TWI889038B - Microfluidic particle sorter - Google Patents

Abstract

A microfluidic particle sorter is used for classifying target particles and non-target particles in a specimen using a deterministic-lateral displacement technique. The microfluidic particle sorter comprises at least one first deterministic-lateral displacement pillar array that is disposed in a chip body. The at least one first deterministic-lateral displacement pillar array includes a plurality of first deterministic-lateral displacement pillar series that are arranged in a longitudinal direction and that are shifted along a width direction in order. Each of the first deterministic-lateral displacement pillar series includes a plurality of first split pillars that are arranged along the width direction. Each of the first split pillars has a first micro-gap that extends from a waterside to a backwater side and that is for the non-target particles to pass therethrough after deformation. By virtue of the structure design of each of the first split pillars with the first micro-gap, it is used for classifying target particles and non-target particles that has similar diameters and different deformation energies.

Description

Microfluidic Particle Sorter

The present invention relates to a microfluidic chip, and more particularly to a microfluidic chip for particle sorting based on deterministic lateral displacement technology.

Currently, the common technology used to screen circulating tumor cells (CTCs) in samples is antibody-based CTC enrichment and separation methods. In the CTC enrichment and separation method, the positive selection method uses EpCAM and surface antibodies to capture CTCs. Although it is more efficient, this method may lose tumor cells with low antigen expression. Negative selection uses markers such as CD45/14 to remove non-target cells in the sample, such as white blood cells (WBC). Although it has high efficiency and high CTC recovery rate, CD/14/45/ and other markers will also remove cells that have expressed cancer markers, and the number of antibodies required to remove a large number of white blood cells is not small, and the cost is high. Another CTC enrichment method is a filtration method based on filters or microporous devices. Although it can be used to capture CTCs, mutant cells and CTC clusters, it has low purity and the high shear stress during filtration will lead to reduced viability of the captured cells. Other CTC enrichment methods include microfluidic chip sorting methods, such as dielectrophoresis-based microfluidic chips and DLD (deterministic lateral) separation methods. Among them, although the dielectrophoresis microfluidic chip has a higher CTC sorting purity, due to the low flow rate and the need for a medium solution with a lower ion concentration, the specimen needs to be significantly diluted, which will increase the specimen sample volume and sorting time. Although the DLD separation method also has a higher CTC sorting purity and does not need to consider the medium ion concentration problem, the DLD separation method cannot be used to separate other cells with a similar particle size to CTC (such as white blood cells). Therefore, the current DLD separation technology still has room for improvement.

Therefore, an object of the present invention is to provide a microfluidic particle sorter that can improve at least one disadvantage of the prior art.

Therefore, the microfluidic particle sorter of the present invention is suitable for sorting target particles and non-target particles in a sample liquid by using a deterministic lateral displacement technique. The microfluidic particle sorter comprises a chip body and at least one first deterministic lateral displacement column array disposed in the chip body.

The chip body has a micro-channel extending along a length direction. The micro-channel has an opposite sample injection end and a sample outflow end, and has a first side and a second side opposite in a width direction.

The at least one first deterministic transverse displacement column array is disposed in the microfluidic channel, and includes a plurality of first transverse displacement column arrays arranged along the length direction and sequentially offset laterally by a predetermined distance (Δd) toward the second side toward the sample outflow end. Each of the first transverse displacement column arrays has a plurality of first split columns arranged upright and arranged at intervals along the width direction W. The first split columns cooperate with the microfluidic channel to define a plurality of guide channels arranged along the width direction and interconnected, and extending obliquely toward the sample outflow end and toward the second side along the length direction. Each of the first split columns has a water-incoming side facing the sample injection end and a water-repelling side facing the sample outflow end, and each of the first split columns has two vertically cut column parts that are spaced and face each other and cooperate to define the water-incoming side and the water-repelling side, and the vertically cut column parts cooperate to define a first micro-gap extending from the water-incoming side to the water-repelling side and can be used for the non-target particles to pass through after deformation. Each of the first micro-gap is offset from the length direction by an angle θ1, and extends obliquely toward the second side toward the sample outflow end, 1∘≤θ1≤89∘.

The effect of the present invention lies in that: through the structural design that each of the first split columns of the first deterministic lateral displacement column array has the first micro-gap, in addition to being able to sort the target particles and the non-target particles of different particle sizes through the arrangement structural design of the first split columns, the first micro-gap of the first split columns can also be used to allow the non-target particles of larger particle sizes to be squeezed through by deformation, thereby achieving the effect of sorting the target particles and the non-target particles of similar particle sizes but different deformation energies.

Before the present invention is described in detail, it should be noted that similar components are represented by the same reference numerals in the following description.

Referring to Figs. 1, 2, and 3, a first embodiment of the microfluidic particle sorter 200 of the present invention is suitable for sorting target particles 901 (not shown) and non-target particles 902 (not shown) in a sample fluid by using a deterministic lateral displacement technique (DLD). The sample fluid may be, for example, but not limited to, blood, pleural effusion, ascites, urine, or other diluted samples of body fluids. The target particles 901 may be, for example, but not limited to, circulating tumor cells (CTCs), tumor hybrid cells (THCs), etc., and the minimum particle size is Dt. The non-target particles 902 are, for example but not limited to, blood cells such as white blood cells and red blood cells that can be deformed. The maximum width of the narrow side of the non-target particles 902 after deformation is Ddnt, wherein Dt＞Ddnt.

