JP4543994B2 - Micro total analysis system - Google Patents

Description

  The present invention relates to a micro total analysis system for automatically detecting required information in a test chip by incorporating a test chip in which a sample and a reagent are mixed in a fine flow path into a fluid control detection device. More specifically, the present invention relates to a micro total analysis system that can stably feed a small amount of fluid sent by a micropump.

In recent years, by making full use of micromachine technology and ultrafine processing technology, devices and means (for example, pumps, valves, flow paths, sensors, etc.) for performing conventional sample preparation, chemical analysis, chemical synthesis, etc. have been miniaturized. Systems integrated on a chip have been developed.

This is a micro-TAS (Micro Total Analysis System), bioreactor, love-on
It is also called a chip (Lab-on-chips), biochip, etc., and its application is expected in the medical examination / diagnosis field, the environmental measurement field, the agricultural product manufacturing field, and the like.

  In particular, as seen in genetic testing, when complicated processes, skilled techniques, instrument operations, etc. are required, the test chip as an automated, accelerated and simplified micro analysis system is Since the analysis can be performed not only on the cost, the required amount of sample, and the time required, but also on any time and place, the benefit is great.

  In the field where various tests such as clinical tests are performed, the quantitativeness of analysis, the accuracy of analysis, and the economy of these test chips that produce results quickly regardless of location are regarded as important. On the other hand, since the inspection chip is severely restricted by its size and form, it is required to establish a highly reliable liquid delivery system with a simple configuration.

  As the micro pump, various types such as a check valve type pump provided with a check valve in the outflow / inflow hole of the valve chamber provided with the actuator can be used. For example, as disclosed in Patent Document 1, It is preferable to use a piezo pump.

  FIGS. 10A and 10B are a sectional view and a top view showing an example of a piezo pump suitably used as a micro pump. In this micropump, a substrate 42 on which a first liquid chamber 48, a first flow path 46, a pressurization chamber 45, a second flow path 47, and a second liquid chamber 49 are formed and laminated on the substrate 42. Upper substrate 41, diaphragm 43 stacked on upper substrate 41, piezoelectric element 44 stacked on the side of diaphragm 43 facing pressure chamber 45, and drive unit 40 for driving piezoelectric element 44. And are provided.

  In this example, a photosensitive glass substrate is used as the substrate 42 and etching is performed, whereby the first liquid chamber 48, the first flow path 46, the pressurizing chamber 45, the second flow path 47, and the second liquid chamber 49 are formed. Forming.

  By stacking the upper substrate 41, which is a glass substrate, on the substrate 42, the upper surfaces of the first liquid chamber 48, the first flow path 46, the second liquid chamber 49, and the second flow path 47 are formed. A portion of the upper substrate 41 that corresponds to the upper surface of the pressurizing chamber 45 is processed by etching or the like and penetrates.

  A diaphragm 43 made of thin glass is laminated on the upper surface of the upper substrate 41, and a piezoelectric element 44 made of, for example, lead zirconate titanate (PZT) ceramics is laminated thereon.

  In such a micropump, the piezoelectric element 44 and the vibration plate 43 attached thereto are vibrated by the drive voltage from the drive unit 40, thereby increasing or decreasing the volume of the pressurizing chamber 45. The first flow path 46 and the second flow path 47 have the same width and depth, and the length of the second flow path is longer than that of the first flow path. When the differential pressure increases, a turbulent flow is generated so as to create a vortex around the entrance / exit of the flow path and the vicinity thereof, and the flow path resistance increases. On the other hand, in the second flow path 47, since the length of the flow path is long, a laminar flow tends to occur even if the differential pressure increases, and the change rate of the flow resistance with respect to the change in the differential pressure is smaller than that of the first flow path. Become.

