Sample filtration device and sample filtration method

Abstract

A sample filtering device and a sample filtering method, the sample filtering device comprises a storage container, a driving member, a filter and a weight detector which are sequentially communicated, the driving member comprises a liquid outlet end which is communicated with the filter, a first pipeline is communicated between the liquid outlet end and the filter, a second pipeline is connected between the liquid outlet end and the storage container, the second pipeline has a damping effect, and is used for returning the fluid in the first pipeline to the storage container when the fluid pressure in the first pipeline exceeds a preset value; the storage container is arranged on the weight detector, the weight detector is used for detecting the weight of the fluid in the storage container, and whether the filter is blocked can be judged according to the fluid weight change value. The sample filtering device provided by the application can realize low-cost detection in a contact mode without introducing a pollution source, can predict pipeline pressure and has an overpressure safety protection function, reduces the risk of liquid overflow, pump pipe and filter membrane damage caused by filter blockage, and has high detection reliability.

Description

Technical Field

[0001] This application relates to the field of sample processing technology, and in particular to a sample filtering device and a sample filtering method. Background Technology

[0002] Extracellular vesicles (EVs) are vesicle-like nanoparticles secreted or shed from cell membranes. EVs typically range in size from 30 to 200 nm and have a bilayer membrane structure similar to the cell membrane. Studies have shown that EVs can play a significant role in early disease screening, disease treatment, and regeneration. This is mainly due to the fact that EVs contain complex biomolecules such as proteins and nucleic acids, participating in the transmission of information in various physiological and pathological processes, including immune signaling pathways and inflammation amplification.

[0003] EVs exhibit high specificity, showing significant differences from other impurities in their sample source, primarily in size, density, and surface functional groups. These differences allow for the screening, purification, and separation of EVs. Commonly used EV purification methods include ultracentrifugation, density gradient centrifugation, ultrafiltration (dead-end filtration and tangential flow filtration), polymer precipitation, size exclusion chromatography, and affinity trapping.

[0004] However, due to the diverse and varied sources of exosomes, and the complexity and difficulty in thoroughly analyzing the other biological and chemical components in each sample besides exosomes, the separation process of exosomes has become very limited. It is extremely difficult and challenging to achieve the separation of the above types of exosomes using one or more separation methodologies, and to reach the goals of high purity (with almost no other substances besides exosomes) and high yield (rich in exosomes, with exosome particle loss of <30% compared to the original solution). Summary of the Invention

[0005] In view of this, in order to solve at least one of the above technical problems, it is necessary to propose a sample separation device and a sample separation method.

[0006] In a first aspect, embodiments of this application provide a sample filtration device, comprising: a storage container, a driving component, and a filter connected in sequence. The storage container is used to store fluid. The driving component includes a liquid outlet end connected to the filter. A first pipeline connects the liquid outlet end to the filter. A second pipeline connects the liquid outlet end to the storage container. The second pipeline has a damping function, used to return the fluid in the first pipeline to the storage container when the fluid pressure in the first pipeline exceeds a preset value. The sample filtration device also includes a weight detector. The storage container is disposed on the weight detector. The weight detector is used to detect the weight of the fluid in the storage container to obtain a change in the weight of the fluid in the storage container. The pressure in the first pipeline can be determined based on the change in the fluid weight.

[0007] In some possible embodiments, the inner diameter and length of the second conduit are calculated using the following formula (1): (1), where ΔP: target pressure drop, since the outlet ends of the first pipeline and the second pipeline are at atmospheric pressure, the target pressure drop is the liquid outlet pressure of the drive component; λ: friction coefficient; L: pipeline length; D: pipeline inner diameter; ρ: fluid density; v: average flow velocity of the fluid in the pipeline, the average flow velocity is obtained by formula: Calculate, where Q is the volumetric flow rate.

[0008] In some possible embodiments, the pressure at the outlet of the drive element does not exceed the maximum pressure resistance of the filter.

