Separation chip

Abstract

This technology provides a method for achieving a desired combination of particle type and liquid type within a separation chip for dielectrophoresis. [Solution] The separation chip 1 includes a first injection channel 31 into which a sample solution containing a first liquid and multiple types of particles is injected, a second injection channel 32 into which a second liquid is injected, a third injection channel 33 into which a third liquid is injected, a first replacement section 40, a separation and extraction section 50, and a second replacement section 60. The upstream end of the first replacement section 40 is connected to the first injection channel 31 and the second injection channel 32, and it removes the first liquid from the sample solution and mixes it with the second liquid. The separation and extraction section 50, downstream of the first replacement section 40, separates the target particle-containing solution containing the target particles and the target particle-free solution containing the target particles by dielectrophoresis, and branches them into two downstream branched channels. The upstream end of the second replacement section 60 is connected to the third injection channel 33 and one of the branched channels, and it removes the liquid component of the target particle-containing solution from the target particle-containing solution and mixes it with the third liquid.

Description

Technical Field

[0001] The present invention relates to a separation chip that separates minute dielectric particles by dielectrophoresis.

Background Art

[0002] Conventionally, as a method for separating and concentrating rare cells such as circulating tumor cells (CTC) in blood in a label-free and non-damaging manner, there are a hydro-dynamic filtration method (Hydro-Dynamic Filtration, HDF) and a separation chip using dielectrophoresis. A conventional separation chip is described in, for example, Patent Document 1.

[0003] The separation chip described in Patent Document 1 has an HDF unit that performs a hydro-dynamic filtration method and a DEP unit that performs dielectrophoresis (DEP). In the HDF unit, a sample liquid containing particles and a buffer liquid are caused to flow into a main flow path so as to form a laminar flow, and a plurality of fine branch flow paths are provided on the sample liquid side, whereby the liquid component and the fine particles in the sample liquid are discharged from the main flow path. As a result, on the downstream side of the HDF unit, particles having a predetermined size or more in the sample liquid are included in the buffer liquid flow. That is, in the HDF unit, fine particles are removed and the liquid in the sample liquid is replaced with a buffer liquid suitable for dielectrophoresis. Thereafter, in the DEP unit, particles having specific electrical characteristics are induced by dielectrophoresis to separate and recover desired types of particles.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the separation chip described in Patent Document 1, there are limitations on the types of particles and liquids that can be obtained, such as the target particles being contained in the surrounding medium (liquid) for dielectrophoresis. Therefore, there was a problem in that it was not possible to obtain a desired combination of particle types and liquid types with a single chip.

[0006] This invention has been made in view of these circumstances, and aims to provide a technology that allows for a desired combination of particle type and liquid type within a separation chip for dielectrophoresis. [Means for solving the problem]

[0007] To solve the above problems, the first invention of the present application is a separation chip for separating target particles from a sample solution containing a first liquid and a plurality of types of particles, comprising: a first injection channel into which the sample solution is injected; a second injection channel into which a second liquid is injected; a third injection channel into which a third liquid is injected; a first replacement section whose upstream end is connected to the first and second injection channels, and which removes the first liquid from the sample solution and mixes it with the second liquid; a separation and extraction section located downstream of the first replacement section, which separates the sample solution into a target particle-containing solution containing the target particles and a target particle-free solution containing the target particles by dielectrophoresis, and branches it into two branched channels provided downstream; and a second replacement section whose upstream end is connected to either one of the branched channels and the third injection channel, and which removes the liquid component of the target particle-containing solution from the target particle-containing solution and mixes it with the third liquid.

[0008] The second invention of the present application is a separation chip of the first invention, wherein the first replacement section has a first main flow path through which the sample liquid and the second liquid flow in a laminar flow, with the connection portion to the first injection passage and the connection portion to the second injection passage aligned in the width direction at the upstream end; a plurality of first sub-flow paths whose upstream ends are connected to the side of the first main flow path on the first injection passage side; and a first discharge passage connected to the downstream ends of the plurality of first sub-flow paths.

[0009] The third invention of this application is a separation chip according to the first or second invention, wherein the second replacement section has a second main flow path through which the target particle-containing liquid and the third liquid flow in a laminar flow, with the connection portion to the third injection passage and the connection portion to one of the branch flow paths aligned in the width direction at the upstream end; a plurality of second sub-flow paths whose upstream ends are connected to the side of the second main flow path on the branch flow path side; and a second discharge passage connected to the downstream ends of the plurality of second sub-flow paths.

[0010] The fourth invention of this application is a separation chip according to any one of the first to third inventions, wherein the separation extraction unit has a separation channel whose upstream end is connected to the downstream end of the first replacement unit, two pairs of comb-shaped electrodes arranged on the separation channel at an angle to the flow direction of the separation channel and facing each other, and two branch channels that branch off from the downstream end of the separation channel downstream of the comb-shaped electrodes.

[0011] The fifth invention of this application is a separation chip according to any one of the first to fourth inventions, wherein the third liquid is the same liquid as the first liquid.

[0012] The sixth invention of this application is a separation chip according to any one of the first to fourth inventions, further comprising a plurality of third sub-channels connected to the side of the first injection channel upstream of the second replacement section, the third injection channel being connected to the downstream end of the plurality of third sub-channels, and the third liquid being a liquid containing the first liquid separated from the first injection channel.

[0013] The seventh invention of this application is a separation chip according to any one of the first to fourth inventions, wherein the third injection channel is a channel branched from the first injection channel, and the third liquid is the sample liquid branched from the first injection channel. [Effects of the Invention]

[0014] According to the first to seventh inventions of this application, the liquid component of the liquid containing the target particles after dielectrophoresis can be replaced with a desired liquid within a separation chip for dielectrophoresis. [Brief explanation of the drawing]

[0015] [Figure 1] It is a top view of the separation chip according to the first embodiment. [Figure 2] It is a top view of the separation chip according to the second embodiment. [Figure 3] It is a top view of the separation chip according to the third embodiment. [Figure 4] It is a top view of the separation chip according to the fourth embodiment. [Figure 5] It is a top view of the separation chip according to the fifth embodiment. [Figure 6] It is a top view of the separation chip according to the sixth embodiment. [Figure 7] It is a top view of the separation chip according to the seventh embodiment. [Figure 8] It is a top view of the separation chip according to the eighth embodiment.

