Particle sorting system, method of use, and chip

Abstract

The application provides a particle sorting system, a use method and a chip, the microfluidic chip of the system comprises two-stage DLD channels, a first outlet of the first-stage DLD channels is communicated with an inlet of the second-stage DLD channels, and the second-stage DLD channels gather particles into linear queue flows according to a specified route. After receiving a sub-sorting task start instruction, the injection device is automatically controlled to inject a sample solution, the imaging device is automatically controlled to continuously shoot particle images, the categories of the particles in the images are acquired and recognized, and instructions corresponding to the categories of the particles are sent to the sorting device according to the categories; and the sorting device automatically moves the particles to a target outlet of the particle sorting chip to flow out according to the instructions sent by the processor. The scheme can improve the injection flow rate of the sample solution while ensuring that the flow rate of the target particles matches the imaging and sorting speed, break through the efficiency bottleneck of the particle sorting technology of the imaging and sorting in processing a large amount of sample solution, and meet the timeliness demand of blood cell sorting and the like scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of particle sorting, in particular to a particle sorting system, a use method and a chip. BACKGROUND

[0002] As an indispensable key preprocessing step in the fields of biomedical detection, in vitro diagnosis, cell analysis, etc., the technical performance of particle sorting technology directly affects the accuracy and reliability of subsequent detection and analysis results. The core goal of this technology is to achieve high-throughput and high-purity non-destructive separation of target particles (such as cells, exosomes, etc.) from complex mixed samples while strictly maintaining the biological activity and structural integrity of the target particles. In practical applications, especially in the sorting scenarios of target particles such as circulating tumor cells, stem cells or rare exosomes in whole blood samples, due to the complexity of whole blood samples and the extremely low content of target particles, the throughput level and the gentleness of the sorting technology are put forward more stringent requirements: not only need to ensure sufficient processing efficiency to meet the timeliness requirements of clinical detection, but also need to avoid damage to the biological activity of the target particles during the sorting process, so as to ensure the smooth development of subsequent cell culture, molecular detection and other experiments.

[0003] To achieve the above goal, a technical scheme of "microfluidic chip + imaging + dielectrophoresis sorting" has been proposed in the prior art. This scheme takes advantage of the micro-scale fluid control capability of the microfluidic chip, combines imaging technology to identify and locate particles in the sample in real time, and then realizes specific capture and separation of target particles through dielectrophoresis effect, to a certain extent, solves some problems of traditional sorting technology in separation precision and operation gentleness, and is currently applied in scenarios with fewer particles in particle solution or smaller sample solution volume.

[0004] However, the above-mentioned "microfluidic chip + imaging + dielectrophoresis sorting" technical scheme has significant application limitations: it is only suitable for processing samples with few particles or small sample solution volume. When facing practical application scenarios with large sample solution volume and more particles, the sorting efficiency of this scheme is greatly reduced, which easily leads to a significant increase in sorting time, and it is difficult to meet the timeliness requirements of blood cell sorting scenarios. SUMMARY

[0005] The purpose of the present specification is to provide a particle sorting system, a use method and a chip to solve the problem of low efficiency and poor timeliness in the case of using "gentle and non-destructive, high-precision" particle sorting technology to sort target particles from "a sample solution with a larger volume and more particles" in the prior art.

[0006] To solve the above technical problems, the first aspect of the present specification provides a particle sorting system, comprising: a particle sorting chip, comprising: a two-stage DLD channel, wherein the first-stage DLD channel has at least a first outlet and a second outlet, the first outlet is in communication with the inlet of the second-stage DLD channel, and the second-stage DLD channel aggregates particles into a linear queue flowing according to a specified route; the particle sorting system further comprises: an injection device for automatically injecting a sample solution in a storage tank into the inlet of the first-stage DLD channel during a particle sorting process; an imaging device for capturing images of particles at a specified position of the linear queue; a sorting device for automatically moving particles to a target outlet corresponding to a particle category to flow out according to instructions; and a processor for controlling the injection device to start automatically injecting the sample solution into the particle sorting chip after receiving an instruction to start a particle sorting task, controlling the imaging device to automatically and continuously capture particle images, acquiring and identifying the category of particles in the particle images, and sending instructions corresponding to the category of particles to the sorting device according to the category of particles.

[0007] In some embodiments, the injection device adjusts the injection speed of the sample solution according to the average flow rate of the target particle stream captured by the imaging device.

[0008] In some embodiments, the first-stage DLD channel comprises at least two segments in cascade, wherein each segment has a different particle size sorting range; and the particle size sorting ranges of the first-stage DLD channels in cascade have overlaps.

[0009] In some embodiments, the first-stage DLD channel has an asymmetric design, and the second-stage DLD channel has a symmetric design.

[0010] In some embodiments, the first-stage DLD channel comprises at least two parallel channels.