[0009] In some possible embodiments, the sample filtering device further includes a fluid detector disposed outside the second conduit, the fluid detector being used to detect whether fluid is flowing through the second conduit.

[0010] In some possible embodiments, the fluid detector is disposed at one end of the second conduit near the storage container; and / or, the fluid detector includes an ultrasonic fluid identification sensor or an optically coupled fluid identification sensor.

[0011] In some possible embodiments, the sample filtering device further includes an alarm that is activated when the weight detector detects a change in the fluid weight in the storage container exceeding a preset threshold.

[0012] In some possible embodiments, the drive is a peristaltic pump; and / or, the filter includes a Nyquist filter, a chromatography column, or a tangential flow filter.

[0013] Secondly, embodiments of this application provide a sample filtration method using the sample filtration device described above, comprising: providing driving force through the driving component to inject a sample in the storage container into the filter via the first pipeline for filtration, wherein, during the sample filtration process, the weight detector detects the weight of the fluid in the storage container to obtain a fluid weight change value, and determines the pressure in the first pipeline based on the fluid weight change value, thereby determining whether the filter is clogged.

[0014] In some possible embodiments, when the sample filtering device includes the fluid detector, the method further includes, during the sample filtering process, detecting whether fluid flows through the second pipeline using the fluid detector, and determining whether the filter is clogged based on the detection result.

[0015] In some possible embodiments, the method further includes: determining whether the weight detector is working properly based on the detection result of the fluid detector, and determining whether the fluid detector is working properly based on the detection result of the weight detector.

[0016] The sample filtration device provided in this application, by incorporating a second pipeline and a weight detector, can predict the fluid pressure in the first pipeline during filtration or purification without relying on a pressure gauge (as contact between the pressure gauge and the sample poses a risk of contamination). This reduces overflow and pump issues caused by filter blockage, as well as membrane damage that could affect filtration or purification efficiency. Furthermore, the second pipeline design allows for pressure release within the pipeline, providing overpressure protection. It can also predict the flow rate and pressure through the filter, providing a basis for judging the purification or filtration effect. In addition, this contact detection method offers high reliability, is pollution-free, and low-cost, making it suitable for filtration processes in various scenarios. Using the sample filtration device of this application, high-purity and high-yield separation and recovery of exosomes can be achieved. Attached Figure Description

[0017] Figure 1 This is a hardware architecture diagram of a sample filtering device provided in an embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the structure of a sample filtering device provided in an embodiment of this application.

[0019] Figure 3 For the purposes of this application Figure 2 A schematic diagram of the data verification structure of the sample filtering device in the image.

[0020] Figure 4 This is a schematic diagram of the structure of a sample filtering device provided in another embodiment of this application.

[0021] Figure 5 This is a flowchart of a sample filtering method provided in an embodiment of this application.

[0022] Explanation of main component symbols Sample filtration devices 100, 200; storage container 1; inlet pipe 11; drive unit 2; inlet end 21; outlet end 22; filter 3, 3a; filter membrane 31; outlet 32, 33; collection container 4; first pipe 5; second pipe 6; fluid detector 7; weight detector 8; three-way valve 9; display and control module 10; controller 101; alarm 102; display screen 103.

[0023] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0025] It should be noted that when a component is described as "fixed to" or "mounted to" another component, it can be directly on the other component or may be interspersed with an intermediate component. When a component is described as "set to" another component, it can be directly set on the other component or may be interspersed with an intermediate component. The term "and / or" as used herein includes all and any combination of one or more of the associated listed items.

