JP2013101081A - Microchip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microchip for achieving simple and highly accurate analyses.SOLUTION: Disclosed is a microchip by which a backflow prevention structure in which a part of a channel wall is deformed and projected to an inner space of a channel to narrow or block the channel is formed in the channel. The backflow prevention structure is formed in the channel so as to prevent backflow of solution filled in wells, and to prevent contamination due to flow of the solution between those wells. Thus, even when different analyses are simultaneously performed in a plurality of wells in the microchip, it is possible to achieve highly accurate analyses.

Description

  The present technology relates to a microchip capable of preventing backflow. More specifically, the present invention relates to a microchip that can prevent backflow by deformation of a flow path wall.

In recent years, microchips having wells and flow paths for performing chemical analysis or biological analysis on a silicon or glass substrate have been developed by applying microfabrication technology in the semiconductor industry. These microchips are beginning to be used in, for example, electrochemical detectors for liquid chromatography and small electrochemical sensors in medical settings.

Such an analysis system using a microchip is called μ-TAS (micro-Total-Analysis System), a lab-on-chip, a biochip, and the like. As a technology that enables downsizing, integration, or downsizing of analyzers, it is attracting attention. Since μ-TAS can be analyzed with a small amount of sample and can be used as a disposable microchip, it is expected to be applied to biological analysis, especially for handling precious trace samples and many specimens. Has been.

In the above microchip, in order to perform highly accurate analysis, the sample solution or the like introduced into the microchip is correctly fed in the designed forward direction, and does not flow or reverse to the unintended flow path. Is required. For example, in a microchip in which a plurality of wells are formed, each well can be filled with solutions having different compositions and mixing ratios, and a plurality of analyzes can be performed simultaneously. In such a case, if the solution flows backward between the wells, the inside of the well is contaminated, making accurate analysis difficult.

  For example, Patent Document 1 discloses a structure that prevents a back flow of a solution by forming a pressure difference by changing a cross-sectional area of a flow channel in a microchip between upstream and downstream.

In addition, as an example in which a structure for preventing a backflow is provided in the space through which a liquid flows, a microvalve that holds a floating valve body in a flow path is disclosed (Patent Documents 2 and 3). When liquid is fed in the forward direction in the microvalve, the floating valve body remains in a position that does not prevent downstream flow, but when the solution flows in the backward direction, the floating valve body communicates upstream. Blocks the part and prevents backflow.

International Publication No. 2006/109397 JP 2006-214492 A JP 2006-214837 A

  The main object of the present technology is to provide a microchip capable of preventing backflow.

  In order to solve the above problems, the present technology provides a solution introduction port, a well serving as an analysis site for a substance contained in the solution or a reaction product of the substance, and the solution introduced into the introduction port into the well. A flow path for supplying liquid, and the flow path includes a main flow path communicating with the introduction port at one end, and a branch flow path branched from the main flow path and connected to the well, The branch channel is provided with a microchip having a backflow prevention structure in which the inner space of the channel is narrowed or closed by deformation of the channel wall. The backflow prevention structure may be formed so that the flow path wall is pressed by the expansion of a pressurizing portion provided in the vicinity of the branch flow path and protrudes into the flow path. The pressurizing part may be expanded by the introduction pressure of the solution into the pressurizing part that can be filled with the solution.

  The microchip is connected to one or more of the pressure units at one end, and connected to the main channel at the other end after branching from a branch channel communicating with the farthest well from the inlet. In addition, an adjustment channel may be provided. The microchip has an adjustment channel connected to the well at one end of the microchip and facing the communicating portion between the branch channel and the well, and connected to one or more pressure units at the other end. It can also be provided. Furthermore, in the microchip, the well to which the control channel is connected at one end may be only one or two or more wells arranged at the farthest position from the introduction port.

  The present technology also provides a microchip in which the pressurizing unit expands by heating the pressurizing unit capable of holding a thermal expansion member. The thermal expansion member may be made of a coiled metal or a thermal expansion resin.

  According to the present technology, a backflow prevention structure is formed in a flow path, and contamination of an analysis target is prevented by preventing backflow, and a microchip that enables highly accurate analysis is provided.