[0011] In some embodiments, each first-stage DLD channel is arranged in parallel with the second-stage DLD channel, and at least two parallel first-stage DLD channels are arranged on both sides of the second-stage DLD channel; and / or each first-stage DLD channel is arranged in parallel with the second-stage DLD channel, and at least two first-stage DLD channels are arranged on at least one side of the second-stage DLD channel.

[0012] In some embodiments, the shape, size and distribution parameters of the barrier pillars in each first-stage DLD channel are the same.

[0013] In some embodiments, the parameters of the barrier pillars in at least two channels in each first-stage DLD channel are different, so that the particle size sorting ranges of the at least two channels are different.

[0014] In some embodiments, the particle sorting chip comprises a reservoir interface to facilitate mounting of a container for transporting particle solution onto the particle sorting chip as a reservoir.

[0015] In some embodiments, the particle sorting chip comprises one or more reservoir interfaces.

[0016] In some embodiments, the particle sorting system is used for blood cell sorting.

[0017] The second aspect of the present specification provides a method of using a particle sorting system, for the particle sorting system of any one of the first aspect; the method comprises: after a sample solution is filled into a reservoir in communication with an inlet of a first-stage DLD channel, sending an instruction of starting a particle sorting task to the particle sorting system; after receiving the instruction of starting the particle sorting task, controlling the injection device to start injecting the sample solution into the inlet of the first-stage DLD channel, controlling the imaging device to start capturing particle images, acquiring and identifying the categories of the particles in the particle images, and sending an instruction corresponding to the category of the particles to the sorting device according to the category of the particles; and the sorting device automatically moves the particles to a target outlet corresponding to the category of the particles to flow out according to the instruction sent by the processor.

[0018] The third aspect of the present specification provides a particle sorting chip, comprising: a two-stage DLD channel, wherein the first-stage DLD channel has at least a first outlet and a second outlet, the first outlet is in communication with an inlet of a second-stage DLD channel, and the second-stage DLD channel aggregates particles into a linear queue flowing along a specified route.

[0019] The particle sorting system, use method and chip provided by the present specification can perform cross-sectional pre-reduction processing on the target particle-containing particle flow (i.e., the fluid component containing the target particles) under the premise of ensuring that the target particles are not lost by adding a first-stage DLD channel in front of a second-stage DLD channel of a particle sorting chip. Based on the principle of fluid mechanics, the pre-reduction processing can significantly improve the overall injection speed of the sample solution under the condition that the flow rate of the particle flow itself remains unchanged, so that the particle flow is preliminarily adapted to the speed requirement of imaging and sorting; further, the target particles in the particle solution flowing into the inlet are focused into a linear queue through the second-stage DLD channel, so that the cross-sectional area of the pre-reduced particle flow can be compressed again without losing the target particles, and thus even if the flow rate of the particle solution flowing into the inlet of the second-stage DLD channel is significantly increased, the particle flow can still further approach the imaging and sorting speed. As can be seen, by providing the first-stage DLD channel and the second-stage DLD channel, the present application can increase the injection flow rate of the sample solution while ensuring that the flow rate of the target particles to be detected matches the imaging and sorting speed, so that the particle sorting technology similar to "microfluidic chip + imaging + dielectrophoresis sorting" can be applied to "efficiently" sort target particles from "a sample solution with a larger volume and a larger number of particles", break through the efficiency bottleneck of processing a large amount of sample solution for this type of technology, and meet the timeliness requirements of blood cell sorting and other scenarios.

[0020] By providing the first-stage DLD channel and the second-stage DLD channel in cascade, the flow rate of the final particle flow to be detected (the particle flow to be detected refers to the part of the fluid containing the target particles) can be several hundred times or several thousand times different from the flow rate of the sample solution. Therefore, even if the imaging and sorting speed is slow, the particle sorting system, use method and chip provided by the present specification can significantly improve the injection speed of the sample solution while using "microfluidic chip + imaging + dielectrophoresis sorting", thereby improving the sorting efficiency of the sample solution and realizing high-throughput sorting of the sample solution. Experimental research has found that the particle sorting system, use method and chip provided by the present specification can sort 5ml of whole blood within half an hour, while the sorting processing time of the prior art is at least 1 hour.

[0021] Based on this, the particle sorting system, the use method and the chip provided in the specification can set the imaging device, the sorting device and the processor while using the microfluidic chip, and make the processor control the injection device to automatically inject the sample solution into the particle sorting chip after receiving the instruction of starting the particle sorting task, control the imaging device to automatically and continuously shoot the particle images, acquire and identify the list of particles in each particle image, and send the instruction corresponding to the particle category to the sorting device according to the category of the particle. Therefore, the particle sorting scheme provided in the specification realizes the combination of the advantages of “gentle and non-destructive, high-precision” and “high efficiency, high throughput” and automatic sorting without manual intervention.