Mode for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0017] <1. First Embodiment> FIG. 1 is a top view of the separation chip 1 according to the first embodiment. This separation chip 1 is a separation chip for separating target particles from a raw sample liquid containing a plurality of types of particles including the target particles and obtaining an adjusted sample liquid in which the target particles are suspended in a desired dispersion medium. The raw sample liquid is, for example, blood, the target particles are, for example, circulating tumor cells (CTC) in the blood, and the desired dispersion medium is, for example, a culture medium. As another example, the target particles may be, for example, other cells or microorganisms, and the desired dispersion medium may be, for example, seawater, physiological saline, pure water, a chemical, a sample liquid, or a sample liquid from which unnecessary particles have been removed.

[0018] The separation chip 1 is a plate-like device in which a flow path for liquid to flow is provided inside a plate-like main body 10. The main body 10 is composed of, for example, a transparent substrate. The main body 10 is composed of an upper layer, a middle layer, and a lower layer. Each flow path described later is formed by the middle layer becoming a cavity. Also, each injection port, each discharge port, and the sample acquisition port described later are formed by the upper layer and the middle layer becoming cavities, and are communicatively connected to any one of the flow paths formed in the middle layer.

[0019] As shown in FIG. 1, the separation chip 1 has a first injection port 21, a second injection port 22, a third injection port 23, a first injection path 31, a second injection path 32, a third injection path 33, a first replacement part 40, a separation and extraction part 50, a second replacement part 60, and a target particle collection port 90.

[0020] In the present embodiment, in the separation chip 1, the liquid flows from the left side to the right side in FIG. 1. That is, the longitudinal direction of the separation chip 1 is the flow path direction in which the liquid flows, the left side in FIG. 1 is the upstream side, and the right side is the downstream side. The flow path direction does not necessarily have to be the longitudinal direction of the separation chip 1. Hereinafter, when referring to the "width direction" with respect to the flow path, the direction orthogonal to the direction in which the flow path extends is referred to as the "width direction". In the drawings and the description of the following embodiments, one side in the longitudinal direction of the separation chip 1 is the upstream side, the other side is the downstream side, one side in the short-side direction of the separation chip 1 is the one side in the width direction, and the other side is the other side in the width direction.

[0021] In this separation chip 1, for a raw sample liquid in which a plurality of types of particles are suspended in a first liquid, the first liquid is removed in the first replacement part 40 and replaced with a second liquid that is a buffer solution for dielectrophoresis, to obtain a sample liquid for dielectrophoresis in which a plurality of types of particles are suspended in the buffer solution. That is, the sample liquid for dielectrophoresis is one in which a plurality of particles including target particles are suspended in the buffer solution.

[0022] Next, in the separation and extraction unit 50, dielectrophoresis is performed on the sample solution for dielectrophoresis to separate the predetermined particles. This separates the buffer solution into one containing the predetermined particles and another containing particles other than the predetermined particles. Then, in the second replacement unit 60, the buffer solution is removed from the suspension containing the target particles to be extracted from the two separated suspensions and replaced with the third solution to be used in the next step. This makes it possible to obtain a prepared sample solution in which the target cells are suspended in the third solution.

[0023] The first inlet 21 is a location for injecting the raw sample solution into the separation tip 1. The raw sample solution is a first solution in which multiple types of particles are suspended. The first inlet 21 is a cylindrical recess provided in the upper and middle layers of the main body 10. The first inlet 21 is connected to the upstream end of the first injection channel 31.

[0024] The shape of the first inlet 21 is not limited to the shape described above. It does not have to be cylindrical, and it does not have to open upwards, but may open downwards or horizontally, or in any other direction, as long as it can communicate with the first injection passage 31 and the outside. The same applies to the second inlet 22, the third inlet 23, the first outlet 44, the separation outlet 55, the second outlet 64, and the target particle collection port 90, which will be described later.

[0025] The second injection port 22 is a location for injecting the second liquid into the separation chip 1. The second liquid is a buffer solution for dielectrophoresis. The second injection port 22 is a cylindrical recess provided in the upper and middle layers of the main body 10. The second injection port 22 is connected to the upstream end of the second injection channel 32.

[0026] The third injection port 23 is a location for injecting the third liquid into the separation tip 1. The third liquid is the dispersion medium for the final prepared sample solution. The third injection port 23 is a cylindrical recess provided in the upper and middle layers of the main body 10. The third injection port 23 is connected to the upstream end of the third injection channel 33.

[0027] The first injection channel 31 is a flow path for injecting the raw sample liquid from the first injection port 21 to the first replacement section 40. The first injection channel 31 is a cavity provided in the middle layer of the main body 10. The upstream end of the first injection channel 31 is connected to the first injection port 21. The downstream end of the first injection channel 31 is connected to the upstream end of the first main flow path 41 of the first replacement section 40, which will be described later.

[0028] The second injection channel 32 is a flow path for injecting buffer liquid from the second injection port 22 to the first replacement section 40. The second injection channel 32 is a cavity provided in the middle layer of the main body 10. The upstream end of the second injection channel 32 is connected to the second injection port 22. The downstream end of the second injection channel 32 is connected to the upstream end of the first main flow path 41 of the first replacement section 40, which will be described later.

[0029] The third injection channel 33 is a flow path for injecting the third liquid from the third injection port 23 to the second replacement section 60. The third injection channel 33 is a cavity provided in the middle layer of the main body 10. The upstream end of the third injection channel 33 is connected to the third injection port 23. The downstream end of the third injection channel 33 is connected to the upstream end of the second main flow path 61 of the second replacement section 60, which will be described later.

