JP2007315936A - Microchip having fluid control section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microchip having a new fluid control section allowing easy control of flow. <P>SOLUTION: This microchip comprises a rectangular substrate having a micro flow channel of a predetermined shape in its one surface, a facing substrate for sealing the micro flow channel, and the fluid control section in the micro flow channel. In the fluid control section, a wall structure section, having a notch, is disposed to block the micro flow channel, and the notch is disposed in the depth direction of the micro flow channel. The fluid control section has a pressurizing means. The fluid control section allows fluid control in the micro flow channel and allows control of the progression of the chemical reaction carried out inside the microchip. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure in a microchannel of a microchip used for detecting a biological substance such as DNA (deoxyribonucleic acid).

  Conventionally, a micrometer-order groove is formed on the surface of a substrate such as glass by lithography or the like, and this groove is used as a liquid or gas micro-channel, for chemical reaction, biochemical reaction, solvent extraction, gas-liquid There is known a microchip technology that enables separation, chemical analysis of trace components based on these, non-contact optical analysis, and the like.

In this microchip technology, it is one of the important issues to control the flow in the microchannel, and so far a method of providing a fixed damming structure in the microchannel (non-patent Proposed to control the flow by a method using a valve structure that drives a diaphragm by gas or liquid (Non-patent Document 2), a method using a microchannel with surface modification, etc. (Non-Patent Document 3) Has been.
A. Russom et al. (2002) Proceedings of the microTAS 2002 symposium, Nara, pp. 218-220. K. Ikuta et al. (2002) ibid, pp. 37-39. N. Y. Lee et al. (2002) ibid, pp. 667-669.

  However, these conventional methods have problems such as a complicated method for forming the structure, weak damming force, and reverse flow or control.

  An object of the present invention is to provide a microchip having a new fluid control unit that solves the above-described problems of the prior art and enables easy flow control.

The invention according to claim 1 is a microchip comprising a rectangular substrate having a predetermined-shaped fine flow path disposed on one surface and a facing substrate that seals the fine flow path. A microchip comprising a fluid control unit in a flow path.
By providing the fluid control unit, it is possible to control the fluid in the microchannel and to control the progress of the chemical reaction performed in the microchip.

The invention according to claim 2 is a rectangular substrate having a PCR amplification reaction tank for performing an amplification reaction for amplifying DNA and a reservoir for storing a reagent used for the amplification reaction, along the longitudinal direction thereof. In turn, in a microchip comprising a substrate on which a reservoir and a PCR amplification reaction tank are provided via a fine channel, and a facing substrate that seals the reservoir, the PCR amplification reaction vessel and the fine channel A microchip comprising a fluid control unit in the fine channel.
Since it is a microchip having a facing substrate that seals a reservoir, a PCR amplification reaction tank, and a fine channel disposed so as to connect them, evaporation of trace reagents and reaction products used for PCR amplification reaction It becomes possible to prevent contamination of impurities. In addition, by providing a fluid control unit, it is possible to dissolve and mix the reagent used for the amplification reaction in the reservoir with water or a buffer without causing the reagent to flow into the PCR amplification reaction tank. It becomes possible to make it a reaction.

According to a third aspect of the present invention, the fluid control unit is a structure in which a wall structure having a cut is installed so as to block the fine flow path, and the cut is provided in a depth direction of the fine flow path. The microchip according to claim 1, wherein the microchip is a microchip.
Since the fluid control part has a very simple structure in which a wall structure part provided so as to block the fine flow path in the fine flow path is cut in the depth direction, the fluid control part is very easy to manufacture. As will be described later, the flow in the fine flow path can be controlled by a valve body whose notches are opened and closed by pressurization.

The invention according to claim 4 is the microchip according to claim 3, wherein the size of the cut is 30% or more and 100% or less with respect to the depth of the fine channel.
If the depth of cut is less than 30% of the depth of the fine flow path, the fluid will overload the fluid control unit and damage to the fluid control unit may occur. Is preferred.

A fifth aspect of the present invention is the microchip according to any one of the first to fourth aspects, wherein the length of the fluid control unit in the longitudinal direction is not less than 500 μm and not more than 1000 μm.
If the length of the fluid control unit in the longitudinal direction, in other words, the thickness of the wall structure portion is smaller than 500 μm, the force for damaging the fluid in the fine flow path is weak, and if it is larger than 1000 μm, the force for damaging the fluid becomes strong. However, it is difficult for the notch to open and close, and there is a risk that it will not function as a valve body.

The invention according to claim 6 is the microchip according to any one of claims 1 to 5, wherein the fluid control unit is made of a polymer.
Since the fluid control unit is made of a polymer, the fluid control unit can have a necessary flexibility as a valve body.

The invention according to claim 7 is the microchip according to claim 6, wherein the polymer is polydimethylsiloxane.
Polydimethylsiloxane is not only flexible but also self-adsorbing, so no special bonding process is required, and it can be modified in various ways due to its excellent heat resistance. Furthermore, since it is a low-cost material with excellent transparency, the structure and manufacturing method of the fluid control unit can be simplified at a low cost.