The microfluidic particle sorter 200 includes a chip body 3, and a plurality of first deterministic lateral displacement column arrays 4 and a plurality of second deterministic lateral displacement column arrays 5 disposed in the chip body 3.

It must be explained that, since the structures of the first deterministic lateral displacement column arrays 4 and the second deterministic lateral displacement column arrays 5 are both at the micron level, the structural dimensions of each component shown in the drawings are only for reference and are not limited to the scale of the drawings during implementation.

The chip body 3 has a microchannel 33, a sample liquid injection channel 34, a buffer liquid injection channel 35, a waste liquid outflow channel 36, and a target particle collection channel 37.

In the first embodiment, the chip body 3 is a microfluidic chip manufactured by a microelectromechanical systems (MEMS) process, including a substrate 31 and a cover plate 32 stacked on the substrate 31 and having grooves and perforations on the bottom surface. The substrate 31 cooperates with the grooves and perforations of the cover plate 32 to define the flow channel and the channel. The manufacturing materials of the substrate 31 and the cover plate 32 include, but are not limited to, PDMS (polydimethylsiloxane), silicone elastomer, silicon crystal material, glass, PMMA (poly (methyl methacrylate), COC (Cyclic olefin copolymer)) and PC (Polycarbonate). Since the manufacturing of the chip body 3 is a prior art and the material types of its layered structure are numerous, it will not be described in detail and is not limited to the above-mentioned materials.

The microchannel 33 extends horizontally back and forth along a length direction L, and has a sample injection end 333 and a sample outflow end 334 spaced apart along the length direction L, and has a first side 331 and a second side 332 opposite to each other along a width direction W horizontally orthogonal to the length direction L. The microchannel 33 also has two sorting sections 335 spaced apart along the width direction W and adjacent to the first side 331 and the second side 332, respectively, and a collection section 336 between the sorting sections 335.

The sample liquid injection channel 34 and the buffer liquid injection channel 35 are connected to the sample injection end 333, and both have openings exposed on the top side of the chip body 3. The sample liquid injection channel 34 has two sample liquid injection sections 341 connected at one end and connected at the other end to the sorting sections 335, respectively, and can be used to drain and inject the sample liquid into the sorting sections 335. The buffer liquid injection channel 35 is spaced between the sample liquid injection sections 341 and connected to the converging section 336, and can be used to drain and inject the buffer liquid into the converging section 336.

The waste liquid outflow channel 36 and the target particle collection channel 37 are connected to the sample outflow end 334 of the microfluidic channel 33, and both have openings exposed on the top side of the chip body 3. The waste liquid outflow channel 36 has two waste liquid outflow sections 361 connected at one end and connected at the other end to the sorting sections 335, respectively, and can be used to drain the liquid from the sorting sections 335 out of the chip body 3. The target particle collection channel 37 is connected to the converging section 336 and is located between the waste liquid outflow sections 361. The target particle collection channel 37 can be used to drain the liquid from the converging section 336 out of the chip body 3.

2 and 3, the first deterministic transverse displacement column arrays 4 and the second deterministic transverse displacement column arrays 5 are connected between the substrate 31 and the cover plate 32, and are respectively disposed in the selection intervals 335 of the microchannel 33 in a left-right mirror-symmetrical manner, and are respectively adjacent to the first side 331 and the second side 332. The first deterministic transverse displacement column arrays 4 and the second deterministic transverse displacement column arrays 5 are arranged in sequence along the length direction L toward the sample outflow end 334.

Since the structures of the first deterministic lateral displacement column arrays 4 and the second deterministic lateral displacement column arrays 5 are bilaterally mirror-symmetrical, for the convenience of explanation, the following structural description is made by taking one of the first deterministic lateral displacement column arrays 4 as an example.

Referring to FIGS. 3, 4, and 5, the first deterministic transverse displacement column array 4 includes a plurality of first transverse displacement column rows 41 arranged in parallel and spaced apart along the length direction L. The arrangement spacing of the first transverse displacement column rows 41 in the length direction L is D1. Each of the first transverse displacement column rows 41 has a plurality of columnar first split columns 410 extending up and down and spaced apart from each other along the width direction W, and the distance between two adjacent first split columns 410 in the width direction W is D2, D2≧D1. The center distance between two adjacent first split columns 410 of each first transverse displacement column row 41 is λ. Among them, 0.33＜Dt/D2＜1.2, the particle size of the target particle 901 needs to be larger than 0.33D2 to produce a deterministic lateral displacement effect, but the particle size of the target particle 901 is not larger than 1.2 times the gap between two first crack columns 410 or two second crack columns 510 adjacent to each other in the horizontal direction, otherwise the target particle 901 will be stuck.

