JP2013003011A - Micro fluid device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro fluid device that can save the amount of liquid to be used.SOLUTION: A micro fluid device 1 comprises: a plurality of parallel main channels A which are formed on a substrate 11; connection channels B for placing the main channels into communication with each other; and connection channel valves b for opening and closing the connection channels B. The micro device includes main channel valves a for controlling the flow of liquid in the main channels A. In the micro fluid device 1, one end of a first main channel of the plurality of the main channels A and one end of adjacent main channel communicate with each other via the connection channel B, while the other end of the first main channel and the other end of the adjacent main channel does not communicate with each other, and all of the plurality of the main channels A are connected in series via the connecting channels B.

Description

  The present invention relates to a microfluidic device that can reduce the amount of liquid to be used. The present invention is expected to be used in a DNA sequencer using SBS (Sequencing by Synthesis) performed in the biochemical field.

A micro device having a plurality of parallel flow paths formed using MEMS (Micro Electro Mechanical System) technology is known. Liquid feeding to the microdevice is performed by connecting a tube to each parallel flow path and switching a plurality of types of solutions in the tank with a valve. Since the parallel flow paths are independent of each other, the solution is sent to separate flow paths.
More specifically, the microdevice has a structure in which a tube can be jointed to each of a plurality of flow paths formed in glass, silicone, or other resin.

In general, a gate valve, a globe valve, a ball valve, a butterfly valve, and the like are known as valves for controlling the flow of fluid in a pipe (Non-Patent Document 1).
On the other hand, silicone rubber microvalves (Non-patent Documents 2 and 3), electromagnetically driven microvalves (Non-patent Document 4), and slide micros are used as microvalves that control the flow of fluid in the flow path of the microfluidic device. A valve (Non-Patent Document 5) is known.

“Basic knowledge of valves”, [online], KITZ Co., Ltd. [searched on April 21, 2011], Internet <URL: http://www.kitz.co.jp/kiso/hajimete_03.html> “Journal of Micromechanics and Microengineering”, Volume 10, 2000, p.415-420 Review of Shimadzu, Vol.60, No.1, No.2, October 2004, p.91-98 “Development of electromagnetically driven microvalves” [online], Graduate School of Natural Science, Okayama University, [Search April 21, 2011], Internet <URL: http: //www.act.sys.okayama-u. ac.jp/kouseigaku/research/nakahira_micro_valve_07/nakahira_micro_valve_07-j.html> “Slide Microvalve”, [online], Toshiba Corporation, [searched on April 21, 2011], Internet <URL: http://www.toshiba.co.jp/rdc/rd/fields/06_t36.htm >

  In the case where different reagents (such as different-origin DNA or different types of reaction liquids) are sent to the respective flow paths, it is preferable that the flow paths are separated. On the other hand, when the same reagent (rinse solution or the like) is fed, it is preferable from the viewpoint of the liquid amount that the flow paths are not separated. This is because the volume existing in the tube connecting the solution valve and the microdevice only contributes to liquid feeding, and the loss of the solution increases as the number of flow paths increases.

  In view of the above, an object of the present invention is to provide a microfluidic device that can save the volume of liquid to be used.

As a result of intensive studies, the present inventors have found that the object of the present invention can be achieved by further providing a flow path that shortcuts the flow paths in parallel and a valve that opens and closes the flow path. The present invention has been completed.
The present invention includes the following inventions.
(1)
A plurality of parallel main flow paths formed on the substrate;
A combined flow path for communicating the main flow paths;
A microfluidic device having a coupling channel valve for opening and closing the coupling channel.
(2)
The microfluidic device according to (1), wherein a supply / discharge tube is connected to both ends of the main flow path.

(3)
The microfluidic device according to (2), wherein the feeding / draining tube is connected to both ends of the main flow path by being attached to a tube mounting plate provided on a substrate.
(4)
One end of one main flow path of the plurality of main flow paths and one end of a main flow path adjacent to the one main flow path are communicated with each other by the combined flow path. The microfluidic device according to any one of (1) to (3), wherein the other end and the other end of the adjacent main channel are not communicated with each other.

(5)
One end of the one main flow path and one end of the main flow path located next to the one main flow path on the opposite side of the adjacent main flow path are not communicated, and the one main flow The other end of the channel and the other end of the main channel located next to the opposite side are communicated with each other by the combined channel, so that all the plurality of main channels are connected in series with the combined channel. The microfluidic device according to (4), which is coupled to the microfluidic device.