The invention according to claim 8 is the microchip according to any one of claims 1 to 7, further comprising a pressurizing unit for the fluid control unit.
Since the fluid control unit has a valve body structure that opens and closes when pressure is applied using a pressurizing means, it is possible to control the flow of fluid in the fine flow path by pressurization.

  In the invention according to claim 1, by providing the fluid control section, it is possible to control the fluid in the microchannel and to control the progress of the chemical reaction performed in the microchip.

  In the invention according to claim 2, since it is a microchip having a facing substrate that seals a reservoir, a PCR amplification reaction tank, and a fine channel disposed so as to connect them, it is used for a PCR amplification reaction. It is possible to prevent evaporation of trace reagents and reaction products and contamination of impurities. In addition, by providing a fluid control unit, it is possible to dissolve and mix the reagent used for the amplification reaction in the reservoir with water or a buffer without causing the reagent to flow into the PCR amplification reaction tank. It becomes possible to make it a reaction.

  In the invention according to claim 3, the fluid control unit has a very simple structure in which a cut is made in the depth direction in the wall structure provided to block the fine channel in the fine channel. The production is also very simple. As will be described later, the flow in the fine flow path can be controlled by a valve body whose notches are opened and closed by pressurization.

  In the invention which concerns on Claim 4, when the magnitude | size of a cut is smaller than 30% with respect to the depth of a fine flow path, the load to the fluid control part by a fluid will become excessive, and there exists a possibility that the damage to a fluid control part may arise. For this reason, it is preferably set to 30% or more.

  In the invention according to claim 5, when the length of the fluid control unit in the longitudinal direction, in other words, the thickness of the wall structure part is smaller than 500 um, the force for blocking the fluid in the fine flow path is weak and larger than 1000 um. However, there is a possibility that the notch does not open and close easily and does not function as a valve body.

  In the invention which concerns on Claim 6, the fluid control part can have the softness | flexibility as a valve body by consisting of a polymer.

  In the invention according to claim 7, polydimethylsiloxane is not only flexible but also self-adsorbing, so no special bonding process is required, and because it has excellent heat resistance, various surface modifications are possible. In addition, since the material has excellent shape transferability, and is inexpensive and excellent in transparency, the structure and manufacturing method of the fluid control unit can be simplified at a low cost.

  In the invention according to claim 8, since the fluid control unit has a valve body structure that opens and closes when pressure is applied using a pressurizing means, the flow of fluid in the fine flow path is controlled by pressurization. It becomes possible to do.

The present invention is described in detail below.
The substrate in the present invention is formed of a polymer having flexibility and self-adsorption. An example is polydimethylsiloxane (PDMS). A plan view of one embodiment of the microchip in the present invention is shown in FIG. On one surface of the rectangular substrate, a reagent inlet 1, a reservoir 2, a reaction vessel 5, etc. are appropriately arranged at a predetermined position in a predetermined shape according to the purpose of use of the microchip, In addition, a fine channel 9 having a predetermined shape is disposed so as to connect the inlet, the reservoir, and the reaction tank.

  The microchip in the present invention can also be provided with a PCR amplification reaction tank for performing an amplification reaction for amplifying DNA on one surface of a rectangular substrate, and a reservoir for storing a reagent used for this amplification reaction. A reservoir and a PCR amplification reaction tank are provided in order along the longitudinal direction of the substrate via a fine channel. The reagent used for the amplification reaction in the reservoir is dissolved and mixed with water or a buffer solution, and then the mixed solution is moved to the PCR amplification reaction tank through the fine channel to perform the amplification reaction.

  A fluid control unit 3 is provided in the fine channel 9. The fluid control unit has a valve body structure that opens and closes by pressurization. The fluid control unit is formed by providing a wall structure portion 7 so as to block the fine flow channel at a part of the fine flow channel, and making a cut 8 serving as a fluid passage in the wall structure portion. An example of the fluid control unit viewed from the direction perpendicular to the longitudinal direction of the microchip is shown in FIG. Here, since the cut 8 of the fluid control unit is normally in close contact, the cross-sectional area of the cut portion is zero. The cut size d is preferably 30% or more and 100% or less with respect to the depth D of the fine channel. If it is less than 30%, the load on the fluid control unit by the fluid becomes excessive, and the fluid control unit may be damaged. The thickness of the wall structure 7, that is, the length t in the longitudinal direction of the fluid control unit is preferably 500 μm or more and 1000 μm or less. Further, the position where the cut 8 is made may be at any position with respect to the width of the flow path.

  The fluid control unit has a valve body structure that opens and closes when pressure is applied using a pressurizing means described later. By opening and closing the fluid control unit having this valve body structure, it becomes possible to control the flow of the fluid in the fine flow path.

  The position where the fluid control unit is provided is appropriately arranged in the fine channel in accordance with the purpose of use of the microchip. Moreover, it can be provided at one place or a plurality of places according to the purpose of use of the microchip.

