JP2022032224A - Particle separator and separation method - Google Patents

Abstract

To provide a particle separator and a particle separation method which improve particle separation treatment in HDF.SOLUTION: It has been found that by a simple channel structure such that a channel width in a wall surface of a main channel comprising a branch port is elongated, a particle separation treatment amount is improved in substantially proportional to a length of the channel width in the wall surface of the main channel comprising the branch port.SELECTED DRAWING: Figure 2

Description

The present invention relates to a separation device for particles contained in a fluid and a method for manipulating particles contained in a fluid using the device.

Techniques for separating microscale or smaller particles and cells by size are techniques used in biochemistry, diagnostic medicine and various industrial fields. For example, hematopoietic stem cells that differentiate into other cells and stem cells such as ES cells need to separate only stem cells from many cell groups in order to study cell differentiation. In addition, in order to diagnose cancer, the examination of whether or not the blood of a patient contains circulating tumor cancer cells (CTC) is attracting attention as a new method of cancer screening. In general, these stem cells and CTCs are different in size from other cells, so it can be expected to separate from other cell groups by utilizing the size difference. The technique of separating cells is an extremely important technique.

As a technique for separating these particles and cells, a technique such as centrifugation or filtration, or a technique using an electric field or a magnetic field using an external force is known as a technique that is relatively easy to operate. However, since centrifugation and filtration give physical stimulation when used for cell separation, there are problems that the survival rate is lowered and the separation accuracy is low. Further, the method using an electric field or a magnetic field has a problem that the operation becomes complicated because an operation such as modifying a sample may be required and a device or equipment for applying an external force is required.

On the other hand, in recent years, using microfabrication technologies such as photolithography and 3D printing, particle and cell separation technology using minute flow paths (micro flow paths) with a width of several microns to several hundred microns has been widely researched and developed. (Non-Patent Documents 1 and 2). Since the laminar flow is stably maintained in the microchannel, the fluid in the channel can be precisely controlled, and particles and cells suspended in the fluid can be separated with high accuracy.

For example, Patent Document 1 reports a method called hydrodynamic filtration (HYDRO-DYNAMIC FILTRATION) (hereinafter referred to as HDF). This method does not require complicated equipment and devices, and particles can be continuously separated according to size by simply introducing a fluid containing particles into the flow path in the microchip, and separation into multiple fractions is also possible. Become. That is, for example, when separating by size, it is possible to separate into groups of 3 or more groups according to size, not only in two stages of large and small.

The HDF uses a channel structure having at least one branching channel with respect to the main channel, and the diameter of the particles flowing into the branching channel is the diameter of the particles and the shape and size of the branch port of the branching channel. , And a separation method that focuses on the fact that one or more of the scales such as the length of the branch flow path is appropriately adjusted, and is a technique capable of continuous and precise separation. As described in Patent Document 1, HDF can use a structure having one fluid inlet and two or more fluid recovery ports, for example, a liquid containing target particles from the fluid inlet (hereinafter, sample liquid). ), And only particles with a certain diameter or less flow in the branch flow path, so that particle separation can be performed.

Here, in the flow path structure of the bird's-eye view (FIG. 1), the flow direction (longitudinal direction) of the flow path is defined as the x-axis, the depth direction of the paper surface is defined as the z-axis, and the direction orthogonal to the x and z-axis is defined as the y-axis. In some cases, the amount of particle separation processing in HDF is generally improved by increasing the flow rate of the sample liquid or parallelizing the microchips having the flow path structure (Non-Patent Document 4).

Japanese Unexamined Patent Publication No. 2007-021465

Analytical Chemistry, 76, 5465-5471, 2004. Lab on a chip, 9, 939-948, 2009. Lab on a chip 5, 778-784, 2005. Lab on a chip, 10, 1828-1837, 2019.

However, when the flow rate of the sample liquid is increased in order to improve the processing amount, breakage of the flow path and liquid leakage from the pipe connection portion become problems due to the influence of the increase in pressure loss. When the material of the flow path is a flexible material (for example, polydimethylsiloxane (hereinafter PDMS)), the flow path width 50 in the narrow portion in the y-axis direction is widened due to the increase in shear force due to the increase in flow rate, and the separation ability is increased. There is a limit to the increase in the amount of processing due to the increase in the flow rate, for example, there is a concern that the amount will decrease. On the other hand, when microchips are parallelized, the processing amount increases in proportion to the number of parallel chips, but the material and manufacturing cost of the microchips also increase in proportion to this, which may be a barrier to industrial use.