It is an upper surface schematic diagram explaining the structure of the microchip A which concerns on 1st embodiment of this technique. FIG. 2 is a schematic cross-sectional view for explaining a backflow prevention structure in the microchip A (FIG. 1, P-P ′ cross section). It is a cross-sectional schematic diagram explaining the backflow prevention structure in the modification of 1st embodiment of this technique. It is a partial schematic diagram explaining the structure in the modification of 1st embodiment of this technique. It is a partial schematic diagram explaining the structure in the modification of 1st embodiment of this technique. It is an upper surface schematic diagram explaining the structure of the microchip B which concerns on 2nd embodiment of this technique. It is a cross-sectional schematic diagram (FIG. 6, Q-Q 'cross section) explaining the backflow prevention structure in the microchip B. It is a cross-sectional schematic diagram explaining the backflow prevention structure in the modification of 2nd embodiment of this technique. It is a partial schematic diagram explaining the backflow prevention structure in 3rd embodiment of this technique.

Hereinafter, preferred embodiments for carrying out the present technology will be described. In addition, embodiment described below shows an example of typical embodiment of this technique, and, thereby, the scope of this technique is not interpreted narrowly. The description will be made in the following order.

1. 1. First Embodiment of the Present Technology (1) Configuration of Microchip A (2) Formation of Backflow Prevention Structure (3) Configuration of Modified Example of First Embodiment 2. Second Embodiment of the Present Technology (1) Configuration of Microchip B (2) Formation of Backflow Prevention Structure About the third embodiment of the present technology

1. First Embodiment of the Present Technology (1) Configuration of Microchip A A first embodiment of a microchip according to the present technology is schematically shown in FIG. The microchip denoted by reference symbol A includes an introduction port 1 through which a solution is introduced from the outside, a well 6 serving as an analysis site for a substance contained in the solution or a reaction product of the substance, and a main channel that communicates with the introduction port 1 at one end. 21 and a branch channel 22 branched from the main channel 21 and communicating with the well 6.

The microchip A is formed with an adjustment channel 23, one end communicating with the main channel 21, and the other end branching and communicating with the plurality of pressure units 4. In the microchip A shown in FIG. 1, a storage portion 3 that temporarily stores a solution is provided in a part of the adjustment channel 23. Thus, the adjustment flow path 23 may be provided with a part with a changed cross-sectional area or structure.

FIG. 1 illustrates a case where five wells 6 are arranged for one main channel 21 and five main channels 21 are arranged for one microchip A. The number of main flow paths 21 and wells 6 arranged in the microchip A according to the embodiment is not limited to the numbers shown in FIG. Further, the branch channel 22 and the like can be appropriately arranged according to the number of the wells 6 and the like.

The solution introduced into the microchip A refers to a solution containing an analyte or a substance that reacts with another substance to generate the analyte. Examples of the analysis target include nucleic acids such as DNA and RNA, proteins including peptides, antibodies, and the like. Moreover, the biological sample itself containing the said analysis target object, such as blood, or its diluted solution can also be used as the solution introduce | transduced into the microchip based on this technique.

  The microchip A is composed of a plurality of substrate layers. The material of the substrate layer can be glass or various plastics (polypropylene, polycarbonate, cycloolefin polymer, polydimethylsiloxane, etc.). Although there are a plurality of substrate layers constituting the microchip A, the number of the substrate layers is not limited. Alternatively, the microchip A may be formed by bonding substrate layers made of different materials, such as bonding a plastic substrate layer to a glass substrate layer. In addition, it is preferable that the board | substrate layer in which the branch flow path 22 and the pressurization part 4 are formed consists of a material which has elasticity, respectively.

Examples of the material having elasticity include acrylic elastomers, urethane elastomers, fluorine elastomers, styrene elastomers, epoxy elastomers, natural rubber, etc., in addition to silicone elastomers such as polydimethylsiloxane. In the case of optically analyzing the substance held in the well 6, the material of the substrate layer should be selected from materials having optical transparency, low autofluorescence and small wavelength dispersion due to small wavelength dispersion. Is preferred.

  The molding of each flow path to the substrate layer, the well 6, the pressure unit 4 and the like is performed, for example, by wet etching or dry etching of the glass substrate layer, or by a method such as nanoimprinting, injection molding, or cutting of the plastic substrate layer. It can be carried out. For the bonding of the substrate layers, for example, a method using an adhesive or a sticky sheet, or a method such as heat fusion, anodic bonding, or ultrasonic bonding can be used. Further, the surface of the substrate layer can be activated and bonded by oxygen plasma treatment or vacuum ultraviolet light treatment.

