JP6965953B2 - Microchip and fine particle analyzer - Google Patents

Description

The present invention relates to a microchip and a microparticle analyzer. More specifically, the present invention relates to a microchip or the like for optically, electrically or magnetically analyzing the characteristics of fine particles such as cells and microbeads in the arranged flow path.

In recent years, by applying microfabrication technology in the semiconductor industry, microchips having regions and flow paths for performing chemical and biological analysis on a silicon or glass substrate have been developed. These microchips are beginning to be used, for example, in liquid chromatography electrochemical detectors and small electrochemical sensors in medical practice.

Analysis systems using such microchips are called μ-TAS (micro-Total-Analysis System), lab-on-a-chip, biochip, etc., and they are called high-speed and high-efficiency chemical and biological analysis. It is attracting attention as a technology that enables integration, integration, or miniaturization of analyzers.

Since μ-TAS can be analyzed with a small amount of sample and the disposable microchip can be used (disposable), it is expected to be applied to biological analysis that handles a particularly valuable trace amount of sample or 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 flow path arranged on a microchip. In this fine particle analysis technique, as a result of analysis, populations (groups) satisfying a predetermined condition are separately collected from the fine particles.

For example, Patent Document 1 discloses "a microchip for separating fine particles having a fine particle-containing solution introduction flow path and a sheath flow forming flow path arranged on at least one side of the flow path". There is. This fine particle separation microchip further includes "a fine particle measurement site for measuring introduced fine particles and two or more fine particles for separately collecting fine particles installed downstream of the fine particle measurement site. It has a sorting 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 measuring site to the fine particle sorting flow path.

The microparticle separation microchip disclosed in Patent Document 1 is provided by a "three-pronged flow path" including a fine particle-containing solution introduction flow path for introducing a sample liquid containing fine particles and two sheath flow forming flow paths. It forms a fluid laminar flow (see the document "Fig. 1").

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

According to such a three-pronged flow path, by sandwiching the sample liquid layer flow with the sheath liquid layer flow from the left and right, the sample liquid is placed at an arbitrary position in the flow path in the sandwiching direction (Y-axis direction in FIG. 17). The laminar flow can be deflected and the liquid can be sent. However, it was not possible to control the liquid feeding position of the sample liquid layer flow in the vertical direction of the flow path (Z-axis direction in FIG. 17). That is, in the conventional trident flow path, only a vertically long sample liquid layer flow can be formed in the Z-axis direction.

Therefore, in a conventional microchip provided with a three-pronged flow path, for example, when a solution containing fine particles is passed through the flow path as a sample liquid for optical analysis, the microchip is minute in the vertical direction (depth direction) of the flow path. There was variation in the flow position of the particles. For this reason, there is a problem that the flow speed of the fine particles differs depending on the flow position, the variation of the detection signal becomes large, and the analysis accuracy is lowered.

In Patent Document 2, the sample liquid laminar flow is introduced by introducing the sample liquid into the center of the sheath liquid laminar flow from an opening provided at the center of the flow path through which the sheath liquid laminar flow is sent. A flow path structure for sending liquid in a state of being surrounded by a sheath liquid laminar flow is disclosed (see the relevant document, FIGS. 2 and 3). According to this flow path structure, the sample liquid can be introduced into the center of the sheath liquid laminar flow, so that high analysis accuracy can be obtained by eliminating variations in the flow position of fine particles in the depth direction of the flow path. Can be done.

FIG. 18 shows a conventional flow path structure (A) adopted for introducing the sample liquid into the center of the sheath liquid laminar flow, and a sample liquid laminar flow (B) formed by the conventional flow path structure (A). In this flow path structure, the sheath liquid laminar flow is introduced into the flow paths 102 and 102 from the direction of arrow T in (A), respectively, and is sent to the flow path 103. Then, the sample liquid sent to the flow path 101 in the direction of arrow S can be introduced from the opening 104 into the center of the sheath liquid layer flow to which the flow path 103 is sent. As a result, as shown in FIG. 18B, the sample liquid laminar flow can be focused and sent to the center of the flow path 103. 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 path structure, when the sample liquid layer flow is introduced into the sheath liquid layer flow, the sample liquid layer flow is disturbed and the sample liquid layer flow is flat and stable. It has been pointed out that the laminar flow may not occur (see the relevant document, page 4, lines 12 to 46 on the right). Here, the "flat laminar flow" means a laminar flow focused in the depth direction (Z-axis direction) of the flow path in FIG. 18, and the "non-flat laminar flow" means the flow path of the flow path. It means a laminar flow that diffuses in the depth direction and spreads.

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

Japanese Unexamined Patent Publication No. 2003-1070999 Special Fair 7-196686

According to the plate-shaped protrusion 18 disclosed in Patent Document 2, the sample liquid flowing out from the opening is guided, and the sample liquid is made into a stable laminar flow focused in the depth direction of the flow path. It is said that it can be flushed to.