[0026] It should be noted that although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown in the flowchart. The methods disclosed in the embodiments of this application include one or more steps or actions for implementing the method. Method steps and / or actions may be interchanged with each other without departing from the scope of the claims. Unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0027] The separation and purification process of exosomes mainly includes clarification filtration and subsequent sterilization filtration. Traditionally, peristaltic pumps are used as the power source to pump the sample into the filter for purification. However, the inventors discovered that when the filter becomes oversaturated or clogged, the positive pressure in the tubing connecting the peristaltic pump and the filter increases dramatically, even reaching 200 kPa to several MPa. This pressure can easily lead to pump-tubular phenomena or membrane rupture, rendering the filter ineffective. Since purification requires maintaining a sterile environment, the liquid generally cannot come into contact with the pressure sensor. Therefore, non-contact pressure sensors are used for pressure detection, which is complex and costly.

[0028] For this purpose, please refer to Figure 1 and Figure 2 As shown, this application provides a novel sample filtration device 100, which can be used for sample pretreatment, terminal filtration, purification separation (tangential flow filtration), and chromatographic filtration (gel permeation chromatography filtration), etc. The sample is a fluid, including but not limited to biological samples, such as exosomes.

[0029] The sample filtration device 100 includes a storage container 1, a drive unit 2, a filter 3, and a collection container 4 connected in sequence. The storage container 1 stores the aforementioned sample. The drive unit 2 includes an inlet end 21 and an outlet end 22. The inlet end 21 is connected to the storage container 1 via an inlet pipe 11, and the outlet end 22 is connected to the filter 3 via a first pipe 5. Specifically, the drive unit 2 can be a peristaltic pump. A second pipe 6 is also connected between the outlet end 22 and the storage container 1. The second pipe 6 has a damping function, used to return the fluid in the first pipe 5 to the storage container 1 when the fluid pressure in the first pipe 5 exceeds a preset value. The sample filtration device 100 also includes a weight detector 8. The storage container 1 is mounted on the weight detector 8. The weight detector 8 is used to detect the weight of the fluid in the storage container 1, thereby obtaining the yield of the filtered product. It can also obtain the change value of the fluid weight in the storage container 1, and based on the change value of the fluid weight, it can determine the pressure in the first pipe 5, and thus determine whether the filter 3 is blocked.

[0030] The second pipe 6 is a very long and thin pipe compared to the first pipe 5. During the filtration process, the fluid mainly flows through the first pipe 5, while the flow rate through the second pipe 6 is extremely low. When the filter 3 becomes clogged, the pressure inside the first pipe 5 increases. This higher internal pressure causes the fluid to flow into the second pipe 6, increasing the flow rate in the second pipe 6. At this time, the fluid will flow back from the second pipe 6 into the storage container 1, causing a change in the reduction of sample weight in the storage container 1 (the reduction in sample weight becomes smaller). The weight detector 8 can identify the amount of sample filtered in the storage container 1. When liquid backflow occurs in the second pipe 6, that is, when the sample flows through the second pipe 6 into the storage container 1 containing the sample, the rate of weight change (sample weight reduction rate) of the weight detector 8 will decrease, thus indicating that the filter 3 is clogged. The degree of clogging of the filter 3 can be estimated based on the degree of reduction in the sample weight reduction rate. The more severe the clogging, the less sample passes through the filter 3, and more sample flows back from the second pipe 6 into the storage container 1, resulting in a smaller reduction in sample weight in the storage container 1. When filter 3 becomes clogged (especially severely clogged), an alarm will be triggered, and filtration can be stopped to prevent pump pipe damage and filter membrane damage that could affect filtration quality.

[0031] In addition, the sample filtration device 100 also includes a fluid detector 7, which is disposed outside the second pipeline 6. The fluid detector 7 is used to detect whether fluid is flowing through the second pipeline 6. When the filter 3 is clogged, the pressure in the first pipeline 5 increases, causing an increase in the amount of fluid flowing through the second pipeline 6, and the fluid detector 7 can detect the fluid. When the filter 3 is filtering normally, the fluid in the first pipeline 5 flows smoothly, so the fluid will not enter the second pipeline 6, or only a small amount of fluid will enter the second pipeline 6, but it is difficult to reach the position where the fluid detector 7 is set. Therefore, the fluid detector 7 cannot detect the fluid flowing through. Thus, the detection result of the fluid detector 7 can be used to determine whether the filter 3 is clogged.