In the case of plastics such as polydimethylsiloxane, Si-O-Si silanol bond, which has high affinity with glass, and when the surface is activated and brought into contact with oxygen plasma treatment etc., the dangling bond reacts and is a strong covalent bond And a sufficiently strong bond can be obtained. Further, by bonding the plurality of substrate layers under a negative pressure relative to the atmospheric pressure, the main flow path 21, the branch flow path 22, the adjustment flow path 23, the storage section 3, the pressurization section 4, the well 6 and the like Each region in the chip A is hermetically sealed with a negative pressure relative to the atmospheric pressure. In this case, the introduction port 1 is preferably sealed in order to keep the inside of the microchip under a negative pressure. For sealing the inlet 1, it is preferable to use an elastic material that can be punctured and injected with a solution and that can be sealed by a restoring force due to its own elastic deformation after the injection.

When the microchip A is used, the solution is sent to each region provided in the microchip A by the pressure applied when being injected into the inlet 1. Moreover, in the microchip A produced by bonding a plurality of substrate layers under a negative pressure, the solution is introduced into each region such as the well 6 formed in the microchip after introduction due to the pressure difference between the inside and the outside of the microchip. It can be passed without pressure.

  Regardless of the introduction method by pressurization or introduction by the pressure difference between the inside and outside of the microchip, when the solution is introduced from the introduction port 1 in the microchip A, the solution flows through the main channel 21. Each well 6 is filled via the branch channel 22. A part of the solution that has not branched to the branch flow path 22 flows through the main flow path 21 to the adjustment flow path 23 and collects in the storage unit 3 provided in the middle of the adjustment flow path 23. The solution is filled in the reservoir 3 and then filled into each pressurizing unit 4 from the end of the adjustment channel 23 (see FIG. 1).

(2) Formation of Backflow Prevention Structure FIGS. 2 and 3 are diagrams for explaining the formation of the backflow prevention structure in the microchip A and its modification. FIG. 2 shows an example in which one pressurizing portion 4 is formed in the vicinity of the branch flow path 22 in the horizontal direction with respect to the bottom surface of the well 6. FIG. 3 shows an example in which two pressurizing portions 4 are formed in the vicinity of the branch flow path 22 in the direction perpendicular to the bottom surface of the well 6.

PP ′ shown in FIG. 2A corresponds to a partial cross section of PP ′ shown in FIG. The microchip A is composed of two substrate layers in which a substrate layer a ₁ and a substrate layer a _{2 on} which the branch channel 22 and the pressure unit 4 are formed are bonded together. It is desirable branch channel 22 and the pressurizing board layer a ₁ to pressure portion 4 is formed is made of a material having elasticity. FIG. 2A shows a state before the solution reaches the pressurizing unit 4 through the flow path shown in FIG. The branch flow path 22 is not narrowed or blocked, and is in a state in which a solution can flow.

On the other hand, FIG. 2 (B) shows a state where the pressurizing unit 4 is filled with a solution. Due to the introduction pressure of the solution, the pressurizing unit 4 expands and presses the channel wall of the branch channel 22. By the compression by the pressurizing unit 4, the flow path wall of the branch flow path 22 is deformed and protrudes into the flow path interior, and the branch flow path 22 is narrowed or closed. That is, the backflow prevention structure is formed in the branch flow path 22. In the microchip A, the backflow prevention structure shown in FIG. 2B is formed, so that the backflow of the solution through the branch channel 22 can be prevented.

  The appropriate time for forming the backflow prevention structure shown in FIG. 2B is adjusted by the configuration of the flow path through which the solution shown in FIG. 1 flows. The solution flows through the main flow channel 21 and reaches the control flow channel 23 after connecting to the branch flow channel 22 communicating with the well 6. Since the adjustment channel 23 includes the storage unit 3, the solution is held in the adjustment channel 23 for a certain time until the solution is filled in the storage unit 3. After a certain time, the solution again flows through the adjustment channel 23 and is filled in the pressurizing unit 4. By providing the adjustment flow path 23 and the reservoir 3 in this way, a backflow prevention structure is formed after a certain time, and the branch flow path 22 is narrowed or blocked before filling the well 6 with the solution. It is prevented. The storage unit 3 is not an essential component for the adjustment flow path 23. For the adjustment flow path 23 that does not include the storage section 3, the flow path length and flow path diameter may be configured so that the solution reaches the pressurization section 4 after the solution is filled in the well 6.

  As described above, the timely formation of the backflow prevention structure is a time when the solution is introduced into the microchip A by pressurization because the timeliness is adjusted by the configuration of the adjustment flow path 23 and the storage unit 3 described above. Even if it is introduced by a pressure difference between the inside and outside of the microchip, the backflow prevention structure is automatically formed after the introduction of the solution without requiring any additional operation.