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

In order to solve the above problems, the present invention is arranged so as to sandwich the first introduction flow path for introducing the sample liquid and the first introduction flow path, and each joins the first introduction flow path from the side. A merging flow path that communicates with the two second introduction flow paths for introducing the sheath liquid and the first and second introduction flow paths, and the fluids sent from these flow paths merge and flow through. And are formed in the laminated substrate layer, the first introduction flow path is formed only in one of the substrate layers, and the second introduction flow path is formed in both one and the other of the substrate layers. In the merging flow path, the sample liquid flows through the center of the sheath liquid, and the merging flow path is at least a confluence portion between the first introduction flow path and the second introduction flow path. Downstream in the flow direction, a tapered portion in which the width of the flow path in the sandwiching direction of the second introduction flow path with respect to the first introduction flow path gradually decreases according to the flow direction of the fluid, and the first downstream portion of the tapered portion. It has a detection unit for fine particles contained in the fluid sent from one introduction flow path, the tapered portion is formed on both one and the other of the substrate layer, and the detection unit is the substrate layer. Provided is a microchip formed on only one side.
In the tapered portion, it is preferable that the flow path depth in the direction perpendicular to the plane including the first introduction flow path and the second introduction flow path gradually decreases according to the fluid flow direction.
Further, the second introduction flow path may be formed on both one and the other of the substrate layer.
Further, in the second introduction flow path, the flow path depth in one of the substrate layers can be made larger than the flow path depth in the other of the substrate layers.
In addition, the merging flow path may be partially formed on both one and the other of the substrate layer, and the other part may be formed on only one of the substrate layers.
Further, the taper angle of the tapered portion in the depth direction of the flow path may be larger than the merging angle of the second introduction flow path to the first introduction flow path or the throttle angle of the merging flow path. can.
Further, the flow path depth of the first introduction flow path is formed to be smaller than the flow path depth of the second introduction flow path, and the communication port of the first introduction flow path to the merging flow path is formed. It may be provided at a substantially central position in the flow path depth direction of the second introduction flow path.
In addition, the communication port of the first introduction flow path to the merging flow path may be opened in the region including each flow path wall of the second introduction flow path.
Further, it is possible that the starting point of the tapered portion is provided at a position corresponding to the communication port or on the upstream side or the downstream side of the communication port.
In addition, a laminar flow can be formed by the sample liquid and the sheath liquid in the confluence flow path.
Further, downstream of the tapered portion in the flow direction, a flow contraction portion in which the depth of the flow path and / or the width of the flow path gradually decreases in the flow direction can be provided.
Further, it is preferable that the flow path depth and the flow path width at the start point of the contracted portion are the same as the flow path depth and the flow path width at the end point of the tapered portion.
Further, it is preferable that the depth and / or width of the flow path formed between the tapered portion and the contracted portion is constant .
Also, in the present invention, the first inlet flow path for introducing a sample liquid, wherein the first disposed to sandwich the introduction flow path, the sheath liquid merges laterally into the first introduction channel, respectively The two second introduction flow paths that introduce the The first introduction flow path is formed in only one of the substrate layers, and the second introduction flow path is formed in both one and the other of the substrate layers. In the merging flow path, the sample liquid flows through the center of the sheath liquid, and the merging flow path is downstream in the flow direction of the merging portion of the first introduction flow path and the second introduction flow path. A tapered portion in which the width of the flow path in the sandwiching direction of the second introduction flow path with respect to the first introduction flow path gradually decreases according to the fluid flow direction, and the first introduction flow path downstream of the tapered portion. It has a detection part for fine particles contained in the fluid sent from the substrate, the tapered part is formed on both one and the other of the substrate layer, and the detection part is formed on only one of the substrate layers. that, a microchip, an irradiation system for irradiating a laser light to microparticles flowing the merge channel, a detection system for detecting light from the fine particles, even fine particle analyzing apparatus comprising a providing ..

In the present invention, the "fine particles" broadly include biologically related fine particles such as cells, microorganisms and liposomes, or synthetic particles such as latex particles, gel particles and industrial particles.
Biologically-related microparticles include chromosomes, liposomes, mitochondria, organelles (organelles) and the like that make up various cells. The cells of interest include animal cells (such as blood cell lineage cells) and plant cells. Microorganisms include bacteria such as Escherichia coli, viruses such as tobacco mosaic virus, and 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. Organic polymer materials include polystyrene, styrene / divinylbenzene, polymethylmethacrylate and the like. Inorganic polymer materials include glass, silica, magnetic materials and the like. Metals include colloidal gold, aluminum and the like. The shape of these fine particles is generally spherical, but may be non-spherical, and the size and mass are not particularly limited.

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

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 cross-sectional view. It is a schematic diagram explaining the cross section of the confluence flow path 12 of the microchip which concerns on 1st Embodiment of this invention. (A) is a cross-sectional view taken along the line PP in FIG. 1, (B) is a cross-sectional view taken along the line QQ, and (C) is a cross-sectional view taken along the line RR. 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 row shows a top view, and the lower row 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 cross-sectional view. It is a schematic diagram explaining the cross section of the confluence flow path 12 of the microchip which concerns on the 2nd Embodiment of this invention. (A) is a cross-sectional view taken along the line PP in FIG. 6, (B) is a cross-sectional view taken along the line QQ, and (C) is a cross-sectional view taken along the line RR. 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 row shows a top view, and the lower row shows a cross-sectional view. It is a schematic diagram explaining the taper angle in the flow path depth direction of the taper part 123 of the microchip which concerns on 2nd Embodiment of this invention. The upper row shows a top view, and the lower row shows a cross-sectional view. It is a schematic diagram explaining the modification of the taper portion 123 and the condensing portion 121 of the microchip according to the second embodiment of the present invention. (A) is a top view, and (B) is a cross-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 cross-sectional view. It is a schematic diagram explaining the cross section of the confluence flow path 12 of the microchip which concerns on the 3rd Embodiment of this invention. (A) is a cross-sectional view taken along the line PP in FIG. 11, (B) is a cross-sectional view taken along the line QQ, and (C) is a cross-sectional view taken along the line RR. It is a schematic diagram explaining the modification of the taper part 122, 123 of the microchip which concerns on the 3rd Embodiment of this invention. The upper row shows a top view, and the lower row shows a cross-sectional view. It is a schematic diagram explaining the modification of the taper portion 123 and the condensing portion 121 of the microchip according to the third embodiment of the present invention. (A) is a top view, and (B) is a cross-sectional view. It is a figure explaining the molding method of the microchip which concerns on this invention, and is the top surface schematic diagram of the substrate which comprises a chip. It is a figure explaining the molding method of the microchip which concerns on this invention, and is the cross-sectional schematic diagram of a chip. (B) corresponds to the middle PP cross section of (A). It is a schematic diagram explaining the flow path structure (A) of the conventional trident 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 for introducing a sample liquid into the center of a sheath liquid laminar flow, and the sample liquid laminar flow (B) formed by this structure. It is a schematic diagram explaining the conventional flow path structure shown in FIG. (A) is a top view, and (B) is a cross-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. (A) is a cross-sectional view taken along the line PP in FIG. 19, (B) is a cross-sectional view taken along the line QQ, and (C) is a cross-sectional view taken along the line RR. It is a schematic diagram explaining the flow velocity vector field of the fluid in the conventional flow path structure shown in FIG.