[0030] The first replacement section 40 is a part for removing the first liquid from the original sample solution and mixing it with the second liquid, which is the buffer solution. That is, in the first replacement section 40, the first liquid in the original sample solution is replaced with the second liquid. In this application, "removal" does not mean removing all of it, but rather removing 50% by volume or more. Similarly, "replacement" does not mean replacing the liquid components completely, but rather replacing 50% by volume or more of the liquid components. The first replacement section 40 has a first main flow path 41, a plurality of first sub-flow paths 42, a first discharge path 43, and a first discharge port 44.

[0031] The first main channel 41 is a cavity located in the middle layer of the main body 10. At the upstream end of the first main channel 41, the connection point to the first injection channel 31 and the connection point to the second injection channel 32 are aligned in the width direction. As a result, the original sample liquid and the second liquid flow laminarly within the first main channel 41.

[0032] It should be noted that the connection points between the two flow paths being "aligned in the width direction" does not necessarily mean that the connection points between the two flow paths (in this case, the first injection channel 31 and the second injection channel 32) are arranged symmetrically in the width direction, as shown in Figure 1. In this application, with respect to the downstream flow path, the connection points between the two upstream flow paths being "aligned in the width direction" means that laminar flow aligned in the width direction can be obtained within the downstream flow path. For example, the first injection channel 31 and the first main flow path 41 may be connected in a straight line, and the second injection channel 32 may be connected in a T-shape at the connection point from a direction perpendicular to the first injection channel 31 and the first main flow path 41. Even in that case, in the width direction of the first main flow path 41, the second liquid flows on the side to which the second injection channel 32 is connected, and the raw sample liquid flows on the opposite side, as laminar flow aligned in the width direction.

[0033] In this embodiment, one half of the upstream end of the first main channel 41 is connected to the downstream end of the first injection channel 31, and the other half is connected to the downstream end of the second injection channel 32. As a result, the raw sample liquid flows laminarly in one side of the first main channel 41, and the buffer liquid flows laminarly in the other side.

[0034] Each of the first sub-channels 42 is a cavity located in the middle layer of the main body 10, extending in a direction perpendicular to the first main channel 41. The width of the first sub-channel 42 is smaller than the width of the first main channel 41. The upstream end of the first sub-channel 42 is connected to the side of the first main channel 41 on the first injection channel 31 side. In this embodiment, the upstream end of the first sub-channel 42 is connected to the side of the first main channel 41 on one side in the width direction.

[0035] The first discharge channel 43 is a cavity located in the middle layer of the main body 10. The first discharge channel 43 is connected to the downstream end of a plurality of first sub-channels 42.

[0036] The first outlet 44 is a part for discharging the liquid separated in the first replacement section 40. The first outlet 44 is a cylindrical recess provided in the upper and middle layers of the main body 10. The first outlet 44 is connected to the downstream end of the first discharge passage 43.

[0037] The first replacement section 40 removes the first liquid from the raw sample liquid using hydrodynamic filtration (HDF) and mixes in the second liquid. In the first main channel 41, particles in the raw sample liquid move downstream along one side wall in the width direction. At the connection point with the first sub-channel 42, fluid at a certain distance from the side wall of the first main channel 41 to which the first sub-channel 42 connects flows into the first sub-channel 42. As a result, small diameter particles with their center of gravity closer to the side wall than this set certain distance flow into the first sub-channel 42. On the other hand, large diameter particles with their center of gravity further away from the side wall than this certain distance travel straight along the flow direction of the first main channel 41. Therefore, particles of a size that can pass through the first sub-channel 42 do not necessarily flow into the first sub-channel 42.

[0038] In this way, the first liquid and fine particles of a predetermined size or smaller, from among the first liquid and multiple types of particles contained in the raw sample liquid, flow into the first subchannel 42. Depending on the flow velocity in the first main channel 41, even if it is smaller than the width of the first subchannel 42, it will not proceed into the first subchannel 42 but will instead travel straight through the first main channel 41.

[0039] At multiple connection points with the first subchannel 42, the discharge of the first liquid and fine particles from the first main channel 41 into the first subchannel 42 is repeated, thereby removing most of the first liquid from the original sample solution and replacing it with the second liquid, which is the buffer solution. As a result, downstream of the connection points with the multiple first discharge channels 43, the first main channel 41 flows a sample solution for dielectrophoresis in which multiple types of particles are suspended in the buffer solution.

[0040] The separation and extraction unit 50 separates the dielectrophoretic sample solution into a target particle-containing solution and a target particle-free solution by dielectrophoresis downstream of the first replacement unit 40. The separation and extraction unit 50 then branches the target particle-containing solution and the target particle-free solution into two branched channels 53 and 54 provided downstream. The separation and extraction unit has a separation channel 51, a pair of comb-shaped electrodes 52, a first branched channel 53, a second branched channel 54, and a separation outlet 55.

[0041] The separation channel 51 is a cavity located in the middle layer of the main body 10. The upstream end of the separation channel 51 is connected to the downstream end of the first main channel 41 of the first replacement section 40.

[0042] A pair of comb-shaped electrodes 52 are positioned on the separation channel 51 at an angle to the flow direction of the separation channel 51 and face each other. An AC voltage is applied between the two comb-shaped electrodes 52. By appropriately adjusting the applied AC voltage and frequency, desired particles that meet the conditions can be induced and separated from other types of particles. Note that the particles separated by dielectrophoresis are not limited to just one type.

[0043] The first branch channel 53 is a cavity located in the middle layer of the main body 10. The second branch channel 54 is a cavity located in the middle layer of the main body 10. The upstream end of the first branch channel 53 and the upstream end of the second branch channel 54 are connected to the downstream end of the separation channel 51, aligned in the width direction. That is, at the downstream end of the separation channel 51, the connection point of the first branch channel 53 and the connection point of the second branch channel 54 are aligned in the width direction. As a result, the flow within the separation channel 51 is divided in the width direction and flows into the first branch channel 53 and the second branch channel 54.

[0044] The separation outlet 55 is a section for discharging the target particle-free liquid that has flowed into the second branch channel 54. The separation outlet 55 is a cylindrical recess provided in the upper and middle layers of the main body 10. The separation outlet 55 is connected to the downstream end of the second branch channel 54.

