JP2007155491A - Micro reactor system and liquid feed method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micro reactor system where sample solutions and buffer solution flow into a reaction tank section without diffusing or mixing inside a flow channel of a micro reactor, they are made to react with each other in completely the same state as in inflow, and coupling constant or dissociation constant can be measured. <P>SOLUTION: When various solutions are sequentially supplied to a micro reactor with a supplying means, the solutions are fed in a partitioned state by gas so that solutions are not diffused or mixed. The gas having partitioned them just in front of the reaction tank section is removed by a branch channel for degassing disposed near the inlet of the reaction tank section, and only the solutions flow into the reaction tank section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention comprises a disposable microchip for immobilizing a biochemical substance and measuring a chemical substance such as an enzyme, an antibody, a protein, a hormone, a sugar chain, or a compound that specifically adsorbs or binds to the biochemical substance. The present invention relates to a microreactor system for performing measurement and a liquid feeding method for feeding an analysis solution to a reaction tank.

  In recent years, development of a bioreactor microreactor called a Lab-on-a-chip, a biomicrochip, or a microreactor, and a microreactor system including the bioreactor have been actively developed. Since these microreactors are compact and inexpensive, for example, it is possible to regularly check the health condition of a person with a small amount of sample at home. In addition, since it is assumed that it is disposable, it can be easily inspected without worrying about contamination. As a sensor capable of directly measuring the mass of the reactant in this microreactor, a sensor incorporating the QCM biosensor described in Patent Document 1, surface plasmon resonance (SPR) described in Non-Patent Documents 1 and 2 : Surface Prasmon Resonance), and other methods are being studied.

  When a QCM biosensor is used, a change in mass due to adsorption / bonding of a reactive substance on an electrode of the crystal resonator can be measured using an oscillation frequency shift of the crystal resonator. An example of the QCM biosensor is described in, for example, Japanese Patent Application Laid-Open No. 2003-307481 (FIG. 6), which is shown in FIG. As shown in FIG. 6, a plurality of detection channels 101 on which a sensitive film that captures only an analysis target contained in the sample solution 103 is fixed, and a plurality of correction channels 102 without a sensitive film disposed in the vicinity thereof are formed. By providing the QCM biosensor 100, a method is proposed in which the reaction process can be monitored sequentially without being affected by the viscosity and density of the sample solution 103 by utilizing the change in the electrical characteristics of both channels 101 and 102. ing.

Furthermore, by incorporating the above-mentioned QCM biosensor into a microreactor and using a liquid delivery means such as a pump to flow the sample solution, the reaction rate is higher than that of the conventional method (well type cell structure) that does not flow the sample solution. Since it can be made faster, real-time measurement of the entire reaction is possible in a short time. Therefore, the microreactor system is provided with a mechanism for sequentially supplying solutions necessary for the reaction such as a buffer solution and a sample solution to the microreactor at the time of measurement.
Japanese Patent Laid-Open No. 2003-307481 Kaori Morimoto, “Plasmon Resonance Analysis Type Analyzer”, Clinical Examination, Medical School, October 2003, vol. 47, no. 11, 2003 Special Issue, p. 1319-1327 Kazuhiro Nagata, Hiroshi Handa, "Real-time analysis experiment method of biological material interaction", Springer Fairlark Tokyo Co., Ltd., November 1998

  The method of incorporating the QCM biosensor as described above into the microreactor can measure the reaction of the sample solution in a short time. However, when sending several types of sample solutions and buffer solutions to react, each solution It is necessary to feed the solution so as not to mix. However, in the conventional microreactor system, since each solution flows through the flow path without any break, the contents inevitably diffuse at the boundary of the solution, resulting in mixing of the sample solution and change in concentration. It was.

  Therefore, in order to solve the above-mentioned problems, the present invention allows sample solutions and buffer solutions to flow into the reaction tank without diffusion mixing inside the microreactor flow path, react in the same state as at the time of inflow, and combine them. It is an object of the present invention to provide a microreactor system capable of measuring constants and dissociation constants.

  The microreactor system of the present invention includes a microreactor having a reaction tank section, a supply path for supplying a solution for analysis to the reaction tank section, a waste liquid path for discharging the solution from the reaction tank section, and the microreactor system. A microreactor system having a supply means connected to the supply path of the reactor to supply the solution; and the supply means supplies a plurality of different solutions and gases to the supply path; A gas removal means comprising a control section for controlling the liquid feeding from the supply section and a storage section for storing the solution and the gas, and the supply path extracts the gas at a predetermined position reaching the reaction tank. Is provided.