  Moreover, the microchip in the present invention is provided with a facing substrate so as to seal the fine flow path. The material of the facing substrate is not particularly limited, but can be appropriately selected from polydimethylsiloxane, acrylic polymer, glass and the like. In the case of providing a facing substrate, it is preferable to perform a surface treatment on the surface of the substrate on which the fine flow path is formed in order to improve adhesion with the substrate having the fine flow path. For example, corona discharge treatment is performed.

  The microchip in the present invention having the fluid control unit described above has a pressurizing means. Alternatively, it can be connected to another pressurizing means. The pressurizing means must be provided on the fine flow channel upstream of the fluid control unit. For example, by pressing and pressurizing the reservoir, the fluid control unit can be opened from the notch, and at the same time, the reagent in the reservoir can move through the fluid control unit in the fine channel. Examples of the means for pushing the reservoir include a linear actuator. As another example, a syringe pump can be connected to the inlet, and the pressure is increased by increasing the flow rate.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, the technical scope of this invention is not limited to these embodiment.

The microchip having the fluid control unit was manufactured using a photolithography technique.
First, a PDMS device mold was prepared. This mold was prepared using a 26 mm × 76 mm glass slide (made by Matsunami Glass) washed with ethanol as a substrate. 2 mL of SU-8 2100 (manufactured by Kayaku Microchem), which is a negative photoresist, was placed on a glass substrate and coated with a spin coater at 1000 rpm for 30 seconds. Then, the solvent was removed from the photoresist by prebaking at 95 ° C. for 120 minutes. A photomask printed on a PET film so that the microchannels, reservoirs, reaction tanks, and other parts that are to be used for chip formation are white and the wall structure that forms the fluid control unit is not white. As a result, photolithography was performed. Photolithography uses an ultrahigh pressure mercury lamp (manufactured by USHIO) to irradiate ultraviolet rays for about 380 mJ / cm ² for 500 seconds, and then unpolymerized using a SU-8 developer (manufactured by Kayaku Microchem). Except for the photoresist, a mold for SU-8 was used.

Next, the PDMA monomer and its cross-linking agent (manufactured by Toray Dow Corning) were thoroughly mixed at a volume ratio of 10: 1, and bubbles generated during mixing were removed under vacuum. The resulting mixture was poured into a SU-8 mold surrounded by an adhesive tape and cured at 65 ° C. for 90 minutes. The cured PDMS was peeled off from the SU-8 mold to obtain a substrate having a wall structure that blocks the fine flow path. A fluid control unit was made by cutting with a scalpel near the center of the wall structure part blocking the fine channel under the microscope. In addition, the inlet and the outlet were formed in the shape of eyelet removal. After the corona discharge treatment is performed on the surface on which the PDMS microchannel is formed, a fluid control unit that controls the flow by bonding an ethanol-washed glass slide substrate as the facing substrate that becomes the bottom of the microchannel A microchip (FIG. 1) having was obtained.

The reagent A injected from the first injection port 1 is stored in the reservoir 2 through the fine channel. A syringe pump is connected to the second inlet 4 to supply the reagent B. The first injection port 1 was sealed with an adhesive tape, and the reservoir 2 was appropriately pushed to move the reagent A in the reservoir 2 into the fine flow path through the fluid control unit 3. Even if the pushing of the reservoir was stopped, the reagent in the fine channel did not flow backward to the reservoir 2 side.

It is a top view which shows one Example of the microchip which has a fluid control part of this invention. It is sectional drawing which shows one Example of the fluid control part of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st injection port 2 Reservoir and pressurization part 3 Fluid control part 4 2nd injection port 5 Reaction tank 6 Reaction liquid collection port 7 Wall structure part 8 Cutting 9 Fine flow path D Depth of fine flow path d Depth of cut t Length of fluid control unit in the longitudinal direction

Claims (8)

  In a microchip including a rectangular substrate having a microchannel with a predetermined shape disposed on one surface and a facing substrate that seals the microchannel, the microchannel includes a fluid control unit. A microchip characterized by   It is a rectangular substrate having a PCR amplification reaction tank for performing an amplification reaction for amplifying DNA and a reservoir for storing a reagent used for this amplification reaction, and in that order along the longitudinal direction of the reservoir, the PCR amplification reaction In a microchip including a substrate in which a tank is provided via a fine channel, and a facing substrate that seals the reservoir, the PCR amplification reaction vessel, and the fine channel, a fluid control unit is provided in the fine channel. A microchip comprising:   2. The fluid control unit has a structure in which a wall structure having a cut is installed so as to block the fine flow path, and the cut is provided in a depth direction of the fine flow path. Or the microchip of 2.   The microchip according to claim 3, wherein the size of the cut is 30% or more and 100% or less with respect to the depth of the fine channel.   5. The microchip according to claim 1, wherein a length of the fluid control unit in a longitudinal direction is not less than 500 μm and not more than 1000 μm.   The microchip according to claim 1, wherein the fluid control unit is made of a polymer.   The microchip according to claim 6, wherein the polymer is polydimethylsiloxane. The microchip according to claim 1, further comprising a pressurizing unit for the fluid control unit.

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