[0045] In this embodiment, the two comb-shaped electrodes 52 are arranged so that they move from one side in the width direction to the other side as you move from the upstream side to the downstream side of the separation channel 51. As a result, predetermined particles to be separated by dielectrophoresis are separated along the comb-shaped electrodes 52 to the other side in the width direction as they move downstream. Meanwhile, the other particles move downstream along the side wall on one side in the width direction of the separation channel 51, following the flow from the first main channel 41.

[0046] In this embodiment, the other half of the downstream end of the separation channel 51 is connected to the upstream end of the first branch channel 53, and the other half of the downstream end is connected to the upstream end of the second branch channel 54. As a result, the suspension containing predetermined particles to be separated by dielectrophoresis, which flows through the other side of the separation channel 51, flows into the first branch channel 53. The suspension flowing through the one side of the separation channel 51 that does not contain the predetermined particles to be separated by dielectrophoresis flows into the second branch channel 54.

[0047] Furthermore, the suspension flowing into the first branch channel 53 does not necessarily contain all of the predetermined particles separated by dielectrophoresis, and may contain some particles other than those separated by dielectrophoresis. Similarly, the suspension flowing into the second branch channel 54 does not necessarily contain all of the particles other than those in the dielectrophoretic sample solution, and may contain some of the predetermined particles separated by dielectrophoresis.

[0048] Here, if the target particles are more easily separated by dielectrophoresis than the unwanted particles, or if the unwanted particles are particles that cannot be separated by dielectrophoresis, the suspension flowing into the first branch channel 53 becomes a target particle-containing solution containing the target particles, and the suspension flowing into the second branch channel 54 becomes a target particle-free solution that does not contain the target particles. On the other hand, if the predetermined particles separated by dielectrophoresis are not the target particles, the suspension flowing into the second branch channel 54 becomes a target particle-containing solution containing the target particles, and the suspension flowing into the first branch channel 53 becomes a target particle-free solution that does not contain the target particles.

[0049] This embodiment is configured for use when the predetermined particles separated by dielectrophoresis are the target particles. For this reason, the first branch channel 53 is connected to the second replacement section 60, and the second branch channel 54 is connected to the separation outlet 55. The liquid containing the target particles that flows into the first branch channel 53 flows into the second main channel 61 of the second replacement section 60, which will be described later. The liquid that does not contain the target particles that flows into the second branch channel 54 is discharged from the separation outlet 55.

[0050] The second replacement section 60 is a part for removing the buffer liquid from the target particle-containing liquid and mixing it with the third liquid. That is, in the second replacement section 60, the second liquid in the target particle-containing liquid is replaced with the third liquid. The second replacement section 60 has a second main flow path 61, a plurality of second subflow paths 62, a second discharge path 63, and a second discharge port 64.

[0051] The third solution is, for example, the same liquid as the first solution. This allows for the separation of the target particles from other particles and creates the same environment as the sample solution. Furthermore, for example, if the target particles are cells and these cells are subsequently cultured, using the third solution as the culture medium allows the resulting suspension to be used directly for cell culture.

[0052] The second main channel 61 is a cavity provided in the middle layer of the main body 10. At the upstream end of the second main channel 61, the connection point with the first branch channel 53 and the connection point with the third injection channel 33 are aligned in the width direction. As a result, the target particle-containing liquid and the third liquid flow laminarly within the second main channel 61. In this embodiment, one half of the upstream end of the second main channel 61 in the width direction is connected to the downstream end of the first branch channel 53, and the other half in the width direction is connected to the downstream end of the third injection channel 33. As a result, the target particle-containing liquid flows laminarly on one side in the width direction, and the third liquid flows laminarly on the other side in the width direction.

[0053] Each second sub-channel 62 is a cavity located in the middle layer of the main body 10, extending in a direction perpendicular to the direction in which the second main channel 61 extends. The width of the second sub-channel 62 is smaller than the width of the second main channel 61. The upstream end of the second sub-channel 62 is connected to the side of the second main channel 61 on the first branch channel 53 side. In this embodiment, the upstream end of the second sub-channel 62 is connected to the side of the second main channel 61 on one side in the width direction.

[0054] The second discharge channel 63 is a cavity located in the middle layer of the main body 10. The second discharge channel 63 is connected to the downstream end of a plurality of second sub-channels 62.

[0055] The second outlet 64 is a section for discharging the liquid separated in the second replacement section 60. The second outlet 64 is a cylindrical recess provided in the upper and middle layers of the main body 10. The second outlet 64 is connected to the downstream end of the second discharge passage 63.

[0056] Similar to the first replacement section, the second replacement section 60 removes the second liquid from the target particle-containing liquid using a hydraulic filtration method and mixes in the third liquid. In the second main channel 61, the particles in the target particle-containing liquid move downstream along one side wall in the width direction. At the connection point with the second subchannel 62, the buffer liquid and fine particles of a predetermined size or smaller, which are among the buffer liquid, target particles, and other particles contained in the target particle-containing liquid, flow into the second subchannel 62.

[0057] At multiple connection points with the second subchannel 62, the buffer liquid and fine particles are repeatedly discharged from the second main channel 61 into the second subchannel 62, thereby removing most of the buffer liquid from the target particle-containing liquid and replacing it with the third liquid. As a result, downstream of the connection points with multiple second discharge channels 63, the second main channel 61 flows a prepared sample liquid in which the target particles are suspended in the third liquid.

[0058] The width, number, and length of the second sub-channels 62 in the second replacement section 60, as well as the spacing between the second sub-channels 62, may differ from those of the first sub-channels 42 in the first replacement section 40.

[0059] The target particle collection port 90 is a cylindrical recess provided in the upper and middle layers of the main body 10. The target particle collection port 90 is connected to the downstream end of the second main flow channel 61 of the second replacement section 60. This allows the prepared sample solution obtained in the second replacement section 60 to be obtained from the target particle collection port 90.

[0060] As mentioned above, in conventional separation chips, the target particles are obtained contained within the surrounding medium (liquid) used for dielectrophoresis. Therefore, depending on the subsequent purpose, it was necessary to replace the liquid containing the target particles again. In this process, there was a possibility of damaging the target particles due to centrifugation or other methods, as well as a risk of contamination during the process. Furthermore, depending on the method, the number of target particles obtained after the liquid replacement operation may be reduced compared to before the operation, depending on the operator's skill.