Hereinafter, suitable embodiments for carrying out the present invention will be described with reference to the drawings. It should be noted that the embodiments described below show an example of typical embodiments of the present invention, and the scope of the present invention is not narrowly interpreted by this. The explanation will be given in the following order.

1. 1. Flow velocity vector field of fluid in conventional flow path structure 2. 3. Microchip according to the first embodiment of the present invention. Deformation example of the flow path structure of the microchip according to the first embodiment 4. 5. Microchip according to the second embodiment of the present invention. 2. Deformation example of the flow path structure of the microchip according to the second embodiment. 6. Microchip according to the third embodiment of the present invention. 8. Deformation example of the flow path structure of the microchip according to the third embodiment. 9. Method for molding a microchip according to the present invention. Microparticle analyzer according to the present invention

1. 1. Fluid flow velocity vector field in the conventional flow path structure In the conventional flow path structure adopted for introducing the sample liquid into the center of the sheath laminar flow shown in FIG. 18, the sample liquid layer is in the sheath laminar flow. When introducing the flow, there is a problem that the sample laminar flow is disturbed and the sample laminar flow is not converged at the center of the flow path.

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 paths 102 and 102 and flows through the flow path 103, respectively, the sample liquid The laminar flow S sometimes diffused in the depth direction (Z-axis direction) of the flow path. If the sample liquid laminar flow S is not converged to the center of the flow path in this way, the flow position of the fine particles contained in the sample liquid laminar flow S varies in the depth direction of the flow path, so that the detection signal of the fine particles is also included. Variations occur and analysis accuracy decreases.

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

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

When the sample laminar flow S is introduced from the opening 104 into the center of the sheath laminar flow T to which the flow path 103 is sent, a fast flow velocity vector appears in the center of the flow path in the depth direction immediately after that ( (A), see arrow). It is considered that this fast flow velocity vector is generated because the merged sample laminar flow S and the sheath laminar flow T are concentrated in the center of the flow path in the depth direction and try to flow quickly.

Further, in the process in which the flow fields from the flow paths 101 and the flow paths 102 and 102 merge and develop into one flow field, a fast flow velocity vector generated in the center of the flow path in the depth direction is shown in FIG. 20 (B). As shown in FIG. 20, it becomes a flow field that swirls in the positive or negative direction of the Z axis, 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 this flow field and diffused in the depth direction of the flow path. It was also clarified that the deformation of the sample laminar flow S due to this spiral flow field increases depending on the flow rate of the sheath liquid sent from the flow paths 102 and 102.

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

FIG. 21 schematically shows a slow flow field generated near the opening 104 of the conventional flow path 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, shear is performed between the sheath liquid laminar flow T and the sample liquid laminar flow S as the sheath liquid sent from the flow paths 102 and 102 merges with the sample liquid discharged from the opening 104. Force 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 stagnant is formed. Then, it was found that the sample liquid laminar flow S became unstable due to this stagnant flow field and was diffused in the depth direction of the flow path. It was also clarified that the deformation of the sample laminar flow S due to this stagnant flow field increases as the flow rate of the sample liquid discharged from the opening 104 decreases.

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

FIG. 1 is a schematic view showing a flow path structure formed on 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 cross-sectional view.

In the figure, reference numeral 11 indicates a first introduction flow path (hereinafter, referred to as “sample liquid introduction flow path 11”) into which the first fluid (hereinafter, referred to as “sample liquid”) is introduced. Reference numerals 21 and 22 are arranged so as to sandwich the sample liquid introduction flow path 11, and each of them joins the sample liquid introduction flow path 11 from the side to introduce a second fluid (hereinafter, referred to as “sheath liquid”). The second introduction flow path (hereinafter, referred to as “sheath liquid introduction flow path 21 and 22”) is shown. Further, reference numeral 12 indicates a merging flow path that communicates with the sample liquid introduction flow path 11 and the sheath liquid introduction flow paths 21 and 22, and the sample liquid and the sheath liquid sent from these flow paths merge and flow through. show.

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

By introducing the sample liquid laminar flow S into the center of the sheath liquid laminar flow T from the communication port 111, the sample liquid laminar flow S can be fed as being surrounded by the sheath liquid laminar flow T (next). See also FIG. 2 described in). The position where the communication port 111 is provided is the sheath liquid introduction flow paths 21 and 22 as long as the sample liquid layer flow S is surrounded by the sheath liquid layer flow T in the confluence flow path 12 and the liquid can be fed. It can be located not only at the center position in the depth direction of the flow path but also near it. Similarly, the position of the merging flow path 12 of the communication port 111 in the flow path width direction 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 spiral flow field generated after the merging of the sample laminar flow and the sheath laminar flow described with reference to FIG. The tapered portion 122 is provided in the confluence flow path 12 in the vicinity of the confluence portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22. The tapered portion 122 is formed so that the flow path width in the sandwiching direction (Y-axis direction) of the sheath liquid introduction flow paths 21 and 22 with respect to the sample liquid introduction flow path 11 gradually expands and increases in the liquid feeding direction.

