JPWO2009131043A1 - Microchip - Google Patents

Abstract

An object of the present invention is to provide a microchip that can be stored for a long time and stores a reagent liquid therein. For this purpose, the fine flow path r1, the reagent liquid storage part 133 storing the reagent liquid for feeding the fine flow path r1 and mixing with the sample, and the dummy liquid storage part storing the dummy liquid for evaporation are stored. 150 is housed in a packaging bag having a moisture barrier property or a gas barrier property.

Description

  The present invention relates to a microchip in which a reagent liquid is stored.

  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. A system integrated on a chip has been developed (for example, Patent Document 1). This is also referred to as μ-TAS (Micro Total Analysis System), and in a member called a microchip, a specimen (for example, urine, saliva, blood extracted from DNA subjected to DNA treatment) and a reagent liquid are collected. In this method, the characteristics of the specimen are examined by mixing and detecting the reaction.

  Microchip performs a photolithographic process (a method of creating a groove by etching a pattern image with a chemical) or a groove processing using laser light on a substrate made of a resin material or a glass material, and causes a reagent liquid or specimen to flow. A fine flow path that can be used and a reservoir for storing reagent liquid are provided, and various patterns have been proposed (for example, Patent Document 1).

  In a microchip, a reaction or the like is performed by mixing a small amount of reagent liquid in a fine channel and a specimen at a predetermined mixing ratio. In the reaction, it is necessary to accurately control the mixing ratio of the two, and for that purpose, it is important to manage the amount of the reagent liquid.

  In order to perform the test smoothly, it is preferable to store a reagent liquid in the microchip in advance and to inject only the sample when the test is performed. However, in such a case, if the reagent liquid is stored in the microchip and not immediately inspected and stored for a long period of time, the reagent liquid will evaporate, so the mixing ratio can be controlled. May be difficult.

  With respect to such a problem, Patent Document 2 discloses a microchip that prevents the reagent liquid from evaporating by sealing the outside of the reagent liquid in the flow path with an inert liquid.

JP 2004-28589 A JP 2005-274199 A

  However, in the microchip disclosed in Patent Document 2, since the liquid in contact with the outside air of the microchip continues to evaporate, the sealing liquid will eventually disappear, which is suitable for long-term storage. Absent. Further, the seal liquid and the reagent liquid must be inert to each other, and there is a possibility that the combination of the seal liquid and the reagent liquid may be restricted.

  In view of the above problems, an object of the present invention is to provide a microchip having a reagent liquid stored therein that can be stored for a long period of time.

1. A microchip stored in a packaging bag having a moisture barrier property or a gas barrier property,
A microfluidic channel, a reagent liquid reservoir that stores a reagent liquid for feeding the microfluidic channel and mixing it with a sample, a dummy liquid reservoir that stores a dummy liquid for evaporation, and the dummy liquid An opening connected to the reservoir,
The microchip according to claim 1, wherein the evaporation component from the dummy liquid is common to at least a part of the evaporation component from the reagent liquid.

  2. 2. The microchip as described in 1 above, further comprising an inlet for injecting the reagent liquid into the reagent liquid reservoir.

  3. 3. The microchip as described in 1 or 2 above, wherein the dummy liquid storage part and the opening part are connected by a fine channel.

  4). 4. The microchip according to any one of 1 to 3, wherein the reagent liquid is an aqueous solution, and the dummy liquid for evaporation is an aqueous solution or water.

  5. 4. The microchip according to any one of 1 to 3, wherein the reagent liquid is an alcohol solution, and the evaporation dummy liquid is an alcohol solution or alcohol.

  6). 6. The microchip housed in the packaging bag, wherein the injection port is closed by a sealing member, and the opening is not closed. Microchip.

  According to the present invention, it is possible to provide a microchip that can be stored for a long period of time and stores a reagent liquid therein.

It is a schematic diagram which shows an example of a micro analysis system. 2A is a top view of the microchip 100, and FIG. 2B is a side view of the microchip 100. FIG. 1 is a schematic diagram showing an internal structure of a microchip 100. FIG. It is a perspective view of the microchip 100 accommodated in the packaging bag 5 in this embodiment. FIG. 5A is a top view of the microchip 100 according to the second embodiment, and FIG. 5B is a schematic diagram showing the internal structure of the microchip 100. It is a graph which shows transition of the evaporation amount of the reagent liquid with the elapsed days in an Example and a comparative example.