In addition, the first transverse displacement column rows 41 of each first deterministic transverse displacement column array 4 are sequentially shifted laterally toward the second side 332 toward the sample outflow end 334 by a predetermined distance (Δd). The number of the first transverse displacement column rows 41 of each first deterministic transverse displacement column array 4 is designed so that the first-ranked first transverse displacement column row 41 is shifted toward the second side 332 by the distance λ relative to the last-ranked first transverse displacement column row 41. Wherein, Δd/λ represents the tilt angle (θ3) of the transverse displacement of the split column. The first split columns 410 of each first deterministic transverse displacement column array 4 cooperate with the corresponding sorting section 335 to define a plurality of guide channels 416 arranged left and right and connected to each other laterally and extending obliquely from front to back toward the gathering section 336. Due to the transverse offset structural design of the first transverse displacement column arrays 41, the guide channels 416 of the first deterministic transverse displacement column arrays 4 are connected front to back in a staggered manner.

Each of the first split columns 410 has a water-facing side 411 and a water-receiving side 412 facing each other in the front and rear directions, and has two vertically cut column parts 413 with a vertical section 414 spaced apart in the width direction W and cooperating to define the water-facing side 411 and the water-receiving side 412. The vertical sections 414 of each of the first split columns 410 cooperate to define a first micro-gap 415 extending obliquely backward from the water-facing side 411 to the water-receiving side 412, and each of the first micro-gap 415 is obliquely inclined backward toward the first side 331 at an oblique angle (θ1) with respect to the length direction L. The width of each of the first micro-gap 415 is Gp, and is designed to allow the non-target particles 902 to pass through after deformation. Among them, 1∘≤θ1≤89∘.

In the first embodiment, the first split columns 410 are cylindrical, the vertically cut column parts 413 are semi-cylindrical with symmetrical structure in top view, and the deflection angles (θ1) of the first micro gaps 415 are the same, θ1=8∘.

Referring to FIGS. 3, 5, and 6, each of the second deterministic transverse displacement column arrays 5 includes a plurality of second transverse displacement column rows 51, and the arrangement spacing between two adjacent second transverse displacement column rows 51 in the length direction L is D1. Each of the second transverse displacement column rows 51 has a plurality of second split columns 510, and the spacing between two adjacent second split columns 510 in the width direction W is D2, D2≧D1, and 0.33＜Dt/D2＜1.2. The center spacing between two adjacent second split columns 510 of each second transverse displacement column row 51 is λ.

The second transverse displacement column rows 51 of each second deterministic transverse displacement column array 5 are sequentially offset laterally by a predetermined distance (Δd) toward the first side 331 toward the sample outflow end 334. The number of the second transverse displacement column rows 51 of each second deterministic transverse displacement column array 5 is designed so that the first-ranked second transverse displacement column row 51 is offset by a distance λ toward the first side 331 relative to the last-ranked second transverse displacement column row 51. The second split columns 510 of each second deterministic transverse displacement column array 5 cooperate with the corresponding sorting section 335 to define a plurality of guide flow channels 516 that are arranged left and right and are laterally connected to each other and extend obliquely from front to back toward the collection section 336. Furthermore, due to the lateral offset structural design of the second lateral displacement column arrays 51, the guide channels 516 of the second deterministic lateral displacement column arrays 5 are connected front to back in a left-right staggered manner.

Each of the second split columns 510 has a water-facing side 511 and a water-receiving side 512 facing each other in the front and rear directions, and has two vertically cut column parts 513 which are spaced apart and face each other in the width direction W with a vertical section 514 and cooperate to define the water-facing side 511 and the water-receiving side 512. The vertical sections 514 of each of the second split columns 510 cooperate to define a second micro-gap 515 extending obliquely backward from the water-facing side 511 to the water-receiving side 512. Each of the second micro-gap 515 is obliquely inclined backward toward the second side 332 at an oblique angle (θ2) with respect to the length direction L. The width of each of the second micro-gap 515 is Gp, which can be used for the non-target particles 902 to pass through after deformation. Among them, 1∘≤θ2≤89∘.

In the first embodiment, the second split columns 510 are cylindrical, and the vertically cut column parts 513 are semi-cylindrical with symmetrical structure in top view. The deflection angles (θ2) of the second micro gaps 515 are the same, θ2=8∘.

2, 3, and 5, the microfluidic particle sorter 200 of the present invention is used to sort the target particles 901 (e.g., circulating tumor cells) and non-target particles 902 (e.g., blood cells) in the sample fluid (e.g., blood sample) by using the deterministic lateral displacement technique, and the buffer fluid can be continuously injected into the collection section 336 from the buffer fluid injection channel 35, and the sample fluid can be injected into the sorting sections 335 from the sample fluid injection channel 34. The buffer fluid is then made to flow backward toward the target particle collection channel 37, and the sample fluid is then made to flow backward through the guide channels 416, 516 in the sorting sections 335, and then flow out from the waste fluid outflow sections 361.