3A and 3B are partial cross-sectional views of the pressurizing unit 4 and the branch flow path 22 in the modification of the present embodiment. In the cross-sectional portion shown in FIG. 3, the microchip includes four substrate layers, a ₁ , a ₂ , a ₃ , and a ₄ . The substrate layers a ₁ and a ₃ on which the pressurizing unit 4 is formed and the substrate layer a ₂ on which the branch channel 22 is formed are bonded together, and the pressurizing unit 4 is sealed by the substrate layer a ₄ . As in FIG. 2, the substrate layers a ₁ , a ₂ , and a _{3 on} which the pressurizing unit 4 and the branch flow path 22 are formed are preferably made of a material having elasticity. FIG. 3A shows a state before the solution reaches the pressurizing unit 4 through each flow path shown in FIG. The branch flow path 22 is not blocked by the stenosis and is in a state in which the solution can flow.

On the other hand, FIG. 3B shows a state where the pressurizing unit 4 is filled with the solution and expanded. The flow path wall of the branch flow path 22 is compressed and deformed by the expansion of the pressurizing unit 4 and protrudes into the air in the flow path, and the branch flow path 22 is narrowed or blocked. Even when the pressurizing unit 4 is formed on a substrate layer different from the substrate layer on which the branch flow path 22 is formed, the pressurizing unit 4 is filled with a solution and expands, whereby FIG. ) To the flow path wall of the branch flow path 22 shown in FIG. 2), and a backflow prevention structure can be provided in the microchip. Timely adjustment of the formation of the backflow prevention structure is performed by forming the adjustment flow path 23 and the reservoir 3 in the microchip, as in the case of FIG. 2 described above. In addition, as in the case of the microchip A, the backflow prevention structure is automatically formed in this modified example without an additional operation after the operation of introducing the solution into the microchip.

  As described above, the backflow prevention structure in the microchip is formed by expanding the pressurizing unit 4 due to the pressure of introducing the solution into the pressurizing unit 4 and pressing the branch flow channel 22 from the outside. This is done by deforming the road wall and projecting into the air in the flow path (see FIGS. 2B and 3B). Moreover, the pressurization part 4 may be formed in any substrate layer as long as it is close to the branch flow path 22, and the number of pressurization parts 4 provided for one branch flow path is not limited.

(3) Configuration of Modified Example of First Embodiment FIGS. 4A to 4D show a modified example of the configuration of the adjustment channel and the pressurizing unit of the first embodiment of the microchip according to the present technology.

  In the present embodiment, the adjustment channel 23 may be connected to the well 6 instead of the main channel 21. 4 (A) is connected to the well 6 farthest from the introduction port 1 (not shown in FIG. 4 (A)) at a position facing the branch channel 22 and the communicating portion of the well 6. doing. After the solution is introduced into the microchip, it flows through the main channel 21 and reaches the well 6 via the branch channel 22. After the solution reaches the farthest well 6 from the inlet 1 and the well 6 is filled, a part of the solution flows through the control channel 23 to form a backflow prevention structure for each branch channel 22. In order to do so, it is filled in the pressure unit 4 provided. In such a configuration, the flow of the solution to the adjustment channel 23 is performed after the solution is filled in all the wells 6 filled with the solution by the single main channel 21. As in the case of, the time for forming the backflow prevention structure is adjusted.

  In the present embodiment, the well 6 to which the adjustment channel 23 is connected is not necessarily limited to the well 6 farthest from the introduction port 1, and each of the wells 6 arranged in the microchip has an adjustment channel 23. Can be configured to be connected. As shown in FIGS. 4B and 4C, the adjustment channel 23 is connected to the well 6 at a position facing the communicating portion between the branch channel 22 and the well 6 at one end and connected at the other end. It communicates with the pressurizing part 4 for forming a backflow prevention structure for preventing backflow from the well 6.

The number of pressurizing units 4 connected to one adjustment channel 23 can be one (FIG. 4B) or plural (FIG. 4C), and the number is limited. Not. Even in such a configuration, the solution flow into the control channel 23 is after the filling of the solution into the well 6 is completed, and the appropriate time for forming the backflow prevention structure is adjusted as in the case of the microchip A. The

  When the adjustment flow path 23 is connected to all the wells 6 arranged in the microchip as in the above-described backflow prevention structure, the pressurizing unit 4 that communicates with the adjustment flow path 23 is connected to each adjustment flow path 23. It is not limited to the pressurization part 4 for forming the backflow prevention mechanism which prevents the backflow from the well 6 which the flow path 23 connects.