(6)
The microfluidic device according to any one of (2) to (5), wherein the coupling channel is a tube that couples the liquid supply / drainage tubes.
(7)
The microfluidic device according to any one of (3) to (5), wherein the coupling channel is a tube attached to the tube mounting plate separately from the liquid feeding / draining tube.
(8)
The microfluidic device according to any one of (3) to (5), wherein the coupling channel is an internal channel formed in the tube mounting plate.
(9)
The microfluidic device according to (8), wherein a part of the internal flow path formed in the tube mounting plate is opened upward and a gate valve as the coupling flow path valve is provided.

(10)
A plurality of parallel main flow paths A formed on the substrate, a combined flow path B communicating the main flow paths, a main flow path valve a for controlling the liquid flow in the main flow path A, and the combined flow paths A liquid feeding method using a microfluidic device having a coupling flow path valve b for opening and closing, and a liquid feeding tube and a drainage tube respectively connected to both ends of the main flow path A, the following steps:
(I) Open the main flow path valve a corresponding to the plurality of main flow paths A to be fed,
Closing the coupling channel valve b corresponding to the coupling channel B communicating with the plurality of main channels A to be fed,
A step of producing a parallel liquid flow by feeding from the liquid feeding tube and draining from the drainage tube; and (II) a main flow located at the outermost side among the plurality of main flow paths A to be fed. Open the main flow path valves a _E1 and a _E2 corresponding to one end of each of the paths A _E1 and A _E2 ,
Close the main flow path valve a _I corresponding to the main flow path A _I located on the inner side,
Open the coupling flow path valve b corresponding to the coupling flow path B located between the main flow paths A _E1 and A _E2 ,
By sending liquid from a liquid feeding tube connected to one end of the main flow path A _E1 and draining from a drainage tube connected to one end of the main flow path A _E2 , a series liquid flow A method comprising the step of generating.

(11)
The method according to (10), wherein the composition of at least one of the liquids fed in the step (I) and the liquid sent in the step (II) are different.
(12)
The method according to (10) or (11), wherein a sample containing a substance selected from the group consisting of a nucleic acid, a nucleotide and a modified form thereof is sent and discharged.

According to the present invention, a liquid-saving microfluidic device that can save the volume of liquid to be used can be provided.
According to the present invention, when using DNAs of different origins or different types of reaction solutions, it is possible to handle multiple types of treatment on a single microfluidic device by generating a parallel flow, and the same type of reagents. , The amount of reagent used can be saved by creating a series flow using the same flow path of the same microfluidic device.

1 schematically shows an example of a liquid-saving microfluidic device of the present invention. 4 schematically shows another example of the liquid-saving microfluidic device of the present invention. Sectional drawing (i)-(iii) and those structural members (i ')-(iii') of the board | substrate in the liquid-saving microfluidic device of this invention are shown. The example of the external appearance perspective view of the liquid-saving type microfluidic device of this invention is shown. It is a fragmentary sectional view which follows the VV line in FIG. FIG. 5 is a partial cross-sectional view taken along the line VI-VI in FIG. 4, showing one embodiment of the coupling channel B in the liquid-saving microfluidic device of the present invention. 4 shows another embodiment of the coupling channel B in the liquid-saving microfluidic device of the present invention. 6 shows still another embodiment of the coupling channel B in the liquid-saving microfluidic device of the present invention. 1 is a block diagram showing an example of a liquid feeding system using a liquid-saving microfluidic device of the present invention. FIG.

1: Microfluidic device A: Main flow path B: Bonding flow path a: Main flow path valve b: Bonding flow path valve 11: Substrate 12: Opening 13: Feed / drain tube 42: Tube mounting plate 43: Feed / drain tube mounting Through hole 61: Through hole for mounting a coupling flow path tube 72: Membrane 73: Valve body

[1. Configuration of liquid-saving microfluidic device]
FIG. 1 schematically shows an example of a liquid-saving microfluidic device of the present invention.
The microfluidic device 1 has a plurality of parallel main flow paths A and a combined flow path B that connects the main flow paths. At least the main flow path A is formed inside the substrate 11, and both end portions of the main flow path A communicate with the opening portions 12 opened on the upper surface of the substrate 11.