The present invention provides a particle separation apparatus and a method thereof for improving the particle separation processing amount per unit time while utilizing the same separation principle as HDF and being simpler and lower cost.

In view of the above problems, the present invention improves the simple flow path structure by lengthening the flow path width 51 in the z-axis direction, so that the amount of particle separation processing is substantially proportional to the length of the flow path width 51 in the z-axis direction. It was made with a focus on improvement.

Therefore, from the above viewpoint, the present invention relates to the following.
[1] Formed from at least two sets of two opposing walls, fluidly connected to at least one fluid inlet at one end and fluidly connected to at least one fluid recovery port at the other end. Main flow path and
At least one branch flow path that branches from one wall surface of the main flow path and is fluidly connected to at least one fluid recovery port at the end.
It is a particle separation device including
(1) The branch port formed at the branch point of the main flow path and the branch flow path is continuously or intermittently located over the flow path width on the wall surface of the main flow path in which the branch port is formed. (2) The branch flow. By appropriately adjusting the shape and size of the branch port of the road and the length of the branch flow path, the branch flow path is provided so that particles having a size larger than a certain size do not flow in.
(3) The flow path width on the wall surface of the main flow path provided with the branch port is longer than the distance between the wall surface of the main flow path provided with the branch port and the wall surface of the main flow path facing the wall surface of the main flow path provided with the branch port. The particle separation device, characterized in that.
[2] The branch flow path is characterized in that at least two or more branch flow paths are present, each end of the branch flow path joins the merging flow path, and the merging flow path has one or more fluid recovery ports. The particle separation device described above.
[3] The particle separation device according to the above description, wherein any one or both of the two sets of facing wall surfaces of the merging flow path expands along the downstream direction with respect to the fluid flow. ..
[4] The particle separation device according to the above description, wherein the length of the branch flow path in the z-axis direction is substantially the same as the length of the main flow path in the z-axis direction.
[5] The particle separation device according to the above description, wherein the branch flow path is composed of a plurality of pillar shapes.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a particle separation apparatus and a method thereof that achieves a simpler, lower cost and higher particle separation processing amount while utilizing the same separation principle as HDF. This makes it possible to achieve both precise separation by particle size and high particle separation processing amount, which was difficult in the past.

FIG. 1 is a diagram schematically showing a state of particle separation in the present invention, FIG. 1 (a) is a schematic view of an xy plane cross section in which particles are separated, and FIG. 1 (b) is x. -Z is a schematic view of a plane cross section. FIG. 2A is a perspective schematic view of a structure including an embodiment of a particle separation device and a method thereof according to an embodiment of the present invention. FIG. 2B shows the structure of a bird's-eye view of the xz plane. 2 (b-1) to 2 (b-3) show a structure in which the arrangement of the main flow path fluid introduction port 12 and the main flow path fluid recovery port is changed. A configuration excluding the fluid introduction port relay flow path 14 and the fluid recovery port relay flow path 15 (FIG. 2 (b-2)), and a configuration excluding the fluid introduction port expansion channel 16 and the fluid recovery port expansion flow path 17 (FIG. 2 (b-2)). FIG. 2b-3) is shown. FIG. 2C shows a schematic perspective view of a substrate forming the main flow path and a substrate forming the branch flow path, respectively. FIG. 3A is a perspective schematic view of the structure shown in FIG. 2 in which the merging flow path is connected to the end of the branch flow path. FIG. 3C shows a schematic perspective view of a substrate forming a main flow path, a substrate forming a branch flow path, and a substrate forming a merging flow path, respectively. FIG. 4 is a perspective schematic view of the structure shown in FIG. 2 when a pillar structure is used as the branch flow path. FIG. 5 is a perspective schematic view of the structure shown in FIG. 4, in which the merging flow path is connected to the end of the branch flow path. FIG. 6 is a diagram showing an outline of the separation principle of HDF.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, the present invention can be implemented in many different embodiments, and is not limited to the examples of the embodiments and examples shown below.