[0061] In contrast, this separation chip 1 allows the liquid component of the liquid containing the target particles after dielectrophoresis to be replaced with a third liquid, which is a desired liquid, within the separation chip 1.

[0062] <2. Second Embodiment> Figure 2 is a top view of the separation chip 1A according to the second embodiment. Similar to the separation chip 1, this separation chip 1A is used to separate target particles from a raw sample solution containing multiple types of particles including the target particles, and to obtain a prepared sample solution in which the target particles are suspended in a desired dispersion medium. Many of the components of the separation chip 1A are common to the separation chip 1 according to the first embodiment. For this reason, components common to the first embodiment will use the same reference numerals in the figure as in the first embodiment, and their descriptions will be omitted.

[0063] This separation chip 1A is used when the target particles are difficult to separate by dielectrophoresis compared to unwanted particles, or when the target particles are particles that cannot be separated by dielectrophoresis. For example, it is useful when the target particles are difficult to separate by dielectrophoresis, the size of particles other than the target particles in the original sample solution is relatively large, and particles that make up a relatively large proportion of the original sample solution are particles that are easily separated by dielectrophoresis. In this separation chip 1A, the shape of the third injection channel 33A, the connection destinations of the two branch channels 53A and 54A of the separation extraction section 50A, and the relative position of the second replacement section 60 differ from the separation chip 1 of the first embodiment.

[0064] The third injection channel 33A is a flow path for injecting the third liquid from the third injection port 23 to the second replacement section 60. The downstream end of the third injection channel 33A is connected to the upstream end of the second main flow path 61 of the second replacement section 60. Because the relative position of the second replacement section 60 is different from that of the first embodiment, the shape of the third injection channel 33A is different from that of the third injection channel 33 in the first embodiment.

[0065] Similar to the first embodiment, in the separation and extraction section 50A, a suspension containing predetermined particles separated by dielectrophoresis flows into the first branch channel 53A. A suspension not containing the predetermined particles separated by dielectrophoresis flows into the second branch channel 54A. In this case, in the raw sample solution using the separation chip 1A, the target particles are not the predetermined particles separated by dielectrophoresis in the separation and extraction section 50A. Therefore, the suspension flowing into the first branch channel 53A becomes a target particle-free solution, while the suspension flowing into the second branch channel 54A becomes a target particle-containing solution.

[0066] Here, the downstream end of the first branch channel 53A of the separation and extraction unit 50A is connected to the separation outlet 55A. As a result, the liquid that does not contain the target particles and flows into the first branch channel 53A is discharged from the separation outlet 55A. On the other hand, the downstream end of the second branch channel 54A is connected to the upstream end of the second main channel 61 of the second replacement unit 60. As a result, the liquid containing the target particles that flows into the second branch channel 54A flows into the second main channel 61 of the second replacement unit 60, where the liquid component is replaced by the third liquid, and a prepared sample solution is obtained. The prepared sample solution obtained in the second replacement unit 60 can then be obtained from the target particle collection port 90.

[0067] Thus, the separation chip 1A of this embodiment is configured for use when the target particles are more difficult to separate by dielectrophoresis than unwanted particles, or when the target particles are particles that cannot be separated by dielectrophoresis. In this case as well, with this embodiment, similar to the first embodiment, the liquid component of the liquid containing the target particles after dielectrophoresis can be replaced with a third liquid, which is a desired liquid, within the separation chip 1A.

[0068] <3. Third Embodiment> Figure 3 is a top view of the separation chip 1B according to the third embodiment. Many of the components of the separation chip 1B are the same as those of the separation chip 1 according to the first embodiment. For this reason, components common to the first embodiment are given the same reference numerals as in the first embodiment in the figure, and their descriptions are omitted.

[0069] Similar to the first embodiment, this separation chip 1B is used when the target particles are more easily separated by dielectrophoresis than unwanted particles, or when the unwanted particles are particles that cannot be separated by dielectrophoresis. In this separation chip 1B, the method of supplying the third liquid to the third injection channel 33B differs from that of the separation chip 1 of the first embodiment. Specifically, the third liquid supplied to the second replacement section 60 via the third injection channel 33B is the original sample liquid itself. Accordingly, the relative position of the first injection port 21 and the shapes of the first injection channel 31B and the third injection channel 33B are different, and the separation chip 1B does not have a third injection port.

[0070] In this embodiment, the upstream end of the third injection channel 33B is connected to the middle of the flow path of the first injection channel 31B. That is, the third injection channel 33B is a flow path branched off from the first injection channel 31B. Therefore, the third liquid is the sample liquid separated from the first injection channel 31B. The downstream end of the third injection channel 33B is connected to the upstream end of the second main flow path 61 of the second replacement section 60, as in the first embodiment. As a result, in the second replacement section 60, the buffer liquid contained in the target particle-containing liquid is replaced with the original sample liquid as the third liquid. The resulting adjusted sample liquid is the original sample liquid with the separated target particles added. That is, the adjusted sample liquid is a suspension with an increased concentration of target particles compared to the original sample liquid.

[0071] <4. Fourth Embodiment> Figure 4 is a top view of the separation chip 1C according to the fourth embodiment. Similar to the separation chip 1, this separation chip 1C is used to separate target particles from a raw sample solution containing multiple types of particles including the target particles, and to obtain a prepared sample solution in which the target particles are suspended in a desired dispersion medium. Many of the components of the separation chip 1C are common to the separation chip 1 according to the first embodiment. For this reason, components common to the first embodiment will use the same reference numerals in the figure as in the first embodiment, and their descriptions will be omitted.

[0072] Similar to the second embodiment, this separation chip 1C is used when the target particles are more difficult to separate by dielectrophoresis than unwanted particles, or when the target particles are particles that cannot be separated by dielectrophoresis. For this reason, each part of the separation and extraction unit 50C has the same configuration as the separation and extraction unit 50A according to the second embodiment.