With reference to FIGS. 1 and 2, the flow velocity vector field of the fluid in the merging flow path 12 and the function of the tapered portion 122 will be described. FIG. 2 is a schematic cross-sectional view of the merging flow path 12. 2 (A) corresponds to a PP cross-sectional view in FIG. 1, (B) corresponds to a QQ cross-sectional view, and (C) corresponds to an RR cross-sectional view.

When the sample liquid laminar flow S is introduced from the opening 111 into the center of the sheath liquid laminar flow T flowing through the merging flow path 12, a fast flow velocity vector appears in the center of the flow path in the depth direction immediately after that (Fig. 2 (A), see the dotted arrow). This fast flow velocity vector is generated because the merged sample laminar flow S and the sheath laminar flow T are concentrated in the center of the flow path in the depth direction and tend to flow faster, as described above.

In the tapered portion 122, when the laminar flow widths of the sample laminar flow S and the sheath laminar flow T after merging are expanded in the Y-axis direction, the direction is opposite to the fast flow velocity vector generated in the center of the depth direction of the flow path. Flow field (see solid arrow in FIG. 2B) is generated. By generating the flow field in the opposite direction, the tapered portion 122 cancels out the flow field generated in the center of the flow path in the depth direction and suppresses the development into a spiral flow field. As a result, the sample liquid laminar flow S is maintained in a state of being converged to the center of the flow path 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 laminar flow portion that functions to narrow the laminar flow widths of the sample laminar flow S and the sheath laminar flow T after merging in the Y-axis and Z-axis directions. The condensing portion 121 is provided downstream of the tapered portion 122 in the merging flow path 12. The condensing portion 121 is formed so that the width of the flow path gradually narrows again in the liquid feeding direction and becomes smaller. Further, the flow condensing portion 121 is formed so that the depth of the flow path gradually narrows and becomes smaller according to the liquid feeding direction. That is, the flow path wall of the condensing 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 condensing portion 121 has a vertical cross section with respect to the liquid feeding direction (X-axis positive direction). It is formed so that the area of is gradually reduced. Due to this shape, the laminar flow portion 121 narrows the laminar flow widths of the sample laminar flow S and the sheath laminar flow T after merging in the Y-axis and Z-axis directions to feed the liquid.

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

A more specific description will be given with reference to FIG. First, the configuration of the opening 104 of the conventional flow path structure (see FIG. 18) will be described with reference to FIG. 4 (B). In the conventional flow path structure, between the sheath liquid layer flow T and the sample liquid layer flow S as the sheath liquid sent from the flow paths 102 and 102 merges with the sample liquid discharged from the opening 104. Due to the generated shearing force, an unstable flow field (hatched area in the figure) in which the flow stagnated was formed near the opening 104 (see also FIG. 21).

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

On the other hand, the communication port 111 of the microchip according to the present embodiment is opened in the region including the flow path walls 211 and 221 of the sheath liquid introduction flow path 21 and the sheath liquid introduction flow path 22, and thus is a communication port. The sample liquid discharged from 111 comes into direct contact with the fast-flowing sheath flow sent 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 port 111, is stably maintained in a state of being converged to the center of the flow path, and does not diffuse in the depth direction.

In the shape of the communication port 111 described here, the end of the communication port 111 side of the sample liquid introduction flow path 11 is cut out by the flow path walls 211 and 221 of the sheath liquid introduction flow path 21 and the sheath liquid introduction flow path 22. It can also be said that it has a shape. Since the shape of the communication port 111 is notched by the flow path walls 211 and 221 of the sheath liquid introduction flow paths 21 and 22, the flow path width indicated by reference numeral W in FIG. 4 is larger than the flow path width after the notch indicated by reference numeral C. Is also formed small.

3. 3. Deformation example of the flow path structure of the microchip according to the first embodiment In FIG. 1, the tapered portion 122 is formed in the merging flow path 12 at the merging portion of the sample liquid introducing flow path 11 with the sheath liquid introducing flow paths 21 and 22. The case where it is provided downstream of a certain communication port 111 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 portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22.

FIG. 5 shows a modified example of the tapered portion 122. The upper part of the figure shows a schematic upper surface view of the tapered portion 122, and the lower part shows a schematic cross-sectional view. As shown in FIG. 5A, for example, the tapered portion 122 may be provided so that the starting point at which the flow path 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 at which the flow path width in the Y-axis direction begins to expand coincides with the communication port 111. Note that FIG. 5C shows a case where the starting point at which the flow path width in the Y-axis direction starts to expand is positioned downstream of the communication port 111 and the tapered portion 122 is provided downstream of the communication port 111, as in FIG. Is shown.

4. Microchip according to the second embodiment of the present invention FIG. 6 is a schematic view showing a flow path structure formed on the microchip according to the second embodiment of the present invention. FIG. 4A is a top view of the microchip, and FIG. 4B is a cross-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 indicate sheath liquid introduction flow paths 21 and 22 which are arranged with the sample liquid introduction flow path 11 interposed therebetween and join the sample liquid introduction flow path 11 from the side to introduce the sheath liquid. Further, reference numeral 12 indicates a merging flow path that communicates with the sample liquid introduction flow path 11 and the sheath liquid introduction flow paths 21 and 22, and the sample liquid and the sheath liquid sent from these flow paths merge and flow through. show.