FIG. 2 shows a schematic diagram of a microchip provided with an embodiment of the particle separation device and method according to the present invention. The x-axis direction shown in FIG. 2 indicates the direction in which the fluid in the main flow path 100 flows, and is parallel to the wall surface of the main flow path provided with the branch port of the branch flow path and perpendicular to the direction in which the fluid in the main flow path 100 flows. Is the z-axis direction, and the direction orthogonal to the x-axis and the z-axis is the y-axis direction. In the first embodiment, the branch flow path can be formed in the y-axis direction, whereby the branch flow path is orthogonal to the main flow path.

In the first embodiment, the main flow path 100 is a space surrounded by a set of facing wall surfaces 10a and 10b parallel to the xy plane and a set of facing wall surfaces 11a and 11b parallel to the xy plane. Suppose that it has. At this time, the present invention is characterized in that the flow path width 51 in the z-axis direction is longer than the flow path width 50 in the y-axis direction, and is at least 3 times longer, preferably 5 times or more longer, more preferably. Is preferably 10 times or more longer. In the present invention, the flow path width on the wall surface of the main flow path in which the branch port is formed refers to the distance between the main flow path wall surfaces intersecting the wall surface, and in one embodiment, refers to the flow path width 51 in the z-axis direction. In the present invention, the distance between the wall surface of the main flow path provided with the branch port and the wall surface of the main flow path facing the wall surface of the main flow path provided with the branch port refers to the flow path width 50 in the y-axis direction.

At one end of the main flow path of the particle separator of the present invention, it is fluidly connected to at least one fluid inlet, and at the other end it is fluidly connected to at least one fluid recovery port. Fluidly connected means that when the fluid is placed in the flow path, the fluid is connected without leaking. By being surrounded by the wall surface on the terminal side, it is fluidly connected to the fluid inlet or fluid recovery port. A relay flow path or an expansion flow path may be provided for connecting the main flow path to the fluid introduction port or the fluid recovery port.

The flow path structure of the main flow path 100 in FIG. 2 has a rectangular cross-sectional shape in the yz plane at any point, and the flow path width 50 is uniform. Further, a pillar structure may be provided in the main flow path as needed so that the length of the flow path width 50 is constant. The cross-sectional shape of the pillar (xz plane cross-sectional shape) is preferably rectangular or substantially circular from the viewpoint of ease of structure fabrication, but polygonal or amorphous shapes may be used. However, it is assumed that the pillar structure exists in contact with the wall surface of the main flow path parallel to the xz plane in FIG.

The cross-sectional shape of the main flow path (yz plane in FIG. 2) is preferably rectangular because of the ease of manufacturing the flow path structure, but the cross section may be circular, elliptical, polygonal, or the like. It may have a shape other than a rectangular shape, and may be partially formed. Similarly, the flow path width 50 in the flow path structure of the main flow path 100 is preferably constant because of its ease of manufacture, but the depth may be partially different. On the other hand, if you want to send the fluid downstream more accurately, you can suppress the backflow to the flow path into which the sample liquid is introduced, or suppress the backflow to the flow path where the sample liquid is introduced, by providing a structure with partially different depths and adjusting the pressure loss. Since it is possible to suppress flow rate fluctuations caused by external factors such as pressure, it may be preferable to provide a structure having partially different depths.

As shown in FIG. 2B-1, the shape of the xz plane of the main flow path 100 (that is, the shape when viewed from the y-axis direction) is the fluid introduction port 12, the fluid introduction port relay flow path 14, and the fluid introduction. It may be composed of a port expansion flow path 16, a separation flow path 18, a fluid recovery port expansion flow path 17, a fluid recovery port relay flow path 15, and a fluid recovery port 13, but for the sake of simplification of the flow path structure, the fluid may be composed. The introduction port relay flow path 14 and the fluid recovery port relay flow path 15 may be deleted (FIG. 2 (b-2)), and the fluid introduction port expansion flow path 16 and the fluid recovery port expansion flow path 17 may be deleted. It may be good (Fig. 2 (b-3)).

Here, the fluid introduction port and the fluid recovery port may have any shape, and as an example, a rectangle or a substantially circular shape may be used in addition to the circular shape shown in FIG. The fluid inlet may be any as long as it has a function of holding the fluid introduced from the outside of the microchip, and the fluid recovery port may be any as long as it has a function of discharging or recovering the fluid to the outside of the microchip.