  FIG. 4D is a partial schematic view of a modification of the present embodiment. The well 6a and the well 6b are disposed adjacent to each other, and are filled with the solution from the same main channel 21 via a branch channel communicating with each other. The well 6b is located farther from the introduction port 1 than the well 6a (the main flow path and a part of the branch flow path are omitted in FIG. 4D). The solution that has reached the well 6b via the branch channel 22b is filled into the well 6b and then passed to the regulation channel 23b. The adjustment flow path 23b is connected to the pressurization part 4b, and the backflow from the well 6a is prevented by filling the pressurization part 4b with the solution. As described above, the solution flowing from the well 6b formed farther from the inlet 1 to the control channel 23b forms a backflow prevention structure for the branch channel communicating with the well 6a closer to the inlet 1 By filling the pressurizing unit 4b, the backflow prevention structure is prevented from being formed in the branch channel communicating with the well that has not been completely filled with the solution. Accordingly, also in the configuration of the adjustment flow path and the like, as in the case of the microchip A, the time for forming the backflow prevention structure is adjusted.

In the present embodiment, as shown in FIG. 5, the adjustment flow path 23 is formed so that the solution reaches the pressurizing unit 4 in the same order as the order in which the well 6 is filled with the solution to form the backflow prevention structure. May be formed. FIG. 5A shows an example in which the adjustment channel 23 communicates with the main channel 21, and FIG. 5B shows an example in which the regulation channel 23 communicates with the well 6. Regardless of the configuration, the formation of the backflow prevention structure due to the expansion of the pressurizing unit 4 is sequentially performed from the branching channel communicating with the well close to the inlet 1 by the arrangement of the adjustment channel 23 shown in the figure. (In FIGS. 5A and 5B, part of the main flow path is omitted). Accordingly, in the configuration of the adjustment channel 23 and the like, the time for forming the backflow prevention structure is adjusted as in the case of the microchip A.

  As described above, in the microchip A according to the present embodiment and the modification thereof, a part of the solution reaches the pressurizing unit 4 by introducing the solution into the microchip, and the solution is introduced by the introduction pressure of the solution. The pressurizing unit 4 is expanded, compresses the flow path wall of the branch flow path 22, the flow path wall is deformed and protrudes into the flow path, and the branch flow path 22 is narrowed or closed. The formation of the backflow prevention structure is automatically performed after the solution is introduced into the microchip, and the appropriate time of formation is adjusted by the configuration of the adjustment channel and the like described above. Therefore, a complicated operation and a dedicated tool for forming the backflow prevention structure are not required. The timely adjustment of the formation of the backflow prevention structure may be performed as long as the adjustment channel 23 communicates with each well 6 or the main channel 21 so that the solution reaches the pressure unit 4 after filling the well. It is not limited to the configuration of the embodiment.

  In the microchip of this embodiment, a backflow prevention structure is formed in the branch channel 22 that automatically communicates with the well after the introduction of the solution, and the backflow from the well 6 is prevented. Contamination of the well 6 due to movement or the like does not occur. Therefore, it is possible to perform highly accurate analysis using the microchip according to the present technology.

When a microchip is used for analysis of a solution during or after a reaction, such as a nucleic acid amplification reaction, the use of the microchip is performed by holding a part of a substance necessary for the reaction in the well 6 as a reaction field in advance. Sometimes, it is possible to start the reaction by introducing only the remaining substances necessary for the reaction, and the operation becomes simple. Further, by holding substances having different compositions in each well, a plurality of analyzes can be performed simultaneously. However, if substances with different compositions are held in each well, the solution introduced into the wells at the start of the analysis will flow backward, and if the solution is contaminated between the wells and other wells, the accuracy will increase. High analysis becomes difficult. The formation of the backflow prevention structure in the microchip according to the present technology prevents the contamination between the wells when the analysis is performed with the microchip including the wells holding the substances having different compositions as described above, and performs the analysis with high accuracy. Make it possible. In other words, the microchip capable of forming the backflow prevention structure according to the present technology enables a plurality of analyzes to be performed simultaneously in one microchip, thereby improving the convenience in analysis.