A communication port 111 for introducing the sample liquid is provided at the center of the confluence flow path 12 through which the sheath liquid laminar flow T flows at the confluence portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22. Has been done.

The flow path depth of the sample liquid introduction flow path 11 in the Z-axis direction is formed to be smaller than the flow path depth of the sheath liquid introduction flow paths 21 and 22, and the communication port 111 is the sheath liquid introduction flow path 21 and 22. It is provided at a substantially central position in the depth direction of the flow path. Further, the communication port 111 is provided at a substantially central position also in the flow path width direction (Y-axis direction) of the merging flow path 12.

By introducing the sample liquid laminar flow S into the center of the sheath liquid laminar flow T from the communication port 111, the sample liquid laminar flow S can be fed as being surrounded by the sheath liquid laminar flow T (next). See also FIG. 7 described in). The position where the communication port 111 is provided is the sheath liquid introduction flow paths 21 and 22 as long as the sample liquid layer flow S is surrounded by the sheath liquid layer flow T in the confluence flow path 12 and the liquid can be fed. It can be located not only at the center position in the depth direction of the flow path but also near it.
Similarly, the position of the merging flow path 12 of the communication port 111 in the flow path width direction may be not only the central position but also the vicinity thereof.

In the figure, reference numeral 123 indicates a tapered portion that functions to suppress the spiral flow field generated after the merging of the sample laminar flow and the sheath laminar flow described with reference to FIG. The tapered portion 123 is provided in the confluence flow path 12 in the vicinity of the confluence portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22. In the tapered portion 123, the flow path depth in the direction (Z-axis direction) perpendicular to the plane (XY plane) including the sample liquid introduction flow path 11 and the sheath liquid introduction flow path 21 and 22 gradually narrows according to the flow direction and becomes smaller. It is formed to be.

With reference to FIGS. 6 and 7, the flow velocity vector field of the fluid in the merging flow path 12 and the function of the tapered portion 123 will be described. FIG. 7 is a schematic cross-sectional view of the merging flow path 12. 7 (A) corresponds to a PP cross-sectional view in FIG. 6, (B) corresponds to a QQ cross-sectional view, and (C) corresponds to an RR cross-sectional view.

When the sample liquid laminar flow S is introduced from the opening 111 into the center of the sheath liquid laminar flow T flowing through the merging flow path 12, a fast flow velocity vector appears in the center of the flow path in the depth direction immediately after that (Fig. 7 (A), see dotted arrow). This fast flow velocity vector is generated because the merged sample laminar flow S and the sheath laminar flow T are concentrated in the center of the flow path in the depth direction and tend to flow faster, as described above.

In the tapered portion 123, when the laminar flow widths of the sample laminar flow S and the sheath laminar flow T after merging are narrowed in the Z-axis direction, the direction is opposite to the fast flow velocity vector generated in the center of the depth direction of the flow path. Flow field (see the solid line arrow in FIG. 7B) is generated. By generating the flow field in the opposite direction, the tapered portion 123 cancels out the flow field generated in the center of the flow path in the depth direction and suppresses the development into a spiral flow field. As a result, the sample liquid laminar flow S is maintained in a state of being converged to the center of the flow path without being stretched in the Z-axis direction by the spiral flow field (see FIGS. 7B and 7C).

In the figure, reference numeral 121 indicates a laminar flow portion that functions to narrow the laminar flow widths of the sample laminar flow S and the sheath laminar flow T after merging in the Y-axis and Z-axis directions. Since the configuration and operation of the condensing portion 121 are the same as those of the microchip according to the first embodiment, the description thereof will be omitted here. Further, the configuration and operation of the communication port 111 are the same as those of the microchip according to the first embodiment.

5. Deformation example of the flow path structure of the microchip according to the second embodiment FIG. 6 describes a case where the tapered portion 123 is provided so that the starting point at which the flow path depth in the Z-axis direction starts to narrow coincides with the position of the communication port 111. bottom. However, the position where the tapered 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 portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22.

FIG. 8 shows a modified example of the tapered portion 123. The upper part of the figure shows a schematic upper surface view of the tapered portion 123, and the lower part shows a schematic cross-sectional view. As shown in FIG. 8A, for example, the tapered portion 123 may be provided so that the starting point at which the flow path depth in the Z-axis direction begins to narrow is located upstream of the communication port 111. Further, as shown in FIG. 8C, the starting point at which the flow path depth in the Z-axis direction begins to narrow may be provided so as to be located downstream of the communication port 111. Note that FIG. 8B shows a case where the starting point at which the flow path depth in the Z-axis direction starts to narrow is provided so as to coincide with the position of the communication port 111, as in FIG.

The taper angle of the tapered portion 123 in the flow path depth direction (see reference numeral θz in FIG. 9) can be freely set as long as the function of the tapered portion 23 is exhibited. By setting the taper angle θz larger than the merging angle of the sheath liquid introduction flow paths 21 and 22 into the sample introduction flow path 11 (see reference numeral θy in FIG. 9A), the generation of a spiral flow field can be generated. The effect of suppressing can be enhanced. Further, when the flow path width of the merging flow path 12 is formed so as to gradually narrow and become smaller according to the liquid feeding direction, the throttle angle of the merging flow path 12 (see reference numeral θy in FIG. 9B). However, by increasing the taper angle θz, a sufficient effect of suppressing the vortex-shaped flow field can be obtained.

In FIG. 6, the case where the tapered portion 123 and the contracted flow portion 121 are discontinuously configured has been described, but the tapered portion 123 and the contracted flow portion 121 may be continuous as shown in FIG. ..