  Although the present invention will be described based on an embodiment, the present invention is not limited to the embodiment.

  In the present specification, “microchip” refers to a chip in a micro total analysis system used for various applications such as synthesis and inspection, and “microchip” particularly used for inspection of biological materials. Sometimes called. In the narrow sense, the “fine channel” may refer only to a narrow channel portion excluding a structure portion that may be formed wide, but in a broad sense includes such a structure portion. Refers to a series of flow paths. In many cases, the fluid flowing in the communicating fine flow path is actually a liquid, and specifically, various reagent liquids, sample liquids, denaturant liquids, cleaning liquids, driving liquids, and the like are applicable.

  The present invention can be applied to a reaction detection apparatus using a microchip regardless of the use of the microchip. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the micro comprehensive analysis system in this embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram illustrating an example of a micro analysis system.

  FIG. 1 shows a state in which the microchip 100 according to the present embodiment is loaded into the inspection apparatus 20 that is the micro analysis system according to the present embodiment. In FIG. 1, the inspection apparatus 20 is included in a micropump unit 210 that feeds liquid in the microchip, a heating / cooling unit 230 for promoting and suppressing the reaction in the microchip, and a product liquid obtained by the reaction in the microchip. A detection unit 250 that detects the target substance to be detected, and a drive control unit 270 that drives, controls, and detects each unit in the inspection apparatus.

  The micropump unit 210 includes a micropump 211 that performs liquid feeding, a chip connection unit 213 that connects the micropump 211 and the microchip 100, a driving liquid tank 215 that is filled with driving liquid for liquid feeding, and a driving liquid tank 215. The driving liquid supply unit 217 and the like for supplying the driving liquid to the micro pump 211. The driving liquid tank 215 can be removed and replaced from the driving liquid supply unit 217 for replenishment of the driving liquid. The micropump 211 is formed by one or a plurality of pumps. In the case of a plurality of micropumps 211, the micropumps 211 can be driven independently or in conjunction with each other.

  The heating / cooling unit 230 includes a cooling unit 231 including a Peltier element, a heating unit 233 including a heater, and the like. Of course, the heating unit may also be composed of Peltier elements. The detection unit 250 includes a light emitting diode (LED) 251 and a light receiving element (PD) 253, and optically detects a target substance contained in a product solution obtained by a reaction in the microchip.

  The microchip 100 and the micropump 211 are connected and communicated with each other via a chip connection unit 213, and when the micropump 211 is driven, various reagent liquids and specimens stored in a plurality of storage units in the microchip 100 are transferred. Then, the liquid is fed through the air by the driving liquid flowing into the microchip 100 from the micropump 211 via the chip connection portion 213.

  2A is a top view of the microchip 100, and FIG. 2B is a side view of the microchip 100. FIG. As shown in FIG. 2B, the microchip 100 includes a groove forming substrate 108 and a covering substrate 109 that covers the groove forming substrate 108. The groove forming substrate 108 is formed with respective structural parts such as a reagent liquid storage part, which will be described later, and fine flow channels r1 and r2 (see FIG. 3) for communicating these structural parts. The widths and heights of the fine channels r1 and r2 are about several μm to several hundreds of μm. The size of the microchip 100 is usually about several tens mm in length and width and about several mm in height.

  The microchip 100 is configured by bringing the covering substrate 109 into close contact with the groove forming substrate 108 and covering these structural portions and the fine flow path. In addition, when it is set as the structure which detects the reaction in the microchip 100 optically, at least to-be-detected part needs to use the light-transmitting material with respect to detection light among said structure parts.

  Further, the microchip 100 is usually manufactured by appropriately combining one or more molding materials. Examples of the molding material for the microchip 100 include plastic resins, various inorganic glasses, silicon, ceramics, and metals. Above all, it is desirable to be disposable for chips that target a large number of samples to be measured, especially clinical samples that are at risk of contamination and infection, and it is also desirable to have versatility and mass productivity. From the viewpoint, it is preferable to use a plastic resin as a molding material of the microchip 100. In the substrate for forming and processing the flow path such as the groove forming substrate 108, the flow path is not easily deformed due to water absorption, and a hydrophobic and water-repellent plastic is used so that a small amount of sample liquid can be fed without loss in the middle. preferable. Examples of such materials include resins such as polystyrene, polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyethylene vinyl alcohol, polycarbonate, polymethylpentene, fluorocarbon, and saturated cyclic polyolefin. Among them, polystyrene is preferable as a material for forming the groove forming substrate 108 because it is excellent in transparency, mechanical properties, and moldability, and can be finely processed.