A coupling channel B that opens and closes the coupling channel B is provided in the coupling channel B that communicates the main channels A with each other. The combined flow path B and the combined flow path valve b make it possible to generate both parallel flow and serial flow in the same microfluidic device 1. Specifically, when the combined flow path valve b is closed, the plurality of parallel main flow paths A do not communicate with each other (parallel flow), and when the combined flow path valve b is opened, the plurality of parallel main flow paths A A can communicate through the coupling channel B (series flow). That is, the combined flow path B connects the main flow paths A so that both the liquid flows can be generated.
Here, in FIG. 1, an arrow indicates the direction of the liquid flow. Therefore, the right side in FIG. 1 may be described as the liquid feeding side, and the left side as the draining side.

  Specifically, as shown in FIG. 1, the coupling flow path B includes one end of one main flow path A among the plurality of main flow paths A (for example, the liquid feeding side) and the adjacent one main flow path. The end of one side (liquid feeding side) of the same side in the main flow path located in is connected. On the other hand, the end of one main channel on the other (drainage side) and the other (drainage) end of the main channel located next to the one main channel are not in communication. Also, one end (liquid feeding side) of one main flow path and one end (liquid feeding side) of the same side of the main flow path located next to the opposite side of the main flow path located next to the main flow path. Is not communicated with. On the other hand, the other (drainage side) end of one main channel and the other (drainage) end of the main channel located next to the opposite side are connected by a coupling channel B. Yes. In this way, one end of the main channel and the other end of the main channel are alternately connected to the end of the adjacent main channel (preferably at the shortest distance) by the coupling channel B.

  FIG. 2 shows a modification of the microfluidic device of the present invention. The coupling channel B may be coupled to the end of the main channel A as shown in FIG. 1, or may be coupled to a location slightly away from the end of the main channel A as shown in FIG. .

  The liquid flow in the main flow path A is controlled by the main flow path valve a. The feed / drain tube 13 is connected to both ends of the main flow path A. A liquid supply tube is connected to an end of the main channel A on the liquid supply side, and a liquid discharge tube is connected to an end of the liquid discharge side. In the present invention, the liquid feeding tube and the draining tube are collectively referred to as a feeding / draining tube, and in particular, when referring to liquid feeding or draining, respectively, the liquid feeding tube Or it may be described as a drainage tube.

More specifically, a liquid supply / drainage tube 13 for liquid supply or liquid discharge is connected to the opening 12 leading to the main flow path A. Therefore, the main flow path valve a can be provided in the feed / drain tube 13 as shown in FIG. Preferably, it is provided at a place as close as possible to the main flow path A in the feed / drain tube 13. In such a case, the liquid flow in the main flow path A can be controlled by the main flow path valve a opening and closing the feed / drain tube 13.
Moreover, the main flow path valve a can also be provided in the main flow path A, as shown in FIG. Preferably, it is provided at both ends of the main channel A. In such a case, the liquid flow in the main flow path A can be controlled by the main flow path valve a directly opening and closing the main flow path A. In FIG. 2, the main flow path valve a can be provided closer to the feed / drain tube 13 than the combined flow path B, but may be provided on the opposite side.

  3 (i) to 3 (iii) show examples of cross-sectional views of the substrate 11. FIG. As shown in these figures, at least a main flow path A is formed inside the substrate 11, and openings 12 communicating with both ends of the main flow path A are opened on the upper surface. The substrate 11 can be composed of a pair of plate-like members 31 and 32 as shown in FIGS. A plurality of parallel main flow channel grooves are formed on at least one surface of the pair of plate-like members. For example, in FIG. 3 (i ′), the main channel groove 33 is formed in the plate-like member 31. In FIG. 3 (ii ′), the main channel groove 33 is formed in the plate-like member 32. Further, in FIG. 3 (iii ′), the main channel groove 33 is formed in both the plate-like members 31 and 32.

Further, a through hole 34 is formed in the plate-like member 32.
The plate-like members 31 and 32 are bonded together so that the main flow path groove 33 is on the inner side, and constitute the substrate 11. The main flow path groove 33 forms the main flow path A by configuring the substrate 11. The open end of the through hole 34 forms the opening 12 in the substrate 11.

