Patent Publication Number: US-2023145735-A1

Title: Microchannel chip

Description:
TECHNICAL FIELD 
     The present invention relates to a microchannel chip. 
     BACKGROUND ART 
     There are many attempts to perform various tests such as a blood test and a genetic test as well as biochemical analysis using a chip having microchannels so as to control supply and/or reactions of various kinds of specimens and samples. Such a microchannel chip for tests or analyses includes a channel structure capable of merging and mixing a plurality of kinds of fluid with each other. 
     Especially in the fields such as the medical field and the biochemical field, there is a demand for downsizing and simplifying analytical equipment. Also, analyzing a trace specimen is required in consideration of high-speed analysis and reduction of burden on a human body. Thus, microchannel chips are also required to contribute to size reduction and simplified structure, and to perform stable analysis of a trace specimen. 
     The conventional microchannel chips take time to supply and react a specimen after introduction, which occasionally causes drying or coagulation of the specimen. Therefore, it is difficult to accurately react or measure the specimen. Taking into account the above, a microchannel chip is proposed, for example in Patent Document 1, to which a supply tank for anticoagulant, a pump and the like are attached. With this configuration, the anticoagulant, which causes anticoagulation reaction of blood, is supplied to the channel. 
     PRIOR ART DOCUMENT 
     Patent Document 
     [Patent Document 1] WO 2011/065176 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     However, providing a supply tank for a compound or an antibody to serve as anticoagulant causing the anticoagulation reaction on the microchannel chip, as disclosed in Patent Document 1, increases costs. Moreover, it is not preferable from the viewpoint of size reduction and simplification of the device. In addition to the above, sometimes it is necessary for a human body to make directly contact with the microchannel chip when introducing a specimen, which may result in health damage caused by the compound or the antibody erroneously touched by the human body. 
     The present invention was made in consideration of the above problems, an object of which is to provide a microchannel chip with a simple structure, which is capable of supplying liquid or causing reaction rapidly without using any compound or antibody causing the anticoagulation reaction of the blood. 
     Means for Solving the Problem 
     In order to achieve the above object, a microchannel chip of the present invention, which is a microchannel chip that mixes first liquid and second liquid to supply the thus mixed liquid, includes: a first channel; a first liquid holder provided on the first channel to store the first liquid; a gas inlet that communicates with the first channel and is opened to the outside of a system on the upstream side of the first liquid holder; a lid closing the gas inlet; a second channel provided downstream of the first channel; and a second liquid holder to hold the second liquid, which is capable of communicating with the downstream side of the first liquid holder. The downstream side of the second channel is opened to the outside of the system. When the lid is closed, gas is supplied to the first channel and pushes out the first liquid downstream from the first liquid holder, and the thus pushed-out first liquid merges with the second liquid in the second channel. 
     The microchannel chip as described above preferably includes: a first base plate, in a first surface of which the first channel is formed; and a second base plate laminated on and bonded to the first base plate so as to face the first surface. It is also preferable that the gas inlet is provided in the first base plate so as to open to a second surface on an opposite side of the first surface, and that the lid is to be attached facing to the second surface. 
     In the microchannel chip as described above, the second channel may be formed in the first base plate, and the second channel may be connected to the first channel downstream of the first liquid holder. 
     In the microchannel chip as described above, it is preferable that the second liquid holder is provided on the second channel. Also, it is preferable that the second liquid holder includes an opening part provided in the second surface so as to introduce the second liquid, and furthermore that the lid includes a first closing part that closes the gas inlet and a second closing part that closes the opening part. 
     The microchannel chip as described above may have a configuration in which the lid includes a third channel capable of being connected to the first channel, so that when the lid is closed, the first channel is connected to the second channel provided in the first base plate via the third channel. 
     The microchannel chip as described above may have a configuration in which the second liquid holder is provided on the second channel, and an opening part to introduce the second liquid is formed in the second surface. Also, it is preferable that the second liquid holder is provided so as to protrude from the second surface. 
     In the microchannel chip as described above, it is preferable that the second liquid holder is provided on the third channel, and that an opening part to introduce the second liquid is formed in the lid so as to open to a surface facing the second surface. Also, the second liquid holder may be formed in a downstream end of the third channel, and may be connected to the second channel when the lid is closed. 
     The microchannel chip as described above may have a configuration in which the lid includes a fourth channel whose upstream end is opened to the outside of the system and whose downstream end is capable of being connected to the second channel, so that when the lid is closed, the upstream end of the fourth channel is closed while the downstream end of the fourth channel is connected to the second channel. 
