JP6708978B2 - Microchip and microparticle analyzer - Google Patents

Description

The present invention relates to a microchip and a microparticle analysis device. More specifically, the present invention relates to a microchip or the like for optically, electrically, or magnetically analyzing the characteristics of microparticles such as cells and microbeads in a channel provided.

In recent years, microchips in which regions and channels for performing chemical and biological analyzes are provided on a substrate made of silicon or glass have been developed by applying fine processing technology in the semiconductor industry. These microchips have begun to be used, for example, in electrochemical detectors for liquid chromatography and small electrochemical sensors in the medical field.

Such an analysis system using a microchip is called a μ-TAS (micro-Total-Analysis System), a lab-on-chip, a biochip, etc., and is used for high speed and high efficiency of chemical and biological analysis. This technology is attracting attention as a technology that enables integration, integration, or downsizing of analysis equipment.

μ-TAS can be analyzed with a small amount of sample, and disposable tip (disposable) of a microchip is possible, so it is expected to be applied to biological analysis that handles particularly valuable trace amount samples and a large number of samples. Has been done.

As an application example of μ-TAS, there is a microparticle analysis technique for optically, electrically, or magnetically analyzing the characteristics of microparticles such as cells and microbeads in a channel arranged on a microchip. In this microparticle analysis technique, as a result of the analysis, a population (group) satisfying a predetermined condition is also separately collected from the microparticles.

For example, Patent Document 1 discloses a "microparticle fractionation microchip having a microparticle-containing solution introducing flow channel and a sheath flow forming flow channel disposed on at least one side of the flow channel". There is. This microparticle separation microchip further includes a "microparticle measurement site for measuring introduced microparticles, and two or more microparticles for separating and collecting microparticles installed downstream of the microparticle measurement site. It has a separation flow path and two or more electrodes for controlling the moving direction of the fine particles installed near the flow path opening from the fine particle measurement site to the fine particle separation flow path.

The microparticle separation microchip disclosed in Patent Document 1 has a “trifurcated flow path” including a microparticle-containing solution introduction flow path for introducing a sample solution containing microparticles and two sheath flow formation flow paths. A laminar fluid flow is formed (see the document “FIG. 1” in the document).

FIG. 17 shows a conventional three-way channel structure (A) and a sample liquid laminar flow (B) formed thereby. In this trifurcated flow path, in (A), the sample liquid laminar flow that flows through the flow path 101 in the direction of the solid line arrow is sandwiched from the left and right by the sheath liquid laminar flow that is introduced into the flow paths 102 and 102 from the direction of the dotted line arrow. Then, the sample liquid laminar flow can be sent to the center of the channel as shown in FIG. Note that in FIG. 17B, the sample liquid laminar flow is shown by a solid line and the flow channel structure is shown by a dotted line.

According to such a three-pronged channel, the sample liquid laminar flow is sandwiched by the sheath liquid laminar flow from the left and right, so that the sample liquid is located at an arbitrary position in the flow channel in the sandwiching direction (Y-axis direction in FIG. 17). The laminar flow can be deflected to deliver the liquid. However, with respect to the vertical direction of the flow path (Z-axis direction in FIG. 17), it was not possible to control the liquid sending position of the sample liquid laminar flow. That is, in the conventional three-way channel, only the sample liquid laminar flow that is vertically long in the Z-axis direction can be formed.

Therefore, in a conventional microchip having a three-way channel, for example, when a solution containing fine particles as a sample solution is flowed through the channel for optical analysis, a microscopic amount in the vertical direction (depth direction) of the channel is used. There was variation in the position where the particles were sent. Therefore, there is a problem in that the flow velocity of the fine particles varies depending on the flow position, the detection signal varies greatly, and the analysis accuracy decreases.

In Patent Document 2, a sample liquid laminar flow is introduced by introducing the sample liquid into the center of the sheath liquid laminar flow through an opening provided at the center of the flow path through which the sheath liquid laminar flow is fed. A flow path structure is disclosed in which the liquid is sent while being surrounded by the sheath liquid laminar flow (see the document, FIGS. 2 and 3). According to this flow channel structure, since the sample liquid can be introduced into the center of the sheath liquid laminar flow, it is possible to eliminate variations in the delivery position of the fine particles in the depth direction of the flow channel and obtain high analysis accuracy. You can

FIG. 18 shows a conventional flow channel structure (A) adopted for introducing the sample liquid into the center of the sheath liquid laminar flow, and the sample liquid laminar flow (B) formed thereby. In this flow channel structure, the sheath liquid laminar flow is introduced into the flow channels 102 and 102 from the direction of arrow T in (A) and is sent to the flow channel 103. Then, the sample liquid sent to the channel 101 in the direction of the arrow S can be introduced from the opening 104 to the center of the laminar flow of the sheath liquid sent to the channel 103. Accordingly, as shown in FIG. 18B, it is possible to focus the sample liquid laminar flow on the center of the channel 103 and send the liquid. In addition, in FIG. 18B, the sample liquid laminar flow is shown by a solid line and the flow path structure is shown by a dotted line.

On the other hand, in Patent Document 2, in such a flow channel structure, when the sample liquid laminar flow is introduced into the sheath liquid laminar flow, the sample liquid laminar flow is disturbed and the sample liquid laminar flow is flat and stable. It has been pointed out that the above-mentioned laminar flow may not occur (see the document, page 4, right column, lines 12 to 46). Here, the "flat laminar flow" means a laminar flow focused in the depth direction of the flow channel (Z-axis direction) in FIG. 18, and the "non-flat laminar flow" is the flow channel of the flow channel. It means a laminar flow that diffuses and spreads in the depth direction.

In this document, in order to suppress the turbulence (wake) of the laminar flow at the confluence of the sample liquid laminar flow and the sheath liquid laminar flow, a pair of plate-shaped projections (corresponding to It is proposed to provide documents, FIG. 10, reference numeral 18) and the like. The plate-like protrusion 18 extends in the flow direction of the sample liquid laminar flow from the opening wall of the flow path into which the sample liquid laminar flow is introduced, and guides the sample liquid flowing out from the opening.

JP, 2003-107099, A Japanese Patent Publication No. 7-196686

According to the plate-like protrusion 18 disclosed in Patent Document 2, the sample liquid flowing out from the opening is guided, and the sample liquid is stabilized as a laminar flow focused in the depth direction of the flow path. It is possible to flush it.

However, when such a guide structure is provided at the opening of the flow channel into which the sample liquid laminar flow is introduced, the flow channel structure becomes complicated. Further, in order to form such a flow channel structure on the microchip, it is necessary to bond three or more substrates. Therefore, there is a problem that high precision is required for forming the flow channel structure on each substrate and bonding the substrates, and the manufacturing cost of the microchip becomes high.

Therefore, it is a main object of the present invention to provide a microchip capable of concentrating a sample liquid laminar flow in the center of a flow path and sending the liquid, and being easy to mold.