During the flow of the sample liquid and the buffer liquid, the target particles 901 to be separated have a large particle size and a small deformation amplitude, and are not easy to move laterally away from the collection interval 336 through the gap between the two first split columns 410 or the two second split columns 510 spaced in front and back. Therefore, the deterministic transverse displacement column arrays 4 and the second deterministic transverse displacement column arrays 5 can be used to generate the deterministic transverse displacement column arrays 4 and 5. The target particle 901 is displaced backward along the guide channel 416 or 516 and enters the corresponding connected guide channel 416 or 516 in the next first deterministic lateral displacement column array 4 or the second deterministic lateral displacement column array 5, thereby getting closer to the gathering section 336, or directly enters the gathering section 336 from the guide channel 416 or 516. At the same time, the non-target particles 902 with a smaller particle size are easy to move laterally away from the collection interval 336 through the gaps between the two first split columns 410 or the two second split columns 510 spaced in front and back, so that the non-target particles 902 are gradually moved away from the collection interval 336 and concentrated toward the first side 331 and the second side 332. Then, the selected target particles 901 can be collected from the target particle collection channel 37, and the remaining non-target particles 902 will be carried to the waste liquid outflow channel 36 by the sample liquid.

In addition, during the backward flow of the sample liquid, some non-target particles 902 with smaller particle sizes will directly pass through or slightly deform through the first micro-gaps 415 or the second micro-gaps 515 when colliding with the water-facing side 411 of the first fissure columns 410 or the water-facing side 511 of the second fissure columns 510, and deviate to the adjacent first side 331 or the second side 332.

When the non-target particles 902, such as white blood cells, have a particle size similar to that of the target particles 901 and are easily deformed in the sample fluid, when the non-target particles 902 collide with the opening of the first micro-gap 415 of one of the first fissure columns 410 or the opening of the second micro-gap 515 of one of the second fissure columns 510, they will be driven by the flow of the sample fluid and deformed to squeeze into the first micro-gap 415 or the second micro-gap 515, and displaced along the extension direction of the first micro-gap 415 or the second micro-gap 515, thereby deviating away from the first side 331 or the second side 332 of the converging section 336.

This design can be used to gradually separate the non-target particles 902 of other large particle sizes that are easy to deform in a direction away from the gathering interval 336, thereby achieving the effect of separating the target particles 901 and non-target particles 902 of similar particle sizes.

When the microfluidic particle sorter 200 of the present invention is used to sort the target particles 901 and the non-target particles 902, the width Gp of the first micro-gap 415 of each first split column 410 and the width Gp of the second micro-gap 515 of each second split column 510 can be designed according to the desired recovery effect of the target particles 901, and there are the following two implementation modes.

First implementation mode: high recovery mode.

The high recovery rate mode refers to maximizing the recovery of the target particles 901, and can achieve the effect of sorting out most of the target particles 901 in the sample liquid. In this mode, the width of the first micro-gap 415 and the second micro-gap 515 is designed to be: 0.2Dt＜Gp＜0.8Dt.

The second implementation mode: high purity mode.

The high recovery purity mode is to maximize the purity of the target particles 901 in the particles collected in the target particle collection channel 37, that is, to separate most of the non-target particles 902 in the sample liquid to the waste liquid outflow section 361. In this mode, the widths of the first micro-gap 415 and the second micro-gap 515 are designed to be: Ddnt＜Gp＜0.8Dt.

For example, if the particle size Dt of the target particle 901 is 15 um, and the narrow side width Ddnt of the non-target particle 902 after maximum deformation is less than 6 um regardless of its original size, the GP is designed to be 6 um, D1=20 um, D2=32 um, Δd=0.9 um, and λ=68 um. This can be used to drive most of the target particles 901 in the sample liquid to be displaced laterally to the collection interval 336 and be sorted out.

If the recovery rate of the target particles 901 is to be maximized, the GP can be designed to be 3 um. With this design, most of the target particles 901 will be sorted into the collection section 336, but because the GP is too small, some of the non-target particles 902 will not be able to deform and pass through, so that some of the non-target particles 902 with larger particle sizes will also be sorted into the collection section 336.

If the recovery purity of the target particles 901 is to be optimized, the GP can be designed to be 12 um. With this design, most of the non-target particles 902 can be easily deformed to pass through the first micro-gaps 415 and the second micro-gaps 515 and be retained in the sorting sections 335, which can improve the purity of the target particles 901 sorted to the collection section 336. However, there is a possibility that the target particles 901 may pass through or get stuck in the first micro-gaps 415 and/or the second micro-gaps 515 due to slight deformation, so some of the target particles 901 may not be sorted to the collection section 336.

Referring to FIGS. 5 and 7 , in the first embodiment, the overall shape of each first split column 410 and each second split column 510 is designed to be cylindrical, and the paired vertically cut column parts 413 and 513 are semi-cylindrical with symmetrical structure in top view. However, in practice, in another embodiment of the present invention, the size of the paired vertically cut column parts 413 and 513 can also be designed to be asymmetrical in top view, so that the paired vertically cut column parts 413 and 513 are asymmetrically cut cylindrical (as shown in FIG. 7 ).

When the vertically cut column parts 413, 513 of the first split columns 410 and the second split columns 510 are asymmetrical in top view, the first deterministic transverse displacement column array 4 shown in FIG. 7 can be used to make the relatively small vertically cut column part 413 adjacent to the gathering interval 336, or the second deterministic transverse displacement column array 5 shown in FIG. 7 can be used to make the relatively small vertically cut column part 413 adjacent to the gathering interval 336. The arrangement makes the relatively larger vertically cut column portion 513 adjacent to the gathering section 336. As long as the front openings of the first micro-gap 415 and the second micro-gap 515 are located at the corresponding water-facing side 411 of the first split column 410 and the water-facing side 511 of the second split column 510, they can be used to guide the deformed non-target particles 902 to pass backward.