  The coated substrate 109 is made of a flexible material such as polyolefin, and is provided with openings (holes) that connect each internal structure portion and the outside air, or connect the fine flow path and the outside air. Examples of the opening include an injection port for injecting a reagent liquid or a specimen sample, a connection port connected to a micropump via a chip connection portion, and various holes opened to the outside air. Examples of polyolefins include polypropylene, polycarbonate, polystyrene, polyethylene, and cycloolefin polymers.

  Next, the internal configuration of the microchip 100 according to the first embodiment will be described with reference to FIG. FIG. 3 is a schematic diagram showing the internal structure of the microchip 100 and shows a state where the covering substrate 109 is removed. 133a and 133b are reagent liquid storage units for storing reagent liquids, and 137 is a sample storage unit for storing sample samples.

  In the specification of the present application, when constituent elements are collectively referred to, reference numerals with alphabetical subscripts omitted are indicated, and when referring to individual constituent elements, reference numerals with additional subscripts are indicated.

  Further, an injection port i1 for injecting a reagent liquid and an injection port i3 for injecting a specimen sample are provided beside each storage unit. Further, connection ports 132a and 132b opened from one surface of the microchip 100 to the outside are provided on the upstream side in the liquid feeding direction of the storage unit. The microchip 100 is connected to the micropump 211 through the connection ports 132 a and 132 b and the chip connection part 213 so as to be connected to the micropump 211.

  A reaction unit 139 that mixes and reacts the reagent liquid from the reagent liquid storage unit 133 and the liquid from the sample storage unit 137 is provided downstream of the reagent liquid storage unit 133 and the sample storage unit 137.

  A detected part 148 is provided downstream of the reaction part 139, and a waste liquid part 60 is provided further downstream. The detection unit 250 detects the reaction of the detected unit 148.

  The reagent liquid stored in the reagent liquid storage unit 133 is driven via air by the driving liquid sent from the micropump 211 communicating with the connection port 132a (flowed) and flows into the reaction unit 139. On the other hand, the sample stored in the specimen storage unit 137 is driven by the driving liquid sent from the separate micro pump 211 communicating with the connection port 132b and flows into the reaction unit 139. Thereby, in the reaction part 139, the reagent liquid sent from the reagent liquid storage part 133 and the sample sent from the sample storage part 137 are mixed.

  The reagent liquid and the sample mixed in the reaction unit 139 are heated by the heating unit 233 provided in the inspection apparatus 20 to start the reaction. The liquid after the reaction is sent to the detected part 148. In the detected part 148, the target substance is detected by an optical detection method, for example. The liquid detected by the detected part 148 is sent to the waste liquid part 60.

  In the present embodiment, the example in which the reagent liquid or the like is sent via the air by the driving liquid sent by the micropump 211 has been described. However, the present invention is not limited to this, and the pressurized air is directly connected by the syringe pump. The reagent liquid or the like may be fed by being fed into the port 132.

[Dummy liquid reservoir 150]
The dummy liquid storage unit 150 stores a dummy liquid. The dummy liquid is not used for inspection. If the reagent liquid is an aqueous solution, the dummy liquid uses an aqueous solution or pure water. If the reagent liquid is an alcohol solution, the dummy liquid also uses an alcohol solution or alcohol. By doing so, the dummy liquid or its solvent is shared with the reagent liquid solvent. That is, the evaporation component from the dummy liquid is common with at least a part of the evaporation component from the reagent liquid, and therefore the evaporation component from the dummy liquid (or its solvent) that more actively evaporates causes the inside of the packaging bag 5 to be inside. Can be prevented from evaporating from the reagent liquid using the same solvent.

  Further, the dummy liquid may be stored not only in one type but also in different types of dummy liquids in the plurality of dummy liquid storage units 150. In particular, when reagent liquids using different types of solvents are stored in the reagent liquid storage units 133a and 133b, it is preferable to use dummy liquids corresponding to the plurality of types of solvents.