     The microchannel chip as described above may have a configuration in which the second liquid holder is provided in the downstream end of the fourth channel, and an opening part to introduce the second liquid is formed in the lid so as to open to a surface facing the second surface. In this way, when the lid is closed, gas is supplied to the fourth channel and pushes out the second liquid downstream from the second liquid holder, and that the thus pushed-out second liquid merges with the first liquid in the second channel. 
     The microchannel chip as described above may have a configuration in which the second liquid holder is provided so as to protrude from a surface of the lid, which faces the second surface. 
     Effects of the Invention 
     With the present invention, a microchannel chip with a simple structure is provided, which is capable of supplying liquid or causing reaction rapidly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       [ FIG.  1   ] 
         FIG.  1 ( a )  and  FIG.  1 ( b )  are partial sectional views schematically illustrating a microchannel chip according to Embodiment 1 of the present invention. 
       [ FIG.  2   ] 
         FIG.  2    is a front view illustrating a chip body of the microchannel chip. 
       [ FIG.  3   ] 
         FIG.  3 ( a )  and  FIG.  3 ( b )  are partial sectional views schematically illustrating a microchannel chip according to Embodiment 2 of the present invention. 
       [ FIG.  4   ] 
         FIG.  4 ( a )  and  FIG.  4 ( b )  are partial sectional views schematically illustrating a microchannel chip according to Embodiment 3 of the present invention. 
       [ FIG.  5   ] 
         FIG.  5 ( a )  and  FIG.  5 ( b )  are partial sectional views schematically illustrating a microchannel chip according to Embodiment 4 of the present invention. 
       [ FIG.  6   ] 
         FIG.  6 ( a )  and  FIG.  6 ( b )  are partial sectional views schematically illustrating a microchannel chip according to Embodiment 5 of the present invention. 
       [ FIG.  7   ] 
         FIG.  7 ( a )  and  FIG.  7 ( b )  are partial sectional views schematically illustrating a microchannel chip according to Embodiment 6 of the present invention. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, a microchannel chip  1  according to the embodiments of the present invention will be described with reference to the drawings. 
     Embodiment 1 
       FIG.  1 ( a )  and  FIG.  1 ( b )  are partial sectional views schematically illustrating a main part of a microchannel chip  1  according to Embodiment 1 of the present invention.  FIG.  2    is a front view illustrating a chip body  10  of the microchannel chip  1 .  FIG.  1 ( a )  and  FIG.  1 ( b )  correspond to cross-sectional views taken along the line A-A of  FIG.  2   . 
     The microchannel chip  1  is a chip for testing or analyzing. The microchannel chip  1  includes fine channels for, for example, mixing a reagent  30  as a first liquid and a specimen  40  as a second liquid and supplying the mixture to be subjected to a desired treatment step. As shown in  FIG.  2   , the microchannel chip  1  has a rectangular-plate shape. However, the general shape of the microchannel chip  1  is not limited to the rectangular-plate shape. It may have any shape, for example, a disk shape or a sector shape. 
     As shown in  FIG.  1 ( a ) , the microchannel chip  1  is provided with the chip body  10  and a lid  50  to be attached to the chip body  10 . The chip body  10  includes a first base plate  110  and a second base plate  120 . The first base plate  110  is a plate-like member having a lower surface (first surface)  111  and an upper surface (second surface)  112  on the opposite side of the lower surface  111 . The second base plate  120  is also a plate-like member that is laminated on and bonded to the lower surface  111  of the first base plate  110 . The first base plate  110  and the second base plate  120  each may be formed by an injection molded body made of synthetic resin, or also may be formed by laminating a plurality of synthetic resin sheets. 
     In the following description, the lid  50  is provided on the upper side of the chip body  10  of the microchannel chip  1  while the second base plate  120  is bonded to the bottom surface of the first base plate  110 , as shown in  FIG.  1 ( a )  and  FIG.  1 ( b ) . However, this definition of the vertical direction is only for understandability of the description, and thus does not limit the direction when using the microchannel chip  1  according to this embodiment. 
     In the microchannel chip  1  according to Embodiment 1, the chip body  10  includes a first channel  201  and a second channel  202 . The first channel  201  is disposed upstream of the second channel  202  (i.e. on the left side in  FIG.  1 ( a )  and  FIG.  1 ( b ) ). The first channel  201  and the second channel  202  are provided in this order in the liquid feeding direction X so as to communicate with each other. In these schematically shown drawings, the channels  201  and  202  have a linear shape. However, the channels  201  and  202  may have any shape. 