In order to solve the above problems, the present invention is provided with a first introduction channel for introducing a sample liquid and the first introduction channel sandwiched therebetween, and each merges into the first introduction channel from the side. Two second introduction flow passages for introducing sheath liquid with the first and second introduction flow passages, and confluence passages through which fluids sent from these flow passages merge and flow Are formed on the laminated substrate layers, the first introduction channel is formed only on one side of the substrate layer, and the second introduction channel is formed on both one side and the other side of the substrate layer. In the merging flow channel, the sample liquid flows through the center of the sheath liquid, and the merging flow channel is at least a merging portion of the first introducing flow channel and the second introducing flow channel. the flow sending direction downstream taper portion gradually decreases with flow sending direction of the channel width fluid is provided in said second pinching direction of the introduction passage with respect to the first inlet flow path, flow sending of the tapered portion Downstream of the direction, a flow-contracting portion in which the flow-channel depth and the flow-channel width gradually decrease in accordance with the flow direction is provided. Provided is a microchip provided with a flow channel having a constant flow channel width up to a starting point .
It is preferable that the taper portion has a channel depth in a direction perpendicular to a plane including the first introduction channel and the second introduction channel that gradually decreases in a fluid flow direction.
Further, the second introduction channel may be formed in both one and the other of the substrate layers.
Furthermore, in the second introduction flow channel, the flow channel depth in one of the substrate layers can be made larger than the flow channel depth in the other of the substrate layers.
In addition, a part of the confluence channel may be formed in both one and the other of the substrate layers, and a part other than the part may be formed in only one of the substrate layers.
Further, the taper portion may have a taper angle in a flow channel depth direction larger than a confluence angle of the second introduction flow channel to the first introduction flow channel or a throttle angle of the confluence flow channel. it can.
Furthermore, the flow path depth of the first introduction flow path is formed smaller than the flow path depth of the second introduction flow path, the communication port of the first introduction flow path to the confluent flow path, It may be provided at a substantially central position of the second introduction channel in the channel depth direction.
In addition, the communication port of the first introduction flow path to the merging flow path may be opened in a region including each flow path wall of the second introduction flow path.
Further, the starting point of the tapered portion may be provided at a position that coincides with the communication port or at an upstream side or a downstream side of the communication port.
In addition, a laminar flow can be formed by the sample liquid and the sheath liquid in the confluent channel .
Pressurized forte, the merge channel may be assumed to have a detection portion of the fine particles contained in the fluid flowing sent from said first introducing flow path downstream of the contraction portion.
Further, in the present invention, a first introduction flow path for introducing the sample liquid and the first introduction flow path are disposed so as to sandwich the first introduction flow path, and the first introduction flow path and the first introduction flow path are joined together from the side to form the sheath liquid. Two second introduction flow paths to be introduced and a merge flow path that communicates with the first and second introduction flow paths and through which the fluids sent from these flow paths merge and flow Formed on the substrate layer, the first introduction channel is formed only on one side of the substrate layer, the second introduction channel is formed on both one and the other of the substrate layer, the confluence In the flow channel, the sample liquid is configured to flow through the center of the sheath liquid, and the confluent flow channel is downstream in the flow direction of the confluent portion of the first introduction flow channel and the second introduction flow channel, A taper portion is provided in which a flow path width in the sandwiching direction of the second introduction flow path with respect to the first introduction flow path is gradually reduced according to a fluid flow direction, and a flow path is provided downstream of the tapered portion in the flow direction. A contraction part whose depth and channel width become gradually smaller according to the flow direction is provided, and between the taper part and the contraction part, the channel width from the end point of the taper part to the start point of the contraction part. A microchip provided with a constant flow path, an irradiation system for irradiating the microparticles flowing through the confluent flow path with laser light, and a detection system for detecting light from the microparticles, Also provided is a microparticle analyzer.

In the present invention, "microparticles" are intended to broadly include biologically relevant microparticles such as cells, microorganisms and liposomes, or synthetic particles such as latex particles, gel particles and industrial particles.
The biologically related microparticles include chromosomes, liposomes, mitochondria, organelles (cellular organelles), etc. that make up various cells. Target cells include animal cells (such as hematopoietic cells) and plant cells. Microorganisms include bacteria such as Escherichia coli, viruses such as tobacco mosaic virus, fungi such as yeast. Further, the bio-related microparticles may include bio-related macromolecules such as nucleic acids, proteins and complexes thereof.
Further, the industrial particles may be, for example, an organic or inorganic polymer material, a metal or the like. The organic polymer material includes polystyrene, styrene/divinylbenzene, polymethylmethacrylate and the like. The inorganic polymer material includes glass, silica, magnetic material and the like. Metals include gold colloid and aluminum. The shape of these fine particles is generally spherical, but may be non-spherical, and the size and mass are not particularly limited.

According to the present invention, a microchip capable of concentrating a sample liquid laminar flow in the center of a flow path to send a liquid and easily forming the microchip is provided.

It is a schematic diagram explaining the flow path structure formed in the microchip which concerns on 1st embodiment of this invention. (A) is a top view and (B) is a sectional view. It is a schematic diagram explaining the cross section of the confluence|merging flow path 12 of the microchip which concerns on 1st embodiment of this invention. 1A is a sectional view taken along line PP of FIG. 1, FIG. 6B is a sectional view taken along line QQ, and FIG. It is a schematic diagram explaining the structure of the communication port 111 of the microchip which concerns on 1st embodiment of this invention. It is a schematic diagram explaining the structure (A) of the communication port 111 of the microchip which concerns on 1st embodiment of this invention, and the opening 104 (B) of the conventional flow path structure shown in FIG. It is a schematic diagram explaining the modification of the taper part 122 of the microchip which concerns on 1st embodiment of this invention. The upper stage shows a top view and the lower stage shows a cross-sectional view. It is a schematic diagram explaining the flow path structure formed in the microchip which concerns on 2nd embodiment of this invention. (A) is a top view and (B) is a sectional view. It is a schematic diagram explaining the cross section of the confluence|merging flow path 12 of the microchip which concerns on 2nd embodiment of this invention. 6A is a sectional view taken along the line PP of FIG. 6, FIG. 6B is a sectional view taken along the line QQ, and FIG. It is a schematic diagram explaining the modification of the taper part 123 of the microchip which concerns on 2nd embodiment of this invention. The upper stage shows a top view and the lower stage shows a cross-sectional view. It is a schematic diagram explaining the taper angle in the flow channel depth direction of the taper part 123 of the microchip which concerns on 2nd embodiment of this invention. The upper stage shows a top view and the lower stage shows a cross-sectional view. It is a schematic diagram explaining the modification of the taper part 123 of the microchip and the constriction part 121 which concern on 2nd embodiment of this invention. (A) is a top view and (B) is a sectional view. It is a schematic diagram explaining the flow path structure formed in the microchip which concerns on 3rd embodiment of this invention. (A) is a top view and (B) is a sectional view. It is a schematic diagram explaining the cross section of the confluence|merging flow path 12 of the microchip which concerns on 3rd embodiment of this invention. 11A is a sectional view taken along the line PP of FIG. 11, FIG. 11B is a sectional view taken along the line QQ, and FIG. It is a schematic diagram explaining the modification of the taper parts 122 and 123 of the microchip which concerns on 3rd embodiment of this invention. The upper stage shows a top view and the lower stage shows a cross-sectional view. It is a schematic diagram explaining the modified example of the taper part 123 and the constriction part 121 of the microchip which concerns on 3rd embodiment of this invention. (A) is a top view and (B) is a sectional view. It is a figure explaining the shaping|molding method of the microchip which concerns on this invention, and is an upper surface schematic diagram of the board|substrate which comprises a chip. It is a figure explaining the shaping|molding method of the microchip which concerns on this invention, and is a cross-sectional schematic diagram of a chip. (B) corresponds to the PP cross section in (A). It is a schematic diagram explaining the flow path structure (A) of the conventional trifurcated flow path, and the sample liquid laminar flow (B) formed by this. It is a schematic diagram explaining the conventional flow path structure (A) adopted in order to introduce|transduce a sample liquid into the center of a sheath liquid laminar flow, and the sample liquid laminar flow (B) formed by this. It is a schematic diagram explaining the conventional flow path structure shown in FIG. (A) is a top view and (B) is a sectional view. It is a schematic diagram explaining the flow velocity vector field of the fluid in the conventional flow-path structure shown in FIG. 19A is a sectional view taken along the line PP of FIG. 19, FIG. 19B is a sectional view taken along the line QQ, and FIG. It is a schematic diagram explaining the flow velocity vector field of the fluid in the conventional flow-path structure shown in FIG.

Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. The embodiments described below are examples of typical embodiments of the present invention, and the scope of the present invention should not be construed narrowly. The description will be given in the following order.

1. 1. Flow velocity vector field of fluid in conventional flow path structure 2. Microchip according to the first embodiment of the present invention Modification of Microchip Channel Structure According to First Embodiment 4. Microchip according to the second embodiment of the present invention 5. Modified example of flow path structure of microchip according to second embodiment 7. Microchip according to the third embodiment of the present invention Modification of Microchip Channel Structure According to Third Embodiment 8. 8. Microchip molding method according to the present invention Microparticle analyzer according to the present invention

1. Flow velocity vector field of fluid in conventional flow channel structure In the conventional flow channel structure adopted for introducing the sample liquid into the center of the sheath liquid laminar flow shown in FIG. When the flow is introduced, there is a problem that the sample liquid laminar flow is disturbed and the sample liquid laminar flow is not converged at the center of the flow channel.

That is, as shown in FIG. 19, when the sample liquid laminar flow S is introduced from the opening 104 at the center of the sheath liquid laminar flow T which is introduced into the flow channels 102 and 102 and flows through the flow channel 103, The laminar flow S may be diffused in the depth direction of the flow path (Z-axis direction). If the sample liquid laminar flow S is not converged to the center of the flow path in this way, the delivery positions of the fine particles contained in the sample liquid laminar flow S will vary in the depth direction of the flow path, and therefore the detection signal of the fine particles will also be detected. Variations occur and analysis accuracy decreases.

The present inventors numerically calculated the flow velocity vector field (flow field) of the fluid in the flow channel structure in order to clarify the cause of the turbulence of the sample liquid laminar flow that has occurred in the conventional flow channel structure. As a result, it was clarified that the vortex-like flow field generated after the merging of the sample liquid laminar flow and the sheath liquid laminar flow causes the turbulence of the sample liquid laminar flow.

The flow velocity vector field of the fluid in the conventional flow channel structure will be described with reference to FIGS. 20A and 20B are schematic cross-sectional views of a conventional flow path structure. FIG. 20A corresponds to the P-P cross-sectional view in FIG. 19, FIG. 20B corresponds to the Q-Q cross-sectional view, and FIG. ..

When the sample liquid laminar flow S is introduced from the opening 104 to the center of the sheath liquid laminar flow T which is fed through the flow channel 103, a fast flow velocity vector appears immediately after that at the center in the depth direction of the flow channel ( In FIG. 20(A), refer to the arrow). It is considered that this fast flow velocity vector is generated because the combined sample liquid laminar flow S and sheath liquid laminar flow T concentrate in the center in the depth direction of the flow channel and try to flow quickly.

Further, in the process of the flow fields from the flow channel 101 and the flow channels 102 and 102 joining and developing into one flow field, a fast flow velocity vector generated at the center of the flow channel in the depth direction is shown in FIG. The flow field swirls in the Z-axis positive direction or in the negative direction as shown in, and eventually develops into a spiral flow field as shown in FIG. 20(C). Then, it was found that the sample liquid laminar flow S was stretched in the positive and negative directions of the Z axis by the flow field and diffused in the depth direction of the flow channel. It was also clarified that the deformation of the sample liquid laminar flow S due to the vortex-like flow field becomes large depending on the flow rate of the sheath liquid sent from the flow paths 102, 102.

In addition, as a result of the numerical calculation of the flow velocity vector field (flow field), the inventors found that the slow flow field generated near the opening for introducing the sample liquid laminar flow into the center of the sheath liquid laminar flow was the sample liquid laminar flow. It has also revealed that it is causing the disorder.

FIG. 21 schematically shows a slow flow field generated in the vicinity of the opening 104 of the conventional flow channel structure adopted for introducing the sample liquid into the center of the sheath liquid laminar flow shown in FIG. 18 (in the figure, (See arrow).

In the vicinity of the opening 104, shearing occurs between the sheath liquid laminar flow T and the sample liquid laminar flow S as the sheath liquid fed from the flow channels 102 and 102 merges with the sample liquid discharged from the opening 104. Power is generated. Due to this shearing force, a slow flow velocity vector is generated in the vicinity of the opening 104, and an unstable flow field in which the flow is settled is formed. Then, it was found that the laminar flow S of the sample liquid became unstable due to the stagnant flow field and was diffused in the depth direction of the flow channel. It was also clarified that the deformation of the sample liquid laminar flow S due to the stagnant flow field becomes larger as the flow rate of the sample liquid discharged from the opening 104 becomes smaller.

2. Microchip according to the first embodiment of the present invention A microchip according to the present invention suppresses a vortex-like flow field generated after the above-described merging of a sample liquid laminar flow and a sheath liquid laminar flow, and disturbs the sample liquid laminar flow. The first feature is that a flow path structure that does not cause the above is provided. Furthermore, the microchip according to the present invention suppresses the stagnant flow field generated near the opening for introducing the sample liquid laminar flow into the center of the sheath liquid laminar flow as described above, and causes the turbulence of the sample liquid laminar flow. A second feature is that a flow path structure that does not prevent the flow is provided.

FIG. 1 is a schematic diagram showing a flow channel structure formed in a microchip according to the first embodiment of the present invention. FIG. 1A is a top view of the microchip, and FIG. 1B is a sectional view.