  In addition, the supply unit receives the solution from the storage unit and sends it out while pressurizing the solution, and the supply unit that feeds the solution from the pressurization pump so that the different types of the solution are separated from each other. And a valve for sequentially switching the solution and the gas while interposing the gas between the solutions and supplying the gas to the supply path.

  In addition, the gas removing means includes a degassing branch flow path that branches from the supply path at the predetermined position and communicates with the outside or the atmosphere.

  The liquid feeding method of the present invention is a liquid feeding method for feeding a plurality of different types of solutions to a reaction tank via a supply path, and each of the above-mentioned different types of solutions is partitioned so as to partition each type. A state in which a gas is interposed between the solution and the solution is caused to flow through the supply path; a step of extracting the gas at a predetermined position reaching the reaction vessel; and a state where the gas is extracted and the partition by the gas is eliminated And sequentially supplying the solution to the reaction vessel for each type.

  According to the present invention, since the supplied buffer solution or the sample solution necessary for the reaction is separated and sent by gas at the time of supply, there is no boundary between the solutions, and diffusion and mixing of the solution cannot occur. In addition, when gas is introduced into the reaction vessel, sensors such as QCM output an abnormal signal due to the influence of the gas. In the present invention, the flow channel is connected to branch from the supply channel before the reaction vessel. Therefore, the gas that has partitioned the solution is discharged to the degassing branch immediately before the reaction tank section, and only the solution enters the reaction tank section at this point. Therefore, in the microreactor, there is no diffusion mixing of the solution when supplying the solution, and there is no influence of the gas on the sensor, and it is possible to measure the coupling constant and the dissociation constant with high accuracy.

(Outline of the embodiment)
The buffer solution and the sample solution are sequentially supplied to the microreactor 1 by the supply means, and the binding constants and dissociation constants of the antibody 42 immobilized on the reaction tank unit 2 and the antigen 43 contained in the sent sample solution are measured. The solution is partitioned and sent by air so that the buffer solution and the sample solution are not diffusively mixed, and the air partitioned in front of the reaction vessel 2 is removed via the degassing branch 8. As a structure for removing air, a degassing branching path 8 is connected so that air can flow from the vicinity of the inlet of the reaction tank unit 2 connected to the supply path 3, and the other end is open to the atmosphere. .
(Details of the embodiment)
Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following embodiment.
(Embodiment 1)
FIG. 1 is a diagram illustrating the configuration of a microreactor system according to the present invention. First, the configuration of the microreactor 1 will be described. The base slope portion of the microreactor 1 is made of a resin substrate 21. The resin substrate 21 has a structure in which a recess is formed in PDMS (polydimethylsiloxane) which is a kind of silicon rubber, and these are laminated and bonded together. The concave portion becomes a part through which the fluid flows, and the gas vent branch path 8 branches from the supply path 3 in front of the reaction tank section 2 and is connected to the open port 9. In addition, a solution supply port 5, a discharge path 7 from the reaction tank unit 2, and a discharge port 4 are formed.

  Next, the configuration of the microreactor system 14 will be described. The microreactor system includes the microreactor 1 described above and a supply unit that supplies a solution to the microreactor 1, and the supply unit supplies a plurality of different solutions and gases to a supply path, and the supply unit The control part 23 which controls the liquid feeding from a part, and the storage parts (tank) 10, 11, and 12 which store the said solution and gas are comprised. A supply unit 17 is connected to the supply port 5 of the microreactor 1 using a tube 20, and this connection means 17 extends from the first solution container 11, the second solution container 12, and the gas container 10. The respective pipes 13, 25, 24 are connected. A tube 20 is also attached to the discharge port 4 and connected to the waste liquid tank 16. The supply unit 17 is connected to a control unit 23 via a signal line 22, and the control unit 23 is configured to control liquid feeding. However, the drive / detection circuit of the QCM biosensor is omitted in the figure.