     On the upstream side of the first channel  201 , a gas inlet  210  is provided so as to open to the outside of the system. In the embodiment exemplarily shown, the gas inlet  210  is provided so as to open to the upper surface  112  of the first base plate  110 . 
     On the first channel  201 , a reagent holder (first liquid holder)  230  is provided so as to store the reagent  30 . On the upstream side of the reagent holder  230 , the gas inlet  210  is provided. Thus, the reagent holder  230  and the gas inlet  210  communicate with each other via the first channel  201 . 
     Since the reagent holder  230  has a constriction structure, the reagent  30  can be stably stored therein. When comparing the cross-sectional areas of the respective cross sections orthogonally intersecting with the liquid feeding direction X, the cross-sectional area of the first channel  201  downstream of the reagent holder  230  is, for example, smaller than the cross-sectional area of the reagent holder  230 . In this way, the channel resistance at the time of movement of the reagent  30  downstream in the reagent holder  230  increases, which contributes to stable storing of the reagent  30  in the reagent holder  230 . 
     On the second channel  202  downstream of the first channel  201 , a specimen holder (second liquid holder)  240  is provided so as to store the specimen  40 . The specimen holder  240  is provided downstream of the reagent holder  230 , and also is connected to the first channel  201  provided on the downstream side of the reagent holder  230 . The second channel  202  is opened to the outside of the system on the downstream side of the specimen holder  240 . 
     In the microchannel chip  1  according to Embodiment 1, the specimen holder  240  is disposed in the chip body  10 , and an opening part  241  is formed in the upper surface  112  of the first base plate  110  so as to introduce the specimen  40 . The opening part  241  communicates with the specimen holder  240  on the second channel  202 . The specimen  40  is introduced into the specimen holder  240  using a syringe or a pipette via the opening part  241 . 
     The upper surface  112  and the lower surface  111  of the first base plate  110  of the chip body  10  are parallel to each other. Respective recesses to be the first channel  201  and the second channel  202  are formed in the lower surface  111  of the first base plate  110 . Thus, when the second base plate  120  is laminated on the first base plate  110 , the first channel  201  and the second channel  202  are formed as spaces sandwiched between the first base plate  110  and the second base plate  120 . 
     The microchannel chip  1  is provided with the first channel  201  and the second channel  202  as the fine channels generating micro effects when feeding the liquid. It is preferable, for example, that these channels respectively have a cross-sectional size (i.e. width, height or inner diameter) of the cross-section orthogonally intersecting with the liquid feeding direction X in the range of 0.01 to 10 mm, from the viewpoint of reduction in the channel resistance. The channels may have any cross-sectional shape, for example, a rectangle shape and a circle shape. 
     The lid  50  is attached to the upper surface  112  of the first base plate  110  of the chip body  10 . As shown in  FIG.  1 ( a ) , the lid  50  includes a first closing part  510  that closes the gas inlet  210  and a second closing part  520  that closes the opening part  241 . The lid  50  is made of, for example, elastomer or synthetic resin that has elasticity or adherence. 
     The first closing part  510  and the second closing part  520  are provided, in a protruding manner, on a lower surface  501  of the lid  50 . The lower surface  501  faces the upper surface  112  of the first base plate  110 . The first closing part  510  has a protruded shape corresponding to the gas inlet  210  so as to be fitted in the gas inlet  210 . The second closing part  520  has a protruded shape corresponding to the opening part  241  so as to be fitted in the opening part  241 . 
     As shown in  FIG.  1 ( b ) , the lid  50  is attached to the chip body  10  so that the gas inlet  210  and the opening part  241  are closed. Thus, the first closing part  510  closes the gas inlet  210  while the second closing part  520  closes the opening part  241 , so that the liquid is started to be supplied. 
     When the lid  50  is attached to the chip body  10 , the first closing part  510  is press-fitted in the gas inlet  210  so as to close the gas inlet  210 . Since the internal space of the gas inlet  210  is narrowed, the gas (air) in the gas inlet  210  flows into the first channel  201 . The gas supplied to the first channel  201  pushes out the reagent  30  downstream from the reagent holder  230 . The pushed-out reagent  30  flows from the first channel  201  to the second channel  202 . 
     Also, the second closing part  520  is press-fitted in the opening part  241  so as to close the opening part  241 . Thus, the specimen stored in the specimen holder  240  is pushed out from the specimen holder  240  to flow through the second channel  202 . In the second channel  202 , the reagent  30  from the reagent holder  230  merges with the specimen  40 . 