In the figure, reference numeral 11 indicates a first introduction channel (hereinafter referred to as “sample solution introduction channel 11”) into which a first fluid (hereinafter referred to as “sample solution”) is introduced. Reference numerals 21 and 22 are arranged so as to sandwich the sample liquid introduction flow channel 11 and merge into the sample liquid introduction flow channel 11 from the side, and a second fluid (hereinafter, referred to as “sheath liquid”) is introduced. A second introduction channel (hereinafter referred to as "sheath liquid introduction channels 21 and 22") is shown. Further, reference numeral 12 is a confluent flow path communicating with the sample liquid introduction flow path 11 and the sheath liquid introduction flow paths 21 and 22 so that the sample liquid and the sheath liquid sent from these flow paths merge and flow. Show.

A communication port 111 for introducing the sample liquid to the center of the merging flow channel 12 through which the sheath liquid laminar flow T flows is provided at the confluence portion of the sample liquid introducing flow channel 11 with the sheath liquid introducing flow channels 21, 22. Has been. The flow channel depth of the sample liquid introduction flow channel 11 in the Z-axis direction is formed to be smaller than the flow channel depths of the sheath liquid introduction flow channels 21 and 22, and the communication port 111 includes the sheath liquid introduction flow channels 21 and 22. Is provided at a substantially central position in the flow channel depth direction. The communication port 111 is also provided at a substantially central position in the flow channel width direction (Y-axis direction) of the confluent flow channel 12.

By introducing the sample liquid laminar flow S into the center of the sheath liquid laminar flow T through the communication port 111, the sample liquid laminar flow S can be sent in a state of being surrounded by the sheath liquid laminar flow T (next. (See also FIG. 2 described below). The position where the communication port 111 is provided is such that as long as the sample liquid laminar flow S is surrounded by the sheath liquid laminar flow T and can be fed into the confluent flow passage 12, the sheath liquid introduction flow passages 21 and 22 are provided. Not only at the central position of the channel depth direction, but also in the vicinity thereof. Similarly, the position of the communication port 111 in the flow channel width direction of the merging flow channel 12 may be not only the central position but also the vicinity thereof.

In the figure, reference numeral 122 indicates a tapered portion that functions to suppress the vortex-like flow field generated after the merging of the sample liquid laminar flow and the sheath liquid laminar flow described in FIG. The taper portion 122 is provided in the confluence channel 12 in the vicinity of the confluence portion of the sample liquid introduction channel 11 with the sheath liquid introduction channels 21 and 22. The taper portion 122 is formed so that the flow channel width in the sandwiching direction (Y-axis direction) of the sheath liquid introduction flow channels 21, 22 with respect to the sample liquid introduction flow channel 11 gradually increases in accordance with the liquid feeding direction and increases.

With reference to FIGS. 1 and 2, the flow velocity vector field of the fluid in the confluence channel 12 and the function of the taper portion 122 will be described. FIG. 2 is a schematic sectional view of the confluence channel 12. 2A corresponds to the P-P sectional view in FIG. 1, FIG. 2B corresponds to the Q-Q sectional view, and FIG. 2C corresponds to the RR sectional view.

When the sample liquid laminar flow S is introduced from the opening 111 to the center of the sheath liquid laminar flow T flowing through the confluent flow channel 12, immediately after that, a fast flow velocity vector appears at the center in the depth direction of the flow channel (Fig. 2(A), refer to dotted arrow). As described above, the fast flow velocity vector is generated because the combined sample liquid laminar flow S and sheath liquid laminar flow T are concentrated in the depth direction center of the flow channel and try to flow quickly.

When the laminar flow widths of the combined sample liquid laminar flow S and sheath liquid laminar flow T are expanded in the Y-axis direction in the taper portion 122, they are opposite to the fast flow velocity vector generated in the depth direction center of the flow path. Flow field (see the solid line arrow in FIG. 2B). The tapered portion 122 generates the flow field in the opposite direction, cancels the flow field generated at the center of the flow channel in the depth direction, and suppresses the development into the spiral flow field. As a result, the sample liquid laminar flow S is maintained in a state of being converged at the center of the flow channel without being stretched in the Z-axis direction by the spiral flow field (see FIGS. 2B and 2C).

In the figure, reference numeral 121 indicates a contracting portion that functions to narrow the laminar flow widths of the combined sample liquid laminar flow S and sheath liquid laminar flow T in the Y-axis and Z-axis directions. The contraction section 121 is provided downstream of the tapered section 122 in the confluence channel 12. The contraction section 121 is formed such that the flow channel width gradually narrows again and becomes smaller in the liquid feeding direction. In addition, the contraction portion 121 is formed so that the depth of the flow passage gradually narrows and becomes smaller in the liquid feeding direction. That is, the flow path wall of the contracting portion 121 is formed so as to be narrowed in the Y-axis and Z-axis directions according to the liquid feeding direction, and the contracting portion 121 has a cross section perpendicular to the liquid feeding direction (X-axis positive direction). Is formed so that the area of the is gradually reduced. With this shape, the contracting section 121 narrows the laminar flow widths of the combined sample liquid laminar flow S and sheath liquid laminar flow T in the Y-axis and Z-axis directions to feed the liquid.

3 and 4 are schematic diagrams showing the configuration of the communication port 111. The flow channel depth of the sample liquid introduction flow channel 11 in the Z-axis direction is formed to be smaller than the flow channel depths of the sheath liquid introduction flow channels 21 and 22, and the communication port 111 includes the sheath liquid introduction flow channels 21 and 22. Is provided at a substantially central position in the flow channel depth direction (see FIG. 3). Further, the communication port 111 is opened in a region including the flow passage walls 211 and 221 of the sheath liquid introduction flow passage 21 and the sheath liquid introduction flow passage 22 in order to suppress a stagnant flow field generated in the vicinity.

A more specific description will be given with reference to FIG. First, with reference to FIG. 4B, the structure of the opening 104 of the conventional flow channel structure (see FIG. 18) will be described. In the conventional flow channel structure, between the sheath liquid laminar flow T and the sample liquid laminar flow S accompanying the confluence of the sheath liquid fed from the flow channels 102 and 102 and the sample liquid discharged from the opening 104. Due to the shearing force generated, an unstable flow field (shaded area in the figure) where the flow settled was formed near the opening 104 (see also FIG. 21).

In this case, the sample liquid is discharged from the opening 104 to an unstable flow field in which the flow is stagnant. Therefore, the sample liquid laminar flow S becomes unstable before coming into contact with the fast-flowing sheath flow sent from the flow channels 102 and 102, and diffuses in the depth direction of the flow channels.

On the other hand, the communication port 111 of the microchip according to the present embodiment is opened in a region including the flow channel walls 211 and 221 of the sheath liquid introduction flow channel 21 and the sheath liquid introduction flow channel 22, and therefore, the communication port 111. The sample liquid discharged from 111 directly contacts the fast-flowing sheath flow delivered from the sheath liquid introduction channels 21 and 22. Therefore, the sample liquid laminar flow S is accelerated by the sheath flow immediately after being discharged from the through-hole 111, is stably maintained in the state of being converged at the center of the channel, and is not diffused in the depth direction.