  For example, the volume of the pressurizing chamber 45 is reduced while applying a large differential pressure by quickly displacing the vibration plate 43 in the inward direction of the pressurizing chamber 45 by the driving voltage for the piezoelectric element 44, and then from the pressurizing chamber 45 outward. When the volume of the pressurizing chamber 45 is increased while slowly displacing the vibration plate 43 to give a small differential pressure, the liquid is fed in the direction B in FIG. Conversely, the diaphragm 43 is quickly displaced outwardly from the pressurizing chamber 45 to increase the volume of the pressurizing chamber 45 while applying a large differential pressure, and then the diaphragm 43 is slowly displaced inward from the pressurizing chamber 45. If the volume of the pressurizing chamber 45 is decreased while applying a small differential pressure, the liquid is fed in the direction A in FIG.

Thus, according to the piezo pump, the liquid feeding direction and the liquid feeding speed can be controlled by changing the driving voltage and frequency of the pump, for example.
JP 2001-322099 A

  By the way, the inspection chip containing the biological material and the reagent is incorporated in the fluid control detection device equipped with the above micropump, etc., and merged along with the movement of the working fluid. In a micro total analysis system that automatically detects detected information by optical detection means, the amount of sample required is extremely small and the amount of reagent required is small. Appropriate analysis must be completed.

In order to respond to such a request, it is necessary to stabilize the feeding of the working fluid by the micropump.
However, for example, when working fluid is supplied into the inspection chip from an external micropump, the connection with the micropump is reliable in addition to the influence of the piezoelectric element 44 such as pressure change and flow path resistance. Otherwise, liquid leakage may occur and the fluid flowing downstream may not flow at a constant speed, or the flow rate per hour may be excessive or insufficient.

As described above, in the micro integrated analysis system, if the flow rate, the flow rate, and the like are not kept constant, the analysis result may be adversely affected.
The present invention has been made in view of such a situation, in a micro integrated analysis system in which an inspection chip is incorporated in a fluid control detection device and necessary information is automatically detected by an optical detection means. An object of the present invention is to provide a micro total analysis system capable of always sending a small amount of fluid supplied from a micropump in a stable state.

In order to achieve the above object, the micro comprehensive analysis system according to the present invention comprises:
A detection fluid formed in the downstream area of the merging portion by supplying a working fluid into a test chip whose main body is composed of at least two substrates, thereby combining a reagent and a sample previously stored in the test chip. In the micro total analysis system in which the inspection object is automatically inspected by the optical detection means in the part,
In the flow path in the main body of the test chip through which the working fluid flows, continuous to the upstream side in the flow direction of the flow path in which the reagent in the main body of the test chip flows or in the flow path of the sample.
It is characterized in that a detection device for obtaining information of the flow velocity of the working fluid.

According to the present invention as described above, various setting conditions can be adjusted based on the detection result of the detection device.
Further, the detection device may be a flow sensor.

  As described above, if the flow rate sensor is provided, the fluid supplied from the micropump can be electrically detected, and based on this, the flow rate per unit time can be adjusted.

The flow sensor is
A degree of cooling from the heating state of the heater when the working fluid flows from the upstream side of the heater, provided with an electric circuit provided with a heater in or near the flow channel through which the working fluid flows May be a sensor that measures the flow rate of the working fluid based on the detection result.

Furthermore, in the present invention,
The detection device may be a sensor using a fluid meniscus.
In the present invention, the sensor using the meniscus is
Two electrical circuits disposed at a predetermined distance in a flow path through which the working fluid flows,
Time difference between when the working fluid flows from the upstream side and passes between the pair of electrodes of the one electric circuit and when the working fluid further flows and passes between the pair of electrodes of the other electric circuit Preferably, the sensor is a sensor that measures the flow rate of the working fluid.

Here, in the present invention, the sensor using the meniscus is
An electric circuit disposed in the flow path through which the working fluid flows, and a hydrophobic valve provided on the upstream side of the electric circuit,
By detecting that the working fluid flowing from the upstream side of the hydrophobic valve passes through the hydrophobic valve and then flows between the pair of electrodes of the electric circuit, the flow velocity of the working fluid is detected. It is preferred that this is a sensor to measure.

In the present invention, the sensor using the meniscus is
Provided with a single electric circuit in which electrodes arranged between a plurality of adjacent channels are connected in series,
Of the pair of electrodes in each flow path of the electric circuit, a sensor that detects that the working fluid has flowed between all the flow paths when the working fluid flows between the last pair of electrodes may be used.