[0022] The particle sorting chip provided in the specification is formed by cascading two DLD channels, each DLD channel can disperse the particle solution, so that the particle sorting chip and system can effectively prevent particle condensation and avoid particle congestion. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0024] Figure 1 A schematic diagram of the overall structure of the particle sorting system provided in the specification;

[0025] Figure 2 A schematic diagram of the overall structure of the first-stage DLD channel and the second-stage DLD channel;

[0026] Figure 3 A partial enlarged schematic diagram of the inlet of the first-stage DLD channel of a microfluidic chip;

[0027] Figure 4 A partial enlarged schematic diagram of the outlet of the first-stage DLD channel of a microfluidic chip;

[0028] Figure 5 A partial enlarged schematic diagram of the inlet of the second-stage DLD channel of a microfluidic chip;

[0029] Figure 6 A partial enlarged schematic diagram of the outlet of the second-stage DLD channel of a microfluidic chip;

[0030] Figure 7 A schematic diagram of the cascade of two first-stage DLD channels;

[0031] Figure 8 Another schematic view of the overall structure of the particle sorting system provided in the present specification. DETAILED DESCRIPTION

[0032] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0033] The technical solution of "microfluidic chip + imaging + dielectrophoresis sorting" in the prior art is only applicable to samples with a small number of particles or a small volume of sample solution, and the sorting efficiency is greatly reduced in the case of a large volume of sample solution and a large number of particles. The reason is that the imaging technology needs to consume a long time for the identification and positioning of a large number of particles, and the dielectrophoresis sorting process also needs to match a slow particle motion speed to ensure the separation accuracy, which together causes the overall sorting speed of the "imaging + dielectrophoresis sorting" scheme to be slow. The bottleneck of the sorting speed directly limits the injection speed of the sample solution in the microfluidic chip. If the injection speed is forcibly increased, it will lead to insufficient imaging identification and incomplete dielectrophoresis sorting, thereby reducing the sorting purity and accuracy.

[0034] In order to solve the problem that the "gentle and non-destructive, high-precision" particle sorting technology in the prior art has low efficiency and poor timeliness in the case of sorting target particles from a "large volume, large number of particle sample solution", the present specification provides a particle sorting system, as shown in Figure 1 The particle sorting system includes a particle sorting chip 10, an injection device 20, an imaging device 30, a sorting device 40 and a processor 50.

[0035] The particle sorting chip 10 includes two-stage DLD channels, a first-stage DLD channel 11 and a second-stage DLD channel 12 in a cascading relationship, that is, an outlet of the first-stage DLD channel 11 is in communication with an inlet of the second-stage DLD channel 12.

[0036] The first-stage DLD channel 11 has at least a first outlet and a second outlet, the first outlet is in communication with the inlet of the second-stage DLD channel 12, and the second-stage DLD channel 12 aggregates particles into a linear queue flowing according to a specified route. The second outlet of the first-stage DLD can be used as a waste liquid outlet for particle sorting.

[0037] Figure 2 Another schematic view of the overall structure of the first-stage DLD channel and the second-stage DLD channel. Figure 3Fig. 1 is a schematic diagram of a partial enlargement of an inlet of a first-stage DLD channel of a microfluidic chip, Figure 4 Fig. 2 is a schematic diagram of a partial enlargement of an outlet of the first-stage DLD channel of the microfluidic chip, Figure 4 C in Fig. 1 is connected to a waste pool, Figure 5 Fig. 3 is a schematic diagram of a partial enlargement of an inlet of a second-stage DLD channel of the microfluidic chip, Figure 6 Fig. 4 is a schematic diagram of a partial enlargement of an outlet of the second-stage DLD channel of the microfluidic chip.

[0038] A DLD channel (Deterministic Lateral Displacement Microchannel) is a particle separation tool based on microfluidic technology, and its core principle is to make particles of different sizes produce deterministic trajectory differences through an obstacle column array arranged in a specific pattern in a microchannel, thereby achieving efficient and lossless particle sorting.

[0039] The DLD channel includes an obstacle region, and the particles in the obstacle region are arranged in rows and columns, wherein the "row" direction refers to the direction of the obstacle column connecting line that makes an angle of less than 45° with the fluid injection direction at the channel inlet (or the extension direction of the channel side wall), and the "column" direction refers to the direction of the obstacle column connecting line that makes an angle of greater than 45° with the fluid injection direction at the channel inlet (or the extension direction of the channel side wall).

[0040] The obstacle column array in the first-stage DLD channel 11 is arranged in an asymmetric offset manner. For example, Figure 2 The black band-shaped pattern in the dashed box shown in Fig. 1 represents a first-stage DLD channel, and in combination with Figure 3 and Figure 4 it can be understood that each obstacle column in the first-stage DLD channel 11 is arranged in rows and columns, and the top view (i.e., the cross section parallel to the fluid flow direction) of the obstacle region in the first-stage DLD channel 11 has an asymmetric structure.