FIG. 4 shows an example of an external perspective view of the microfluidic device of the present invention. The main flow path valve a and the coupling flow path valve b are not shown. In the example of FIG. 4, a tube mounting plate 42 is provided on the substrate 11 so that the substrate 11 on which the main flow path A is formed is fixed to the fixing base 41 and covers the vicinity of the opening 12 in the substrate 11. . The tube mounting plate 42 has a coupling flow path B.
FIG. 5 shows a partial cross-sectional view along the VV line in the main flow path direction in FIG. A through-hole 43 that communicates with the opening 12 is formed in the tube attachment plate 42, and at least the feed / drain tube 13 is attached to the through-hole 43. A member made of a material such as rubber having flexibility or elasticity, for example, can be provided as a member 44 for preventing liquid leakage at the joint portion between the feed / drain tube 13 and the opening 12.

  6 to 8 show more specific embodiments of the coupling channel B of the microfluidic device of the present invention. FIG. 6 is a partial cross-sectional view taken along line VI-VI in the direction perpendicular to the main flow path direction in FIG. 7 and 8 are variations of FIG. 6 to 8, the fixed base 41 is not shown.

6 and 7, the coupling flow path B is constituted by a tube. 6 and 7, the main flow path valve a and the combined flow path valve b are not shown.
In FIG. 6, the liquid supply / drainage tubes 13 attached to the through holes 43 formed in the tube attachment plate 42 are connected by a tube as the coupling flow path B. That is, the tubes connected to the through holes 43 are branched, and the respective branches form the liquid discharge tube 13 and the combined flow channel tube B.
In FIG. 7, a tube as a coupling flow path B is attached to the tube attachment plate 42 separately from the feed / drain tube 13. That is, the tube mounting plate 42 is formed with a through-hole that branches off on the upper surface side of the tube mounting plate 42, one branch forms a through-hole 43 for connecting a liquid discharge tube, and the other branch is a combined flow. A through hole 61 for connecting the path B tube is formed. The feed / drain tube 13 is connected to the through hole 43, and the coupling channel tube B is connected to the through hole 61.

FIG. 8 (i) shows a mode in which the coupling channel B is an internal channel formed in the tube mounting plate 42. In FIG. 8 (i), the main flow path valve a is not shown, and the coupling flow path valve b is exemplified as a gate valve type (open state). A feed / drain tube is connected to a through hole 43 formed in the tube mounting plate 42. In addition, a groove communicating with the two through holes 43 is formed as an internal flow path inside the tube mounting plate 42, and this internal flow path forms a combined flow path B. At least a part of the coupling channel B opens upward on the upper surface of the tube mounting plate 42 to form an opening 71. The opening 71 is completely covered with a flexible film 72. The membrane 72 seals the opening 71 so that the liquid in the coupling channel B does not leak. A valve body 73 is provided on the membrane 72.
FIG. 8 (ii) shows a state in which the gate valve in FIG. 8 (i) is in a closed state. As shown in FIG. 8 (ii), the valve body 73 is pushed down through the opening 71 so as to move in the vertical direction, and the lower surface of the valve body 73 comes into contact with the bottom of the coupling channel B. As a result, the liquid flow in the coupling channel B is blocked.

In the above description, the gate valve type is given as an example, but the type of the valve is not particularly limited. Other examples of the valve include a globe valve, a ball valve, and a butterfly valve. These are appropriately reduced in size and used by those skilled in the art to match the size of the microfluidic device of the present invention. Other examples of valves include those known as microvalves such as silicone rubber microvalves, electromagnetically driven microvalves, and slide microvalves.
Further, in the case of a valve provided in a flexible tube, it may have a simpler function that can stop the liquid flow by pinching the tube.

The valve may be embodied by a three-way valve. In this case, the three-way valve is provided at the branch point of the flow path, and one main flow path valve a and one combined flow path valve b are caused to function by one three-way valve.
The characteristics of the valves listed above are known by those skilled in the art. For this reason, in consideration of the characteristics of the valve, those skilled in the art can select various types of valves according to the mode of the flow path, or by selecting patterning of the flow path according to the type of valve. Valves can be incorporated into the microfluidic devices of the present invention.

[2. Material and size of microfluidic device components]
The substrate material may be any material that is not undesirably affected by the liquid to be sent and discharged. From the viewpoint of TIRF (Total Internal Reflection Fluorescence) observation, a material having high transparency is preferable. Specific examples include glass and two-part silicone such as polydimethylsiloxane.
Examples of the substrate include those made of the plate-like members 31 and 32 of FIG. 3, but these plate-like members 31 and 32 may be made of the same material or different materials.