     More specifically, the specimen  40  pushed out from the specimen holder  240  wets and spreads over the inner wall of the second channel  202 . Thus, the wet and spread specimen  40  remains in the second channel  202  while forming a space where the gas can pass through. Therefore, the reagent  30  that has flowed in the liquid feeding direction X merges with the specimen  40  that has wetted and spread on the second channel  202 , so that mixed liquid is prepared. By making the inner wall of the second channel  202  of material having a high affinity for the specimen  40 , the specimen  40  effectively wets and spreads, which results in reliable merge of the reagent  30  with the specimen  40 . 
     In the microchannel chip  1  as described above according to this embodiment, by attaching the lid  50  to the chip body  10  after introducing the specimen  40  into the specimen holder  240 , the reagent  30  is immediately mixed with the specimen  40  so as to be held as the mixed liquid. Therefore, it is possible to prevent drying and coagulation of the specimen  40  without using any compound or antibody to serve as anticoagulant causing the anticoagulation reaction, which contributes to accurate reaction and measurement of the specimen  40 . Also, since it is not required to use the compound or the antibody, which results in no supply tank being needed, it is possible to reduce production costs and to form the microchannel chip  1  with a simple configuration. 
     Embodiment 2 
       FIG.  3 ( a )  and  FIG.  3 ( b )  are partial sectional views schematically illustrating a main part of the microchannel chip  1  according to Embodiment 2.  FIG.  3 ( a )  and  FIG.  3 ( b )  correspond to cross-sectional views taken along the line A-A of  FIG.  2   . 
     Since the general configuration of the microchannel chip  1  according to Embodiments 2 to 6 described below is substantially the same as that in Embodiment 1, the common configuration is indicated by the same reference numerals as those in Embodiment 1, and the repetitive description thereof is omitted. 
     In the microchannel chip  1  according to Embodiment 1, the first closing part  510  of the lid  50  is fitted in the gas inlet  210  while the second closing part  520  of the lid  50  is fitted in the opening part  241 . In contrast to the above, in the microchannel chip  1  according to Embodiment 2, the gas inlet  210  is fitted in the lid  50 . 
     As shown in  FIG.  3 ( a ) , a protruding gas inlet  211  is provided, in a protruding manner, on the upper surface  112  of the first base plate  110 . The gas inlet  210  as an opening is formed in the protruding gas inlet  211 . Also, a specimen introducing protruding part  242  is provided, in a protruding manner, on the upper surface  112  of the first base plate  110 . The opening part  241  is provided in the specimen introducing protruding part  242  so as to communicate with the specimen holder  240 . A certain amount of specimen  40  is introduced into the specimen holder  240  using a pipette or the like via the opening part  241  of the specimen introducing protruding part  242 . 
     On the other hand, a recess part  511  corresponding to the protruding gas inlet  211  is provided in the first closing part  510  of the lid  50  while a recess part  521  corresponding to the specimen introducing protruding part  242  is provided in the second closing part  520  of the lid  50 . 
     As shown in  FIG.  3 ( b ) , when the lid  50  is attached to the chip body  10 , the protruding gas inlet  211  is fitted in the first closing part  510  so that the gas inlet  210  is closed. Also, the specimen introducing protruding part  242  is fitted in the second closing part  520  so that the opening part  241  is closed. 
     In this way, the gas is supplied from the gas inlet  210  to the first channel  201 , and the gas supplied to the first channel  201  pushes out the reagent  30  downstream from the reagent holder  230 . The pushed-out reagent  30  merges with the specimen  40  in the second channel  202 . 
     Therefore, in the microchannel chip  1  according to this embodiment also, by attaching the lid  50  to the chip body  10  after introducing the specimen  40  into the specimen holder  240 , the reagent  30  is immediately mixed with the specimen  40  so as to be held as the mixed liquid, similarly to Embodiment 1. 
     Embodiment 3 
       FIG.  4 ( a )  and  FIG.  4 ( b )  are partial sectional views schematically illustrating a main part of the microchannel chip  1  according to Embodiment 3.  FIG.  4 ( a )  and  FIG.  4 ( b )  correspond to cross-sectional views taken along the line A-A of  FIG.  2   . 
     In the microchannel chip  1  according to Embodiment 1, the first channel  201  of the chip body  10  is directly connected to the second channel  202 . In contrast to the above, in the microchannel chip  1  according to Embodiment 3, the first channel  201  of the chip body  10  is connected to the second channel  202  of the chip body  10  via a third channel  203  provided in the lid  50 . 