[0041] The first-stage DLD channel 11 causes each particle to be distributed according to the particle size in the width direction (i.e., the direction substantially perpendicular to the fluid flow direction) at the end of the obstacle region. For example, from one end to the other end of the width direction at the end of the obstacle region, the particles are distributed from small to large or from large to small.

[0042] The width of each outlet of the first-stage DLD channel 11 is less than the width of the end of the barrier region, and at least one of the outlets of the first-stage DLD channel 11 is used to introduce particles in a specified size range into the second-stage DLD channel 12, which is referred to as the first outlet. There can be one first outlet. There can also be more than one first outlet if the width of the end of the barrier region is wide enough, and different outlets are used to introduce particles in non-continuous size ranges into the second-stage DLD channel 12.

[0043] By arranging the first-stage DLD channel 11 before the second-stage DLD channel 12, the cross-sectional area of the flow of particles to be detected (which refers to the partial flow of fluid containing the target particles) can be reduced in advance without losing the target particles, so that the injection speed of the sample solution can be greatly increased without changing the flow rate of the flow of particles to be detected, and the flow of particles to be detected can be closer to the imaging and sorting speed even if the injection speed of the sample solution is greatly increased, and thus the particle sorting technology like "microfluidic chip + imaging + dielectrophoresis sorting" that is "gentle and non-destructive and high-precision" can be applied to efficiently sort the target particles from a "sample solution with a large volume and a large number of particles".

[0044] In a case where the target particles are to be sorted from a particle solution, a particle sorting chip whose size sorting range of the first-stage DLD channel 11 contains the size range of the target particles can be selected. For example, if the size range of the target particles is 9-10 μm, a particle sorting chip whose size sorting range of the first-stage DLD channel 11 is 2-15 μm can be selected. The size sorting range of the first-stage DLD channel 11 can be much larger than the size range of the target particles.

[0045] As can be seen, the purpose of the first-stage DLD channel 11 in the present application is not to sort the target particles (in fact, the particles in the solution flowing out of the first outlet of the first-stage DLD channel are not necessarily the target particles to be sorted), but to greatly reduce the flow rate of the particle solution to be sorted without changing the injection speed of the particles to match the subsequent image-based sorting speed.

[0046] In the particle sorting chip, the first inlet A is used to inject the sample solution, and the second inlet B is used to inject the buffer solution (i.e., the sheath fluid).

[0047] The cross-section of the first outlet of the particle sorting chip is smaller than the cross-section of the second-stage DLD channel. After the sample solution flows from the first-stage DLD channel into the second-stage DLD channel through the first outlet, the flow channel becomes wider, so that the flow rate of the target particles to be sorted is slowed down, and is further closer to the subsequent image-based sorting speed.

[0048] In some embodiments, each first-stage DLD channel 11 may include at least two cascaded segments, each segment having a different particle size sorting range, and the particle size sorting ranges of the cascaded segments of the first-stage DLD channel 11 overlap. For example, a first-stage DLD channel F is composed of two cascaded segments, where the first segment F1 has a particle size sorting range of 10 μm and the second segment F2 has a particle size sorting range of 15 μm. Therefore, after the first segment F1 and the second segment F2 of the first-stage DLD channel F are cascaded, the first-stage DLD channel F can achieve particle sorting in the 10-15 μm particle size range. Figure 7 In the process, particles with a diameter greater than 10 μm flow out through port f1, particles with a diameter greater than 15 μm flow out through port f2, and particles with a diameter of 10-15 μm flow out through port f3.

[0049] By setting the first-stage DLD channel 11 as a series of channels with different particle size sorting ranges, a more precise particle size sorting range that cannot be achieved by the barrier column array design can be realized, thereby further reducing the number of impurity particles entering the second-stage DLD channel 12 and reducing the number of particles that need to be sorted one by one in the subsequent stages.

[0050] In some embodiments, such as Figure 2 and Figure 8 As shown, the first-level DLD channel 11 includes at least two parallel channels. Figure 2 It includes four items, Figure 8 There are five channels. The term "parallel" means that the outlets of these channels converge at the inlet of the second-stage DLD channel. By setting the first-stage DLD channel 11 as multiple parallel channels, the flux of the particle solution to be sorted can be further reduced without losing target particles. This allows for a further reduction in the flow rate of the particle solution to be sorted while maintaining the particle injection rate, thus matching the subsequent sorting rate.

[0051] In some embodiments, each first-level DLD channel 11 and the second-level DLD channel 12 are arranged in parallel, and at least two parallel first-level DLD channels 11 are arranged on both sides of the second-level DLD channel 12.

[0052] In some embodiments, at least two of the at least two parallel first-level DLD channels 11 are located on the same side of the second-level DLD channel.