6. Microchip according to the third embodiment of the present invention FIG. 11 is a schematic view showing a flow path structure formed on the microchip according to the third embodiment of the present invention. FIG. 11A is a top view of the microchip, and FIG. 11B is a cross-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 indicate sheath liquid introduction flow paths 21 and 22 which are arranged with the sample liquid introduction flow path 11 interposed therebetween and join the sample liquid introduction flow path 11 from the side to introduce the sheath liquid. Further, reference numeral 12 indicates a merging flow path that communicates with the sample liquid introduction flow path 11 and the sheath liquid introduction flow paths 21 and 22, and the sample liquid and the sheath liquid sent from these flow paths merge and flow through. show.

A communication port 111 for introducing the sample liquid is provided at the center of the confluence flow path 12 through which the sheath liquid laminar flow T flows at the confluence portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22. Has been done.

The flow path depth of the sample liquid introduction flow path 11 in the Z-axis direction is formed to be smaller than the flow path depth of the sheath liquid introduction flow paths 21 and 22, and the communication port 111 is the sheath liquid introduction flow path 21 and 22. It is provided at a substantially central position in the depth direction of the flow path. Further, the communication port 111 is provided at a substantially central position also in the flow path width direction (Y-axis direction) of the merging flow path 12.

By introducing the sample liquid laminar flow S into the center of the sheath liquid laminar flow T from the communication port 111, the sample liquid laminar flow S can be fed as being surrounded by the sheath liquid laminar flow T (next). See also FIG. 12 described in). The position where the communication port 111 is provided is the sheath liquid introduction flow paths 21 and 22 as long as the sample liquid layer flow S is surrounded by the sheath liquid layer flow T in the confluence flow path 12 and the liquid can be fed. It can be located not only at the center position in the depth direction of the flow path but also near it. Similarly, the position of the merging flow path 12 of the communication port 111 in the flow path width direction may be not only the central position but also the vicinity thereof.

In the figure, reference numerals 122 and 123 indicate tapered portions that function to suppress the spiral flow field generated after the merging of the sample laminar flow and the sheath laminar flow described with reference to FIG. The tapered portions 122 and 123 are provided in the confluence flow path 12 in the vicinity of the confluence portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22. The tapered portion 122 is formed so that the flow path width in the sandwiching direction (Y-axis direction) of the sheath liquid introduction flow paths 21 and 22 with respect to the sample liquid introduction flow path 11 gradually expands and increases in the liquid feeding direction. Further, in the tapered portion 123, the flow path depth in the direction (Z-axis direction) perpendicular to the plane (XY plane) including the sample liquid introduction flow path 11 and the sheath liquid introduction flow paths 21 and 22 gradually narrows according to the flow direction. , Is formed to be small. In the microchip according to the present embodiment, the tapered portions 122 and 123 are configured in a partially overlapping region in the merging flow path 12.

The flow velocity vector field of the fluid in the merging flow path 12 and the functions of the tapered portions 122 and 123 will be described with reference to FIGS. 11 and 12. FIG. 12 is a schematic cross-sectional view of the merging flow path 12. 12 (A) corresponds to a PP cross-sectional view in FIG. 11, (B) corresponds to a QQ cross-sectional view, and (C) corresponds to an RR cross-sectional view.

When the sample liquid laminar flow S is introduced from the opening 111 into the center of the sheath liquid laminar flow T flowing through the merging flow path 12, a fast flow velocity vector appears in the center of the flow path in the depth direction immediately after that (Fig. In 12 (A), see the dotted arrow). This fast flow velocity vector is generated because the merged sample laminar flow S and the sheath laminar flow T are concentrated in the center of the flow path in the depth direction and tend to flow faster, as described above.

In the tapered portion 122, the laminar flow width of the sample liquid flow S and the sheath liquid flow T after merging is widened in the Y-axis direction, and in the tapered portion 123, the sample liquid laminar flow S and the sheath liquid layer after merging are expanded. When the laminar flow width of the flow T is narrowed in the Z-axis direction, a flow field (see the solid line arrow in FIG. 12B) is generated in the direction opposite to the fast flow velocity vector generated in the center of the flow path in the depth direction. do. The tapered portions 122 and 123 cancel the flow field generated in the center of the flow path in the depth direction by generating the flow field in the opposite direction, and suppress the development into a spiral flow field. As a result, the sample liquid laminar flow S is maintained in a state of being converged to the center of the flow path 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 laminar flow portion that functions to narrow the laminar flow widths of the sample laminar flow S and the sheath laminar flow T after merging in the Y-axis and Z-axis directions. Since the configuration and operation of the condensing portion 121 are the same as those of the microchip according to the first embodiment, the description thereof will be omitted here. Further, the configuration and operation of the communication port 111 are the same as those of the microchip according to the first embodiment.

7. Deformation example of the flow path structure of the microchip according to the third embodiment In FIG. 11, the tapered portion 122 is formed at the merging flow path 12 at the merging portion of the sample liquid introducing flow path 11 with the sheath liquid introducing flow paths 21 and 22. The case where it is provided downstream of a certain communication port 111 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 portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22.

Further, in FIG. 11, the case where the tapered portion 123 is provided so that the starting point at which the flow path depth in the Z-axis direction starts to narrow coincides with the position of the communication port 111 has been described. 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 portion of the sample liquid introduction flow path 11 with the sheath liquid introduction flow paths 21 and 22.

Further, in FIG. 11, a case has been described in which a starting point at which the flow path depth of the tapered portion 123 in the Z-axis direction begins to narrow is provided upstream from the starting point at which the flow path width in the Y-axis direction of the tapered portion 122 begins to widen. 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, there is a case where the end point where the flow path width of the tapered portion 122 in the Y-axis direction ends to widen and the end point where the flow path depth of the tapered portion 123 ends in narrowing in the Z-axis direction are provided at the same positions. As described above, the positions of the end point of the tapered portion 122 and the end point of the tapered portion 123 may be different or the same.