2. Second Embodiment of Present Technology (1) Configuration of Microchip B A second embodiment of a microchip according to the present technology is schematically shown in FIG. The microchip denoted by reference symbol B includes an introduction port 1 through which a solution is introduced from the outside, a well 6 serving as an analysis site for a substance contained in the solution or a reaction product of the substance, and a main channel that communicates with the introduction port 1 at one end. 21 and a branch channel 22 branched from the main channel 21 and communicating with the well 6. Further, in the microchip B, the pressurizing unit 4 is disposed in the vicinity of the branch channel 22. In FIG. 6, the case where five wells 6 are arranged for one main channel 21 and five main channels 21 are arranged for one microchip B is illustrated. The number of the main flow paths 21 and the wells 6 arranged in the microchip B according to the embodiment is not limited to the numbers shown in FIG. Further, the branch channel 22 and the like can be appropriately arranged according to the number of the wells 6.

  The microchip B is composed of a plurality of substrate layers. With respect to the material of the substrate layer, the method of forming the flow path to the substrate layer, and the method of bonding the substrate layer, the same material and method as those of the microchip A in the first embodiment described above can be used. On the other hand, a thermal expansion member 5 is held in the pressure unit 4 of the microchip B. The thermal expansion member 5 is made of a material having a property of expanding when heat is applied. As a thermal expansion member built in the microchip B according to the present embodiment, an organic solvent or the like can be used even if it is made of only a material having thermal expansion properties such as a metal formed into a coil shape. A composite material in which a material having a thermal expansion property such as a thermal expansion particle encapsulated in a capsule is combined with another material may be used.

(2) Formation of Backflow Prevention Structure FIGS. 7 and 8 are diagrams for explaining the formation of the backflow prevention structure in the microchip B and its modifications. FIG. 7 shows an example in which two pressurizing parts 4 are formed in the vicinity of the branch flow path 22 in the horizontal direction with respect to the bottom surface of the well 6. FIG. 8 shows an example in which two pressurizing portions 4 are formed in the vicinity of the branch flow path 22 in the direction perpendicular to the bottom surface of the well 6.

QQ ′ shown in FIG. 7A corresponds to a partial cross section of QQ ′ in FIG. Microchip B is composed of the branch passage 22 and the pressurizing section 4 is formed in the substrate layer a ₁ and the substrate layer a ₂ is bonded, two-layer substrate layer. It is desirable branch channel 22 and the pressurizing board layer a ₁ to pressure portion 4 is formed is made of a material having elasticity. FIG. 7A shows a state before the thermal expansion member 5 held by the pressure unit 4 is heated. The branch channel 22 is neither narrowed nor blocked, and is in a state in which the solution can flow.

On the other hand, FIG. 7B shows a state in which the microchip B is heated and the thermal expansion member 5 held by the pressure unit 4 is expanded. Due to the expansion of the thermal expansion member 5, the pressurizing unit 4 presses the channel wall of the branch channel 22. Due to the compression by the pressurizing unit 4, the flow path wall of the branch flow path 22 is deformed and protrudes into the air in the flow path, thereby narrowing or closing the branch flow path 22. That is, the backflow prevention structure is formed in the branch flow path 22. As described above, in the microchip B, the backflow prevention structure shown in FIG. 7B is formed, so that the backflow of the solution through the branch channel 22 can be prevented.

  The backflow prevention structure shown in FIG. 7B is formed by heating the thermal expansion member 5 held on the microchip B. Therefore, the time for forming the backflow prevention structure in the microchip B is determined by the operator. In addition, when nucleic acid amplification reaction such as conventional PCR (Polymerase Chain Reaction) method for performing temperature cycling and various isothermal amplification methods not involving temperature cycling is performed using the microchip B, it is introduced into the microchip B. The solution must be heated. By utilizing this heating procedure in the nucleic acid amplification reaction, the thermal expansion member 5 can be expanded to form the backflow prevention structure shown in FIG.

8A and 8B are cross-sectional views of a portion where the pressurizing unit 4 and the branch flow path 22 are formed in a modification of the present embodiment. In the cross-sectional portion shown in FIG. 8, the microchip includes four substrate layers, a ₁ , a ₂ , a ₃ , and a ₄ . The substrate layers a ₁ and a ₃ on which the pressurizing unit 4 is formed and the substrate layer a ₂ on which the branch channel 22 is formed are bonded together, and the pressurizing unit 4 is sealed by the substrate layer a ₄ . As in FIG. 7, the substrate layers a ₁ , a ₂ , and a _{3 on} which the pressurizing unit 4 and the branch flow path 22 are formed are preferably made of an elastic material. FIG. 8A shows a state before the thermal expansion member 5 held by the pressure unit 4 is heated. The branch flow path 22 is not narrowed or blocked, and is in a state in which a solution can flow.