In the shape of the communication port 111 described here, the end of the sample liquid introduction channel 11 on the communication port 111 side is cut by the channel walls 211 and 221 of the sheath liquid introduction channel 21 and the sheath liquid introduction channel 22. It can be said that it has a different shape. Since the shape of the communication port 111 is notched by the channel walls 211 and 221 of the sheath liquid introduction channels 21 and 22, the channel width indicated by the symbol W in FIG. 4 is smaller than the channel width after notch indicated by the symbol C. Is also formed small.

3. Modified Example of Microchip Channel Structure According to First Embodiment In FIG. 1, the taper portion 122 is formed at the confluence portion of the confluence channel 12 with the sheath liquid introduction channels 21 and 22 of the sample liquid introduction channel 11. The case where the communication port 111 is provided downstream has been described. However, the position where the tapered portion 122 is provided is not limited to the position shown in FIG. 1 as long as it is in the vicinity of the confluence of the sample liquid introduction flow passage 11 with the sheath liquid introduction flow passages 21 and 22.

FIG. 5 shows a modification of the tapered portion 122. The upper part of the figure shows a schematic top view of the tapered portion 122, and the lower part shows a schematic cross-sectional view. For example, as shown in FIG. 5A, the tapered portion 122 may be provided so that the starting point where the flow passage width in the Y-axis direction begins to expand is located upstream of the communication port 111. Further, as shown in FIG. 5B, the tapered portion 122 may be provided at a position where the starting point where the width of the flow passage in the Y-axis direction starts to expand coincides with the communication port 111. Note that, similar to FIG. 1, FIG. 5C shows a case where the starting point where the width of the flow channel in the Y-axis direction begins to be widened is located downstream of the communication port 111 and the tapered portion 122 is provided downstream of the communication port 111. Indicates.

4. Microchip According to Second Embodiment of the Present Invention FIG. 6 is a schematic diagram showing a flow channel structure formed in a microchip according to a second embodiment of the present invention. FIG. 4A is a top view of the microchip and FIG. 4B is a sectional view.

In the figure, reference numeral 11 indicates a sample liquid introduction flow path into which the sample liquid is introduced. Reference numerals 21 and 22 denote sheath liquid introduction flow passages 21 and 22 which are arranged with the sample liquid introduction flow passage 11 sandwiched therebetween and which merge into the sample liquid introduction flow passage 11 from the side and into which the sheath liquid is introduced. Further, reference numeral 12 is a confluent flow path communicating with the sample liquid introduction flow path 11 and the sheath liquid introduction flow paths 21 and 22 so that the sample liquid and the sheath liquid sent from these flow paths merge and flow. Show.

A communication port 111 for introducing the sample liquid to the center of the merging flow channel 12 through which the sheath liquid laminar flow T flows is provided at the confluence portion of the sample liquid introducing flow channel 11 with the sheath liquid introducing flow channels 21, 22. Has been.

The flow channel depth of the sample liquid introduction flow channel 11 in the Z-axis direction is formed to be smaller than the flow channel depths of the sheath liquid introduction flow channels 21 and 22, and the communication port 111 includes the sheath liquid introduction flow channels 21 and 22. Is provided at a substantially central position in the flow channel depth direction. The communication port 111 is also provided at a substantially central position in the flow channel width direction (Y-axis direction) of the confluent flow channel 12.

By introducing the sample liquid laminar flow S into the center of the sheath liquid laminar flow T through the communication port 111, the sample liquid laminar flow S can be sent in a state of being surrounded by the sheath liquid laminar flow T (next. (See also FIG. 7 described below). The position where the communication port 111 is provided is such that as long as the sample liquid laminar flow S is surrounded by the sheath liquid laminar flow T and can be fed into the confluent flow passage 12, the sheath liquid introduction flow passages 21 and 22 are provided. Not only at the central position of the channel depth direction, but also in the vicinity thereof.
Similarly, the position of the communication port 111 in the flow channel width direction of the merging flow channel 12 may be not only the central position but also the vicinity thereof.

In the figure, reference numeral 123 indicates a taper portion that functions to suppress the vortex-like flow field that occurs after the sample liquid laminar flow and the sheath liquid laminar flow described in FIG. 20 merge. The tapered portion 123 is provided in the confluence channel 12 in the vicinity of the confluence of the sample liquid introduction channel 11 and the sheath liquid introduction channels 21, 22. The taper portion 123 has a small channel depth in a direction (Z-axis direction) perpendicular to a plane (XY plane) including the sample liquid introduction channel 11 and the sheath liquid introduction channels 21 and 22 and gradually becomes smaller in the flow direction. Is formed.

With reference to FIGS. 6 and 7, the flow velocity vector field of the fluid in the confluence channel 12 and the function of the taper portion 123 will be described. FIG. 7 is a schematic cross-sectional view of the confluence channel 12. 7A corresponds to the P-P sectional view in FIG. 6, FIG. 7B corresponds to the QQ sectional view, and FIG. 7C corresponds to the RR sectional view.

When the sample liquid laminar flow S is introduced from the opening 111 to the center of the sheath liquid laminar flow T flowing through the confluent flow channel 12, immediately after that, a fast flow velocity vector appears at the center in the depth direction of the flow channel (Fig. 7(A), see dotted arrow). As described above, the fast flow velocity vector is generated because the combined sample liquid laminar flow S and sheath liquid laminar flow T are concentrated in the depth direction center of the flow channel and try to flow quickly.

When the laminar flow widths of the combined sample liquid laminar flow S and sheath liquid laminar flow T are narrowed in the Z-axis direction at the taper portion 123, they are opposite to the fast flow velocity vector generated in the depth direction center of the flow path. Flow field (see the solid line arrow in FIG. 7B) occurs. The taper portion 123 cancels the flow field generated in the center of the flow path in the depth direction by suppressing the flow field in the spiral direction by generating the flow field in the opposite direction. As a result, the sample liquid laminar flow S is not stretched in the Z-axis direction by the spiral flow field but is maintained in a state of being converged at the center of the flow channel (see FIGS. 7B and 7C).

In the figure, reference numeral 121 indicates a contracting portion that functions to narrow the laminar flow widths of the combined sample liquid laminar flow S and sheath liquid laminar flow T in the Y-axis and Z-axis directions. The structure and operation of the flow contracting unit 121 are the same as those of the microchip according to the first embodiment, and thus the description thereof is omitted here. Further, the configuration and operation of the communication port 111 are similar to those of the microchip according to the first embodiment.

5. Modified Example of Microchip Channel Structure According to Second Embodiment In FIG. 6, a case where the tapered portion 123 is provided such that the starting point where the channel depth in the Z-axis direction starts to narrow is aligned with the position of the communication port 111 will be described. did. However, the position where the taper portion 123 is provided is not limited to the position shown in FIG. 6 as long as it is in the vicinity of the confluence of the sample liquid introduction flow passage 11 with the sheath liquid introduction flow passages 21 and 22.