[0053] In some embodiments, each first-level DLD channel 11 is arranged in parallel with the second-level DLD channel 12, and at least two parallel first-level DLD channels 11 are arranged on both sides of the second-level DLD channel 12; furthermore, at least two first-level DLD channels 11 are arranged on at least one side of the second-level DLD channel 12. In this case, the number of first-level DLD channels 11 on both sides of the second-level DLD channel 12 can be the same or different. For example, Figure 8 Two parallel first-level DLD channels 11 are set on one side of the second-level DLD channel 12, and three parallel DLD channels 11 are set on the other side. Alternatively, one first-level DLD channel 11 can be set on one side of the second-level DLD channel 12, and two parallel DLD channels 11 can be set on the other side.

[0054] The second-level DLD channel 12 is designed asymmetrically, such as... Figure 5 As shown, combined with Figure 2 The axis of symmetry of the second-level DLD channel ( Figure 5 The position shown in Figure D extends along the fluid inflow direction at the inlet of the second-stage DLD channel 12, and the angle between the axis of symmetry and the fluid inflow direction at the inlet of the second-stage DLD channel 12 is less than 45°. The barrier column design within the second-stage DLD channel 12 causes the inflowing particles (in the width direction of the second-stage DLD channel) to flow towards the axis of symmetry and to flow in a linear queue along the axis of symmetry. That is, downstream of the second-stage DLD channel 12, the particles flow in a linear queue along the extension direction of the axis of symmetry.

[0055] The separation radius of the second-stage DLD channel is smaller than the radius of the smallest particle among all the particles to be screened (in general, the parameter design of the barrier pillars in the channel of the microfluidic chip makes particles with a diameter larger than the separation radius deviate from their original movement path, while particles with a diameter smaller than the separation radius basically move along their original path), thus allowing all target particles of the particle size range to be screened to move toward the symmetry axis of the channel.

[0056] In some embodiments, the barrier column parameters in the second-stage DLD channel 12 are set such that particles larger than the separation radius move toward the channel axis, and the barrier column parameters on both sides of the second-stage DLD channel axis are symmetrical about the channel axis. As an alternative embodiment, the channel axis can also be replaced with a channel center line that is off-center from the channel center but parallel to the channel extension direction. As an alternative embodiment, the barrier column parameters on both sides of the aforementioned channel axis or channel center line do not need to be symmetrical, as long as the separation radius of the barrier columns on both sides of the line (referring to the aforementioned channel axis or channel center line) is greater than all particle size ranges to be screened, and the particles on both sides of the line move toward the line.

[0057] The second-stage DLD channel gathers target particles from the particle solution flowing into it onto the axis of symmetry, significantly reducing the cross-sectional area of ​​the particle stream (the fluid component containing the target particles) without losing target particles. Based on hydrodynamic properties, this cross-sectional area reduction effect can significantly increase the injection rate of the particle solution while keeping the flow velocity of the target particles constant. This allows the particle stream to approach imaging and sorting speeds even with a significant increase in the inflow velocity of the particle solution at the inlet of the second-stage DLD channel. Consequently, this "mild, non-destructive, and high-precision" particle sorting technology, similar to "microfluidic chip + imaging + dielectrophoretic sorting," can be applied to efficiently sort target particles from "large-volume sample solutions with a large number of particles," overcoming the efficiency bottleneck of this type of technology in processing large sample solutions and meeting the timeliness requirements of scenarios such as blood cell sorting.

[0058] The injection device 20 is used to automatically inject the sample solution from the reservoir into the inlet of the first-stage DLD channel 11 during the particle sorting process. The sample solution here refers to the particle solution initially injected into the particle sorting chip 10.

[0059] The injection device 20 may specifically be a pneumatic device. The specific structure of the injection device 20 is well known to those skilled in the art and will not be described in detail here.

[0060] After receiving the instruction to start the particle sorting task, the injection device 20 can inject the sample solution into the inlet of the first-stage DLD channel 11 at a constant or variable speed.

[0061] In some embodiments, the injection device 20 can adjust the injection rate of the sample solution based on the average flow rate of the target particle stream captured by the imaging device 30. For example, the imaging device 30 captures an image every first predetermined time interval t1 (e.g., 0.5 s). The processor 50 arranges the images captured by the imaging device 30 into an image stream according to time. If the processor 50 detects that the time interval between two consecutive occurrences of adjacent particles is greater than a second time interval t2 (t2 is greater than t1, and t2 is at least twice t1) based on the image stream (i.e., the processor 50 performs a judgment, and the judgment result is yes), then the injection rate of the sample solution is increased. The step size for increasing the injection rate can be preset, and the judgment is performed every third predetermined time interval t3. Each time the judgment result is yes, the injection rate is increased by one step. If the processor 50 detects that the time interval between two consecutive occurrences of adjacent particles is less than a fourth predetermined time interval t4 (t4 is less than t1, and t1 is at least x times t4, where the value of x is determined according to the particle analysis rate) based on the image stream, then the injection rate of the sample solution is decreased. The step size for reducing the injection rate can be preset. This judgment is executed every five predetermined time intervals t5. If the judgment result is yes, the injection rate is reduced by one step. The values ​​of t3 and t5 can be the same.