On the other hand, FIG. 8B shows a state in which the microchip is heated and the thermal expansion member 5 held by the pressure unit 4 is expanded. The expansion of the pressurizing unit 4 compresses and deforms the flow path wall of the branch flow path 22 and projects into the air in the flow path, and the branch flow path 22 is narrowed or closed. Even when the pressurizing unit 4 is formed on a substrate layer different from the substrate layer on which the branch channel 22 is formed, the thermal expansion member 5 held by the pressurizing unit 4 is expanded by heating the microchip, A back flow prevention structure is provided by causing pressure on the flow path wall of the branch flow path 22 shown in FIG. 8B and forming a protrusion into the flow path inner space due to deformation of the flow path wall. The time for forming the backflow prevention structure in the present embodiment is determined by the operator as in the case of FIG.

As described above, in the microchip B according to this embodiment and the modification thereof, the thermal expansion member 5 held in the pressure unit is expanded by heating, so that the pressure unit 4 is expanded and the branch flow path 22 is expanded. The channel wall is pressed, the channel wall is deformed and protrudes into the channel inner space, and the branch channel 22 is narrowed or blocked (FIGS. 7 and 8). In the microchip of this embodiment, the formation position of the pressurizing unit 4 that holds the thermal expansion member 5 is any substrate layer as long as it can press the flow path wall of the branch flow path during expansion. The number of pressurizing units 4 provided for one branch channel 22 is not limited.

Since the formation of the backflow prevention structure occurs only by heating the microchip, only the operation of heating the microchip at the time determined by the operator is necessary. Does not require tools.

  In the microchip of this embodiment, a backflow prevention structure is formed in the branch flow path 22 communicating with the well 6 by a heating operation by the operator at an appropriate time after the introduction of the solution, and backflow from the well 6 is prevented. The contamination of the well 6 due to the movement of the solution between the wells 6 does not occur. Therefore, it is possible to perform highly accurate analysis using the microchip according to the present technology. Further, by preventing contamination of the well 6, different analyzes can be performed simultaneously on the plurality of wells 6, and the convenience of analysis is improved. For this reason, the microchip capable of forming a backflow prevention structure according to the present technology is used in order to increase analysis accuracy when used as a microchip in which substances necessary for analysis are held in a plurality of wells in advance. It is valid.

3. About 3rd Embodiment in this technology The microchip C which is 3rd embodiment which concerns on this technology is a solution from the exterior similarly to the microchip A and microchip B in 1st embodiment mentioned above or 2nd embodiment. An introduction port to be introduced, a well serving as an analysis site for a substance contained in the solution or a reaction product of the substance, a main channel communicating with the introduction port at one end, and a branch flow branched from the main channel and communicating with the well Consists of roads. On the other hand, unlike the microchip A or the microchip B, the pressurizing unit, the adjustment channel, and the storage unit are not essential components. Further, with respect to the substrate layer constituting the microchip C, the material of the substrate layer, the method of forming the flow path to the substrate layer, and the method of bonding the substrate layers are the same as the method of the microchip A in the first embodiment described above. Can be used.

  FIG. 9 schematically shows the formation of the backflow prevention structure in the microchip C. FIG. 9A shows the state of the branch channel 22 before the solution is introduced into the microchip C. FIG. The branch flow path 22 is closed by the check valve 7. The check valve 7 is bonded to the branch channel 22 having a square channel cross section at four sides, but the thickness of the three sides is thinner than the remaining one side, and the adhesive area with the channel wall is small. The adhesive force to the channel wall on the three sides is fragile.

The introduction of the solution into the microchip C may be introduction by the aforementioned pressurization or introduction by a pressure difference between the inside and outside of the microchip. In any case, when the solution is introduced into the microchip C and flows into the branch channel 22 in the direction of arrow F shown in FIG. Arise. The check valve 7 breaks the adhesion with the flow path wall on the three sides where the adhesive force is weak, and the branch flow path 22 is opened by falling to the low pressure side. After the solution is introduced, when the solution reaches a well provided downstream of the branch flow path 22 and the filling in the well is completed, the pressure in the branch flow path 22 becomes equal, and the check valve 7 adheres to the flow path wall. With the one side as an axis, the state returns to the state when the check valve 7 shown in FIG. 9A is molded, and the branch flow path 22 is closed again. Thus, a backflow prevention structure is formed in the branch flow path 22 after the solution is introduced.