The fluid introduction port relay flow path may be a flow path that fluidly connects the fluid introduction port and the fluid introduction port expansion flow path. For example, the distance between a set of facing wall surfaces parallel to the xy plane is , It is preferable that the diameter is the same as or smaller than the diameter of the fluid inlet.

The fluid recovery port relay flow path may be a flow path that fluidly connects the fluid recovery port and the fluid recovery port expansion flow path, and for example, the distance between a set of facing wall surfaces parallel to the xy plane is , It is preferable that the diameter is the same as or smaller than the diameter of the fluid recovery port.

The fluid introduction port expansion flow path may play a role of causing the fluid flowing in from the fluid introduction port or the fluid introduction port relay flow path to flow out to the separation flow path, and as shown in FIG. 2, the flow path gradually flows downstream. The width 51 may be expanded, or a flow path structure that branches toward the downstream may be used.

The fluid recovery port expansion flow path may play a role of allowing the fluid to flow out to the fluid recovery port or the fluid recovery port relay flow path, and as shown in FIG. 2, even if the flow path width 51 gradually decreases toward the downstream side. Often, a flow path structure in which the branches merge toward the downstream may be used.

Here, the above-mentioned branching structure is a structure consisting of one or more branch portions for uniformly introducing the fluid into the flow path in the microchip, and the one having more branch portions introduces the fluid uniformly into the flow path. Therefore, it is preferable to adjust the number of branches according to the width of the flow path. This is generally based on the phenomenon that the flow velocity distribution differs between the vicinity of the wall surface and the center of the flow path in the flow path having a structure in which at least one or more lengths in the x, y, and z axis directions in FIG. 2 have a micro to millimeter level structure. As long as it is a measure and achieves the purpose of uniformly introducing the fluid, it is not always necessary to use the branched structure, another structure may be used, and for example, one or more pillar structures may be provided. ..

The branch flow path 101 is formed by branching from the wall surface of 1 of the main flow path. A branch port is formed at the contact portion between the main flow path and the branch flow path. In one embodiment, it has a space surrounded by a set of facing wall surfaces 20a and 20b parallel to the yz plane and a set of facing wall surfaces 21a and 21b parallel to the xy plane, and has a branched flow. It is assumed that any end of the path is fluidly connected to the main flow path (Fig. 2). As a result, the branch ports formed at the branch points of the main flow path and the branch flow path are continuously located over the flow path width on the wall surface of the main flow path in which the branch port is formed. At this time, the present invention is characterized in that the flow path width 61 in the direction parallel to the xy plane is longer than the flow path width 60 in the direction parallel to the xy plane, and is preferably at least three times longer. Is 5 times or more longer, more preferably 10 times or more. Further, it is preferable that the flow path width 61 of the branch flow path has the same length as the flow path width 51 of the main flow path.

As shown in FIG. 2, it is desirable that the cross section of the xz plane of the branch flow path is rectangular because of the ease of manufacturing the flow path structure, but the cross section of the branch flow path may be circular, elliptical, polygonal, or the like. It may have a shape other than a rectangular shape, and may be partially formed. Similarly, the cross section of the xy plane is preferably rectangular, but it may be a circular, elliptical, polygonal, or other cross section, or it may be partially non-rectangular.

Of the ends of the branch flow path 101, the end on the side that is not fluidly connected to the main flow path may be an open system as shown in FIG. 2, and is fluidly connected to any of the recovery means. May be.

It is preferable to provide at least one branch flow path 101, and it is more preferable to provide a plurality of branch flow paths 101 in order to increase the purity of the sample after separation.

By adjusting the shape and size of the branch port of the branch flow path and the length of the branch flow path, the flow rate in the branch flow path can be adjusted. The diameter of the particles flowing into the branch flow path can be controlled by the flow rate in the branch flow path and the flow rate ratio downstream of the main flow path. In the embodiment in which the branch flow path is orthogonal to the main flow path, the shape and size of the branch port are determined by adjusting the length in the x and z axis directions, and the length in the y-axis direction of the branch flow path is adjusted. By doing so, the length of the branch flow path can be adjusted. The larger the shape and size of the branch port, the larger the amount of inflow to the downstream of the branch flow path. The longer the length of the branch flow path, the smaller the amount of inflow into the branch flow path.