  The material of the tube may be any material as long as it is not undesirably affected by the liquid to be sent and discharged. For example, a flexible material such as silicone resin, polyether ether ketone resin (PEEK resin), polypropylene resin, polyethylene resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin) is preferably exemplified.

The total capacity of the main flow path A and the combined flow path B (not including the capacity of the feed / drain tube) can be, for example, 0.1025 mm ^{3 to} 657 mm ³ . The number of main flow paths A is not particularly limited as long as it is 2 or more, but may be 2 to 20, for example.
The main channel A can be, for example, a width of 1 mm to 3 mm, a depth of 5 μm to 100 μm, and a length of 10 mm to 100 mm.
When the combined flow path B is formed as a groove, the combined flow path B may be, for example, 0.5 mm to 3 mm wide, 5 μm to 100 μm deep, and 1 mm to 10 mm long. When the coupling channel B is a tube, it can be, for example, φ75 μm to φ1 mm and a length of 1.5 mm to 20 mm.
The size of the substrate on which at least the main channel A is formed can be, for example, 15 mm to 120 mm long, 12 mm to 120 mm wide, and 0.5 mm to 5 mm thick.
When the microfluidic device has a tube mounting plate, the size of the tube mounting plate can be, for example, 15 mm to 120 mm in length, 12 mm to 120 mm in width, and 0.8 mm to 2 mm in thickness.
The feed / drain tube may be, for example, φ0.2 mm to φ1 mm and a length of 100 mm to 5 mm.

[3. Flow path creation method]
The flow path of the microfluidic device of the present invention is created by appropriately performing flow path patterning by those skilled in the art based on the flow path layout to be created (for example, the flow path layout described in FIGS. 1 and 2). Specifically, MEMS (Micro Electro Mechanical System) technology can be used.
An example of the flow path creation method will be described with reference to the case of using the substrate of FIG. As shown in FIG. 3 (i ′), the main channel groove 33 is patterned by etching or the like in a plate-like member 31 made of borosilicate glass (or two-part silicone such as polydimethylsiloxane) having a thickness of about 1 mm. On the other hand, a through-hole 34 is formed in a plate member 32 of the same material having a thickness of about 0.15 mm by a sand blaster or the like at a position corresponding to the end portion of the main flow channel groove 33. Thereafter, the plate-like members 31 and 32 are bonded and fused so that the main flow channel 33 is on the inner side.

[4. Delivery method]
In the liquid feeding method of the present invention, the step (I) for generating a parallel flow and the step (II) for generating a serial flow are performed in the same microfluidic device. The order of process (I) and process (II) is not ask | required.
The liquid flow in the microfluidic device in the liquid feeding method of the present invention will be described with reference to FIGS. 1 and 2. In the liquid feeding method of the present invention, the liquid is sent to the plurality of main flow paths A in the microfluidic device. All the main flow paths A existing in the microfluidic device may be targets to be sent, or some of the main flow paths A (usually, the main flow paths A are adjacent to each other) are sent. It may be a target.
In the following description, the plurality of main flow paths A to be fed are all the main flow paths shown in FIGS. 1 and 2. Moreover, the arrow shown in FIG.1 and FIG.2 represents the direction of the flow of a liquid.

  In the parallel flow step (I), as shown in FIGS. 1 (I) and 2 (I), the main flow path valve a corresponding to the main flow path A to be fed is opened, and the main flow path A to be fed The coupling channel valve b corresponding to the coupling channel B that communicates is closed. In addition, the valve corresponding to each flow path refers to a valve that controls the flow of liquid to each flow path. Therefore, in the case of a valve provided directly in the flow path, it refers to a valve that opens and closes the flow path, and in the case of a valve provided in a tube connected to the flow path, a valve that opens and closes the tube. Say.

  By opening and closing the valve as described above, the plurality of main flow paths A arranged in parallel do not communicate with each other and are in an independent state. In this state, a parallel liquid flow can be generated by supplying liquid from the liquid supply tubes communicating (connected) to both ends of the main flow path A and discharging the liquid from the drain tube.