As an example of the microreactor 1, the solution supply port 5 and the solution discharge port 4 were made to have a diameter of about 3 mm, and the supply channel 3 and the discharge channel 7 had a width of about 300 μm and a depth of 50 μm. Moreover, the reaction tank part 2 was produced so that the maximum width might be 6 mm. The degassing branch 8 was manufactured to have a width of 5 μm or less and a flow width of 50 μm or less at the connection portion with the supply path. In addition, the concave portion of the resin substrate 21 was subjected to a hydrophilic treatment coating treatment on the surface in order to allow the solution to flow uniformly. However, the degassing branch 8 does not have a hydrophilic treatment coating on the surface in the flow path and maintains a hydrophobic state.
Here, since the microreactor 1 is formed using a resin having a hydrophobic material, the flow path other than the degassing branch path 8 is subjected to a hydrophilization treatment. However, a hydrophilic material (for example, glass) is used for the microreactor. When the reactor 1 is made, the hydrophobic region 50 may be formed by applying a hydrophobization treatment in the vicinity of the branch portion of the branch path shown by a horizontal line in FIG. 1 so that the solution does not flow into the gas vent branch path 8. The aqueous solution liquid does not flow into the degassing branch flow path 8 formed in this way, and the flow path is in a state in which only gas can pass. In addition, a QCM biosensor 6 is arranged in a part of the bottom surface of the reaction tank in order to measure the adsorption / binding reaction of biochemical substances in the reaction tank 2. The electrodes and wiring of the QCM biosensor 6 are omitted in FIG. In the first embodiment, a QCM biosensor composed of a quartz resonator is used as the biosensor.

Next, the liquid feeding method of the present invention will be described with reference to the flowchart of FIG. 2, and the supply unit 17 will be described with reference to FIG. The supply unit 17 is provided with a pump 26 that can supply liquid under pressure, for example, a roller pump or a diaphragm pump, and has a configuration that allows the solution to be washed away. First, the first solution 19 is supplied from the supply unit 17. Supply (FIG. 2, step S1).
After the interior of the microreactor 1 is filled with the first solution 19, the supply unit 17 supplies the supply solution so that the gas 18 is interposed between the two solutions from the first solution 19 to the second solution 15. Are switched (FIG. 2, step S2).
This switching is performed by a valve (sliding on-off valve) 27 controlled by the control means 23. The supply unit 17 has a structure in which the valve 27 is switched for a moment via the gas piping port 28 at the moment when the liquid feeding is switched, so that a small amount of gas 18 is provided between the first solution 19 and the second solution 15. Get caught. At this time, since the gas 18 is compressed and exists in the pipe 24, the solution does not flow back into the gas pipe 24. Accordingly, the second solution 15 is sent between the first solution 19 and the first solution 19 that has been flown through the gas 18.
Furthermore, when the supply unit 17 continues to supply liquid, the second solution 15 flows into the supply path 3 in the microactor 1. The first solution 19 and the second solution 15 with the gas 18 interposed therebetween flow toward the reaction tank unit 2, and the last part of the first solution 19 is a degassing branch before the reaction tank unit 2. When the gas passes through 8, the gas 18 interposed between the first solution 19 and the second solution 15 is pushed out to the degassing branch 8 (FIG. 2, step S3).
At this time, the liquid interface between the first solution 19 and the second solution 15 contacts for the first time. In this state, the second solution 15 flows into and mixes with the reaction vessel 2 (FIG. 2, step S4), so that no gas flows into the reaction vessel 2. The above is the liquid feeding method of the present invention.

  Next, the measurement of the antigen-antibody reaction was performed using the microreactor system 14 of the first embodiment, which will be described. In the first embodiment, a buffer solution such as phosphoric acid is prepared as the first solution 19, and a sample solution containing an antigen is prepared as the second solution 15, and compressed air is used as the gas 18.

  First, the antibody 42 is modified on the surface of the QCM biosensor 6 via the SAM film 41 (FIG. 4A). Next, a buffer solution such as phosphoric acid (first solution 19) is fed by the supply unit 17. The buffer solution (first solution 19) passes through the supply port 5, is sent to the microreactor 1, and flows from the supply path 3 to the reaction tank unit 2, the discharge path 7, the discharge port 4, and the waste liquid tank 16.

After the buffer solution (first solution 19) fills the flow path in the microreactor 1 and the flow rate is stabilized at about 1 μL / min, the supplied solution is changed to the sample solution containing the antigen 43 (second solution 15). Switched. Here, a total of about 20 μL of the sample solution (second solution 15) is fed. The buffer solution (first solution 19) and the sample solution (second solution 15) flow through the supply path 3 with air (gas 18) sandwiched therebetween (see FIG. 3) at a rate of 1 μL / min. Air (gas 18) intervening at the boundary with the buffer solution (first solution 19) when the sample solution (second solution 15) approaches the reaction vessel 2 before the reaction vessel 2 is reached. Was discharged to the gas vent channel 8.
Then, the buffer solution (first solution 19) flowed into the reaction vessel 2 at the same time when the interface between the buffer solution (first solution 19) and the sample solution (second solution 15) contacted each other. Then, the antigen 43 in the sample solution (second solution 15) caused a binding reaction (antigen-antibody reaction) with the antibody 42 immobilized on the surface of the QCM biosensor 6 (see FIG. 4B). A possible signal was detected by the QCM biosensor 6. This signal did not show a specific signal change as if air (gas 18) was mixed.