[0073] Furthermore, in this separation chip 1C, similar to the third embodiment, the third liquid supplied to the third injection channel 33C is the same raw sample liquid supplied to the first injection port 21. Specifically, the upstream end of the third injection channel 33C is connected to the middle of the flow path of the first injection channel 31C. That is, the third injection channel 33C is a flow path branched off from the first injection channel 31C. Therefore, the third liquid is the sample liquid separated from the first injection channel 31C. For this reason, the position of the first injection port 21 and the connection state between the first injection channel 31C and the third injection channel 33C have the same configuration as the first injection port 21, first injection channel 31B, and third injection channel 33B according to the third embodiment.

[0074] This allows for the preparation of a suspension with an increased concentration of the target particles compared to the original sample solution, in cases where the target particles are less easily separated by dielectrophoresis than unwanted particles, or where the target particles are not separated by dielectrophoresis at all.

[0075] <5. Fifth Embodiment> Figure 5 is a top view of the separation chip 1D according to the fifth embodiment. Many of the components of the separation chip 1D are the same as those of the separation chip 1B according to the third embodiment. In the following, components common to the first and third embodiments will not be described, and components common to the first embodiment will be indicated in the figures using the same reference numerals as in the first embodiment.

[0076] Similar to the first and third embodiments, this separation chip 1D is used when the target particles are more easily separated by dielectrophoresis than unwanted particles, or when the unwanted particles are particles that cannot be separated by dielectrophoresis. In this separation chip 1D, the method of supplying the third liquid to the third injection channel 33D is similar to that of the third embodiment, but there are differences. Specifically, the third liquid supplied to the second replacement section 60 via the third injection channel 33D is the liquid component and fine particles of the original sample solution. Accordingly, a separation section 70D is provided between the first injection channel 31D and the third injection channel 33D.

[0077] The separation section 70D has a plurality of third sub-channels 71D. Each third sub-channel 71D is a cavity provided in the middle layer of the main body 10, extending in a direction perpendicular to the third injection channel. The upstream end of each third sub-channel 71D connects to the side of the first injection channel 31D midway through its flow path. In this embodiment, the upstream end of each third sub-channel 71D connects to one of the sides of the first injection channel 31D in the width direction. The downstream end of each third sub-channel 71D connects to the vicinity of the upstream end of the third injection channel 33D.

[0078] With this configuration, the separation unit 70D uses a hydraulic filtration method to remove a portion of the raw sample liquid flowing through the first injection channel 31D and supplies it to the third injection channel 33D. In other words, the third liquid is the liquid containing the first liquid that has been separated from the first injection channel 31D.

[0079] In this case, by adjusting the width, number, and length of the third subchannel 71D, as well as the spacing between the third subchannels 71D, etc., in order to minimize the amount of fine particles flowing into the third subchannel 71D, the amount of fine particles contained in the third liquid supplied to the third injection channel 33D can be reduced, making it almost entirely the first liquid.

[0080] In this case, downstream of the separation section 70D, the suspension flowing through the first injection channel 31D becomes a concentrated sample solution with less liquid component and a higher content of particles containing the target particles compared to the original sample solution injected at the first injection port 21. By replacing this concentrated sample solution with buffer solution in the first replacement section 40 and separating the target particles in the separation and extraction section 50, a prepared sample solution can be obtained that has a high content of the target particles and a lower content of relatively large particles other than the target particles compared to the third embodiment. Furthermore, if the first liquid is to be used as the liquid component of the prepared sample solution, there is no need to inject it separately as the third liquid.

[0081] On the other hand, if, in addition to the target particles mentioned above, a second set of target particles (hereinafter referred to as "fine target particles") are present in the fine particles of the raw sample solution, the fine target particles can be separated in the separation unit 70D and added to the target particle-containing solution via the third injection channel 33D. Specifically, by adjusting the width, number, and length of the third subchannels 71D, as well as the spacing between the third subchannels 71D, so that fine target particles flow into the third subchannels 71D but target particles that should go to the separation and extraction unit 50 do not flow in, the third solution supplied to the third injection channel 33D will be the first solution with fine target particles added.

[0082] In this case, within the second main channel 61, the target particle-containing liquid flows laminarly on one side in the width direction, and the first liquid containing fine target particles flows laminarly on the other side in the width direction. Here, the width, number, and length of the second subchannels 62, as well as the spacing between the second subchannels 62, are adjusted so that fine target particles do not flow in. Then, the buffer liquid in the target particle-containing liquid is discharged, and a prepared sample liquid containing target particles and fine target particles in the first liquid can be obtained.

[0083] <6. Sixth Embodiment> Figure 6 is a top view of the separation chip 1E according to the sixth embodiment. The separation chip 1E has configurations common to the fourth and fifth embodiments, respectively. In the following, the configurations common to the above embodiments will not be described, and the same reference numerals as in the first embodiment will be used in the figures for the configurations common to the first embodiment.

[0084] Similar to the second and fourth embodiments, this separation chip 1E is used when the target particles are more difficult to separate by dielectrophoresis than unwanted particles, or when the target particles are particles that cannot be separated by dielectrophoresis. For this reason, each part of the separation and extraction unit 50E has the same configuration as the separation and extraction unit 50A according to the second embodiment and the separation and extraction unit 50C according to the fourth embodiment.

[0085] Furthermore, this separation chip 1E has a separation section 70E similar to the separation section 70D of the fifth embodiment. Therefore, the third liquid supplied to the second replacement section 60 via the third injection channel 33E is the liquid component and fine particles of the original sample liquid supplied from the first injection channel 31E to the third injection channel 33E via a plurality of subchannels 71E of the separation section 70E. In other words, the third liquid is a liquid containing the first liquid that has been separated from the first injection channel 31E.

[0086] In this case, by adjusting the width, number, and length of the third subchannels 71E, as well as the spacing between the third subchannels 71E, etc., in order to minimize the amount of fine particles flowing into the third subchannels 71E, the amount of fine particles contained in the third liquid supplied to the third injection channel 3E can be reduced to almost exclusively the first liquid.