FIG. 8 shows a modification of the tapered portion 123. The upper part of the drawing is a schematic top view of the tapered portion 123, and the lower part is a schematic cross-sectional view. For example, as shown in FIG. 8A, the tapered portion 123 may be provided so that the starting point where the flow channel depth in the Z-axis direction starts to narrow is located upstream of the communication port 111. Further, as shown in FIG. 8C, the starting point at which the depth of the flow path in the Z-axis direction starts to narrow may be provided downstream of the communication port 111. Note that FIG. 8B shows a case where the starting point where the flow channel depth in the Z-axis direction starts to narrow is provided at the same position as the communication port 111, as in FIG. 6.

The taper angle of the taper portion 123 in the flow channel depth direction (see reference numeral θz in FIG. 9) can be freely set as long as the function of the taper portion 23 is exhibited. The taper angle θz is set to be larger than the confluence angle of the sheath liquid introduction channels 21 and 22 with the sample introduction channel 11 (see reference numeral θy in FIG. 9A), so that the generation of the vortex-like flow field can be prevented. The suppressing effect can be enhanced. Further, when the flow passage width of the merge flow passage 12 is formed so as to gradually narrow and become smaller in accordance with the liquid feeding direction, from the throttle angle of the merge flow passage 12 (see reference numeral θy in FIG. 9B). However, by increasing the taper angle θz, it is possible to obtain a sufficient effect of suppressing the flow field in a spiral shape.

Although the case where the taper portion 123 and the contraction portion 121 are discontinuously formed has been described with reference to FIG. 6, the taper portion 123 and the contraction portion 121 may be continuous as shown in FIG. 10. ..

6. Microchip According to Third Embodiment of the Present Invention FIG. 11 is a schematic view showing a flow channel structure formed in the microchip according to the third embodiment of the present invention. 11A is a top view of the microchip, and FIG. 11B is a sectional view.

In the figure, reference numeral 11 indicates a sample liquid introduction flow path into which the sample liquid is introduced. Reference numerals 21 and 22 denote sheath liquid introduction flow passages 21 and 22 which are arranged with the sample liquid introduction flow passage 11 sandwiched therebetween and which merge into the sample liquid introduction flow passage 11 from the side and into which the sheath liquid is introduced. Further, reference numeral 12 is a confluent flow path communicating with the sample liquid introduction flow path 11 and the sheath liquid introduction flow paths 21 and 22 so that the sample liquid and the sheath liquid sent from these flow paths merge and flow. Show.

A communication port 111 for introducing the sample liquid to the center of the merging flow channel 12 through which the sheath liquid laminar flow T flows is provided at the confluence portion of the sample liquid introducing flow channel 11 with the sheath liquid introducing flow channels 21, 22. Has been.

The flow channel depth of the sample liquid introduction flow channel 11 in the Z-axis direction is formed to be smaller than the flow channel depths of the sheath liquid introduction flow channels 21 and 22, and the communication port 111 includes the sheath liquid introduction flow channels 21 and 22. Is provided at a substantially central position in the flow channel depth direction. The communication port 111 is also provided at a substantially central position in the flow channel width direction (Y-axis direction) of the confluent flow channel 12.

By introducing the sample liquid laminar flow S into the center of the sheath liquid laminar flow T through the communication port 111, the sample liquid laminar flow S can be sent in a state of being surrounded by the sheath liquid laminar flow T (next. (See also FIG. 12 described below). The position where the communication port 111 is provided is such that as long as the sample liquid laminar flow S is surrounded by the sheath liquid laminar flow T and can be fed into the confluent flow passage 12, the sheath liquid introduction flow passages 21 and 22 are provided. Not only at the central position of the channel depth direction, but also in the vicinity thereof. Similarly, the position of the communication port 111 in the flow channel width direction of the merging flow channel 12 may be not only the central position but also the vicinity thereof.

In the figure, reference numerals 122 and 123 denote tapered portions that function to suppress the vortex-like flow field generated after the merging of the sample liquid laminar flow and the sheath liquid laminar flow described in FIG. The tapered portions 122 and 123 are provided in the confluence channel 12 in the vicinity of the confluence portions of the sample liquid introduction channel 11 and the sheath liquid introduction channels 21 and 22. The taper portion 122 is formed so that the flow channel width in the sandwiching direction (Y-axis direction) of the sheath liquid introduction flow channels 21, 22 with respect to the sample liquid introduction flow channel 11 gradually increases in accordance with the liquid feeding direction and increases. Further, in the taper portion 123, the flow channel depth in the direction (Z-axis direction) perpendicular to the plane (XY plane) including the sample liquid introduction flow channel 11 and the sheath liquid introduction flow channels 21, 22 gradually narrows in the flow direction. , Are formed to be small. In the microchip according to this embodiment, the tapered portions 122 and 123 are formed in regions where the confluence channels 12 partially overlap.

With reference to FIGS. 11 and 12, the flow velocity vector field of the fluid in the confluence channel 12 and the functions of the tapered portions 122 and 123 will be described. FIG. 12 is a schematic cross-sectional view of the merge channel 12. 12A corresponds to the P-P sectional view in FIG. 11, FIG. 12B corresponds to the Q-Q sectional view, and FIG. 12C corresponds to the RR sectional view.

When the sample liquid laminar flow S is introduced from the opening 111 to the center of the sheath liquid laminar flow T flowing through the confluent flow channel 12, immediately after that, a fast flow velocity vector appears at the center in the depth direction of the flow channel (Fig. 12(A), see dotted arrow). As described above, the fast flow velocity vector is generated because the combined sample liquid laminar flow S and sheath liquid laminar flow T are concentrated in the depth direction center of the flow channel and try to flow quickly.

In the tapered portion 122, the laminar flow widths of the combined sample liquid laminar flow S and the sheath liquid laminar flow T are expanded in the Y-axis direction, and in the tapered portion 123, the combined sample liquid laminar flow S and the sheath liquid layer are formed. When the laminar width of the flow T is narrowed in the Z-axis direction, a flow field (see the solid arrow in FIG. 12B) opposite to the fast flow velocity vector generated in the depth direction center of the flow path is generated. To do. The tapered portions 122 and 123 cancel the flow field generated in the center in the depth direction of the flow path by generating the flow field in the opposite direction, and suppress the development into the spiral flow field. As a result, the sample liquid laminar flow S is maintained in a state of being converged at the center of the flow channel without being stretched in the Z-axis direction by the spiral flow field (see FIGS. 12B and 12C).

In the figure, reference numeral 121 indicates a contracting portion that functions to narrow the laminar flow widths of the combined sample liquid laminar flow S and sheath liquid laminar flow T in the Y-axis and Z-axis directions. The structure and operation of the flow contracting unit 121 are the same as those of the microchip according to the first embodiment, and thus the description thereof is omitted here. Further, the configuration and operation of the communication port 111 are similar to those of the microchip according to the first embodiment.

7. Modification Example of Microchip Channel Structure According to Third Embodiment In FIG. 11, the taper portion 122 is formed in the confluent channel 12 at the confluent portion of the sample liquid introduction channel 11 with the sheath liquid introduction channels 21, 22. The case where the communication port 111 is provided downstream has been described. However, the position where the tapered portion 122 is provided is not limited to the position shown in FIG. 11 as long as it is in the vicinity of the confluence of the sample liquid introduction flow passage 11 with the sheath liquid introduction flow passages 21 and 22.