Further, in the present invention, the optical detection means for inspecting the inspection object is configured to be movable, and in addition to inspecting the inspection object by the movable optical detection means, the meniscus of the working fluid is used. Can also be detected.
Moreover, in this invention, it is preferable that the said detection apparatus is arrange | positioned in the flow path through which the said working fluid in the said test | inspection chip main body flows.

  According to the micro total analysis system according to the present invention, even if the flow of the fluid supplied from the micropump is not stable, information such as the flow rate of the fluid can be detected by the detection device. Or by adjusting a pressure driving source such as a piezo pump, so that stable liquid feeding can be performed.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a micro total analysis system according to an embodiment of the present invention.
The micro comprehensive analysis system 10 includes an inspection chip 1 made of a single resin chip, and a fluid control detection device 2 that inspects necessary information by setting the inspection chip 1 at a predetermined position. Yes.

  For example, by injecting a gene sample extracted from blood, sputum or the like, the test chip 1 can automatically perform a gene amplification reaction by the ICAN method or the like in the chip and the detection thereof, and simultaneously perform genetic diagnosis for a plurality of genes. It is comprised as follows. The test chip 1 is a chip having a length and width of several centimeters. For example, a blood sample of about 2 to 3 μL is dropped into the chip and then mounted in the fluid control detection device 2 to automatically Thus, the amplification reaction and its detection can be performed.

  The inspection chip 1 is formed of a laminated body in which appropriate members such as plastic resin, glass, silicone, ceramics are combined, and is preferably formed of a plastic resin that is easy to process, inexpensive, and easy to dispose of by incineration. The

  For example, polystyrene resin is excellent in moldability, has a strong tendency to adsorb streptavidin and the like, and can easily form a detection site on a fine channel. Further, in order to optically detect a fluorescent substance or a product of a color reaction, the surface of the inspection chip 1 needs to be transparent.

If the structure of such a test | inspection chip 1 is shown schematically, it will be comprised as shown in FIG.
That is, the test chip 1 is connected to a sample storage unit 3 that stores a sample such as blood, a reagent storage unit 4 that stores a reagent used for a gene amplification reaction, for example, and the sample storage unit 3 is branched. A liquid passage 3a, a liquid passage 4a having one end connected to the reagent storage unit 4, a fine passage 6 in which the liquid passage 3a and the liquid passage 4a are connected via a Y-shaped passage, and the like. The inspection fluid detection unit 7 is configured in the middle of each fine channel 6. In the test fluid detection unit 7, necessary information is detected by an optical detection device including a light emitting element 8a such as an LED and a light receiving element 8b. A waste liquid storage unit for storing the mixed fluid after detection is formed on the downstream side of the inspection fluid detection unit 7.

  Such a test chip 1 is used as a disposable, but an opening 3b is formed in the sample storage unit 3 so that a sample or a working fluid can be supplied into the sample storage unit 3 from the outside. Similarly, the reagent container 4 also has an opening 4b so that a reagent or a working fluid can be supplied from the outside. In this embodiment, the working fluid is supplied from the outside through the opening 4b. In addition, in each liquid passage from the sample storage unit 3 to the waste liquid storage unit, a fluid is configured to flow by forming a slit for air bleeding or the like.

  By the way, in such a test chip 1, the working fluid is introduced into the specimen storage unit 3 and the reagent storage unit 4 via a micro pump incorporated in the fluid control detection device 2 described in detail later. Then, the sample in the sample container 3 is delivered into the branch passage 3a by the working fluid introduced into the sample container 3. When the working fluid is introduced into the reagent storage unit 4 via the micro pump in the fluid control detection device 2, the reagent is delivered from the liquid passage 4a to the Y-shaped passage by the working fluid. In this way, the specimen and the reagent supplied from the liquid passage 3a or the liquid passage 4a are merged in one passage, and a predetermined reaction is performed in each fine channel 6.