  Then, about 20 minutes after starting the feeding of the sample solution (second solution 15) (after flowing 20 μL), the supply unit 17 switched again to supplying the buffer solution (first solution 19). Then, the solution is sent to the microreactor 1 with air (gas 18) interposed between the sample solution (second solution 15) and the buffer solution (first solution 19). When the liquid (first solution 19) reaches the front of the reaction vessel 2, the air (gas 18) intervening with the sample liquid (second solution 15) is discharged to the gas vent channel 8, The sample solution (second solution 15) flowed into the reaction vessel 2 at the same time when the interface between the sample solution (second solution 15) and the buffer solution (first solution 19) contacted each other. A signal that seems to have dissociated the anti-source 43 adsorbed on the antibody 42 was detected by the QCM sensor. This signal also did not show a specific signal change as if air (gas 18) was mixed.

  As described above, in the first embodiment, the contact with the other solution does not occur and the gas such as air does not enter the reaction tank 2 until just before the sample liquid enters the reaction tank 2. Liquid is possible. Therefore, the antigen-antibody reaction can be measured in real time, and it is possible to measure not only the reaction quantification but also the affinity characteristics related to the reaction rate such as the binding constant and the dissociation constant. Although the antigen-antibody reaction has been described in the first embodiment, it can be used for various biochemical reactions such as DNA hybridization reaction, protein binding, and enzyme reaction.

  In the first embodiment, the QCM biosensor is used as the biosensor. However, an SPR biosensor or an evanescent wave excitation type sensor using light may be used. Further, although a slide type valve is used as a valve, a rotary type valve may be used, and any valve may be used as long as it can be supplied via gas.

It is a block block diagram of the microreactor system of this invention. It is a flowchart figure which shows the liquid feeding method of this invention. It is explanatory drawing for demonstrating the liquid feeding method of this invention. It is explanatory drawing for demonstrating operation | movement of the microreactor of this invention, (a) is the state which fixed the antibody, (b) is a figure which shows the state which is feeding the antigen. It is explanatory drawing for demonstrating operation | movement of the supply means of this invention. It is a general-view figure which shows the structure of the conventional QCM biosensor, (a) is a top view, (b) is BB 'sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microreactor 2 Reaction tank part 3 Supply path 4 Discharge port 5 Supply port 6 QCM biosensor 7 Discharge path 8 Degassing branch path 9 Opening port 10 Gas container 11 First solution container 12 Second solution container 13 Piping 14 Microreactor system 15 Second solution 16 Waste liquid tank 17 Supply unit 18 Gas 19 First solution 20 Tube 21 Resin substrate 22 Signal line 23 Control means 24 Pipe 25 Pipe 26 Pump 27 Valve 28 Gas pipe port 41 SAM membrane 42 Antibody 43 Antigen 50 Hydrophobic region 100 QCM sensor 101 Detection channel 102 Correction channel 103 Sample solution

Claims (5)

A microreactor having a reaction tank part, a supply path for supplying an analysis solution to the reaction tank part, a waste liquid path for discharging the solution from the reaction tank part, and connected to the supply path of the microreactor. A microreactor system having a supply means for supplying the solution,
The supply means includes a supply unit that supplies a plurality of different solutions and gases to the supply path, a control unit that controls liquid feeding from the supply unit, and a storage unit that stores the solution and gas. The microreactor system is characterized in that the supply path is provided with gas removing means for extracting the gas at a predetermined position reaching the reaction tank.   The supply unit receives the solution from the storage unit and sends it out while pressurizing, and the supply unit is configured to partition the solutions sent from the pressurization pump into different types. 2. The microreactor system according to claim 1, further comprising a valve that sequentially switches the solution and the gas while supplying the gas between the solutions and supplies the gas to the supply path.   3. The microreactor system according to claim 1, wherein the gas removing unit includes a degassing branch channel that branches from the supply channel at the predetermined position and communicates with the outside or the atmosphere.   The microreactor system according to any one of claims 1 to 3, wherein the degassing branch channel has hydrophobicity on the entire surface in the branch channel or on the inner surface in the vicinity of the branch part. A liquid feeding method for feeding a plurality of different types of solutions to a reaction tank via a supply path,
Flowing the solution through the supply path by interposing a gas between the solutions so as to partition the solutions of different types for each type;
Extracting the gas at a predetermined position reaching the reaction vessel;
Withdrawing the gas and supplying the solution to the reaction vessel sequentially for each type in a state where partitioning by the gas is eliminated;
A liquid feeding method comprising:

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