In an embodiment in which the branch flow path is orthogonal to the main flow path and a plurality of branch flow paths 101 are provided, at least one of the lengths of each branch flow path in the x, y, and z axis directions is appropriate. It is necessary to be designed so that particles having a size larger than a certain size do not flow in by being adjusted to, and the lengths of multiple branch flow paths in the x, y, and z axis directions are different from each other. (That is, when there is a branch flow path A and another branch flow path B, the length of the branch flow path A in the x-axis direction and the length of the branch flow path B in the x-axis direction may be different. good).

Further, in an embodiment in which a plurality of branch flow paths 101 exist, any one or all of the ends on the side not fluidly connected to the main flow path of each branch flow path 101 are fluidly connected by the merging flow path 19. , Particles flowing in the branch flow path may be collected together. In this case, since the total number of fluid recovery ports is reduced as compared with the aspect of FIG. 2, it is preferable in that the structure of the entire device structure can be simplified.

Further, in the above-mentioned merging flow path, the distance between a set of facing wall surfaces parallel to the xy plane or the xx plane gradually or gradually increases as the merging flow path moves toward the fluid recovery port side of the merging flow path, that is, downstream. It may be expanded stepwise, and may be gradually or stepwise reduced in some cases.

In addition to the rectangular parallelepiped structure shown in FIG. 2, the branch flow path 101 may use the pillar structure shown in FIG. In this case, the cross-sectional shape of the pillar (x-z plane cross-sectional shape) is preferably rectangular or substantially circular from the viewpoint of ease of structure fabrication, but polygonal or amorphous shapes may be used. However, it is assumed that the pillar structure exists in contact with the wall surface of the main flow path parallel to the xz plane. As a result, the branch port formed at the branch point of the main flow path and the branch flow path is intermittently located over the flow path width on the wall surface of the main flow path in which the branch port is formed.

Similarly, when the branch flow path 101 having a pillar structure is used, any one or all of the ends on the side not fluidly connected to the main flow path of each branch flow path 101 are fluidly connected by the merging flow path. , Particles flowing in the branch flow path may be collected together (FIG. 5). Similarly in this embodiment, the above-mentioned merging flow path is the distance between a set of facing wall surfaces parallel to the xy plane or the xy plane as the merging flow path advances toward the fluid recovery port side of the merging flow path, that is, downstream. May be gradually or gradually expanded, and in some cases may be gradually or gradually reduced.

Further, the branch flow paths 101 described so far extend in a direction orthogonal to the x-axis and parallel to the y-axis, that is, both when the main flow path 100 and the branch flow path are viewed from a bird's-eye view on the xy plane. Although only those having a flow path angle of 90 ° are described, the two flow paths may be fluidly connected at an angle of more than or less than that.

The microchip described in the present invention is a microchip for separating particles according to their size and using an appropriate recovery system to separate the particles in the sample liquid by particle size, for example, PDMS. It may have a structure on a flat plate formed of a polymer material such as, or a material such as glass or metal which is hard and has little bending.

Here, the recovery system is a structure or mechanism used for recovering separated particles. For example, the fluid recovery port in FIG. 2 corresponds to a resin-made or metal-made pipe connected to the fluid recovery port. Also included is a container for collecting the separated particles. Further, a container for collecting separated particles may be prepared at the outlet on the downstream side of the pipe. At this time, the distribution ratio of the fluid flowing into the two fluid recovery ports may change due to the resistance of the fluid passing through the fluid recovery port or the pipe, so that the inner diameter of the fluid recovery port or the pipe is changed. , It is preferable to adjust the length as appropriate.