     As shown in  FIG.  4 ( a ) , the lid  50  is provided with the third channel  203  to be connected to the first channel  201 . The third channel  203  is a channel passing through the inside of the lid  50 . The third channel  203  includes an upstream end opening  203   a  and a downstream end opening  203   b,  both of which are opened to the outside of the system. 
     Similarly to Embodiment 1, the chip body  10  includes: the gas inlet  210 ; the first channel  201  communicating with the gas inlet  210 ; and the reagent holder  230  on the first channel  201 . The first channel  201  extending downstream of the reagent holder  230  has a downstream end that is opened to the upper surface  112  of the first base plate  110 . In this case, the first channel  201  downstream of the reagent holder  230  extends from the lower surface  111  of the first base plate  110  to the upper surface  112  side thereof, and the downstream end is opened to the upper surface  112  of the first base plate  110 . 
     A first protruding part  113  and a second protruding part  114  are provided on the upper surface  112  of the first base plate  110  in a protruding manner. These first protruding part  113  and the second protruding part  114  are formed so as to respectively correspond to the upstream end opening  203   a  and the downstream end opening  203   b  of the lid  50 . The first channel  201  is vertically provided inside of the first protruding part  113 , and the downstream end of the first channel  201  is opened to the upper end of the first protruding part  113 . The specimen holder  240  is provided inside of the second protruding part  114  so as to communicate with the second channel  202 . The opening part  241  of the specimen holder  240  is opened to the upper end of the second protruding part  114 . 
     Since the specimen holder  240  is protruded from the upper surface  112  of the first base plate  110 , the specimen  40  can be directly collected without using the pipette or the like. That is to say, the opening part  241  formed in the second protruding part  114  can be used as a specimen collecting port. In this case, when the opening part  241  is come into contact with the specimen  40 , the specimen  40  is introduced into the specimen holder  240  by capillary force till the specimen holder  240  is filled up with the specimen  40 . The specimen holder  240  is a channel having a circular cross-section. Thus, the specimen  40  can be drawn by the capillary force. 
     In order to use the capillary force as drive force to directly collect the specimen  40  in the specimen holder  240 , it is preferable, for example, that the opening part  241  is formed to have an inner diameter in the range of not less than 0.1 mm to not more than 2.0 mm. It is more preferable that the opening part  241  has an inner diameter in the range of not less than 0.4 mm to not more than 1.2 mm. In this way, it is possible to easily collect the specimen  40  such as blood from a finger or the like of a human body by the capillary force. 
     As shown in  FIG.  4 ( b ) , when the lid  50  is attached to the chip body  10 , the gas inlet  210  is closed by the first closing part  510  while the first protruding part  113  and the second protruding part  114  are covered with the lid  50 . In other words, the first protruding part  113  of the chip body  10  is fitted in the upstream end opening  203   a  of the third channel  203  of the lid  50 , and the second protruding part  114  is fitted in the downstream end opening  203   b  of the third channel  203  of the lid  50 . Thus, the first channel  201  is connected to the second channel  202  provided in the first base plate  110  via the third channel  203 . 
     The gas supplied from the gas inlet  210  to the first channel  201  pushes out the reagent  30  downstream from the reagent holder  230  so as to feed the reagent  30  downstream of the first channel  201 . The reagent  30  passes through the first channel  201  and the third channel  203  of the lid  50 , and reaches the specimen holder  240 . The specimen  40  in the specimen holder  240  wets and spreads on the second channel  202 , and then the reagent  30  merges with the specimen  40  to be mixed with the specimen  40 . 
     Therefore, in the microchannel chip  1  according to this embodiment also, by attaching the lid  50  to the chip body  10  after introducing the specimen  40  into the specimen holder  240 , the reagent  30  is immediately mixed with the specimen  40  so as to be held as the mixed liquid. Also, since the specimen  40  can be directly collected in the specimen holder  240 , it does not take time to introduce the specimen  40  into the specimen holder  240 , which contributes to easy collection of the specimen  40 . 
     Embodiment 4 
       FIG.  5 ( a )  and  FIG.  5 ( b )  are partial sectional views schematically illustrating a main part of the microchannel chip  1  according to Embodiment 4.  FIG.  5 ( a )  and  FIG.  5 ( b )  correspond to cross-sectional views taken along the line A-A of  FIG.  2   . 
     In the microchannel chip  1  according to Embodiment 3, the third channel  203  passes through the inside of the lid  50 . In contrast to the above, in the microchannel chip  1  according to Embodiment 4, the third channel  203  is formed between the chip body  10  and the lid  50  when the lid  50  is attached to the chip body  10 . 