[0032] Furthermore, this embodiment of the application employs a weight detector 8 and a fluid detector 7, creating a redundant design. If either detector malfunctions, the other can still function normally, preventing the filter 3 from becoming clogged and failing to detect the problem. Additionally, the detection result of one detector can indicate whether the other is malfunctioning. For example, if the fluid detector 7 detects fluid flowing through the second pipe 6, but the weight detector 8's result is inconsistent, it can be determined that the weight detector 8 may be malfunctioning. This redundancy design improves detection accuracy and reduces the risk of false positives.

[0033] In some embodiments, the weight detector 8 may be a weight sensor.

[0034] In some embodiments, the fluid detector 7 includes an ultrasonic fluid identification sensor or an optical fluid identification sensor, which can monitor in real time whether there is flow in the second pipeline 6, thereby achieving non-invasive fluid detection.

[0035] In some embodiments, the fluid detector 7 can be located at one end of the second pipe 6 near the storage container 1, i.e., at the liquid outlet end of the second pipe 6, which can reduce the risk of false detection. Specifically, the second pipe 6 and the storage container 1 can be connected by a third pipe 61 with a larger inner diameter. The fluid detector 7 is located at one end of the third pipe 61 near the second pipe 6. By setting the third pipe 61 with a larger inner diameter, it is convenient to set up the fluid detector 7 and to detect the fluid.

[0036] Please see Figure 1 , Figure 2 and Figure 4 As shown, the filter 3 includes a nacelle filter, a chromatography column, or a tangential flow filter, etc. The sample filtration device 100 provided in this application embodiment is suitable for various filtration scenarios and can realize various filter anti-clogging warnings.

[0037] Please see Figure 1 As shown, the sample filtering device 100 also includes a display and control module 10, which includes a controller 101 for controlling the coordinated operation of various components in the device. The display and control module 10 also includes an alarm 102, which is used to sound an alarm when the weight detector 8 detects a change in sample weight in the storage container 1 that is lower than a preset threshold. Additionally, it can also sound an alarm when the fluid detector 7 detects fluid flowing through the second pipe 6.

[0038] In some embodiments, the display and control module 10 further includes a display screen 103 for displaying in real time the sample weight change value detected by the weight detector 8 within the storage container 1, so that the operator can view it. Additionally, other visualizeable parameters can also be displayed.

[0039] Please see Figure 2 As shown, in this sample filtration device 100, the outlet pressure of the drive element 2 is related to the maximum pressure resistance of the filter 3, and typically the outlet pressure of the drive element 2 does not exceed the maximum pressure resistance of the filter 3. That is, the length of the second pipeline 6 is related to the maximum pressure resistance of the filter 3, and the inner diameter and length of the second pipeline 6 can be designed according to the actual flow requirements and the maximum pressure resistance of the filter membrane 3.

[0040] The inner diameter D and length L of the pipeline can be calculated using the following formula (Darcy's formula): Where, ΔP: target pressure drop (Pa), since the outlet ends of the first pipeline 5 and the second pipeline 6 are both at atmospheric pressure, the target pressure drop is the liquid outlet pressure of the drive component 2; λ: friction damping coefficient (dimensionless); L: pipeline length (m); D: pipeline inner diameter (m); ρ: fluid density (kg / m³); v: average flow velocity in the pipeline (m / s), the average flow velocity is obtained by formula: Calculate, where Q is the volumetric flow rate (m³ / s).

[0041] The objective of this application is to find a suitable (L,D) combination given Q and ΔP. This design process involves finding an engineering-optimal and feasible (L,D) combination. The specific calculation process is as follows: Step 1, Define the input conditions The expected pressure drop ΔP and volumetric flow rate Q are clearly defined. The volumetric flow rate Q can be determined based on the selected drive unit 2. The expected pressure drop ΔP is the pressure at the outlet of the drive unit 2. The minimum value of this pressure is the minimum pressure value of the fluid flowing in the first pipeline 5 to achieve the flow rate Q, and the maximum value of this pressure is the maximum pressure resistance value of the filter membrane of the filter 3.