In the following description, the main flow path for the outermost of the main flow path A to be feeding described as A _E1 and A _E2, respectively, the main channel which is located inside the them to as A _I. Further, it described as _{a E1} and _{a E2} main channel valves corresponding to the main channel _{A E1} and _{A E2,} respectively, the main channel valves corresponding to the main channel _{A I} to as _{a I.}
In the serial flow step (II), as shown in FIGS. 1 (II) and 2 (II), one end of each of the main flow paths A _E1 and A _E2 located at both ends of the main flow paths to be sent. open the main flow path valve _{a E1} and _{a E2} corresponds to. More specifically, the main flow path valve a _E1 on the liquid supply side is opened in one main flow path (for example, A _E1 ) of the main _flow paths A _E1 and A _E2 , and the discharge is performed in the other main flow path (for example, A _E2 ). Open the liquid side valve. More main channel valves a _I corresponding to the main channel A _I located inside the closed. Further, the coupling flow path valve b corresponding to the coupling flow path B located between the main flow paths A _E1 and A _E2 is opened.
By opening and closing the valve as described above, the plurality of main flow paths A to be fed communicate with each other via the coupling flow path B. In this state, was fed from a liquid supply tube communicating with the end of one (feeding side) of the main flow path A _E1, from the discharge tube which communicates with the end of one (drainage side) of the main flow path A _E2 By draining, a series liquid flow can be generated.

  As for the opening and closing of the main flow path valve a and the coupling valve b necessary for switching between the parallel flow and the series flow, the opening and closing operation of the main flow path valve a and the opening and closing operation of the coupling valve b may be performed separately. You may control by synchronizing those opening / closing operations.

[5. Liquid feeding system]
FIG. 9 is a block diagram showing a configuration of an example of a system using the microfluidic device of the present invention. In the liquid feeding system of FIG. 9, liquid is fed from the reagent tank to the microfluidic device, and discharged from the microfluidic device to the waste liquid tank. Switching between the serial flow path and the parallel flow path is performed by a valve switching device. As the valve switching device, means capable of opening and closing the valve is appropriately selected by those skilled in the art depending on the type of the valve employed. The state of the flow path of the microfluidic device supplied to the predetermined liquid is observed by the microfluidic device observation apparatus. Examples of the microfluidic device observation apparatus include a TIRF apparatus. There are usually a plurality of reagent tanks for one microfluidic device. These reagent tanks can be connected to the microfluidic device by a tube via a liquid transfer switching valve having a plurality of channels.

  The microfluidic device of the present invention is capable of delivering and discharging liquids containing various substances, and may be used for any liquid that has been applied to conventional microfluidic devices. Therefore, the substance contained in the liquid sent and discharged to the microfluidic device of the present invention may be a chemical substance or a biological substance. Biological substances may be proteins (including peptides), amino acids, nucleic acids (including oligonucleotides), nucleotides, lipids, and composites thereof. Moreover, chemical, biochemical, or genetic engineering artificial alterations (for example, modification, mutation, etc.) may be added to these biological materials.

  In the present invention, there is a case where a sample delivery liquid containing a substance selected from the group consisting of nucleic acids, nucleotides, and modified products thereof (particularly fluorescently labeled products) is preferably performed. Such an embodiment is embodied in a DNA sequencer that is one example of a liquid delivery system that combines a TIRF apparatus and a microfluidic device. According to this DNA sequencer, an SBS (Sequencing by Synthesis) method or the like can be performed.

[6. Example of use]
Examples of methods for using the microfluidic device of the present invention are given below. The following method of use can be performed by the DNA sequencer having the configuration shown in FIG.
In the process using the parallel flow, the following processes (1) to (4) can be performed.
(1) The fluorescently labeled template DNA is sent from the reagent tank to fix the fluorescently labeled template DNA onto the flow path. (2) The template DNA fixing position is measured by the microfluidic device observation apparatus ( 3) Dissociate the labeled substance of the template DNA by sending a predetermined reagent from the reagent tank. (4) Rinse the dissociated labeled substance by sending the rinse solution from the reagent tank.