[0087] In this case, downstream of the separation section 70E, the suspension flowing through the first injection channel 31E becomes a concentrated sample solution with less liquid component and a higher content of particles containing the target particles compared to the original sample solution injected at the first injection port 21. By replacing this concentrated sample solution with buffer solution in the first replacement section 40 and separating the target particles in the separation and extraction section 50E, a prepared sample solution can be obtained that has a high content of the target particles and a lower content of relatively large particles other than the target particles compared to the fourth embodiment. Furthermore, if the first liquid is to be used as the liquid component of the prepared sample solution, there is no need to inject it separately as a third liquid.

[0088] On the other hand, if fine target particles are present in the fine particles in the raw sample liquid in addition to the target particles mentioned above, the fine target particles can be separated in the separation unit 70E and added to the target particle-containing liquid via the third injection channel 33E. Specifically, by adjusting the width, number, and length of the third subchannels 71E, as well as the spacing between the third subchannels 71E, so that fine target particles flow into the third subchannels 71E but target particles that should go to the separation and extraction unit 50 do not flow in, the third liquid supplied to the third injection channel 33E will be the first liquid with fine target particles added.

[0089] In this case, within the second main channel 61, the target particle-containing liquid flows laminarly on one side in the width direction, and the first liquid containing fine target particles flows laminarly on the other side in the width direction. Here, the width, number, and length of the second subchannels 62, as well as the spacing between the second subchannels 62, are adjusted so that fine target particles do not flow in. Then, the buffer liquid in the target particle-containing liquid is discharged, and a prepared sample liquid containing target particles and fine target particles in the first liquid can be obtained.

[0090] Thus, in cases where the target particles are less likely to be separated by dielectrophoresis compared to unwanted particles, or where the target particles are not separated by dielectrophoresis at all, the method can be used in the same manner as in the fifth embodiment.

[0091] <7. Seventh Embodiment> Figure 7 is a top view of the separation chip 1F according to the seventh embodiment. Many of the components of the separation chip 1F are the same as those of the separation chip 1D according to the fifth embodiment. In the following, components common to the fifth embodiment will not be described, and components common to the first embodiment will be given the same reference numerals as in the first embodiment.

[0092] This separation chip 1D, like the first, third, and fifth embodiments, is used when the target particles are more easily separated by dielectrophoresis than unwanted particles, or when the unwanted particles are particles that cannot be separated by dielectrophoresis. In this separation chip 1F, the method of supplying the third liquid to the third injection channel 33F differs from that of the fifth embodiment, but other aspects are the same as those of the fifth embodiment. The differences from the fifth embodiment will be explained below.

[0093] In this separation chip 1F, the third injection channel 33F has a first branch injection channel 331F, a second branch injection channel 332F, and an integrated injection channel 333F. The first branch injection channel 331F, the second branch injection channel 332F, and the integrated injection channel 333F are each cavities provided in the middle layer of the main body 10.

[0094] The separation chip 1F has a separation section 70F similar to the separation section 70D of the fifth embodiment. The downstream ends of each third subchannel 71F of the separation section 70F are connected to the upstream end of the first branch injection channel 331F. As a result, liquid components and fine particles separated from the raw sample liquid flowing in the first injection channel 31F flow into the first branch injection channel 331F. Here, the separation section 70F is designed so that fine target particles flow in from the raw sample liquid flowing in the first injection channel 31F. A third injection port 23F is connected to the upstream end of the second branch injection channel 332F. A third liquid is then injected into the third injection port 23F. The third liquid may be the first liquid, which is the liquid component of the raw sample liquid, or it may be a different liquid.

[0095] The downstream end of the first branch injection channel 331F and the downstream end of the second branch injection channel 332F are connected to the upstream end of the integrated injection channel 333F. The downstream end of the integrated injection channel 333F is connected to the second main flow channel 61 of the second replacement section 60. As a result, within the integrated injection channel 333F, the first liquid separated from the original sample liquid and containing fine target particles flows laminarly on one side in the width direction, while the third liquid flows laminarly on the other side in the width direction.

[0096] Then, within the second main channel 61, the target particle-containing liquid, the first liquid containing fine target particles, and the third liquid flow in a laminar flow in three layers, sequentially from one side in the width direction to the other. In the second replacement section 60, the buffer liquid, which is the liquid component of the target particle-containing liquid, and the first liquid, which was the dispersion medium for the fine target particles, are discharged into the second subchannel 62. As a result, a solution containing the target particles and fine target particles in the third liquid can be obtained as a prepared sample liquid.

[0097] <8. Eighth Embodiment> Figure 8 is a top view of the separation chip 1G according to the eighth embodiment. The separation chip 1G has configurations common to the sixth and seventh embodiments, respectively. In the following, the configurations common to the above embodiments will not be described, and the same reference numerals as in the first embodiment will be used in the figures for the configurations common to the first embodiment.

[0098] This separation chip 1G, like the second, fourth, and sixth embodiments, is a separation chip used when the target particles are difficult to separate by dielectrophoresis compared to unwanted particles, or when the target particles are particles that cannot be separated by dielectrophoresis. In this separation chip 1G, the method of supplying the third liquid to the third injection channel 33G differs from that of the sixth embodiment and is the same as that of the seventh embodiment. That is, the difference between this embodiment and the sixth embodiment is that in this separation chip 1G, the third injection channel 33G has the same configuration as the third injection channel 33F in the seventh embodiment.

[0099] In this separation chip 1G, the third injection channel 33G has a first branch injection channel 331G, a second branch injection channel 332G, and an integrated injection channel 333G. The first branch injection channel 331G, the second branch injection channel 332G, and the integrated injection channel 333G are each cavities provided in the middle layer of the main body 10.

[0100] The downstream ends of each third subchannel 71G of the separation unit 70G are connected to the upstream end of the first branch injection channel 331G. As a result, liquid components and fine particles separated from the raw sample liquid flowing in the first injection channel 31G flow into the first branch injection channel 331G. Here, the separation unit 70G is designed to receive fine target particles from the raw sample liquid flowing in the first injection channel 31G, similar to the seventh embodiment. The third injection port 23G is connected to the upstream end of the second branch injection channel 332G. The third liquid is then injected into the third injection port 23G. The third liquid may be the first liquid, which is the liquid component of the raw sample liquid, or it may be a different liquid.