[0042] Fluid properties: Determine the density ρ and dynamic viscosity μ of the filtered sample (for calculating the Reynolds number).

[0043] Pipe material / roughness: This allows estimation of the absolute roughness ϵ of the pipe wall, which is used to calculate λ.

[0044] Step 2, Select and fix a variable Typically, an inner diameter D0 is initially selected, and the selection can be based on the following criteria: Empirical flow rate: Different driving components 2 have specific flow rate ranges, derived from v=4Q / (πD) 2 )Reverse the derivation of D0.

[0045] Step 3, Iterative calculation: Calculate after fixing D0.

[0046] 1. Calculate flow velocity and Reynolds number: Determining whether the flow is laminar or turbulent directly affects the calculation of the damping coefficient λ.

[0047] 2. Calculate the friction damping coefficient λ: Laminar flow: λ=64 / Re=64*u / v / ρ / D.

[0048] Turbulent flow over a smooth wall: F = 0.316Re -0.25 Rough surfaces are not considered for now.

[0049] 3. By reverse-engineering the required length L using the aforementioned Darcy formula, the required length L under the selected D0 can be obtained.

[0050] Step 4, Evaluation and Optimization The evaluation focuses on whether the calculated (D0, L) combination is reasonable. If the pipe length L is too long, it is difficult to implement and the installation space is insufficient, resulting in high costs. In this case, D0 needs to be reduced. A smaller inner diameter results in a higher flow velocity at the same flow rate, leading to a larger pressure drop, thus significantly shortening the required length L. If the pipe length L is too short, the aforementioned damping effect may not be achieved, and the pressure drop may be concentrated at the inlet effect, leading to unstable calculation results. In this case, D0 needs to be increased, which will reduce the flow velocity and require a longer pipe to accumulate the same pressure drop.

[0051] Through continuous optimization, a suitable set of (L,D) is found for the second pipeline 6 under the premise of satisfying ΔP, so that the second pipeline 6 is the most compact in size, feasible in terms of space and process, and has the lowest total cost.

[0052] The following sections will explain the anti-clogging principle and feasibility design process of the sample filtering device 100 provided in this application from both theoretical and experimental perspectives.

[0053] Please see Figure 3 As shown, filter 3 is illustrated using a Nennis filter as an example. During the research process, a pressure gauge is installed at the liquid outlet 22 of the drive unit 2 to detect the pressure value at the liquid outlet 22. The estimated pipeline pressure value can be compared with the actual pressure value detected by the pressure gauge to verify whether the estimated pressure value is accurate, that is, to verify whether the sample filtration device 100 of this application can achieve the anti-clogging function.

[0054] Based on the aforementioned Darcy formula, calculate the relationship between flow rate and pressure in the pipeline: Calculations show that when the flow rate Q is 2 mL / s, the flow in the first pipe 5 is laminar (Re = 47 < 2300). Therefore, the calculated pressure difference is only 1.5 kPa to achieve a flow rate of 2 mL / s in the first pipe 5. The pressure difference ΔP (equal to...) Figure 3 The pressure displayed on the pressure gauge is due to the fact that the outlets of both the first pipe 5 and the second pipe 6 are at normal pressure, so the pressure gauge reading is the pressure difference ΔP. The diameter of the first pipe 5 is 2.4 mm, the equivalent pipe length L is 600 mm (the actual length of the first pipe 5 is 100 mm, and the filter 3 is equivalent to a 500 mm pipe, so the total pipe length is 600 mm), and the fluid viscosity coefficient η (the viscosity at 20 degrees Celsius is 1 mPa•s).