FIG. 13 shows a modified example of the tapered portions 122 and 123. In this modification, the positions of the starting point where the flow path width of the tapered portion 122 starts to widen in the Y-axis direction and the starting point where the flow path depth of the tapered portion 123 starts to narrow in the Z-axis direction are both provided so as to coincide with the communication port 111. ing. Further, the positions of the end point of the tapered portion 122 and the end point of the tapered portion 123 are also provided so as to coincide with each other.

Further, in FIG. 11, the case where the tapered portion 123 and the contracted flow portion 121 are discontinuously configured has been described, but the tapered portion 123 and the contracted flow portion 121 may be continuous as shown in FIG. And.

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

In order to maintain the light transmittance of the microchip, it is desirable to laminate a so-called hard coat layer used for an optical disk on the surface thereof. If stains such as fingerprints adhere to the surface of the microchip, particularly the surface of the optical detection unit, the amount of transmitted light may decrease and the optical analysis accuracy may decrease. By laminating a 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 by using a commonly used hard coat agent, and for example, a UV curable hard coat agent to which an anti-fingerprint agent such as a fluorine-based or silicon-based antifouling additive is added is used. Can form a film. Japanese Patent Application Laid-Open No. 2003-157579 describes a polyfunctional compound (A) having two or more polymerizable functional groups that can be polymerized by active energy rays, an organic group having a mercapto group, and a hydrolyzable group as a hard coding agent. Alternatively, active energy ray curability containing modified colloidal silica (B) having an average particle size of 1 to 200 nm and surface-modified with a mercaptosilane compound in which a hydroxyl group is bonded to a silicon atom, and a photopolymerization initiator (C). The composition (P) is disclosed.

The molding of the sample introduction flow path 11, the sheath liquid introduction flow path 21, 22, the merging flow path 12 including the tapered portions 122, 123, and the condensing portion 121, etc., which are arranged on the microchip, is performed by wet etching of the glass substrate layer. It can be performed by dry etching, nano-imprinting of a plastic substrate layer, injection molding, or cutting. Then, a microchip can be formed by laminating two substrates on which the sample introduction flow path 11 and the like are formed. The substrates can be bonded by a known method such as heat fusion, adhesive, anode bonding, bonding using an adhesive sheet, plasma activation bonding, ultrasonic bonding, or the like.

A method for forming a microchip according to the present invention will be described with reference to FIGS. 15 and 16. FIG. 15 shows a schematic top view of a substrate constituting the microchip according to the present invention. Further, FIG. 16 shows a cross-sectional view of the microchip according to the present invention. FIG. 16B corresponds to the PP cross section in (A).

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

Subsequently, as shown in FIG. 16, the substrate a and the substrate b are bonded together by thermocompression bonding or the like to form a microchip. At this time, the sheath liquid introduction flow paths 21 and 22 have different depths on the substrates a and b so that the sample liquid introduction flow path 11 is located substantially in 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 molded by laminating the substrates a and b on which the sample introduction flow path 11 and the like are formed. Therefore, unlike the microchip in which the guide structure is provided at the opening of the flow path into which the sample liquid layer flow is introduced, which is disclosed in Patent Document 2 described above, it can be manufactured by laminating only two substrates. Therefore, it is easy to form a flow path structure on each substrate and to bond the substrates, and it is possible to suppress the manufacturing cost of the microchip.

9. Microparticle analyzer according to the present invention The microchip described above can be mounted on the microparticle analyzer according to the present invention. This fine particle analyzer can also be applied as a fine particle sorter that analyzes the characteristics of fine particles and separates the fine particles based on the analysis result.

This microparticle analyzer detects fine particles contained in the sample liquid sent from the sample introduction flow path 11 downstream of the taper portion 122 or 123 and the condensing portion 121 in the confluence flow path 12 of the microchip. A detection unit for this purpose (see reference numeral D in FIG. 15) is configured.

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

Further, in the microchip according to the present invention, the laminar flow widths of the sample laminar flow S and the sheath laminar flow T can be narrowed down in the flow path width direction and the depth direction by the condensing portion 121 to supply the liquid. It is said that. By narrowing the laminar flow widths of the sample laminar flow S and the sheath laminar flow T, fine particles can be arranged in a row in the sample laminar flow S, and the fine particles in the depth direction of the flow path can be arranged. The variation in the flow position and the difference in the flow rate of the fine particles due to this can be further reduced. Therefore, by configuring the detection unit D downstream of the condensing unit 121 and detecting the fine particles, the fine particles are detected one by one, and the detection signal varies based on the difference in the flow velocity of the fine particles. Can be detected by eliminating as much as possible.

The detection unit D can be configured as an optical detection system, an electrical detection system, or a magnetic detection system. These detection systems can be configured in the same manner as a conventional microparticle analysis system using a microchip.
Specifically, the optical detection system includes an irradiation system consisting of a laser light source, a condenser lens for condensing and irradiating fine particles with laser light, and light generated from the fine particles by irradiation with the laser light. It is composed of a detection system that detects using a dichroic mirror, a bandpass filter, and the like. The detection of light generated from fine particles can be performed by, for example, a PMT (photomultiplier tube), an area image sensor such as a CCD or CMOS element, or the like.
Further, in the electric detection system or the magnetic detection system, microelectrodes 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. Or, for example, the magnetization, magnetic field change, magnetic field change, etc. of 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 fine particles, scattered light such as Rayleigh scattering or Me scattering, or fluorescence.