In addition, during implementation, the deflection angles of the first micro gaps 415 of the first split columns 410 and the deflection angles of the second micro gaps 515 of the second split columns 510 are not necessarily the same. The deflection angles of the first micro gaps 415 of the first split columns 410 of the same first lateral displacement column row 41 may also be different, and the deflection angles of the second micro gaps 515 of the second split columns 510 of the same second lateral displacement column row 51 may also be different.

Furthermore, in the first embodiment, the first split columns 410 and the second split columns 510 are designed to be cylindrical. However, in practice, in other embodiments of the present invention, the first split columns 410 and the second split columns 510 may also be designed to be other geometric shapes, such as but not limited to the shapes shown in FIGS. 8 to 14 , as long as the first split column 410 has a water-facing side 411 and a water-receiving side 412, and the second split column 510 has a A water-facing side 511 and a water-receiving side 512 are provided, and each of the first micro-gap 415 and each of the second micro-gap 515 extends obliquely backward from the corresponding water-facing side 411, 511 away from the gathering section 336 to the corresponding water-receiving side 412, 512, so that the non-target particles 902 moving backward can pass through by deformation, thereby achieving the effect of guiding the non-target particles 902 to deviate from the gathering section 336.

Cancer cells (CTCs) are used as target particles, and the buffer is PBS (Phosphate buffered saline). After the healthy person's blood is diluted 10 times with PBS buffer, a specific amount of cancer cells is added to make a sample solution, and the microfluidic particle sorter 200 of the present invention is used to perform a sorting test of cancer cells and blood cells (WBCs and RBCs). The structural parameters of the microfluidic particle sorter 200 are as follows: D1 = 20 um, D2 = 32 um, Δd = 0.9 um, λ = 68 um. The first split columns 410 and the second split columns 510 are all asymmetrically beveled. The microgap Gp of each of the first microgap 415 and each of the second microgap 515 is 6 um. The deflection angles of the first micro gaps 415 and the second micro gaps 515 are both 8°. The flow rate of the sample liquid is 12 mL/hr, and the flow rate of the buffer liquid injected from the buffer liquid injection channel 35 is 85 mL/hr.

FIG. 15 to FIG. 17 are microscopic images of different parts of the microfluidic particle sorter 200 of the present invention along the flow direction 800 of the sample liquid.

As shown in FIGS. 15 and 16 , cancer cells (CTCs) migrate and concentrate in the collection zone 336, while blood cells (WBCs and RBCs) are laterally guided away from the collection zone 336. Some white blood cells (WBCs) deform and squeeze through the first micro-gap 415 of the first fissure column 410 or the second micro-gap 515 of the second fissure column 510 they encounter. Referring to FIG. 17 , after the cancer cells and blood cells pass through the last first deterministic transverse displacement column array 4 and the second deterministic transverse displacement column array 5 , it can be clearly seen that the sample flow composed of the cancer cells and the blood cells is clearly separated, and the desired cancer cells can be separated from the blood sample.

Next, a sample purification test was performed. A549/GFP lung cancer cells were used as target particles, and a specific number of lung cancer cells were mixed and added to a blood sample to prepare a blood-A549 sample solution. The microfluidic particle sorter of the present invention was used to sort and purify the A549/GFP lung cancer cells in the blood-A549 sample solution, and the sorter with a traditional DLD structure design was used to sort and purify the A549/GFP lung cancer cells in the same blood-A549 sample solution.

The two sorters will be used to sort the same blood-A549 sample solution, with 5 ml of blood-A549 sample solution used each time. After sorting, the number of A549/GFP lung cancer cells and blood cells in the sample solution after each sorting will be analyzed by microscopic imaging to statistically analyze the recovery rate and sample purification rate.

In this experiment, the buffer is PBS. After the healthy human blood is diluted 10 times with PBS buffer, 29 to 91 A549/GFP lung cancer cells are added to prepare the blood-A549 sample solution. The flow rate of the blood-A549 sample solution injected from the sample solution injection section 341 is 12 mL/hr, and the flow rate of the buffer solution injected from the buffer solution injection channel 35 is 85 mL/hr.

The structure of the sorter with the traditional DLD structure design is roughly the same as that of the microfluidic particle sorter 200 of the present invention, except that the traditional DLD sorter does not have the micro-gap structure of the first split columns 410 and the second split columns 510 of the present invention. The structural parameters of the microfluidic particle sorter 200 of the present invention are as follows: D1 = 20 um, D2 = 32 um, Δd = 0.9 um, λ = 68 um. The first split columns 410 and the second split columns 510 are asymmetrically beveled. The micro-gap Gp of each of the first micro-gap 415 and each of the second micro-gap 515 is 6 um. The deflection angle of the first micro-gap 415 and the second micro-gap 515 is 8∘.