Further, in FIG. 11, the case has been described in which the tapered portion 123 is provided such that the starting point where the flow path depth in the Z-axis direction starts to narrow is aligned with the position of the communication port 111. However, the position where the tapered portion 123 is provided is not limited to the position shown in FIG. 11 as long as it is in the vicinity of the confluence of the sample liquid introduction flow passage 11 with the sheath liquid introduction flow passages 21 and 22.

Further, in FIG. 11, the case where the starting point where the flow path depth of the taper portion 123 starts to narrow in the Z-axis direction is provided upstream of the starting point where the flow path width of the taper portion 122 starts to expand in the Y-axis direction has been described. However, the positions of the starting point of the tapered portion 122 and the starting point of the tapered portion 123 may be different or the same. Similarly, in FIG. 11, a case where the end point where the width of the flow passage in the Y-axis direction of the taper portion 122 ends and the end point where the depth of the flow passage in the Z-axis direction of the taper portion 123 ends decreases are provided at the same position. As described above, the positions of the end points of the tapered portion 122 and the tapered portion 123 may be different or the same.

FIG. 13 shows a modification of the tapered portions 122 and 123. In this modification, the positions of the starting point where the width of the flow passage in the Y-axis direction of the tapered portion 122 starts to expand and the starting point where the depth of the flow passage in the Z-axis direction of the tapered portion 123 starts to narrow are both aligned with the communication port 111. ing. Further, the positions of the end points of the taper portion 122 and the taper portion 123 are also made to coincide with each other.

Further, in FIG. 11, the case where the taper portion 123 and the contraction portion 121 are discontinuously described has been described, but the taper portion 123 and the contraction portion 121 may be continuous as shown in FIG. 14. And

8. Molding Method of Microchip According to the Present Invention The material of the microchip according to the present invention can be glass or various plastics (PP, PC, COP, PDMS). When optically performing analysis using a microchip, it is preferable to select a material having optical transparency, small autofluorescence, and small wavelength dispersion, and thus having a small optical error.

In order to maintain the light transmittance of the microchip, it is desirable to stack a so-called hard coat layer used for an optical disc on the surface thereof. If a stain such as a fingerprint adheres to the surface of the microchip, particularly the surface of the optical detection portion, the amount of transmitted light may decrease, and the accuracy of optical analysis may decrease. By laminating the hard coat layer having excellent transparency and antifouling property on the surface of the microchip, it is possible to prevent such a decrease in analysis accuracy.

The hard coat layer can be formed using a commonly used hard coat agent, for example, by using a UV-curable hard coat agent to which a fingerprint adhesion preventing agent such as a fluorine-based or silicon-based antifouling agent is added. Can form a film. JP-A-2003-157579 discloses, as a hard code agent, a polyfunctional compound (A) having two or more polymerizable functional groups capable of being polymerized by active energy rays, an organic group having a mercapto group and a hydrolyzable group. Or active energy ray curability containing a modified colloidal silica (B) having an average particle diameter of 1 to 200 nm which is surface-modified with a mercaptosilane compound having a hydroxyl group bonded to a silicon atom, and a photopolymerization initiator (C) Composition (P) is disclosed.

The sample introducing channel 11, the sheath liquid introducing channels 21 and 22, the merging channel 12 including the taper portions 122 and 123 and the contracting portion 121, which are arranged in the microchip, are formed by wet etching of the glass substrate layer. Or by dry etching, or by nanoimprinting, injection molding or cutting of the plastic substrate layer. Then, the microchip can be formed by bonding the two substrates on which the sample introduction channel 11 and the like are formed. The substrates can be bonded by known methods such as heat fusion, adhesives, anodic bonding, bonding using a pressure sensitive adhesive sheet, plasma activated bonding, ultrasonic bonding and the like.

A method of molding a microchip according to the present invention will be described with reference to FIGS. FIG. 15 is a schematic top view of a substrate that constitutes the microchip according to the present invention. 16 shows a sectional view of the microchip according to the present invention. FIG. 16B corresponds to the P-P cross section in FIG.

First, a part of the sheath liquid introducing channels 21 and 22 and a part of the confluent channel 12 are formed on the substrate a (see FIG. 15A). On the substrate a, a sample liquid supply port 3 for supplying the sample liquid to the sample introduction flow channel 11, a sheath liquid supply port 4 for supplying the sheath liquid to the sheath liquid introduction flow channels 21, 22 and a confluent flow channel. A discharge port 5 for discharging the sample liquid and the sheath liquid from 12 is also formed. Next, on the substrate b, the sample introduction flow channel 11, a part of the sheath liquid introduction flow channels 21, 22 and a part of the merging flow channel 12 are formed (see FIG. 15B).

Subsequently, as shown in FIG. 16, the substrate a and the substrate b are bonded by thermocompression bonding or the like to form a microchip. At this time, the sheath liquid introduction flow paths 21 and 22 are provided at different depths in the substrates a and b so that the sample liquid introduction flow path 11 is located substantially at the center of the sheath liquid introduction flow paths 21 and 22 in the flow path depth direction. Is formed.

As described above, the microchip according to the present invention can be formed by bonding the substrates a and b on which the sample introduction channel 11 and the like are formed. Therefore, unlike the microchip disclosed in the above-mentioned Patent Document 2 in which the guide structure is provided at the opening of the flow path into which the sample liquid laminar flow is introduced, it can be manufactured by bonding only two substrates. Therefore, it is easy to form the flow channel structure on each substrate and to bond the substrates, and it is possible to suppress the manufacturing cost of the microchip.

9. Microparticle Analysis Device According to the Present Invention The above-described microchip can be mounted on the microparticle analysis device according to the present invention. This microparticle analysis device can also be applied as a microparticle sorting device that analyzes the characteristics of microparticles and sorts the microparticles based on the analysis result.

This microparticle analyzer detects microparticles contained in the sample liquid sent from the sample introduction flow path 11 downstream of the taper part 122 or 123 and the contraction part 121 in the confluence flow path 12 of the microchip. The detection unit (see reference numeral D in FIG. 15) is configured.

In the microchip according to the present invention, the sample liquid laminar flow S is delivered by the tapered portions 122 and 123 in a state of being converged at the center of the confluence channel 12, and the delivery position of the fine particles in the depth direction of the channel. It is possible to eliminate the variation in the flow rate and the flow velocity difference of the fine particles caused by the variation (see FIG. 2 and the like). Therefore, by configuring the detection unit D downstream of the tapered portions 122 and 123 to detect the fine particles, the variation in the detection signal based on the difference in the flow velocity of the fine particles is eliminated, and the fine particles can be detected with high accuracy. Detection can be performed.