On the other hand, as shown in FIG. 1, the fluid control detection device 2 as an inspection device to which the inspection chip 1 is detachably attached can be reduced in weight and size so that the inspection can be performed at an arbitrary place. ing. In addition, an inlet 14 for inserting the inspection chip 1 on the panel surface and a display unit 18 for displaying the detection result outward are formed. An inspection chip transport tray 22 for placing the inspection chip 1 and guiding it toward the inside of the apparatus main body 12 is disposed at the entrance 14 so as to be able to protrude and retract toward the inside of the apparatus main body 12. The inspection chip 1 is guided inward of the apparatus main body 12 along with the movement of the transport tray 22 by operating the hand 22 in the arrow direction or by operating a button from a control panel (not shown). . That is, the inspection chip connecting portion arranged at a predetermined position of the apparatus main body 12 and the micropump connecting portion of the inspection chip 1 are docked, and the working fluid is supplied to the inspection chip 1 side from there, and the apparatus main body 12 is supplied. The inspection object is detected in the inside.

  As shown in FIGS. 3 and 4, in the device main body 12 of the fluid control detection device 2, a pump unit 26 including a micropump for supplying a working fluid into the test chip 1, A main detection unit 60 including a detection unit 8 for detecting information on the mixed liquid and a temperature control unit 38 for setting the temperature at a predetermined portion such as a reagent storage portion and a reaction portion of the test chip 1 to a predetermined temperature is provided. Yes. Further, an inspection chip connection portion 64 is formed downstream of the pump unit 26, and an operating fluid is supplied from the inspection chip connection portion 64 to the inspection chip 1 side.

Further, on the upstream side of the pump unit 26, a pump control device 28 that controls the driving of the micropump and a working fluid storage tank 30 that stores the working fluid 31 are provided.
A piezo pump is preferably used as the micro pump.

According to such a piezo pump, the liquid feeding direction and the liquid feeding speed can be controlled by changing the driving voltage and frequency of the pump.
In the main detection unit 60, the working fluid 31 is supplied from the working fluid storage tank 30 to the pump unit 26 in accordance with a command signal from the pump control device 28, and the inspection chip connection provided downstream from the micropump of the pump unit 26. The working fluid 31 is supplied to the test chip 1 side via the unit 64, and the working fluid 31 is supplied to the specimen storage unit 3 or the reagent storage unit 4.

  After that, as shown in FIG. 2, the sample in the sample storage unit 3 and the reagent in the reagent storage unit 4 are joined and mixed through the Y-shaped flow path, and the temperature control unit in the fine flow path 6 is mixed. The temperature is raised to a predetermined temperature by 38 and the reaction is promoted, and then the detection unit 8 detects the reaction.

  In the micro integrated analysis system 10 according to the present embodiment, when the test chip 1 is incorporated in the fluid control detection device 2, the liquid channel and the like are communicated so that no liquid leakage occurs. It is necessary to closely connect the micropump connector 1a and the inspection chip connector 64 on the fluid control detection device 2 side.

  The micro integrated analysis system 10 according to the present embodiment is provided with a detection device for obtaining information such as the flow speed of the working fluid supplied from the pump unit 26 from the fluid control detection device 2 side to the inspection chip 1 side. ing.

  The micro total analysis system according to the present embodiment is configured as described above. Hereinafter, a detection device for detecting the influence of the output of the micropump or the liquid leakage at the micropump connection, which is the gist of the present invention. Will be described more specifically.

FIG. 5 shows a more specific test chip 80, and particularly shows only a part for preparing a reagent.
In this test chip 80, three flow paths a, b, and c for reagent supply are formed in parallel. The three types of reagents A, B, and C are supplied into the flow paths a, b, and c through the reagent insertion openings 72, 74, and 76, and a predetermined amount is injected in advance. In the inspection chip 80, when the working fluid derived from a micro pump (not shown) is supplied to the openings 82, 84, 86, the reagents A, B, C stored in advance are independent flow paths a. , B, and c, and then the three reagents A, B, and C are merged in the merging portion 52, and then mixed efficiently in the microchannel d. The sample is mixed with a sample such as a biological material stored in the sample storage unit.