[0101] The downstream end of the first branch injection channel 331G and the downstream end of the second branch injection channel 332G are connected to the upstream end of the integrated injection channel 333G. The downstream end of the integrated injection channel 333G is connected to the second main flow channel 61 of the second replacement section 60. As a result, within the integrated injection channel 333G, the first liquid separated from the original sample liquid and containing fine target particles flows laminarly on one side in the width direction, while the third liquid flows laminarly on the other side in the width direction.

[0102] Then, within the second main channel 61, the target particle-containing liquid, the first liquid containing fine target particles, and the third liquid flow in a laminar flow in three layers, sequentially from one side in the width direction to the other. In the second replacement section 60, the buffer liquid, which is the liquid component of the target particle-containing liquid, and the first liquid, which was the dispersion medium for the fine target particles, are discharged into the second subchannel 62. As a result, a solution containing the target particles and fine target particles in the third liquid can be obtained as a prepared sample liquid.

[0103] Therefore, even in cases where the target particles are less easily separated by dielectrophoresis than unwanted particles, or where the target particles are not separated by dielectrophoresis at all, a prepared sample solution containing the target particles and fine target particles in the desired liquid can be obtained, similar to the seventh embodiment.

[0104] <9. Variation> Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment.

[0105] In the figures of the above embodiments, the shapes of each inlet, outlet, and flow path are examples only and can be modified as appropriate, as long as their function remains unchanged.

[0106] Furthermore, in the above embodiment, while particles flow along one side wall in the width direction within the separation channel, the two comb-shaped electrodes were arranged so that they moved from one side to the other in the width direction as the separation channel progressed from upstream to downstream. However, a modified configuration is also conceivable in which, while particles flow along one side wall in the width direction within the separation channel, the two comb-shaped electrodes are arranged so that they move from the other side to the one in the width direction as the separation channel progressed from upstream to downstream. This configuration can be appropriately changed depending on which of the multiple types of particles contained in the original sample solution are to be included in the prepared sample solution.

[0107] Furthermore, the elements that appear in the above embodiments and modifications may be combined as appropriate, to the extent that no contradictions arise. [Explanation of symbols]

[0108] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G: Separation chips 21: 1st injection port 22:Second injection port 23,23F,23G: 3rd injection port 31,31B,31C,31D,31E,31F,31G: 1st injection path 32:Second injection path 33,33A,33B,33C,33D,33E,33F,33G: 3rd injection path 40: First replacement section 41: The first mainstream road 42: First Sub-flow Path 43: First row of routes 44: First row exit 50, 50A, 50C, 50E, 50G: Separation and extraction section 51: Separated Flow Path 52: Purslant electrode 53,53A: 1st branch flow path 54,54A: 2nd branch flow path 55, 55A: Separate discharge outlet 60: Second replacement section 61: Second Main Road 62: Second Sub-flow Path 62: Second Main Road 63: Second row of exits 64: Second row exit 70D, 70E, 70F, 70G: Separation Section 71D, 71E, 71F, 71G: Third secondary flow path 90: Target particles are taken orally 331F, 331G: 1st branch injection path 332F, 332G: 2nd branch injection path 333F, 333G: Integrated Injection Path

Claims

1. A separation chip for separating target particles from a sample solution containing a first liquid and multiple types of particles, A first injection channel into which the sample liquid is injected, A second injection channel into which the second liquid is injected, A third injection channel into which the third liquid is injected, The upstream end is connected to the first injection channel and the second injection channel, and the first replacement section removes the first liquid from the sample liquid and mixes it with the second liquid, A separation and extraction unit is provided downstream of the first replacement unit, which separates the target particle-containing liquid containing the target particles and the target particle-free liquid containing the target particles by dielectrophoresis, and branches the liquid into two branched channels provided downstream. The upstream end is connected to one of the branched flow paths and the third injection path, and the second replacement unit removes the liquid component of the target particle-containing liquid from the target particle-containing liquid and mixes it with the third liquid, A separate chip equipped with this feature.

2. A separation chip according to claim 1, The first substitution part is, At the upstream end, the connection portion to the first injection channel and the connection portion to the second injection channel are aligned in the width direction, and the first main flow channel through which the sample liquid and the second liquid flow in a laminar flow, A plurality of first sub-channels, the upstream end of which is connected to the side of the first main channel on the first injection channel side, A first discharge channel connected to the downstream ends of a plurality of the first sub-channels, A separate chip having

3. A separation chip according to claim 1, The second substitution portion is, At the upstream end, the connection point with the third injection channel and the connection point with one of the branch channels are aligned in the width direction, and the second main channel through which the target particle-containing liquid and the third liquid flow in a laminar flow, A plurality of second sub-channels, the upstream end of which is connected to the side of the second main channel on the side of the branch channel, A second discharge channel connected to the downstream end of a plurality of the second sub-channels, A separate chip having

4. A separation chip according to claim 1, The separation and extraction unit is A separation channel whose upstream end is connected to the downstream end of the first replacement section, On the separation channel, two pairs of comb-shaped electrodes are provided, positioned obliquely to the flow direction of the separation channel and facing each other. Downstream of the comb-shaped electrode, two branch channels branch off from the downstream end of the separation channel, A separate chip having

5. A separation chip according to any one of claims 1 to 4, The third liquid is the same liquid as the first liquid, in the separation chip.

6. A separation chip according to any one of claims 1 to 4, Upstream of the second replacement section, a plurality of third subchannels are connected to the side of the first injection channel. It further possesses, The third injection channel is connected to the downstream end of the plurality of third subchannels, The third liquid is a separation tip, which is a liquid containing the first liquid that has been separated from the first injection channel.

7. A separation chip according to any one of claims 1 to 4, The third injection channel is a flow path branched from the first injection channel. The third liquid is the sample liquid branched off from the first injection channel, and the separation chip.

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