[0055] The parameters are shown in Table 1: Table 1 Therefore, the calculated pressure difference is 1.5 kPa, meaning that at a pressure gauge reading of 1.5 kPa, the flow rate of the first pipeline 5 can reach 2 mL / s. At this pressure, the flow rate of the second pipeline 6 is 0.04 mL / s (the diameter of the second pipeline 6 is 0.45 mm, and its length is 40 mm). At a flow rate of 0.04 mL / s, the total volume flowing through the second pipeline 6 in 1 minute is V = 0.04 * 60 = 2.4 mL.

[0056] The parameters are shown in Table 2: Table 2 When filter 3 is completely clogged, the liquid will flow only from the second pipe 6. At this time, the flow rate of the second pipe 6 is 2 mL / s, and the pressure gauge reading reaches 256 kPa. The volume of liquid flowing through the second pipe 6 in 1 minute is 2 * 60 = 120 mL.

[0057] The parameters are shown in Table 3: Table 3 Based on the above principle, when the flow rate of the driving component 2 is 2 mL / s and the driving component 2 is turned on for 60 s: 1. When filter 3 is not clogged, filter 3 will filter 120mL of sample, and 2.4mL of liquid will flow through the second tube 6 (at a pump flow rate of 2mL / s, a driving pressure of 1.5kPa is generated, the flow rate of the first tube 5 is close to 2mL / s, the flow rate of the second tube 6 is 0.04mL / s, and the flow lasts for 60s).

[0058] 2. When filter 3 is completely clogged, the flow rate of the first pipeline 5 is 0 mL / s, the flow rate of the second pipeline 6 is 2 mL / s, and the pressure gauge reading is 256 kPa. At this time, the fluid detector 7 detects liquid at the outlet of the second pipeline 6, and the alarm 102 will trigger a pressure alarm. Simultaneously, the pressure in the second pipeline 6 will be released from the storage container 1, thus achieving the functions of pressure release and pressure over-limit alarm.

[0059] 3. Redundancy Design: The weight detector 8 can detect the reduction in sample volume (i.e., the filtered sample volume) in the storage container 1. When liquid backflow occurs in the second pipe 6, that is, when the sample flows through the second pipe 6 to the storage container 1, the weight change rate (i.e., the sample weight reduction rate) of the weight detector 8 decreases. Therefore, it can be determined that the filter 3 is clogged, and this can help in the calculation. Figure 3 The pressure at the location of the pressure gauge.

[0060] Based on the above inference, the platform was built and the measured pressure of the pressure gauge was verified (the flow rate of the driving component 2 is 2 mL / s). The specific data are shown in Table 4 below.

[0061] Table 4 Based on the above theory and experimental data, it can be determined that the sample filtration device 100 provided in this application can predict the pressure of the filter 3 under clogging conditions, thereby avoiding excessive pressure, overflow, pump pipe phenomena, and filter membrane damage caused by the complete clogging of the filter 3. By adding a thin tube with greater damping (i.e., the second pipe 6) for drainage, the pressure prediction and pressure relief functions in the first pipe 5 are realized.

[0062] Please see Figure 5 As shown, combined Figure 1 and Figure 2 This application embodiment also provides a method for sample filtering using the aforementioned sample filtering device 100, specifically including the following steps: The driving force provided by the driving component 2 propels the sample from the storage container 1 into the filter 3 via the first conduit 5 for filtration. During sample filtration, the weight detector 8 detects the fluid weight in the storage container 1 to obtain a change in fluid weight. Based on this change in fluid weight, the pressure within the first conduit 5 is determined, thereby indicating whether the filter 3 is clogged. If the detected change in fluid weight (e.g., a decrease in fluid weight) is less than a preset threshold, the filter 3 is considered clogged. By setting different thresholds, different degrees of clogging of the filter 3 can be reflected.

[0063] In some embodiments, different levels of alarms can be set according to different thresholds to alert operators to the degree of blockage in filter 3.