See Figures 18 and 19, which are microscopic images of the sample solution containing the lung cancer cells after sorting by the two sorters. The green fluorescent particles are A549/GFP lung cancer cells, and the remaining particles are blood cells. Compared with the sorting results of the traditional DLD sorter, the blood cells in the sample solution after sorting by the microfluidic particle sorter 200 of the present invention are significantly less, and the purification rate of the sample solution by the microfluidic particle sorter 200 of the present invention can be greatly improved by 1 to 2 logs.

The statistical results in Table 1 show that the average recovery rate of the microfluidic particle sorter 200 for capturing A549/GFP lung cancer cells is 86% (N=8), the highest recovery rate is 95.5%, and the lowest recovery rate is 78.1%. Table 1 No. Number of target particles in the sample solution Target particle recovery number Recovery rate 1 65 60 92.3% 2 87 68 78.1% 3 28 twenty three 82.1% 4 91 77 84.6% 5 54 45 83.3% 6 75 67 89.3% 7 89 85 95.5% 8 29 twenty four 82.8%

Referring to FIG. 20 , a second embodiment of the microfluidic particle sorter 200 of the present invention differs from the first embodiment in that the second deterministic transverse displacement column arrays are not provided. For the sake of convenience, only the differences between the embodiments will be described below.

In the second embodiment, the microfluidic particle sorter 200 includes the chip body 3, and the first deterministic transverse displacement column arrays 4 arranged in a front-to-back arrangement in the microchannel 33 of the chip body 3. The sample liquid injection channel 34 and the buffer liquid injection channel 35 of the chip body 3 are adjacent to the first side 331 and the second side 332 of the microchannel 33, respectively, and the waste liquid outflow channel 36 and the target particle collection channel 37 are adjacent to the first side 331 and the second side 332, respectively.

The first deterministic transverse displacement column arrays 4 are arranged in a front-to-back arrangement in the microchannel 33. The first micro gap 415 of each first split column 410 extends obliquely from the water-facing side 411 backward toward the second side 332 to the water-receiving side 412.

The method for separating the target particles 901 and the non-target particles 902 in the second embodiment is the same as that in the first embodiment, so it will not be described in detail.

During implementation, the recovery rate and the recovery purity can be improved respectively through the structural design of the first embodiment and the second embodiment.

In addition, in another implementation of the second embodiment, only one first deterministic lateral displacement column array 4 may be provided, which can also be used to perform the sorting process of the target particles 901 and the non-target particles 902.

3 and 21 , a third embodiment of the microfluidic particle sorter 200 of the present invention differs from the first embodiment in the structural design of the chip body 3 and the arrangement of the first deterministic lateral displacement column arrays 4 and the second deterministic lateral displacement column arrays 5 .

In the third embodiment, the chip body 3 has two upper and lower spaced portions inside and connected to the microchannel 33 at both ends. The chip body 3 includes a substrate 31 and two cover plates 32 stacked on the substrate 31. The cover plate 32 located at the lower layer cooperates with the substrate 31 to define one of the microchannels 33, and the cover plates 32 stacked on top of each other cooperate to define another of the microchannels 33. The sample liquid injection channel 34 and the buffer liquid injection channel 35 are connected to the sample injection ends 333 of the microchannels 33 in the upper and lower directions, and the waste liquid outflow channel 36 and the target particle collection channel 37 are connected to the sample outflow ends 334 of the microchannels 33 in the upper and lower directions.

The first deterministic transverse displacement column arrays 4 and the second deterministic transverse displacement column arrays 5 are disposed in the microchannels 33 in a left-right mirror-symmetrical manner. Since the distribution and arrangement structure of the first deterministic transverse displacement column arrays 4 and the second deterministic transverse displacement column arrays 5 in each microchannel 33 is the same as that in the first embodiment, they will not be described in detail.

In the third embodiment, two cover plates 32 are stacked to form two microchannels 33. However, in practice, in other embodiments of the present invention, the number of cover plates 32 can be increased to correspond to the increase in the number of microchannels 33, and the first deterministic lateral displacement column arrays 4 and the second deterministic lateral displacement column arrays 5 can be set in each microchannel 33.

By stacking a plurality of cover plates 32 to form a plurality of microchannels 33, and disposing the first deterministic lateral displacement column arrays 4 and the second deterministic lateral displacement column arrays 5 in each of the microchannels 33, the structure can be used to perform sorting processing of the target particles 901 and the non-target particles 902 in a large amount of sample fluid, which helps to improve the processing efficiency.

In summary, through the structural design that each of the first split columns 410 of the first deterministic lateral displacement column arrays 4 has the first micro-gap 415, in addition to being able to sort the target particles 901 and the non-target particles 902 of different particle sizes through the arrangement structural design of the first split columns 410, the first micro-gap 415 of the first split columns 410 can also be used to allow the non-target particles 902 of larger particle sizes to be squeezed through by deformation, thereby achieving the effect of sorting the target particles 901 and the non-target particles 902 of similar particle sizes but different deformation energies, thereby helping to improve the sorting efficiency of the target particles 901 and the non-target particles 902 of various particle sizes in the sample fluid.