As a technique used when manufacturing a microchip, for example, a manufacturing technique using a mold such as molding or embossing is preferable in that a flow path structure can be manufactured accurately and easily, but in addition, photolithography, It is also possible to use 3D printer manufacturing techniques such as soft lithography, wet etching, dry etching, nanoimprinting, laser processing, direct electron beam drawing, and machining. However, when the mold and the flow path are manufactured by general photolithography, the aspect ratio (structural depth / structural width; where the structural depth here is defined as the progress of ultraviolet light that exposes the resist in photolithography). The structural length in the direction is the structural depth, and the structural length in the direction perpendicular to the traveling direction is the structural width.) High-precision micromachining technology is required to produce structures of 3 or more, and the flow path Since the manufacturing operation becomes complicated and leads to an increase in cost, the main flow path is set as the first layer and the branch flow path is set as the second layer so that the microchip can be configured even with a low aspect ratio structure, and these are laminated. The structure may be used. For example, in the case of the structure shown in FIG. 2, as shown in FIG. 2C, the first layer having a main flow path and the second layer having a plurality of through structures serving as branch flow paths are laminated. However, in the case of the structure shown in FIG. 3, as shown in FIG. 3 (b), the first layer having the main flow path, the second layer having a plurality of through structures serving as branch flow paths, and the merging flow path. It may be configured by laminating the third layer having. Further, when the branch flow path is used as a pillar structure as shown in FIG. 4, the above-mentioned through structure may be formed into a pillar structure, and a third layer having a merging flow path may be laminated as the third layer. The configuration of 5 may be used.

Further, various polymer materials such as PDMS and acrylic can be used as the material for producing the microchip, and any two types of substrates among these materials can be used in combination. .. However, it is preferable to use a polymer material in order to inexpensively produce the flow path itself and provide a disposable device.

Subsequently, the separation principle of the present invention will be described in detail with reference to FIG.
In particle separation in HDF, whether particles introduced from the upstream of the main flow path flow directly to the downstream of the main flow path or flow into the branch flow path are determined by (1) particle diameter (2) of the particles. It depends on where the center of gravity is located in the main flow path. That is, the particles having the position of the center of gravity of the particles between the boundary line 80 shown in FIG. 6 and the main flow path wall surface 10a on the side where the branch flow path 101 exists are sent to the branch flow path, and the other particles are on the main flow path side. Inflow to. Here, in the case of particles in which the position of the center of gravity of the particles exists between the boundary line 80 and the wall surface 10a of the main flow path on the side where the branch flow path 101 exists, the position of the center of gravity of the particles can exist closer to the wall surface. Since the particles have a small diameter and the position of the center of gravity of the particles having a large diameter cannot exist near the wall surface, they can be separated by the diameter of the particles themselves as shown in FIG. 6 (boundary line 80 and branch flow path). Assuming that the distance between the main flow path wall surface 10a on the side where 101 exists is w1, the particles flowing into the branch flow path have a radius smaller than w1). As a matter of course, particles having a small diameter having a center of gravity between the boundary line 80 and the main flow path wall surface 10b on the side where the branch flow path 101 does not exist flow as they are to the downstream of the main flow path and are not separated. It is possible to increase the purity of the particles to be separated by repeatedly separating the particles by providing a plurality of branch flow paths or reciprocating the flow of the main flow path.

Here, the boundary line 80 will be described. The velocity distribution in the microchannel under the laminar flow condition shows a parabolic velocity distribution as shown in FIG. 6 in the case of pressure feeding. At this time, assuming that the half value of the flow path width 50 in the main flow path 100 y-axis direction is r, the parabolic function u (r) is the Hagen-Poiseuil equation when the cross section of the yz plane of the main flow path 100 is a circular tube. From Assuming that the flow rate flowing downstream of the main flow path is Qm and the flow rate flowing downstream of the branch flow path is Qb, the relationship of Sb: Sm = Qb: Qm is established. Therefore, by adjusting the ratio of Qb and Qm, the position of the boundary line 80 can be adjusted, which makes it possible to control the diameter of the particles flowing into the branch flow path 101. Here, as described above, the flow rate Qm flowing downstream of the main flow path and the flow rate Qb flowing downstream of the branch flow path are the shape and size of the branch port of the main flow path 100 or the branch flow path 101, and the branch flow path. Since it is adjusted by length, it should be adjusted appropriately according to the diameter of the particles to be separated. In the embodiment in which the branch flow path is orthogonal to the main flow path, the shape and size of the branch port are determined by adjusting the length of the branch flow path in the x and z axis directions, and the length of the branch flow path in the y-axis direction is determined. By adjusting the diameter, the length of the branch flow path can be adjusted.

As a method of adjusting the introduction amount to achieve the flow rate condition inside the flow path, it is convenient and preferable to introduce the solution from the introduction port using a syringe pump or the like, but a method using another pump such as a perista pump is preferable. It is also possible to use a constant pressure liquid feeding method using a cylinder, a pressure device, or the like, a method using a liquid level difference, a liquid feeding method using an electroosmotic flow, centrifugal force, or the like. It is also possible to use a pressure device that applies negative pressure from the fluid recovery port.