In such a test chip 80, in order to detect the speed of the working fluid supplied from the openings 82, 84, and 86, a detection device E is provided in each of the flow paths a, b, and c.
The detection device E is preferably provided slightly downstream of the openings 82, 84, 86, for example. If the detection device E is provided at such a position, necessary information can be obtained effectively.

  This detection device E is for detecting information such as the flow velocity of the working fluid sent from the micropump. As the detection device E, what kind of mechanism is used as necessary. Also good. For example, it can be detected by known means such as optical detection means or electrical detection means.

FIG. 6 shows an example in which a flow sensor 90 is provided as the detection device E.
The flow rate sensor 90 arranges a heating wire heater 94 in the flow path 92 or in the vicinity of the flow path 92 to heat the heater, and when the working fluid 31 flows in the flow path 92, the higher the flow rate, the more This is a flow rate sensor that utilizes the fact that the heat ray heater 94 is well cooled and the electric resistance value is lowered.

  Here, the change in the electrical resistance value is obtained by energizing using a voltage source 96 having a constant voltage and measuring the change in the current amount with an ammeter 98. The heating wire can be formed by using a wire such as a nickel-chromium alloy or tungsten, or by forming a metal thin film (such as chromium, gold, platinum) on the substrate by sputtering or the like. When this metal thin film is formed in the flow path 92, it is desirable to form an insulating film such as SiO2 as a protective film thereon in order to prevent leakage due to direct contact with the liquid.

  As described above, according to the present embodiment, the flow rate can be adjusted based on the detection result from the detection device E, so that stable liquid feeding can always be executed. As a result, the necessary amount of reagent is minimized, which contributes to inspecting the inspection object at an appropriate mixing ratio.

FIG. 7 shows a meniscus sensor 20 using a meniscus of fluid as another detection device E.
In the meniscus sensor 20, an electric circuit including a pair of electrodes 24a and 24b is disposed in the flow path 92, and when the working fluid 31 flows through the portion, the meniscus is passed between the electrodes 24a and 24b. Is a method of detecting As shown in FIG. 7, when two detectors are arranged with a predetermined distance apart, the flow velocity can be measured with the time difference.

FIG. 8 shows still another meniscus sensor 70.
In the meniscus sensor 70, a hydrophobic fluid stopper (hydrophobic valve) 54 is interposed on the upstream side of the flow path 92. Then, if the method in which the meniscus 31a of the working fluid 31 is once stopped by the hydrophobic valve 54 and then fed by a micropump is used, as shown in FIG. Even if there is only one, the time required for the meniscus 31a to move from the hydrophobic valve 54 to the pair of electrodes 24a, 24b can be measured, so that the flow rate and the like can be measured.

FIG. 9 shows still another meniscus sensor 50.
Here, as one of the purposes of use of the meniscus sensor, there may be a case where it is only necessary to know the fact that a malfunction has occurred when a malfunction for some reason occurs and the flow becomes slower than the original purpose. In such a case, if a meniscus sensor is provided in all of the plurality of flow paths 92, the cost increases. Therefore, as shown in FIG. 9, for example, the counter electrodes 24a and 24b in each flow path 92 are connected in series. The number of ammeters 98 can be reduced to one. When such a meniscus sensor 50 is used, it is possible to measure the time for the slowest working fluid 31 in each flow channel 92 to reach the detection unit. Can be detected.

  Further, the detection device E is not limited to the above embodiments. For example, if the flow path 92 is transparent, the passage of the meniscus can be detected optically. Such an optical detection device can be composed of an LED and a photodiode.

  Since the micro total analysis system of the present invention optically detects the result of gene amplification test or the like, its optical detection means (light emitting element 8a and light receiving element 8b in FIG. 2), test chip, If the relative positional relationship is set to be movable, the optical detection means for detecting the inspection object can be used in combination with the meniscus sensor. Further, such a relative position movable unit may be configured to be used also as a moving unit for transporting the inspection chip.

  Furthermore, if the detection result by the detection device E exceeds a certain allowable range, an alarm device or the like can issue a warning by sound.