The present invention can further improve the sorting efficiency of the target particles 901 and the non-target particles 902 by arranging the first deterministic transverse displacement column arrays 4 and the second deterministic transverse displacement column arrays 5 in left-right mirror image symmetry in the microchannel 33. In addition, the sorting recovery rate or recovery purity of the target particles 901 can be improved by designing the width size of the first micro gaps 415 and the second micro gaps 515.

Therefore, the microfluidic particle sorter 200 of the present invention is indeed a very innovative creation and can indeed achieve the purpose of the present invention.

However, the above is only an embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. All simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still within the scope of the present patent.

200: Microfluidic particle sorter 3: Chip body 31: Substrate 32: Cover plate 33: Microchannel 331: First side 332: Second side 333: Sample injection end 334: Sample outflow end 335: Sorting interval 336: Converging interval 34: Sample liquid injection channel 341: Sample liquid injection section 35: Buffer liquid injection channel 36: Waste liquid outflow channel 361: Waste liquid outflow section 37: Target particle collection channel 4: First deterministic transverse displacement column array 41: First transverse displacement column array 410: First split column 411: Upstream side 412: Backward side 413: vertical section of the column 414: vertical section 415: first micro-gap 416: guide channel 5: second deterministic transverse displacement column array 51: second transverse displacement column array 510: second split column 511: water-facing side 512: water-receiving side 513: vertical section of the column 514: vertical section 515: second micro-gap 516: guide channel 800: flow direction 901: target particles 902: non-target particles

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: FIG. 1 is a three-dimensional diagram schematically illustrating the structure of a first embodiment of the microfluidic particle sorter of the present invention; FIG. 2 is an incomplete side sectional view schematically illustrating the structure of the first embodiment; FIG. 3 is an incomplete top view schematically illustrating the arrangement of a plurality of first deterministic transverse displacement column arrays and a plurality of second deterministic transverse displacement column arrays of the first embodiment in a microfluidic channel; FIG. 4 is a three-dimensional diagram schematically illustrating the structure of a first split column of the first embodiment; FIG. 5 is a partial enlarged view of FIG. 3; FIG. 6 is a three-dimensional diagram schematically illustrating the structure of a second split column of the first embodiment; FIG. 7 is a view similar to FIG. 5, illustrating another embodiment of the first split columns and the second split columns of the first embodiment; FIG. 8 to FIG. 14 are top views, schematically illustrating the appearance of other embodiments of the first split column and the second split column of the first embodiment; FIG. 15 to FIG. 17 are microscopic images of different parts along the flow direction of the specimen liquid when the first embodiment is used to sort blood cells and cancer cells in the specimen liquid; FIG. 18 is a microscopic image, illustrating the number of blood cells in the liquid after the traditional DLD sorter sorts A549/GFP lung cancer cells in the blood-A549 specimen liquid; FIG. 19 is a microscopic image diagram illustrating the number of blood cells in the liquid after the A549/GFP lung cancer cells in the blood-A549 specimen liquid are sorted and processed in the first embodiment; FIG. 20 is a top view schematically illustrating the arrangement of the first deterministic transverse displacement column arrays in the microchannel of a second embodiment of the microfluidic particle sorter of the present invention; and FIG. 21 is an incomplete side sectional view schematically illustrating the multi-layer microchannel structure of a third embodiment of the microfluidic particle sorter of the present invention.

3: Chip body

33: Microchannel

331: First side

332: Second side

335: Sorting interval

336: aggregation interval

4: First deterministic horizontal displacement column array

41: First horizontal displacement column row

410: The First Split Pillar

413: Vertically cut column part

415: The first micro gap

416: Guide channel

5: Second deterministic horizontal displacement column array

51: Second horizontal displacement column row

510: The Second Split Pillar

513: Vertically cut column part

515: Second micro gap

516: Guide channel

901: Target particles

902: Non-target particles

Claims (15)