In order to achieve stable and efficient separation of particles, it is desirable to maintain a stable laminar flow in the flow path. Specifically, the particles are fed under conditions where the Reynolds number is 2300 or less. The liquid operation is preferable, and the condition of 1000 or less is more preferable.

As the particles to be separated, polymer particles such as polystyrene, metal fine particles, ceramic particles, or particles whose surface is physically or chemically treated can be used, depending on the purpose. Further, in the present invention, since the force exerting external pressure or deformation on the particles is small, the particles and cells that burst or break in the conventional separation method such as a filter, and biological particles such as organella which are the constituents thereof. , Viruses, bacteria, extracellular vesicles such as exosomes, proteins, and protein aggregates can be treated. If the maximum diameter of the particles to be classified is less than the length in the y-axis direction of the main flow path in the microchip, particles of any size can be separated. For example, when a flow path having a length of the main flow path in the y-axis direction of 100 μm is used, the maximum diameter of the separated particles is less than 100 μm.

As the fluid in which the particles are suspended, any liquid or gas can be used, and various solutions can be used depending on the purpose. For example, when polymer particles or metal particles are used as particles, an organic solution, an ionic fluid, or the like can be used in addition to an aqueous solution containing various chemical substances. Further, when biological particles such as cells are used as particles, it is preferable to use an aqueous solution isotonic with cells such as a cell culture solution or a physiological buffer solution. However, cells that are resistant to relatively hypotonic or hypertonic solutions, such as bacteria and plant cells, do not necessarily have to be isotonic. Further, for convenience of operation, a system in which the difference between the density of the solution and the density of the particles is not large is more preferable. With respect to the viscosity of the fluid, a system having a small difference in these viscosities is more preferable, but a system capable of processing particles may have a difference in viscosity.

10a, b Main flow path wall surface (parallel to xz plane)
11a, b Main flow path wall surface (parallel to xy plane)
12 Main flow path Fluid introduction port 13 Main flow path Fluid recovery port 14 Fluid introduction port Relay flow path 15 Fluid recovery port relay flow path 16 Fluid introduction port expansion flow path 17 Fluid recovery port expansion flow path 18 Separation flow path 19 Confluence flow path 20a, b Branch flow path wall surface (parallel to the xz plane)
21a, b Branch flow path wall surface (parallel to xy plane)
30 Recovery flow path 50 Main flow path width parallel to the xy plane 51 Main flow path width parallel to the xy plane 60 Branch flow path width parallel to the xy plane 61 Parallel to the xy plane Branch flow path width 80 Boundary line 100 Main flow path 101 Branch flow path 300a, 300b Particle 500 region

Claims (5)

A main flow path formed from at least two sets of two opposing walls, fluidly connected to at least one fluid inlet at one end and fluidly connected to at least one fluid recovery port at the other end. When,
At least one branch flow path that branches from one wall surface of the main flow path and is fluidly connected to at least one fluid recovery port at the end.
It is a particle separation device including
(1) The branch port formed at the branch point of the main flow path and the branch flow path is continuously or intermittently located over the flow path width on the wall surface of the main flow path in which the branch port is formed. (2) The branch flow. By appropriately adjusting the shape and size of the branch port of the road and the length of the branch flow path, the branch flow path is provided so that particles having a size larger than a certain size do not flow in.
(3) The flow path width on the wall surface of the main flow path provided with the branch port is longer than the distance between the wall surface of the main flow path provided with the branch port and the wall surface of the main flow path facing the wall surface of the main flow path provided with the branch port. The particle separation device, characterized in that. Claim 1 is characterized in that there are at least two branch flow paths, each end of the branch flow path merges with the merging flow path, and the merging flow path has one or more fluid recovery ports. The particle separator according to the above. The particle separation apparatus according to claim 2, wherein any one or both of the two sets of facing wall surfaces of the merging flow path expands along the downstream direction with respect to the flow of the fluid. .. The particle separation device according to any one of claims 1 to 3, wherein the length of the branch flow path in the z-axis direction is substantially the same as the length of the main flow path in the z-axis direction. The particle separation device according to any one of claims 1 to 4, wherein the branch flow path is composed of a plurality of pillar shapes.

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