In the process using the serial flow, the following processes (5) to (8) can be performed.
(5) An extension reaction is carried out on the template DNA by sending a nucleic acid reaction mixture containing a nucleotide analog in which different fluorescence is labeled on each of four types of bases and a terminator is added from a reagent tank and a polymerase ( 6) Dissociate the fluorescent label and terminator in the extended nucleotide analog by sending a predetermined reagent from the reagent tank. (7) Send the rinse liquid from the reagent tank to remove the dissociated fluorescent label and terminator. Rinse (8) Repeat steps (5) to (7) above

[7. Liquid-saving effect]
Assuming that the number of main flow paths A is n, the capacity per main flow path _A is V _A , the capacity per combined flow path B is V _B , and the capacity per pair of liquid feeding tube and drainage tube is V _t , The total liquid volume in the device when the parallel flow and the series flow are generated is as follows.
Total capacity in parallel: nx (V _A + V _t )
Total capacity in series: V _t + n × V _A + (n−1) × V _B

Specifically, typical channel sizes and the like are as follows.
Size and volume of the drainage tube from the reagent tank to the microfluidic device:
Inner diameter φ0.25 mm, length 1 m, capacity (V _t ) 49 mm ³
Main channel size and capacity:
Length 20 mm, width 1 mm, depth 0.05 mm, capacity (V _A ) 1 mm ³
Bonding channel (shortcut tube) size and volume:
Inner diameter φ0.25 mm, length 3 mm, capacity (V _B ) 0.15 mm ³

For n = 8, the total capacity of at parallel total volume of 400 mm ^3, the time series 58.05Mm ^3, and the serial time can save the amount of liquid 1/7 during parallel.
Therefore, as the number of main flow paths increases, the liquid-saving effect by switching from parallel flow to serial flow increases.

Claims (12)

A plurality of parallel main flow paths formed on the substrate;
A combined flow path for communicating the main flow paths;
A microfluidic device having a coupling channel valve for opening and closing the coupling channel.   The microfluidic device according to claim 1, wherein a feeding / draining tube is connected to both ends of the main flow path.   The microfluidic device according to claim 2, wherein the liquid supply / drainage tube is connected to both ends of the main flow path by being attached to a tube attachment plate provided on a substrate.   One end of one main flow path of the plurality of main flow paths and one end of a main flow path adjacent to the one main flow path are communicated with each other by the combined flow path. The microfluidic device according to any one of claims 1 to 3, wherein the other end and the other end of the adjacent main channel are not communicated with each other.   One end of the one main flow path and one end of the main flow path located next to the one main flow path on the opposite side of the adjacent main flow path are not communicated, and the one main flow The other end of the channel and the other end of the main channel located next to the opposite side are communicated with each other by the combined channel, so that all the plurality of main channels are connected in series with the combined channel. The microfluidic device of claim 4, wherein the microfluidic device is coupled to the microfluidic device.   The microfluidic device according to any one of claims 2 to 5, wherein the coupling channel is a tube that couples the liquid supply / drainage tubes.   The microfluidic device according to any one of claims 3 to 5, wherein the coupling channel is a tube attached to the tube mounting plate separately from the feeding / draining tube.   The microfluidic device according to any one of claims 3 to 5, wherein the coupling channel is an internal channel formed in the tube mounting plate.   The microfluidic device according to claim 8, wherein a part of an internal flow path formed in the tube mounting plate is opened upward and a gate valve as the coupling flow path valve is provided. A plurality of parallel main flow paths A formed on the substrate, a combined flow path B communicating the main flow paths, a main flow path valve a for controlling the liquid flow in the main flow path A, and the combined flow paths A liquid feeding method using a microfluidic device having a coupling flow path valve b for opening and closing, and a liquid feeding tube and a drainage tube respectively connected to both ends of the main flow path A, the following steps:
(I) Open the main flow path valve a corresponding to the plurality of main flow paths A to be fed,
Closing the coupling channel valve b corresponding to the coupling channel B communicating with the plurality of main channels A to be fed,
A step of producing a parallel liquid flow by feeding from the liquid feeding tube and draining from the drainage tube; and (II) a main flow located at the outermost side among the plurality of main flow paths A to be fed. Open the main flow path valves a _E1 and a _E2 corresponding to one end of each of the paths A _E1 and A _E2 ,
Close the main flow path valve a _I corresponding to the main flow path A _I located on the inner side,
Open the coupling flow path valve b corresponding to the coupling flow path B located between the main flow paths A _E1 and A _E2 ,
By sending liquid from a liquid feeding tube connected to one end of the main flow path A _E1 and draining from a drainage tube connected to one end of the main flow path A _E2 , a series liquid flow A method comprising the step of generating.   The method according to claim 10, wherein the composition of at least one of the liquids fed in the step (I) and the liquid sent in the step (II) are different. The method according to claim 10 or 11, wherein a sample containing a substance selected from the group consisting of a nucleic acid, a nucleotide and a modified form thereof is sent and discharged.