FIG. 1 is a perspective view of a micro total analysis system according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the outline of the inspection chip and the inspection method used in the micro integrated analysis system shown in FIG. FIG. 3 is a schematic cross-sectional view when the inspection chip is docked to the main detection unit provided in the fluid control detection device shown in FIG. 4 is a schematic perspective view of the main detection unit shown in FIG. FIG. 5 is a plan view showing only the reagent preparation portion extracted from another inspection chip provided with the inspection apparatus according to the present embodiment. FIG. 6 is a schematic view showing a flow sensor as a specific example of the detection apparatus employed in the micro total analysis system according to the present invention. FIG. 7 is a schematic view showing a meniscus sensor as a specific example of the detection apparatus employed in the micro total analysis system according to the present invention. FIG. 8 is a schematic view showing still another meniscus sensor. FIG. 9 is a schematic view showing still another meniscus sensor. 10A and 10B are explanatory views showing an outline of a piezo pump as an example of a micro pump provided in a conventional micro total analysis system. FIG. 10A is a cross-sectional view and FIG. 10B is a top view thereof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Test | inspection chip 2 Fluid control detection apparatus 3 Sample storage part 3a Flow path 4 Reagent storage part 4a Flow path 20 Meniscus sensor 31 Working fluid 50 Meniscus sensor 54 Hydrophobic valve 70 Meniscus sensor 90 Flow sensor 92 Flow path 94 Heater 96 Voltage source 98 Current Total E detector

Claims (9)

A detection fluid formed in the downstream area of the merging portion by supplying a working fluid into a test chip whose main body is composed of at least two substrates, thereby combining a reagent and a sample previously stored in the test chip. In the micro total analysis system in which the inspection object is automatically inspected by the optical detection means in the part,
In the flow path in the main body of the test chip through which the working fluid flows, continuous to the upstream side in the flow direction of the flow path in which the reagent in the main body of the test chip flows or in the flow path of the sample.
Micro total analysis system, characterized in that a detection device for obtaining information of the flow velocity of the working fluid.   The micro total analysis system according to claim 1, wherein the detection device is a flow sensor. The flow sensor is
A degree of cooling from the heating state of the heater when the working fluid flows from the upstream side of the heater, provided with an electric circuit provided with a heater in or near the flow channel through which the working fluid flows The micro total analysis system according to claim 2, wherein the sensor is a sensor that measures a flow rate of the working fluid based on a detection result based on a change in an electric resistance value of the electric circuit.   The micro total analysis system according to claim 1, wherein the detection device is a sensor using a meniscus of fluid. The sensor using the meniscus is
Two electrical circuits disposed at a predetermined distance in a flow path through which the working fluid flows,
Time difference between when the working fluid flows from the upstream side and passes between the pair of electrodes of the one electric circuit and when the working fluid further flows and passes between the pair of electrodes of the other electric circuit The micro total analysis system according to claim 4, wherein the sensor is a sensor for measuring a flow rate of the working fluid based on the system. The sensor using the meniscus is
An electric circuit disposed in the flow path through which the working fluid flows, and a hydrophobic valve provided on the upstream side of the electric circuit,
By detecting that the working fluid flowing from the upstream side of the hydrophobic valve passes through the hydrophobic valve and then flows between the pair of electrodes of the electric circuit, the flow velocity of the working fluid is detected. The micro total analysis system according to claim 4, wherein the sensor is a sensor for measuring the temperature. The sensor using the meniscus is
Provided with a single electric circuit in which electrodes arranged between a plurality of adjacent channels are connected in series,
When the working fluid flows from the upstream side, the working fluid flows between the last pair of electrodes of each pair of electrodes in each flow path of the electric circuit, thereby operating between all the flow paths. The micro total analysis system according to claim 4, wherein the sensor is a sensor that detects that a fluid has flowed.   An optical detection means for inspecting the inspection object is configured to be movable, and the movable optical detection means is used to detect passage of the working fluid meniscus in addition to inspecting the inspection object. The micro total analysis system according to claim 1 or 4, characterized by the above-mentioned.   The micro total analysis system according to claim 1, wherein the detection device is arranged in a flow path in which the working fluid flows in the inspection chip body.

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