     As shown in  FIG.  5 ( a ) , a channel forming recess part  203   c  for forming the third channel  203  is formed in the lid  50  as a recess part having an opening to the lower surface  501 . Also, the first protruding part  113  and the second protruding part  114  are formed on the chip body  10  as an integrally protruding part having a shape corresponding to the channel forming recess part  203   c.    
     The upper end of the second protruding part  114  is protruded upward further than the upper end of the first protruding part  113 . The specimen holder  240  is provided inside of the second protruding part  114  so as to communicate with the second channel  202 . The opening part  241  of the specimen holder  240  is opened to the upper end of the second protruding part  114 . Thus, when the opening part  241  formed in the second protruding part  114  is come into contact with the specimen  40 , the specimen  40  can be introduced into the specimen holder  240  by the capillary force. 
     As shown in  FIG.  5 ( b ) , when the lid  50  is attached to the chip body  10 , the gas inlet  210  is closed by the first closing part  510  while the first protruding part  113  and the second protruding part  114  are covered with the lid  50 . In other words, the first protruding part  113  and the second protruding part  114  of the chip body  10  are both fitted in the channel forming recess part  203   c  of the lid  50 . The channel forming recess part  203   c  is designed such that neither the upper end of the first protruding part  113  nor the upper end of the second protruding part  114  reaches the inner surface of the channel forming recess part  203   c  when the lid  50  is attached to the chip body  10 . Thus, the third channel  203  is formed in the gap between the inner surface of the channel forming recess part  203   c,  and the first protruding part  113  and the second protruding part  114 . The first channel  201  is connected to the second channel  202  provided in the first base plate  110  via the third channel  203  formed between the chip body  10  and the lid  50  by the channel forming recess part  203   c.    
     The gas supplied from the gas inlet  210  to the first channel  201  pushes out the reagent  30  downstream from the reagent holder  230  so as to feed the reagent  30  downstream of the first channel  201 . The reagent  30  passes through the first channel  201  and the third channel  203  of the lid  50 , and reaches the specimen holder  240 . The specimen  40  in the specimen holder  240  wets and spreads on the second channel  202 , and then the reagent  30  merges with the specimen  40  to be mixed with the specimen  40 . 
     Therefore, in the microchannel chip  1  according to this embodiment also, by attaching the lid  50  to the chip body  10  after introducing the specimen  40  into the specimen holder  240 , the reagent  30  is immediately mixed with the specimen  40  so as to be held as the mixed liquid. Also, since the specimen  40  can be directly collected in the specimen holder  240 , it does not take time to introduce the specimen  40  into the specimen holder  240 , which contributes to easy collection of the specimen  40 . 
     Also, in order to form the third channel  203 , the channel forming recess part  203   c  is provided in the lid  50 , and the channel forming recess part  203   c  is a recess part having the opening to the lower surface  501  of the lid  50 . Thus, the channel forming recess part  203   c  can be provided as a simple configuration, which contributes to easy molding. 
     Embodiment 5 
       FIG.  6 ( a )  and  FIG.  6 ( b )  are partial sectional views schematically illustrating a main part of the microchannel chip  1  according to Embodiment 5.  FIG.  6 ( a )  and  FIG.  6 ( b )  correspond to cross-sectional views taken along the line A-A of  FIG.  2   . 
     In the microchannel chip  1  according to Embodiments 1 to 4, the specimen holder  240  is provided in the chip body  10 . In contrast to the above, in the microchannel chip  1  according to Embodiment 5, the specimen holder  240  is provided in the lid  50 . 
     As shown in  FIG.  6 ( a ) , the lid  50  is provided with the third channel  203  to be connected to the first channel  201 . The third channel  203  is a channel passing through the inside of the lid  50 . The third channel  203  includes: the upstream end opening  203   a  formed in the upstream end thereof so as to open to the outside of the system; and the specimen holder  240  formed in the downstream end thereof. 
     In the case exemplarily shown, the lid  50  is provided with a third protruding part  243  that is protruded from the lower surface  501 . The specimen holder  240  is provided in the third protruding part  243  so as to communicate with the third channel  203 . The opening part  241  for introducing the specimen  40  into the specimen holder  240  is provided in the lower end of the third protruding part  243  so as to open to the lower surface  501  of the lid  50 . Thus, the specimen holder  240  is provided, in a protruding manner, on the lower surface  501  of the lid  50 . 
