of the port  195  and  196  is opened, and air is injected from the port  190  or  191 . Since the passage resistance in the carrier part  130  is lower than that in the resistance part  160 , the mixture from the passage  120  flows to the carrier part  130 . 
         [0029]    In the case of passing the mixture in the passage  121  via the carrier part  130  to the passage  120 , the ports  192 ,  193 , and  194  are closed, at least one of the ports  190  and  191  is opened, and air is injected from the port  195  or  196 . Since the passage resistance in the passage  120  is lower than that in the resistance part  160 , the mixture from the carrier part  130  flows to the passage  120 . When the mixture passes through the carrier part  130 , DNA in the mixture is adsorbed on the surface of the carrier. In the case of passing the mixture in the passage  121  to the waste chamber  115 , the ports  192 ,  193 ,  194 , and  196  are closed, the port  195  is opened, and air is injected from the port  190  or  191 . In such a manner, the mixture is held in the waste chamber  115 . 
         [0030]    The cleaning solution is once fed from the cleaning solution chamber  112  to the passage  120 . The ports  193 ,  194 ,  195 , and  196  are closed, at least one of the ports  190  and  191  is opened, and air is injected from the port  192 . Since the passage resistance in the resistance part  160  is lower than that in the resistance part  161 , the cleaning solution from the cleaning solution chamber  112  flows to the resistance part  160 . Since the passage resistance in the passage  120  is lower than that in the carrier part  130 , the cleaning solution from the resistance part  160  flows to the passage  120 . The cleaning solution is temporarily held in the passage  120 . 
         [0031]    The cleaning solution is fed from the passage  120  via the carrier part  130  to the passage  121 . The ports  192 ,  193 , and  194  are closed, at least one of the ports  195  and  196  is opened, and air is injected from the port  190  or  191 . Since the number of carriers in the carrier part  130  is smaller than that in the resistance part  160  and the passage resistance is lower, the cleaning solution from the passage  120  flows to the carrier part  130 . In the case of passing the cleaning solution in the passage  121  via the carrier part  130  to the passage  120 , the ports  192 ,  193 , and  194  are closed, at least one of the ports  190  and  191  is opened, and air is injected from the port  195  or  196 . Since passage resistance in the passage  120  is lower than that in the resistance part  160 , the cleaning solution from the carrier part  130  flows to the passage  120 . 
         [0032]    When the cleaning solution passes through the carrier part  130 , components other than the DNA on the carrier surface are washed out. In the case of passing the cleaning solution in the passage  121  to the waste chamber  115 , the ports  192 ,  193 ,  194  and  196  are closed, the port  195  is opened, and air is injected from the port  190  or  191 . In such a manner, following the mixture, the cleaning solution is held in the waste chamber  115 . 
         [0033]    The cleaning solution is once fed from the cleaning solution chamber  113  to the passage  120 . The ports  192 ,  194 ,  195 , and  196  are closed, at least one of the ports  190  and  191  is opened, and air is injected from the port  193 . Since the passage resistance in the resistance part  161  is lower than that in the resistance part  164 , the cleaning solution from the cleaning solution chamber  113  flows to the resistance part  161 . 
         [0034]    Since the passage resistance in the resistance part  160  is lower than that in the resistance part  162 , the cleaning solution from the resistance part  161  flows to the resistance part  160 . Since the passage resistance in the passage  120  is lower than that in the carrier part  130 , the cleaning solution from the resistance part  160  flows to the passage  120 . The cleaning solution is temporarily held in the passage  120 . 
         [0035]    The cleaning solution is fed from the passage  120  via the carrier part  130  to the passage  121 . The ports  192 ,  193 , and  194  are closed, at least one of the ports  195  and  196  is opened, and air is injected from the port  190  or  191 . Since the passage resistance in the carrier part  130  is lower than that in the resistance part  160 , the cleaning solution from the passage  120  flows to the carrier part  130 . 
         [0036]    In the case of passing the cleaning solution in the passage  121  via the carrier part  130  to the passage  120 , the ports  192 ,  193 , and  194  are closed, at least one of the ports  190  and  191  is opened, and air is injected from the port  195  or  196 . Since passage resistance in the passage  120  is lower than that in the resistance part  160 , the cleaning solution from the carrier part  130  flows to the passage  120 . When the cleaning solution passes through the carrier part  130 , the components other than DNA on the carrier surface are further washed. 
         [0037]    In the case of passing the cleaning solution in the passage  121  to the waste chamber  115 , the ports  192 ,  193 ,  194 , and  196  are closed, the port  195  is opened, and air is injected from the port  190  or  191 . Following the mixture and the cleaning solution, the cleaning solution is held in the waste chamber  115 . 