[0062] The above settings have the following technical effects: 1. Precisely match imaging speed to ensure imaging quality: When the time interval between adjacent particles in the particle stream is too large (N consecutive times exceeding t2), step-by-step speed increase avoids imaging gaps and low analysis efficiency caused by sparse particle distribution; when the particle interval is too small (M consecutive times less than t4), step-by-step speed decrease prevents imaging blurring and inaccurate feature recognition caused by dense particle overlap, ensuring that the particle stream passes through the imaging area with optimal density, so that the imaging speed dynamically adapts to the particle stream, and always ensures the clarity and integrity of particle imaging. 2. Real-time response to sample fluctuations to improve adjustment stability: Based on the preset judgment period (t3, t5) and speed adjustment step size, the injection speed is smoothly iteratively adjusted, avoiding the impact of sudden speed changes on the stability of the particle stream (in line with the technical characteristics of "mild and non-destructive"); at the same time, the judgment logic of "N consecutive times / M times" filters out accidental fluctuations, ensuring the accuracy of adjustment commands and adapting to the dynamic changes in particle concentration in the sample solution. 3. Optimize particle analysis efficiency and expand system adaptability: The dynamic adjustment mechanism achieves real-time matching between injection speed and imaging analysis capability without manual intervention. This avoids both excessively slow injection speeds leading to lengthy overall analysis cycles and excessively fast speeds causing imaging failures, significantly improving the processing efficiency of large-volume, high-particle-concentration samples. Flexible parameter settings (N, M, t1-t5, x, adjustment step size) allow adaptation to particle detection needs of different particle sizes and analysis speeds, enhancing the versatility and scenario adaptability of the "microfluidic chip + imaging + dielectrophoretic sorting" system. 4. Lay a precise foundation for subsequent sorting stages: A stable particle flow matched to the imaging speed ensures that the imaging device accurately captures the characteristic information of each target particle, providing reliable data support for subsequent dielectrophoretic sorting. This avoids sorting misalignment and target particle loss caused by particle flow speed imbalances, further strengthening the core advantages of the entire sorting system: "high precision and high efficiency."

[0063] The particle sorting system can be equipped with a storage tank, and the first inlet of each first-stage DLD channel 11 is connected to the storage tank. The injection device 20 can simultaneously inject sample solution into each first-stage DLD channel 11 by adjusting the air pressure in the storage tank.

[0064] The particle sorting system can also be configured with "multiple" reservoirs, each reservoir being connected to a different first-stage DLD channel 11, and each reservoir can be connected to one or more first-stage DLD channels 11. Each reservoir is controlled by a different injection device 20 to inject sample solution. Figure 3 A schematic diagram is shown showing that different first-stage DLD channels are connected to different storage tanks.

[0065] Imaging device 30 is used to capture images of particles at designated locations in a linear array. Imaging device 30 may include a light source and a camera. The specific structure of imaging device 30 is well known to those skilled in the art and will not be described in detail here.

[0066] Referring to the above, this designated position is located on the axis of symmetry of the second-level DLD channel 12. In other words, the camera can be fixed in position and face the designated position on the axis of symmetry to take pictures.

[0067] The sorting device 40 is used to automatically move particles to the target outlet corresponding to the particle category for outflow according to instructions.

[0068] To achieve non-destructive particle sorting, a particle sorting region can be set downstream of the second-stage DLD channel 12 of the particle sorting chip, and electrodes can be arranged in the particle sorting region. This particle sorting region is located on the symmetry axis of the second-stage DLD. Figure 6 The location E in the diagram represents the particle sorting region. For example... Figure 8 As shown, the particle sorting region E can be connected to the target outlets of different types of particles. Figure 6 The target exits for different types of particles are not shown.

[0069] The sorting device 40 can use dielectrophoresis to achieve particle sorting. Conventional immunomagnetic bead microfluidics requires the addition of immunomagnetic beads and various reagents, which may not be suitable for situations requiring high-purity, label-free cells, or for simultaneously sorting multiple target blood cells. Inertial microfluidics requires high flow rates, while the particles captured by the imaging device in this scheme move at a relatively slow speed, therefore, inertial microfluidics is also unsuitable for implementing the sorting device 40.

[0070] The sorting device 40 may include multiple sorting channels that operate in parallel (not shown in the accompanying drawings). Accordingly, the particle sorting area is provided with a flow guide channel to uniformly guide the particles that flow linearly along the axis of symmetry of the second DLD channel 12 into different sorting channels for sorting, thereby improving the sorting efficiency.

[0071] The processor 50 is configured to control the injection device 20 to start injecting sample solution into the particle sorting chip 10 after receiving the instruction to start the particle sorting task, control the imaging device 30 to automatically and continuously capture particle images, acquire and identify the particle categories in the particle images, and send instructions corresponding to the particle categories to the sorting device 40 according to the particle categories.