     The first channel  201  provided in the chip body  10  extends, on the downstream side of the reagent holder  230 , from the lower surface  111  of the first base plate  110  to the upper surface  112  side thereof, and the downstream end is opened to the upper surface  112  of the first base plate  110 . The first protruding part  113  is provided on the upper surface  112  of the first base plate  110  in a protruding manner. The downstream end of the first channel  201  is opened to the upper end of the first protruding part  113 . The first protruding part  113  is formed so as to correspond to the upstream end opening  203   a  of the lid  50 . A joining recess part  115 , which has the opening to the upper surface  112 , is provided in the chip body  10  so as to correspond to the third protruding part  243 . 
     As shown in  FIG.  6 ( b ) , when the lid  50  is attached to the chip body  10 , the gas inlet  210  is closed by the first closing part  510 . Also, the first protruding part  113  is fitted in the upstream end opening  203   a  of the lid  50  while the third protruding part  243  of the lid  50  is fitted in the joining recess part  115  of the chip body  10 . The third channel  203  and the first protruding part  113  are formed such that the upper end of the first protruding part  113  does not reach the inner surface of the third channel  203  when the lid  50  is attached to the chip body  10 . 
     In this way, the first channel  201  is connected to the second channel  202  provided in the first base plate  110  via the third channel  203  formed in the lid  50  and the specimen holder  240  of the lid  50 . Since the specimen holder  240  is provided in the downstream end of the third channel  203 , it is connected to the second channel  202  when the lid  50  is hermetically attached. 
     The gas supplied from the gas inlet  210  to the first channel  201  pushes out the reagent  30  downstream from the reagent holder  230  so as to feed the reagent  30  downstream of the first channel  201 . The reagent  30  passes through the first channel  201  and the third channel  203  of the lid  50 , and reaches the specimen holder  240 . The specimen  40  in the specimen holder  240  flows from the lid  50  to the chip body  10 , and wets and spreads on the second channel  202 . Then, the reagent  30  merges with the specimen  40  to be mixed with the specimen  40 . 
     Thus, in the microchannel chip  1  according to this embodiment also, by attaching the lid  50  to the chip body  10  after introducing the specimen  40  into the specimen holder  240 , the reagent  30  is immediately mixed with the specimen  40  so as to be held as the mixed liquid. Also, in addition to direct collection of the specimen  40  in the specimen holder  240 , since the specimen holder  240  is provided on the lid  50  in a protruding manner, it is possible to further easily collect the specimen  40 . 
     Embodiment 6 
       FIG.  7 ( a )  and  FIG.  7 ( b )  are partial sectional views schematically illustrating a main part of the microchannel chip  1  according to Embodiment 6.  FIG.  7 ( a )  and  FIG.  7 ( b )  correspond to cross-sectional views taken along the line A-A of  FIG.  2   . 
     In the microchannel chip  1  according to Embodiment 5, the third channel  203  to be connected to the first channel  201  is provided in the lid  50 . In contrast to the above, in the microchannel chip  1  according to Embodiment 6, a fourth channel  204  to be connected to the second channel  202  is provided in the lid  50 . 
     As shown in  FIG.  7 ( a ) , the lid  50  is provided with the fourth channel  204  whose upstream end is opened to the outside of the system and whose downstream end is to be connected to the second channel  202  of the chip body  10 . The fourth channel  204  is a channel passing through the inside of the lid  50 . The fourth channel  204  includes: an upstream end opening  203   a  formed in the upstream end thereof so as to open to the outside of the system; and the specimen holder  240  formed in the downstream end thereof. 
     In the case exemplarily shown, the lid  50  is provided with a third protruding part  243  that is protruded from the lower surface  501 . The specimen holder  240  is provided in the third protruding part  243  so as to communicate with the fourth channel  204 . The opening part  241  for introducing the specimen  40  is provided in the third protruding part  243 . Thus, the opening part  241  is protruded on the lower surface  501  of the lid  50  and opened to the lower surface  501  of the lid  50 . 
     The first channel  201  provided in the chip body  10  extends, on the downstream side of the reagent holder  230 , in the liquid feeding direction X along the lower surface  111  of the first base plate  110 . The first channel  201  is directly connected to the second channel  202 . 
     The joining recess part  115  and a connecting channel  244  communicating with the joining recess part  115  are connected to the second channel  202 . The joining recess part  115  corresponding to the third protruding part  243  is opened to the upper surface  112  of the first base plate  110 . The connecting channel  244  is disposed between the joining recess part  115  and the second channel  202 . 