  The dummy liquid is injected from the opening i2 into the dummy liquid storage unit 150, and the opening i2 and the dummy liquid storage unit 150 are connected by the fine flow path r1. Here, the dummy liquid storage unit 150 is connected to a fine channel r2 having a different path from the fine channel r1 to which the reagent liquid storage unit 133 storing the reagent liquid is connected.

[Packaging bag 5]
FIG. 4 is a perspective view of the microchip 100 housed in the packaging bag according to the present embodiment. Reference numeral 5 denotes a packaging bag in which the microchip 100 is accommodated in an inside sealed with an adhesive 51. The packaging bag 5 is made of a flexible packaging material having gas barrier properties or moisture barrier properties.

  Here, the “packaging bag having moisture barrier property or gas barrier property” of the present invention refers to a packaging bag formed of a packaging material having a performance higher than a moisture permeability of 10.0 g / m 2 / day.

  As the packaging material, for example, a sheet in which aluminum is deposited on the surface of polyester or polypropylene as a base can be used. The moisture permeability is preferably 0.5 g / m2 / day or less, and more preferably 0.05 g / m2 / day or less. The moisture permeability is measured under conditions of 40 ° C. and 90% RH according to the method described in JIS-Z-0208. The lower the numerical value of moisture permeability, the better because the gas in which the liquid inside has evaporated does not leak to the outside of the packaging bag.

  According to the present embodiment, the microchip 100 in which a dummy liquid of the same system as the reagent liquid is stored is accommodated in the packaging bag 5 having a low moisture permeability value of 0.05 g / m 2 / day. As a result, the dummy liquid also evaporates along with the reagent liquid, so that the inside of the packaging bag 5 can be quickly brought into a saturated state of the evaporated gas (saturated water vapor state if water). Thereby, evaporation derived from the reagent liquid can be suppressed.

  Further, as shown in FIG. 3 and the like, since a plurality of dummy liquid storage portions 150 for storing the dummy liquid are provided, the dummy liquid can be stored in a larger amount than the reagent liquid, and the dummy liquid storage portion Since the flow path 150 communicates with the plurality of openings i2, the evaporation of the dummy liquid is more dominant than the evaporation of the reagent liquid, so that the evaporation of the reagent liquid can be further suppressed.

  Moreover, since the dummy liquid reservoir 150 and the opening i2 of the dummy liquid are connected by the fine flow path r2, it is possible to prevent excessive evaporation and to suppress the occurrence of dew condensation inside the packaging bag 5. it can. Further, since the liquid is connected to the outside via the fine channel r2, the liquid dummy liquid is difficult to move in the fine channel r2 due to its surface tension. As a result, even when the microchip 100 is tilted during transportation or the like, the liquid dummy liquid can be prevented from leaking outside the microchip 100.

  Prior to being housed in the packaging bag 5, the injection port i1 of the microchip 100 is closed with a sealing member such as a thermoplastic resin, and the opening i2 is not closed. . The microchip 100 in such a state is stored in the packaging bag 5. By doing so, the reagent liquid in the reagent liquid storage unit 133 does not come into direct contact with the outside air. Therefore, the evaporation of the reagent liquid to the outside of the microchip 100 (inside the packaging bag 5) occurs on the groove forming substrate 108. Only the amount that evaporates through the substrate. On the other hand, since the dummy liquid directly contacts the outside air (inside the packaging bag 5) through the fine channel r2 and the like, the amount of evaporation is larger than that of the reagent liquid. Since the packaging bag 5 is made of a material having a moisture barrier property or a gas barrier property, the reagent liquid is difficult to evaporate after becoming saturated, and thus the evaporation of the reagent liquid can be further suppressed. Thereby, the amount of the reagent liquid can be accurately maintained over a long period of time, and a long-term storage of the microchip in which the reagent liquid is stored can be realized.

[Microchip 100 in Second Embodiment]
A microchip 100 according to the second embodiment will be described with reference to FIG. FIG. 5A is a top view of the microchip 100 according to the second embodiment, and FIG. 5B is a schematic diagram showing the internal structure of the microchip 100. 2 correspond to FIG. 2A and FIG. 3, respectively, and components having the same functions as those of the microchip 100 in the embodiment shown in FIG. 2, FIG.