[0072] The particle categories can include various target particle categories and non-target particles, with different particle categories corresponding to different instructions. After the processor 50 sends different instructions to the sorting device 40, the sorting device 40 can automatically move the particles to the corresponding target outlet for outflow in response to the instructions.

[0073] The particle sorting system provided in this manual, by adding a first-stage DLD channel before the second-stage DLD channel of the particle sorting chip, can pre-reduce the cross-sectional area of ​​the particle stream containing target particles (i.e., the fluid component containing target particles) without losing target particles. Based on fluid dynamics principles, this pre-reduce process can significantly improve the overall injection speed of the sample solution while keeping the flow velocity of the particle stream constant, allowing the particle stream to initially adapt to the speed requirements of imaging and sorting. Furthermore, by focusing the target particles in the particle solution flowing into the inlet into a linear queue through the second-stage DLD channel, a second significant compression of the pre-reduced cross-sectional area of ​​the particle stream can be achieved without losing target particles. Thus, even if the inflow velocity of the particle solution at the inlet of the second-stage DLD channel is greatly increased, the particle stream can still approach the imaging and sorting speed. Therefore, this solution, through the setting of the first-level DLD channel and the second-level DLD channel, can ensure that the flow rate of the target particles is matched with the imaging and sorting speed while increasing the injection flow rate of the sample solution to be tested. This enables the "mild, non-destructive, and high-precision" particle sorting technology, such as "microfluidic chip + imaging + dielectrophoretic sorting", to be applied to "efficiently" sorting target particles from "sample solutions with large volume and a large number of particles". This breaks through the efficiency bottleneck of this type of technology in processing large amounts of sample solutions and meets the timeliness requirements of scenarios such as blood cell sorting.

[0074] By configuring the first and second cascaded DLD channels described above, the flow rate of the final particle stream to be detected (the particle stream refers to the fluid containing the target particles) can differ from the flow rate of the sample solution injected into the microfluidic chip by hundreds or even thousands of times. Therefore, even with slower imaging and sorting speeds, the particle sorting system provided in this manual can significantly increase the injection speed of the sample solution while employing "microfluidic chip + imaging + dielectrophoretic sorting," thereby improving the sorting efficiency of the sample solution and achieving high-throughput sorting. Experimental studies have shown that the particle sorting system provided in this manual can sort 5 ml of whole blood within half an hour, while the sorting processing time of existing technologies is at least one hour.

[0075] Based on this, the particle sorting system provided in this specification is able to integrate an imaging device, a sorting device, and a processor while employing a microfluidic chip. Upon receiving the command to begin the particle sorting task, the processor controls the injection device to automatically inject sample solution into the particle sorting chip, controls the imaging device to automatically and continuously capture particle images, acquires and identifies a list of particles in each image, and sends commands corresponding to the particle category to the sorting device. Therefore, the particle sorting solution provided in this specification achieves a balance between the advantages of "gentle and non-destructive, high precision" and "high efficiency, high throughput," as well as automated sorting without human intervention.

[0076] The particle sorting chip provided in this manual is composed of two cascaded DLD channels. Each DLD channel can disperse the particle solution, so the particle sorting chip and system can effectively prevent particle agglomeration and avoid particle congestion.

[0077] This manual also provides the method of using the above-mentioned particle sorting system, specifically: first, place the sample solution into the storage tank connected to the inlet of the first-stage DLD channel, and then send a command to the particle sorting system to start the particle sorting task.

[0078] In some embodiments, the reservoir is detachable, and the particle sorting chip includes a reservoir interface to allow a container for transferring the particle solution to be mounted onto the particle sorting chip as a reservoir. In this case, the reservoir can be removed first, the sample solution poured into the reservoir, and then the reservoir can be mounted onto the reservoir interface. The particle sorting chip can have one or more reservoir interfaces.

[0079] Users can send a command to the processor to start the particle sorting task via buttons, voice, or gestures. After sending the start command, no further user intervention is required. Upon receiving the command, the processor controls the injection device to begin injecting sample solution into the inlet of the first-stage DLD channel, controls the imaging device to begin capturing particle images and identifying the particle categories within the images, and sends commands corresponding to the particle categories to the sorting device. The dispensing device automatically moves the particles to the target outlet of the particle sorting chip for outflow based on the commands sent by the processor. These operations are all automatically triggered by the user-sent "particle sorting task start command" and are automatically implemented by the processor in coordination with the various devices.

[0080] In some embodiments, the shape, size, and distribution parameters of the barrier pillars within each first-stage DLD channel are identical, meaning that the particle size sorting range of these first-stage DLD channels is the same. This ensures that the particle size range of particles flowing into the second-stage DLD channel from each first-stage DLD channel is the same. This particle sorting chip design is particularly suitable for sorting target particles with continuous particle size ranges from the same or different particle solutions.

[0081] In some embodiments, at least two channels in each first-stage DLD channel have different barrier column parameters, resulting in different particle size sorting ranges for the at least two channels. Barrier column parameters may include the shape, size, row spacing, column spacing, and offset direction of the rows and columns.