         [0038]    The eluting solution is once fed from the eluting solution chamber  114  to the passage  120 . The ports  192 ,  193 ,  195 , and  196  are closed, at least one of the ports  190  and  191  is opened, and air is injected from the port  194 . Since the passage resistance in the resistance part  161  is lower than that in the resistance part  163 , the eluting solution from the eluting solution chamber  114  flows to the resistance part  161 . Since the passage resistance in the resistance part  160  is lower than that in the resistance part  162 , the eluting solution from the resistance part  161  flows to the resistance part  160 . 
         [0039]    Further, since the passage resistance in the passage  120  is lower than that in the carrier part  130 , the eluting solution from the resistance part  160  flows to the passage  120 . The eluting solution is temporarily held in the passage  120 . 
         [0040]    The eluting solution is fed from the passage  120  via the carrier part  130  to the passage  121 . The ports  192 ,  193 , and  194  are closed, at least one of the ports  195  and  196  is opened, and air is injected from the port  190  or  191 . Since the passage resistance in the carrier part  130  is lower than that in the resistance part  160 , the eluting solution from the passage  120  flows to the carrier part  130 . In the case of passing the eluting solution in the passage  121  via the carrier part  130  to the passage  120 , the ports  192 ,  193 , and  194  are closed, at least one of the ports  190  and  191  is opened, and air is injected from the port  195  or  196 . Since passage resistance in the passage  120  is lower than that in the resistance part  160 , the eluting solution from the carrier part  130  flows to the passage  120 . When the eluting solution passes through the carrier part  130 , the DNA is eluted from the carrier surface and is retained in the eluting solution. 
         [0041]    In the case of passing the eluting solution in the passage  121  to the collection chamber  116 , the ports  192 ,  193 ,  194  and  195  are closed, the port  196  is opened, and air is injected from the port  190  or  191 . In such a manner, the eluting solution retaining the DNA is held in the collection chamber  116 . 
         [0042]    Finally, the eluting solution held in the collection chamber  116  is taken out from the port  196 , and the preparation is finished. The eluting solution retaining the DNA after the preparation is amplified as necessary and used for a test of a living body at a gene level using a DNA sequencer, a DNA chip, and the like. 
         [0043]    As described above, the resistance parts  160  to  164  are disposed between the both of the passage  120  and the carrier part  130  and the group consisting of the cleaning solution chambers  112 ,  113  and the eluting solution chamber  114 , and the magnitude relations of the passage resistances between the passage  120 , the carrier part  130 , and the resistance parts  160  to  164  can be set according to the number of carriers. Therefore, it is easy to dispose the components in such a state that setting of the passage resistance is flexible. 
         [0044]    Also in the case of changing the passage resistance in accordance with fluid properties, the passage resistance can be set by adjusting the number of resistive materials. Further, by changing the arrangement of the resistive materials, the flow direction control can be changed without forming a new chip. 
         [0045]    A preparation chip system (apparatus) of  FIG. 4  has a chip receiving window  201  to which a preparation chip is inserted, a movement stage  203  for moving the preparation chip, a preparation stage  204  for performing the preparation, a valve  205  and a pump  213  for passing solutions in the preparation chip, a power supply  206 , a motor driver  207 , a control board  208 , and an information access panel  209 . The motor driver  207  and the control board  208  are used for operating the movement stage  203 , the valve  205 , and the pump  213 . The power supply  206  supplies electricity to various parts. The information access panel  209  is used for inputting measurement parameters and outputting a measurement result. 
         [0046]    The preparation chip apparatus can extract DNA from a biological material in order to conduct a gene test. A preparation chip is inserted from the chip receiving window  201 . 
         [0047]    In the preparation chip, regents are filled, and a sample containing a biological material is injected. The preparation chip is carried by the movement stage  203  to the preparation stage  204 . In the preparation stage  204 , the sample solution containing the biological material is mixed with the dissolving solution to dissolve the biological material and expose DNA, in the preparation chip. 
         [0048]    The dissolved sample solution is fed through the carrier part to adsorb the DNA on the carrier surface. The cleaning solution is passed through the carrier part to wash away the sample solution remaining on the carrier surface. The eluting solution is passed through the carrier part to elute the DNA adsorbed on the carrier surface. 
         [0049]    The preparation process is performed automatically in the preparation chip apparatus, and the preparation chip is carried by the movement stage  203  to the chip receiving window  201  and is taken out. It is sufficient to load the preparation chip in the preparation chip apparatus and it is unnecessary to accurately control the amount of a solution passed.