  Unlike the microchip 100 shown in FIGS. 2 to 4, the microchip 100 in the second embodiment is not provided with the injection ports i <b> 1 and i <b> 3. Instead of the opening i2 for evaporating the dummy liquid, a line of openings g is newly provided.

  In the microchip 100 shown in FIG. 5, before attaching the covering substrate 109 to the groove forming substrate 108, the dummy liquid is injected into the dummy liquid reservoir 150 and the reagent liquid is injected into the reagent liquid reservoir 133. By attaching the covering substrate 109 in this state, there is an advantage that the injection port can be omitted and there is no need to seal with a sealing member. At the time of examination, injection of the specimen sample into the specimen reservoir 137 is performed, for example, by inserting a syringe needle into the coated substrate 109 above the specimen reservoir 137.

  The opening g is provided above the fine channel r2 adjacent to the dummy liquid reservoir 150, and the opening g and the dummy liquid reservoir 150 are communicated with each other through the fine channel r1. The dummy liquid is evaporated from the opening g.

  Next, examples of the present invention will be described. In the example, the microchip shown in FIGS. 1 to 4 was used. Other detailed conditions are as follows.

[Experimental conditions of Examples]
Volume (volume) inside the packaging bag 20ml
Reagent liquid volume 10 μl
Dummy liquid volume 10μl
Volume ratio Inside packaging bag: reagent liquid: dummy liquid = 2000: 1: 1
Reagent liquid Aqueous solution dummy liquid Pure water packaging bag Water vapor transmission rate 0.05g / m2 / day aluminum vapor deposition sheet Storage environment: 2-8 ° C
Reagent liquid injection hole Sealed state Microchip material Polypropylene (moisture permeability of about 6.5 g / m2 / day)
[Experimental conditions for comparative example]
The comparative example uses the same microchip as in the above example, but differs under the following conditions.
No dummy liquid volume (not stored)
[Measuring method]
The amount of evaporation was measured by measuring the variation in the position of the end face of the reagent liquid disposed in the fine channel having a predetermined cross-sectional area.

[Experimental result]
FIG. 6 is a graph showing the transition of the evaporation amount of the reagent liquid with the elapsed days in the example and the comparative example. As shown in FIG. 6, it can be seen that in the example, evaporation occurs initially but tends to be saturated. The reduction in reagent liquid due to evaporation at saturation is approximately 1%. On the other hand, in the comparative example, it can be seen that the evaporation rate of the reagent liquid is high, and no saturation tendency is observed, and evaporation continues at a constant rate. In the example shown in the figure, the decrease in reagent liquid due to evaporation is about 6% when 120 days have passed. When the storage period is longer than 120 days, since the saturation tendency is not shown in the embodiment, the difference further increases.

20 Inspection device 5 Packaging bag 100 Microchip 108 Groove forming substrate 109 Coated substrate 133, 133a, 133b Reagent liquid storage part 137 Sample storage part 139 Reaction part 150 Dummy liquid storage part r1, r2 Micro flow path i1, i3 Inlet i2, g Opening 211 Micro pump

Claims (6)

A microchip stored in a packaging bag having a moisture barrier property or a gas barrier property,
A microfluidic channel, a reagent liquid reservoir that stores a reagent liquid for feeding the microfluidic channel and mixing it with a sample, a dummy liquid reservoir that stores a dummy liquid for evaporation, and the dummy liquid An opening connected to the reservoir,
The microchip according to claim 1, wherein the evaporation component from the dummy liquid is common to at least a part of the evaporation component from the reagent liquid. The microchip according to claim 1, further comprising an inlet for injecting the reagent liquid into the reagent liquid reservoir. The microchip according to claim 1, wherein the dummy liquid storage portion and the opening are connected by a fine channel. 4. The microchip according to claim 1, wherein the reagent liquid is an aqueous solution, and the dummy liquid for evaporation is an aqueous solution or water. 4. The microchip according to claim 1, wherein the reagent liquid is an alcohol solution, and the evaporation dummy liquid is an alcohol solution or alcohol. 6. The microchip housed in the packaging bag has the injection port closed by a sealing member, and the opening is not closed. Microchip.