[0082] With this setup, the particle sorting system can separate multiple target particles with discontinuous particle size ranges from the same or different particle solutions.

[0083] In some embodiments, the method of using the particle sorting system further includes: selecting a particle sorting system with a reservoir when it is necessary to sort particles from the same sample; and selecting a particle sorting system with the same number of reservoirs as the sample solution types when it is necessary to sort particles from different sample solutions.

[0084] This specification also provides a particle sorting chip, including: two-stage DLD channels, wherein the first-stage DLD channel has at least a first outlet and a second outlet, the first outlet is connected to the inlet of the second-stage DLD channel, and the second-stage DLD channel gathers particles into a linear queue flowing along a specified route.

[0085] For details on particle sorting chips, please refer to the description of particle sorting chips above, which will not be repeated here.

[0086] The above description is merely an embodiment of one or more embodiments of this specification and is not intended to limit the scope of these embodiments. Various modifications and variations can be made to these embodiments by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of the claims.

Claims

1. A particle sorting system, characterized in that, include: The particle sorting chip includes: two-stage DLD channels, wherein the first-stage DLD channel has at least a first outlet and a second outlet, the first outlet being connected to the inlet of the second-stage DLD channel, the second-stage DLD channel being used to gather particles into a linear queue flowing along a specified route; the setting of the barrier column parameters in the second-stage DLD channel causes particles larger than the separation radius to move toward the central line of the channel parallel to the channel extension direction, thereby forming a linear queue; The particle sorting system also includes: An injection device is used to automatically inject the sample solution from the reservoir into the inlet of the first-stage DLD channel during the particle sorting process; An imaging device used to capture images of particles at specified locations in a linear array; The sorting device is used to automatically move particles to the target outlet corresponding to the particle category according to instructions for them to flow out. The processor is configured to, upon receiving an instruction to start a particle sorting task, control the injection device to automatically inject sample solution into the particle sorting chip, control the imaging device to automatically and continuously capture particle images, acquire and identify the particle categories in the particle images, and send instructions corresponding to the particle categories to the sorting device based on the particle categories.

2. The particle sorting system according to claim 1, characterized in that, The injection device adjusts the injection rate of the sample solution according to the average flow rate of the target particle stream captured by the imaging device.

3. The particle sorting system according to claim 1, characterized in that, The first-stage DLD channel comprises at least two cascaded segments, each with a different particle size sorting range; and the particle size sorting ranges of the cascaded segments of the first-stage DLD channel overlap.

4. The particle sorting system according to claim 1, characterized in that, The first-stage DLD channel has an asymmetrical design, while the second-stage DLD channel has a symmetrical design.

5. The particle sorting system according to claim 1, characterized in that, The first-level DLD channel includes at least two parallel channels.

6. The particle sorting system according to claim 5, characterized in that, Each first-level DLD channel is set in parallel with the second-level DLD channel, and at least two parallel first-level DLD channels are set on both sides of the second-level DLD channel; And / or, Each first-level DLD channel is set in parallel with the second-level DLD channel, and at least two first-level DLD channels are set on at least one side of the second-level DLD channel.

7. The particle sorting system according to claim 5, characterized in that, The shape, size, and distribution parameters of the obstacle pillars in each first-level DLD channel are the same.

8. The particle sorting system according to claim 5, characterized in that, In each first-stage DLD channel, at least two channels have different barrier column parameters, resulting in different particle size sorting ranges for the at least two channels.

9. The particle sorting system according to claim 1, characterized in that, The particle sorting chip includes a liquid storage interface, which allows a container for transporting particle solutions to be mounted on the particle sorting chip and used as a liquid storage tank.

10. The particle sorting system according to claim 1, characterized in that, The particle sorting system is used for blood cell sorting.

11. A method of using a particle sorting system, characterized in that, The particle sorting system according to any one of claims 1 to 10; the method comprising: After the sample solution is filled into the storage tank connected to the inlet of the first-stage DLD channel, a command to start the particle sorting task is sent to the particle sorting system. After receiving the instruction to start the particle sorting task, the injection device is controlled to start injecting sample solution into the inlet of the first-stage DLD channel, the imaging device is controlled to start capturing particle images, acquire and identify the particle categories in the particle images, and send instructions corresponding to the particle categories to the sorting device according to the particle categories; the sorting device automatically moves the particles to the target outlet corresponding to the particle category for outflow according to the instructions sent by the processor.

12. A particle sorting chip, characterized in that, include: The two-stage DLD channel, wherein the first-stage DLD channel has at least a first outlet and a second outlet, the first outlet being connected to the inlet of the second-stage DLD channel, the second-stage DLD channel being used to gather particles into a linear queue flowing along a specified route; the setting of the barrier column parameters in the second-stage DLD channel causes particles larger than the separation radius to move toward the central line of the channel parallel to the channel extension direction, thereby forming a linear queue.

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