     The first base plate  110  is provided with a third closing part  116  provided on the upper surface  112  in a protruding manner. The third closing part  116  is protruded to correspond to the upstream end opening  203   a  of the fourth channel  204  of the lid  50 , and is fitted in the upstream end opening  203   a.    
     As shown in  FIG.  7 ( b ) , when the lid  50  is attached to the chip body  10 , the gas inlet  210  is closed by the first closing part  510 . Also, the third closing part  116  is fitted in the upstream end opening  203   a  of the fourth channel  204  of the lid  50  so as to close the upstream end opening  203   a.    
     The third protruding part  243  of the lid  50  is fitted in the joining recess part  115  of the chip body  10 . Accordingly, the fourth channel  204  and the specimen holder  240  of the lid  50  are connected to the connecting channel  244  of the chip body  10 , and furthermore connected to the second channel  202 . 
     When the lid  50  is closed, the gas is supplied to the fourth channel  204 . Since the specimen holder  240  is provided in the downstream end of the fourth channel  204 , the specimen  40  is pushed out from the specimen holder  240  by the supplied gas. The pushed-out specimen  40  flows from the lid  50  through the connecting channel  244  of the chip body  10  to the second channel  202 , and thus wets and spreads on the second channel  202 . Meanwhile, the gas supplied from the gas inlet  210  to the first channel  201  pushes out the reagent  30  downstream from the reagent holder  230  so as to feed the reagent  30  to the second channel  202  via the first channel  201 . In the second channel  202 , the reagent  30  merges with the specimen  40 . 
     Thus, in the microchannel chip  1  according to this embodiment also, by attaching the lid  50  to the chip body  10  after introducing the specimen  40  into the specimen holder  240 , the reagent  30  is immediately mixed with the specimen  40  so as to be held as the mixed liquid. Also, in addition to direct collection of the specimen  40  in the specimen holder  240 , since the specimen holder  240  is provided on the lid  50  in a protruding manner, it is possible to further easily collect the specimen  40 . 
     Therefore, it is possible to prevent drying and coagulation of the specimen  40  without providing any supply tank for the compound or antibody to serve as anticoagulant causing the anticoagulation reaction, which contributes to accurate reaction and measurement of the specimen  40 . Also, the structure of the lid  50  of the microchannel chip  1  according to Embodiment 6 can be the same as that of the lid  50  in Embodiment 5. 
     In the microchannel chip  1  as described above, it is possible to immediately merge the reagent  30  with the specimen  40  so as to hold the mixed liquid without using any compound or antibody to serve as anticoagulant causing the anticoagulation reaction. Thus, it is possible to reduce production costs as well as burden on a human body, which results in the microchannel chip  1  capable of supplying liquid rapidly with a simple structure. Accordingly, the size of the microchannel chip  1  can be further reduced. Furthermore, since the specimen holder  240  is provided in a protruding manner on the chip body  10  or the lid  50 , it is possible to easily introduce the specimen  40  without taking time. 
     The configuration of the microchannel chip of the present invention is not limited to the configurations as described in the above embodiments, but may be implemented according to various other embodiments. As to the liquid to be mixed and supplied, it is not needed to be the reagent  30  as a first liquid, and also it is not needed to be the specimen  40  as a second liquid. Any kinds of liquid can be the object liquid of the present invention. 
     Although it is not shown in the drawings, a micro pump may be provided upstream of the second channel  202  in the above-described embodiments. In this case, by driving the micro pump after mixing of the reagent  30  with the specimen  40 , the mixed liquid can be supplied further downstream. The kind of the micro pump is not particularly limited. For example, a light gas generating tape can be used, which generates gas by light emission. 
     The present invention may be embodied in other forms without departing from the gist or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects as illustrative and not limiting. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all modifications and changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein. This application claims priority based on Japanese Patent Application No. 2019-182331. The entire contents thereof are hereby incorporated in this application by reference. 
     DESCRIPTION OF THE REFERENCE NUMERALS 
       1  Microchannel chip 
       10  Chip body 
       110  First base plate 
       111  Lower surface (first surface) 
       112  Upper surface (second surface) 
       113  First protruding part 
       114  Second protruding part 
       120  Second base plate 
       201  First channel 
       202  Second channel 
       203  Third channel 
       204  Fourth channel 
       210  Gas inlet 
       230  Reagent holder (first liquid holder) 
       240  Specimen holder (second liquid holder) 
       241  Opening part 
       30  Reagent (first liquid) 
       40  Specimen (second liquid) 
       50  Lid 
       501  Lower surface 
       510  First closing part 
       520  Second closing part