[0064] In some embodiments, during the sample filtration process, the method further includes: detecting whether fluid flows through the second pipeline 6 using a fluid detector 7, and determining whether the filter 3 is clogged based on the detection result.

[0065] Based on the redundant design of the fluid detector 7 and the weight detector 8, the method further includes: determining whether the weight detector 8 is working properly based on the detection result of the fluid detector 7. Alternatively, the determination of whether the fluid detector 7 is working properly can be based on the detection result of the weight detector 8.

[0066] Depending on the type of filter 3, the aforementioned anti-clogging scheme can be used in the exosome purification process, specifically in purification and separation pretreatment, TFF purification, and sample recovery.

[0067] Please see Figure 2As shown, the sample filtration device 100 can be used as a pretreatment or terminal filtration module for exosomes. In this case, the filter 3 in the sample filtration device 100 can be a lenticule filter. According to the aforementioned principle, this method can assess the clogging status of the filter 3 and ensure that the pressure in the first pipeline 5 is within a safe pressure of 250 kPa, preventing excessive pressure from causing damage to the pipeline pump and the filter membrane.

[0068] Please refer to it again. Figure 2 As shown, the sample filtration device 100 can also be used as a size exclusion chromatography (SEC) filtration module for exosomes. In this case, the filter 3 in the sample filtration device 100 can be a chromatography column. The length of the second pipeline 6 can be set according to the maximum pressure resistance or the most effective filtration flow rate of the chromatography column. When the filtration pressure of the chromatography column increases, the filtration effect of the chromatography column can be judged according to the flow rate of the second pipeline 6 (flow rate of the second pipeline 6 = initial flow rate of the chromatography column in one cycle - flow rate of the chromatography column in one cycle), and the effects of excessive pressure on the chromatography column, such as packing material rupture, can be avoided.

[0069] Please see Figure 4 As shown, the sample filtration device 100 is applied to the purification and separation process of exosomes. For example, it can be used as a tangential flow filtration (TFF) purification and separation module for exosomes. In this case, the filter 3a in the sample filtration device 100 can be a tangential flow filter, wherein the filter 3a includes an inlet and two outlets (32 and 33), which are located on opposite sides of the filter membrane 31. The outlet 32 ​​is connected to the storage container 1, and the outlet 33 is connected to the collection container 4. At the same time, in this sample filtration device 100, the aforementioned fluid detector can be omitted, and the rate of change of the sample in the storage container 1 can be detected by the weight detector 8 to predict whether the filter 3a is clogged.

[0070] Transmembrane pressure in filter 3a Where P1 is the pressure of the pipeline on the side of outlet 32 ​​and P2 is the pressure of the pipeline on the side of outlet 33. Since both P1 and P2 are at normal pressure, TMP = P0 / 2. Based on the sample weight change detected by the weight detector 8 during the purification process, the flow rate change of the second pipeline 6 during purification can be known, thereby predicting the transmembrane pressure of filter 3a.

[0071] In addition, the length of the second pipeline 6 can be determined based on the maximum pressure resistance of the hollow fiber of filter 3a, thereby ensuring that when the hollow fiber membrane is blocked, the pressure resistance can be determined by judging the length of the thin tube, thus achieving protection of the hollow fiber and pipeline, and preventing membrane rupture caused by excessive pressure.

[0072] Understandable, Figure 4 In the sample filtering device 100 shown, a fluid detector can also be added to the second pipeline 6. This fluid detector is similar to the fluid detector 7 in the aforementioned embodiments (e.g., Figure 2 (As shown) For the specific detection principle, please refer to the above. It can detect the flow rate of the liquid flowing through the second pipe 6. Based on the liquid flow rate value in the second pipe 6, it can also determine whether the filter 3a is blocked.