Further, in the microchip according to the present invention, it is possible to reduce the laminar flow width of the sample liquid laminar flow S and the sheath liquid laminar flow T in the flow channel width direction and the depth direction by the contracting portion 121 and to feed the liquid. It is said that. By narrowing the laminar flow widths of the sample liquid laminar flow S and the sheath liquid laminar flow T, the fine particles can be arranged in a line in the sample liquid laminar flow S, and the fine particles in the depth direction of the channel can be formed. It is possible to further reduce the variation in the feeding position and the difference in the flow velocity of the fine particles caused by the variation. Therefore, by configuring the detection unit D downstream of the contraction unit 121 to detect the fine particles, the fine particles are detected one by one, and the variation of the detection signal based on the flow velocity difference of the fine particles is detected. Can be detected with maximum exclusion.

The detector D can be configured as an optical detection system, an electrical detection system, or a magnetic detection system. These detection systems can be configured similarly to the conventional microparticle analysis system using a microchip.
Specifically, the optical detection system uses a laser light source, an irradiation system including a condenser lens for condensing and irradiating the laser light to the microparticles, and a light generated from the microparticles by the irradiation of the laser light. And a detection system for detecting using a dichroic mirror, a bandpass filter, or the like. The light generated from the fine particles can be detected by, for example, a PMT (photo multiplier tube), an area image pickup device such as a CCD or a CMOS device, or the like.
In the electrical detection system or the magnetic detection system, minute electrodes are arranged in the flow path of the detection unit D, and for example, resistance value, capacitance value (capacitance value), inductance value, impedance, change value of electric field between electrodes, etc. Alternatively, for example, the magnetization, the magnetic field change, the magnetic field change, and the like of the fine particles are measured.

Light, resistance value, magnetization, etc. generated from the fine particles detected by the detection unit D are converted into electric signals and output to the overall control unit. The light to be detected may be forward scattered light or side scattered light of minute particles, scattered light such as Rayleigh scattering or Mie scattering, or fluorescence.

The overall control unit measures the optical characteristics of the fine particles based on this electric signal. The parameters for this optical property measurement are the forward scattered light when determining the size of the fine particles and the side scattered light when determining the structure, according to the target fine particles and the purpose of sorting. In the case of determining the presence or absence of the fluorescent substance labeled on the microparticles, fluorescence or the like is adopted.

Further, in the fine particle analyzer according to the present invention, the fine particle sorting channel as disclosed in the above-mentioned Patent Document 1 and the moving direction of the fine particles installed near the channel opening to the fine particle sorting channel are controlled. It is also possible to dispose the electrodes to be used, analyze the characteristics of the fine particles by the overall control unit, and sort the fine particles based on the analysis result.

The microchip according to the present invention is easy to mold, and it is possible to focus the sample liquid laminar flow on the center of the flow path and send the liquid. Therefore, when analyzing the characteristics of the microparticles by passing a solution containing microparticles as a sample solution through the flow channel, eliminate the variation in the flow position of the microparticles in the depth direction of the flow channel and achieve high analysis accuracy. Can be obtained. Therefore, the microchip according to the present invention is suitably used for a microparticle analysis technique for optically, electrically or magnetically analyzing the characteristics of microparticles such as cells and microbeads.

11 First introduction channel (sample introduction channel)
111 communication port 12 confluent flow channel 121 constricted flow sections 122, 123 tapered sections 21, 22 second introduction flow channel (sheath liquid introduction flow channel)
3 Sample Liquid Supply Port 4 Sheath Liquid Supply Port 5 Discharge Ports a, b Substrate D Detector S Sample Liquid Laminar Flow T Sheath Liquid Laminar Flow

Claims (11)

A first introduction channel for introducing the sample liquid,
Two second introduction channels that are arranged with the first introduction channel sandwiched therebetween and that respectively merge into the first introduction channel from the side to introduce the sheath liquid;
Communicating with the first and second introduction channels, a confluent channel in which fluids sent from these channels merge and flow, and are formed in a laminated substrate layer,
The first introduction channel is formed only on one of the substrate layer,
The second introduction channel is formed in both one and the other of the substrate layer,
In the confluence channel, the sample liquid is configured to flow through the center of the sheath liquid,
The confluent channel is
At least in the flow direction downstream of the merging portion of the first introduction flow path and the second introduction flow path, the flow path width in the sandwiching direction of the second introduction flow path with respect to the first introduction flow path A taper portion is provided that gradually decreases according to the direction of fluid flow ,
Downstream of the taper portion in the flow direction, a flow contracting portion having a flow channel depth and a flow channel width gradually decreasing in the flow direction is provided.
A microchip in which a channel having a constant channel width from the end point of the tapered section to the start point of the contracted section is provided between the tapered section and the contracted section . The microchip according to claim 1, wherein the tapered portion has a channel depth in a direction perpendicular to a plane including the first introduction channel and the second introduction channel that gradually decreases in a fluid flow direction. .. The microchip according to claim 1, wherein the second introduction flow channel has a flow channel depth in one of the substrate layers larger than a flow channel depth in the other of the substrate layers. 4. The confluence channel is partly formed on both of the one and the other of the substrate layers, and the part other than the part is formed on only one of the substrate layers. Microchip. The taper portion, the taper angle in the flow channel depth direction is larger than the confluence angle of the second introduction flow channel or the constriction angle of the confluence flow channel to the first introduction flow channel, 4. The microchip according to any one of 4 above. The channel depth of the first introduction channel is formed smaller than the channel depth of the second introduction channel,
The communication port of the first introduction flow path to the confluence flow path is provided at a substantially central position in the flow path depth direction of the second introduction flow path. Microchip. 7. The communication port of the first introduction flow path to the confluence flow path is opened in a region including each flow path wall of the second introduction flow path. Microchip. The microchip according to claim 6 or 7, wherein a starting point of the tapered portion is provided at a position that coincides with the communication port or on an upstream side or a downstream side of the communication port. The microchip according to claim 1, wherein a laminar flow is formed by the sample liquid and the sheath liquid in the confluence channel. 10. The micro according to any one of claims 1 to 9 , wherein the confluence channel has a detection unit for fine particles contained in a fluid sent from the first introduction channel downstream of the contraction unit. Chips. A first introduction flow channel for introducing the sample liquid and two second flow passages, which are arranged so as to sandwich the first introduction flow channel, and which respectively merge with the first introduction flow channel from the side to introduce the sheath liquid. Is formed on the substrate layer in which the introduction flow path of (1) and the confluence flow path that communicates with the first and second introduction flow paths and through which the fluids sent from these flow paths merge and flow The first introduction channel is formed only on one of the substrate layers, the second introduction channel is formed on both one and the other of the substrate layer, in the confluence channel, the sample The liquid is configured to flow through the center of the sheath liquid, and the merging flow path is at least downstream of the merging portion of the first introducing flow path and the second introducing flow path in the flow direction. A taper portion is provided in which a flow path width in the sandwiching direction of the second introduction flow path with respect to the introduction flow path is gradually reduced in the flow direction of the fluid. A contraction section whose path width gradually decreases in the flow direction is provided, and a flow path having a constant flow passage width from the end point of the taper section to the start point of the contraction section is provided between the taper section and the contraction section. A microchip with a channel ,
An irradiation system for irradiating a laser beam to the fine particles flowing through the confluence channel,
A detection system for detecting light from the microparticles,
Micro particle analyzer.