A microfluidic particle sorter is suitable for sorting target particles and non-target particles in a sample liquid by deterministic lateral displacement technology, and comprises: A chip body having a microchannel extending along a length direction, the microchannel having an opposite sample injection end and a sample outflow end, and having a first side and a second side opposite in a width direction; and At least one first deterministic transverse displacement column array is arranged in the microfluidic channel, including a plurality of first transverse displacement column arrays arranged along the length direction and sequentially offset in the transverse direction toward the second side by a predetermined distance (Δd) toward the sample outflow end, each of the first transverse displacement column arrays having a plurality of first split columns arranged upright and spaced apart along the width direction, each of the first split columns having a water-facing side facing the sample injection end and a water-repelling side facing the sample outflow end, and having two spaced apart, mutually opposing, vertically cut columns defining the water-facing side and the water-repelling side. The vertically cut column parts cooperate to define a first micro gap extending from the water-facing side to the water-retaining side, and can be used for the non-target particles to pass through after deformation. Each of the first micro gaps is offset from the length direction (L) by a deflection angle (θ1), and extends obliquely toward the second side toward the sample outflow end, 1∘≤θ1≤89∘. The first transverse displacement column arrays cooperate in the microchannel to define a plurality of guide channels arranged along the width direction and interconnected, and extending obliquely toward the sample outflow end along the length direction toward the second side. A microfluidic particle sorter as described in claim 1, wherein the deflection angles (θ1) of the first micro gaps are different from each other. A microfluidic particle sorter as described in claim 1, wherein the deflection angles (θ1) of the first micro gaps are partially the same and partially different. A microfluidic particle sorter as described in claim 1, wherein the vertically cut column parts of each of the first split columns are structurally asymmetric when viewed from above. A microfluidic particle sorter as described in claim 1, wherein the vertically cut column parts of each of the first split columns are structurally symmetrical when viewed from above. In the microfluidic particle sorter as described in claim 1, the minimum particle size of the target particle is Dt, the narrow side width of the non-target particle after deformation is Ddnt, Dt＞Ddnt, wherein the arrangement spacing of the first split columns in the length direction (L) is D1, and the arrangement spacing in the width direction (W) is D2, D2≧D1, and 0.33＜Dt/D2＜1.2, and the width of each of the first micro gaps is Gp, Ddnt＜Gp＜0.8Dt. In the microfluidic particle sorter as described in claim 1, the particles are divided into target particles and non-target particles, the particle size of the target particles is Dt, and the narrow side width of the non-target particles after deformation is Ddnt, Dt＞Ddnt, wherein the arrangement spacing of the first crack columns in the length direction is D1, and the arrangement spacing in the width direction is D2, D2≧D1, and 0.33＜Dt/D2＜1.2, and the width of each of the first micro gaps is Gp, 0.2Dt＜Gp＜0.6Dt. The microfluidic particle sorter as described in any one of claims 1 to 7 further includes a second deterministic transverse displacement column array arranged in the microchannel and corresponding in number to the at least one first deterministic transverse displacement column array, and the structure of the second deterministic transverse displacement column array is mirror-symmetrical with the first deterministic transverse displacement column array in the width direction. The microfluidic particle sorter as described in any one of claims 1 to 7 comprises a plurality of first deterministic transverse displacement column arrays disposed in the microchannel and arranged in sequence along the length direction toward the sample outflow end, the center distance between two adjacent first split columns of each first deterministic transverse displacement column array being λ, and the first-ranked first transverse displacement column array in each first deterministic transverse displacement column array will be offset toward the second side by a distance λ relative to the last-ranked first transverse displacement column array. The microfluidic particle sorter as described in claim 9 further comprises a plurality of second deterministic transverse displacement column arrays disposed in the microchannel and arranged in sequence along the length direction toward the sample outflow end, wherein the structures of the second deterministic transverse displacement column arrays and the first deterministic transverse displacement column arrays are mirror-symmetrical in the width direction. A microfluidic particle sorter as described in claim 1, wherein the chip body also has a sample liquid injection channel and a buffer liquid injection channel connected at the sample injection end at intervals in the width direction, and a waste liquid outflow channel and a target particle collection channel connected at the sample outflow end at intervals in the width direction, and the buffer liquid injection channel and the target particle collection channel are relatively adjacent to the second side. A microfluidic particle sorter as described in claim 10, wherein the microchannel has a converging section between the second deterministic lateral displacement column array and the first deterministic lateral displacement column array on opposite sides, and two sorting sections located on both sides of the converging section in the width direction, the second deterministic lateral displacement column array and the first deterministic lateral displacement column array are respectively arranged in the sorting sections, and the chip body also has a sample liquid injection channel and a buffer liquid injection channel connected to the sample injection end at intervals in the width direction, and a buffer liquid injection channel connected to the sample injection end at intervals in the width direction. A waste liquid outflow channel and a target particle collection channel are provided at the sample outflow end. The sample liquid injection channel has two sample liquid injection sections respectively connected to the sorting sections and can be used to guide the sample liquid to be injected into the sorting sections respectively. The buffer liquid injection channel is located between the sample liquid injection sections and can be used to drain the buffer liquid into the collection section. The waste liquid outflow channel has two waste liquid outflow sections respectively connected to the sorting sections and can be used to guide the liquid discharged from the sorting sections. The target particle collection channel is located between the waste liquid outflow sections and can be used to receive the liquid from the collection section. A microfluidic particle sorter as described in any one of claims 1 to 7, wherein the chip body also has another microchannel, and the microchannels are spaced apart vertically, the chip body also has a sample liquid injection channel and a buffer liquid injection channel at the sample injection ends of the microchannels that are spaced apart laterally and connected vertically to the sample injection ends of the microchannels, and a waste liquid outflow channel and a target particle collection channel at the sample outflow ends of the microchannels that are spaced apart laterally and connected vertically to the sample outflow ends of the microchannels, and the number of the first deterministic lateral displacement column arrays is two or more and is arranged in the microchannels. A microfluidic particle sorter as described in claim 13, further comprising a second deterministic transverse displacement column array disposed in the microchannels and having an equal number to the first deterministic transverse displacement column array, wherein the structure of the second deterministic transverse displacement column array is mirror-symmetrical to the first deterministic transverse displacement column array in the width direction. A microfluidic particle sorter as described in claim 14, wherein each of the microchannels has a gathering zone between the corresponding second deterministic lateral displacement column array and the first deterministic lateral displacement column array on opposite sides, and two sorting zones located on both sides of the width direction of the gathering zone, and the second deterministic lateral displacement column array and the first deterministic lateral displacement column array are respectively arranged in the sorting zones.

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