  The check valve 7 may be integrally formed with any one of the substrate layers constituting the microchip C, or may be installed in the branch flow path 22 after being manufactured as one component. The bonded portion between the check valve 7 and the wall surface of the branch flow path 22 is preferably made of a material having a restoring force due to elastic deformation, except for a three-sided fragile bonded portion, and is branched by an elastic material. What is integrally formed with the flow path 22 is suitable.

In FIG. 9, the cross section of the branch flow path 22 is rectangular, but it may be any shape such as a circle or a polygon, and the shape of the check valve 7 may be selected according to the shape of the flow path cross section. . Further, the portion where the adhesive force of the check valve 7 is weak may be a method of forming a broken line on the check valve in addition to the method of forming the adhesive valve by reducing the adhesion area as shown in FIG.

Regardless of the shape of the above, the check valve 7 is weak in adhesion with the flow path wall, leaving a part, so it breaks down when the solution is introduced into the branch flow path 22, and the branch flow path 22 is opened, and a part of adhesion of the check valve 7 to the flow path wall is an adhesive force that can withstand the introduction pressure, so that it remains in a predetermined position of the branch flow path 22 and is restored after filling with the solution. A backflow prevention structure can be formed. The check valve 7 is not limited to the above configuration as long as the check valve 7 performs the same operation by introducing the solution into the microchip. The arrangement position of the check valve 7 is not limited to the branch flow path 22 but may be a main flow path or a communication portion between the introduction port and the main flow path.

In the microchip C of the present embodiment, a backflow prevention structure is automatically formed in the flow path provided with the back support valve 7, and backflow in the branch flow path 22 is prevented. When the reverse branch valve 7 is provided in the branch flow path 22 communicating with the well, the well is not contaminated due to the movement of the solution between the wells after the introduction of the solution. Therefore, highly accurate analysis is possible using the microchip C of this embodiment. Further, by preventing well contamination, different analyzes can be performed simultaneously in a plurality of wells, and the convenience of analysis in the microchip is improved. For this reason, the backflow prevention structure in the present technology is particularly effective for increasing the analysis accuracy when using a microchip in which substances necessary for analysis are held in a plurality of wells in advance.

  In the microchip according to the present technology, the backflow of the solution is formed by preventing the backflow of the solution by narrowing or closing the flow path by deforming the flow path wall and projecting into the air flow path. Contamination between regions such as wells can be prevented. Therefore, according to the microchip according to the present technology, high-precision analysis can be performed even when different analyzes are performed for each well at the same time. Therefore, it can be used for diagnosis of diseases and determination of infectious pathogens in the medical field and public health field.

A, B: Microchip, a ₁ , a ₂ , a ₃ , a ₄ : Substrate layer, 1: Inlet port, 21: Main channel, 22, 22b: Branch channel, 23, 23b: Control channel, 3: Reserving part, 4, 4b, 4c: pressurizing part, 5: thermal expansion member, 6, 6a, 6b: well, 7: check valve

Claims (8)

A solution inlet;
A well serving as an analysis site for a substance contained in the solution or a reaction product of the substance, and a flow path for feeding the solution introduced into the introduction port to the well;
The flow path comprises a main flow path communicating with the inlet at one end, and a branch flow path branched from the main flow path and connected to the well,
A microchip in which the backflow prevention structure is formed in the branch flow path so that the air in the flow path is narrowed or closed by deformation of the flow path wall. 2. The microchip according to claim 1, wherein the backflow prevention structure is formed so that the flow path wall is pressed by expansion of a pressurizing portion provided in proximity to the branch flow path and protrudes into the flow path. . The pressure part expands due to the introduction pressure of the solution into the pressure part that can be filled with the solution.
The microchip according to claim 2. An adjustment flow path connected to one or more of the pressurizing sections at one end and connected to the main flow path after branching with the branch flow path communicating with the farthest well from the introduction port at the other end Arranged,
The microchip according to claim 3. The control channel connected to the well at a position opposite to the communicating portion between the branch channel and the well at one end, and connected to one or more pressurizing units at the other end,
The microchip according to claim 3. The well to which the adjustment channel is connected at one end is only one or two or more wells arranged at the farthest position from the introduction port.
The microchip according to claim 5. The pressure part expands by heating to the pressure part capable of holding a thermal expansion member.
The microchip according to claim 2. The microchip according to claim 7, wherein the thermal expansion member is made of a coiled metal or a thermal expansion resin.

Images