The overall control unit measures the optical characteristics of the fine particles based on this electric signal. The parameters for measuring the optical characteristics are the forward scattered light when determining the size of the fine particles and the lateral scattered light when determining the structure, depending on the target fine particles and the purpose of sorting. When determining the presence or absence of a fluorescent substance labeled on fine particles, fluorescence or the like is adopted.

Further, in the fine particle analyzer according to the present invention, the movement direction of the fine particle separation flow path as disclosed in Patent Document 1 and the movement direction of the fine particle installed near the flow path opening to the fine particle separation flow path are controlled. It is also possible to provide an electrode to be used, analyze the characteristics of the fine particles by the overall control unit, and separate the fine particles based on the analysis result.

The microchip according to the present invention is easy to mold, and the sample liquid laminar flow can be focused at the center of the flow path and fed. Therefore, when a solution containing fine particles is passed through the flow path as a sample liquid to analyze the characteristics of the fine particles, the variation in the flow position of the fine particles in the depth direction of the flow path is eliminated and the analysis accuracy is high. 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 flow path (sample introduction flow path)
111 Communication port 12 Confluence flow path 121 Constriction part 122, 123 Tapered part 21, 22 Second introduction flow path (sheath liquid introduction flow path)
3 Sample liquid supply port 4 Sheath liquid supply port 5 Discharge ports a, b Substrate D Detection unit S Sample liquid laminar flow T Sheath liquid laminar flow

Claims (13)

The first introduction flow path for introducing the sample liquid and
Two second introduction channels, which are arranged so as to sandwich the first introduction channel and join the first introduction channel from the side to introduce the sheath liquid, respectively.
A merging flow path that communicates with the first and second introduction flow paths and that the fluids sent from these flow paths merge and flow through is formed in a laminated substrate layer.
The first introduction flow path is formed only on one of the substrate layers,
The second introduction flow path is formed in both one and the other of the substrate layer.
In the merging flow path, the sample liquid flows through the center of the sheath liquid.
The confluence flow path
At least downstream of the confluence of the first introduction flow path and the second introduction flow path in the flow direction, the flow path width in the sandwiching direction of the second introduction flow path with respect to the first introduction flow path is A tapered part that gradually becomes smaller according to the flow direction of the fluid,
A detection unit for fine particles contained in the fluid sent from the first introduction flow path is provided downstream of the tapered portion.
The tapered portion is formed on both one and the other of the substrate layer.
The detection unit is formed on only one of the substrate layers .
The tapered portion is a microchip in which the depth of the flow path in the direction perpendicular to the plane including the first introduction flow path and the second introduction flow path gradually decreases according to the flow direction of the fluid . The microchip according to claim 1, wherein the second introduction flow path is formed in both one and the other of the substrate layer. The second introducing flow path, the flow path depth at one of the substrate layer is larger than the channel depth in the other of said substrate layer, microchip according to claim 2. The merge channel is partially formed in both one and the other of said substrate layer, said some non formed only on one of the substrate layer, according to any one of claims 1 3 Microchip. The tapered portion has a taper angle in the depth direction of the flow path larger than the merging angle of the second introduction flow path to the first introduction flow path or the throttle angle of the merging flow path, according to claim 1. The microchip according to any one of 4. The flow path depth of the first introduction flow path is formed to be smaller than the flow path depth of the second introduction flow path.
The communication port of the first introduction flow path to the merging flow path is provided at a substantially central position in the flow path depth direction of the second introduction flow path , according to any one of claims 1 to 5. The described microchip. Said communication port, said second is opened in a region including the respective flow path wall of the introduction passage, microchip according to claim 6. The starting point of the taper portion than said communication opening with the position or the communication port match is provided on the upstream side or downstream side, microchip of claim 6 or 7. In the confluent channel, said sample liquid, and the sheath liquid, a laminar flow is formed, the microchip according to any one of claims 1 to 8. The feed stream downstream of the tapered portion, the channel depth and / or channel width is contracted flow section is provided which gradually decreases with flow sending direction, according to any one of claims 1 9 Microchip. The microchip according to claim 10 , wherein the flow path depth and the flow path width at the start point of the condensing portion are the same as the flow path depth and the flow path width at the end point of the tapered portion. The microchip according to claim 11 , wherein the depth and / or width of the flow path formed between the tapered portion and the contracted portion is constant. Two second introduction channels, which are arranged so as to sandwich the first introduction flow path for introducing the sample liquid and the first introduction flow path, and join the first introduction flow path from the side to introduce the sheath fluid. And the merging flow path that communicates with the first and second introduction flow paths, and the fluids sent from these flow paths merge and flow through, are formed in the laminated substrate layer. The first introduction flow path is formed in only one of the substrate layers, the second introduction flow path is formed in both one and the other of the substrate layer, and the sample is formed in the confluence flow path. The structure is such that the liquid flows through the center of the sheath liquid, and the merging flow path is at least downstream of the confluence of the first introduction flow path and the second introduction flow path in the flow direction of the first introduction flow path. A tapered portion in which the width of the flow path in the sandwiching direction of the second introduction flow path with respect to the introduction flow path gradually decreases according to the flow direction of the fluid, and a fluid sent from the first introduction flow path downstream of the tapered portion. It has a detection unit for fine particles contained therein, the tapered portion is formed on both one and the other of the substrate layer, the detection portion is formed on only one of the substrate layers, and the tapered portion is formed. The microchip, in which the depth of the flow path in the direction perpendicular to the plane including the first introduction flow path and the second introduction flow path gradually decreases according to the fluid flow direction .
An irradiation system that irradiates the fine particles passing through the confluence flow path with laser light, and
A detection system that detects light from the fine particles,
A fine particle analyzer consisting of.

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