[0073] In summary, the sample filtration device 100 provided in this application, by setting a second pipeline 6 and combining it with at least one of a fluid detector 7 and a weight detector 8, can predict the pressure of the first pipeline 5 during filtration or purification without relying on a pressure gauge (as contact between the pressure gauge and the sample poses a risk of contamination). This reduces overflow and pump pipe phenomena caused by blockage of the filter 3 (3a), as well as damage to the filter membrane, which affects the filtration or purification effect. Simultaneously, it can release pressure within the pipeline, providing overpressure protection. Furthermore, it can predict the flow rate and pressure through the filter 3 (3a), providing a basis for judging the purification or filtration effect. In addition, this contact-type detection has high reliability, does not introduce contaminants, and is low-cost, making it suitable for filtration processes in various scenarios. Using the sample filtration device 100 of this application, high-purity and high-yield separation and recovery of exosomes can be achieved.

[0074] Furthermore, the sample filtration device 100 of this application is not limited to the separation and purification of exosomes, but can also be applied to the separation and purification of other biological fluids, thus having a wide range of applications.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A sample filtering device, characterized in that, include: The storage container, the driving component, and the filter are connected in sequence. The storage container is used to store fluid. The driving component includes a liquid outlet end that is connected to the filter. The liquid outlet end and the filter are connected to a first pipeline. The liquid outlet end and the storage container are connected to a second pipeline. The second pipeline has a damping function and is used to return the fluid in the first pipeline to the storage container when the fluid pressure in the first pipeline exceeds a preset value. The sample filtering device further includes a weight detector, and the storage container is disposed on the weight detector. The weight detector is used to detect the weight of the fluid in the storage container to obtain the change value of the fluid weight in the storage container. The pressure in the first pipeline can be determined based on the change value of the fluid weight.

2. The sample filtering device as described in claim 1, characterized in that, The inner diameter and length of the second pipeline are calculated using the following formula (1): （1）， Wherein, ΔP: target pressure drop, since the outlet ends of the first pipeline and the second pipeline are both at atmospheric pressure, the target pressure drop is the liquid outlet pressure of the drive component; λ: Friction coefficient; L: Length of the pipeline; D: Inner diameter of the pipe; ρ: fluid density; v: The average flow velocity of the fluid in the pipe, which is expressed by the formula: Calculate, where Q is the volumetric flow rate.

3. The sample filtering device as described in claim 2, characterized in that, The pressure at the outlet of the drive unit does not exceed the maximum pressure resistance of the filter.

4. The sample filtering device as described in claim 1, characterized in that, The sample filtration device also includes a fluid detector, which is disposed outside the second pipeline and is used to detect whether fluid is flowing through the second pipeline.

5. The sample filtering device as described in claim 4, characterized in that, The fluid detector is located at one end of the second pipeline near the storage container; and / or The fluid detector includes an ultrasonic fluid identification sensor or an optically coupled fluid identification sensor.

6. The sample filtering device as described in claim 1, characterized in that, It also includes an alarm that is used to sound an alarm when the weight detector detects that the change in the weight of the fluid in the storage container exceeds a preset threshold.

7. The sample filtering device as described in claim 1, characterized in that, The driving component is a peristaltic pump; and / or The filters include Nympan filters, chromatography columns, or tangential flow filters.

8. A sample filtering method using the sample filtering apparatus as described in any one of claims 1 to 7, characterized in that, include: The driving force is provided by the driving component to inject the sample in the storage container into the filter via the first conduit for filtration. During the sample filtration process, the weight detector detects the weight of the fluid in the storage container to obtain the change in fluid weight, and the pressure in the first pipeline is determined based on the change in fluid weight, thereby determining whether the filter is blocked.

9. The sample filtering method as described in claim 8, characterized in that, When the sample filtering device includes the fluid detector, the method further includes the following during the sample filtering process: The fluid detector detects whether fluid is flowing through the second pipeline, and determines whether the filter is clogged based on the detection result.

10. The sample filtering method as described in claim 9, characterized in that, The method further includes: The determination of whether the weight detector is working properly is based on the detection results of the fluid detector.

Images