Method for detecting background of sample line of sample processing device, and sample processing device

Abstract

The invention relates to a method for background detection of a sample line of a sample processing instrument, a sample processing instrument and a computer readable medium. A sample line connects a sample needle for aspirating a sample from a sample container to the flow cell. The method comprises performing, by a control device, the following steps: supplying sheath fluid to the flow cell via the sample line; and detecting the sheath fluid flowing through the flow type pool to obtain background detection data. According to the method disclosed by the invention, the sheath fluid is used for detecting the background of the sample pipeline of the sample treatment instrument, so that preparation of a special fluid for background detection can be omitted, the cost is remarkably reduced, and background increase caused by introduction of impurities when the special fluid is loaded into the sample treatment instrument can be avoided; therefore, the detection precision and accuracy of the sample treatment instrument can be improved.

Description

Technical Field

[0001] The present disclosure relates to a method for background detection of a sample line of a sample processing instrument and a sample processing instrument including a control device for implementing the method, such as a flow cytometer or an analyzer. Background Art

[0002] The contents in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] Sample processing instruments are generally used to analyze liquid samples including small suspended particles (e.g., biological particles such as extracellular vesicles, non-biological particles such as microspheres (beads)) or cells and / or to sort the particles or cells therein. It is well known that background noise (also referred to as "background signal", or simply "background") can have an adverse effect on the detection results. For example, for a sample processing instrument for detecting nanoparticles in a sample, background noise can have a significant impact on the detection results.

[0004] Before processing the sample, it is necessary to ensure that the sample pipeline used to transport the sample is sufficiently clean, that is, the sample pipeline is cleaned to reduce the adverse effects of background noise on the test results. Further, before processing the sample, it is also necessary to detect the background noise of the sample pipeline in order to determine whether the background noise is low enough to meet the test requirements. To this end, it is necessary to prepare a detection agent (e.g., pure water) with a sufficiently low background signal, and allow the detection agent to flow through the sample pipeline to detect the background noise of the sample pipeline. Summary of the invention

[0005] Technical issues

[0006] For the existing sample processing instruments, the cost of preparing the detection agent is high. In particular, the greater the amount of detection agent used, the higher the preparation cost. On the other hand, if there is not enough detection agent for background detection, it is not possible to effectively determine whether the background noise meets the requirements. In addition, impurities are easily introduced during the preparation, storage and / or replacement of the detection agent in the sample pipeline, resulting in an increase in background noise.

[0007] Technical Solution

[0008] In view of the above technical problems, the present disclosure provides a simplified solution for background detection of a sample pipeline of a sample processing instrument. The solution of the present disclosure can save the preparation of detection agents, significantly reduce costs, and is not easy to introduce impurities, and can ensure sufficiently low background noise.

[0009] According to one aspect of the present disclosure, a method for background detection of a sample pipeline of a sample processing instrument is provided, wherein the sample pipeline connects a sample needle for aspirating a sample from a sample container to a flow cell. The method comprises executing the following steps by a control device: supplying a sheath fluid to the flow cell via the sample pipeline; and detecting the sheath fluid flowing through the flow cell to obtain background detection data.

[0010] In some embodiments according to the present disclosure, the method further comprises: filtering the sheath fluid by allowing the sheath fluid to flow through a filter before introducing the sheath fluid into the sample line.

[0011] In some embodiments according to the present disclosure, the filter is configured to filter nano-sized particles.

[0012] In some embodiments of the present disclosure, a cleaning station is provided at the sample needle, a sheath fluid detection pipeline is provided between the cleaning station and the sheath fluid container, and the filter is provided in the sheath fluid detection pipeline. The method further includes: supplying the sheath fluid in the sheath fluid container to the cleaning station via the sheath fluid detection pipeline; and supplying the sheath fluid in the cleaning station to the flow cell via the sample pipeline for background detection.

[0013] In some embodiments according to the present disclosure, the method further includes: cleaning the sample needle in the cleaning station before introducing the sheath fluid into the sample line for background detection; and discharging the waste liquid after cleaning through a waste liquid pump via a waste liquid line connected to the cleaning station, or discharging it from the flow cell through the sample line by a vacuum pump.

[0014] In some embodiments according to the present disclosure, during sheath fluid washing of the sample needle and during the background detection, the open end of the sample needle is maintained in the washing station.

[0015] In some embodiments according to the present disclosure, a valve is provided in the sheath fluid detection pipeline for controlling the connection or interruption of the sheath fluid detection pipeline.

[0016] In some embodiments according to the present disclosure, the method further comprises: before introducing the sheath fluid into the sample line for background detection, cleaning the sample line.

[0017] In some embodiments according to the present disclosure, the method further includes: comparing the background detection data with predetermined background data; if the background detection data is greater than the predetermined background data, the method further includes cleaning the sample pipeline; and if the background detection data is less than or equal to the predetermined background data, preparing to test the sample.

[0018] According to another aspect of the present disclosure, a sample processing instrument is provided, comprising a control device for implementing the above method.

[0019] In some embodiments according to the present disclosure, a peristaltic pump is disposed in the sample pipeline, and the peristaltic pump is configured to pump sheath fluid or sample from the sample needle to the flow cell.

[0020] In some embodiments according to the present disclosure, a piston pump and a reversing valve are provided in the sample pipeline. The reversing valve can switch between a first position in which the sample needle is connected to the piston pump and a second position in which the piston pump is connected to the flow cell. The sheath fluid or sample is pumped from the sample needle to the flow cell by switching the piston pump and the reversing valve.

[0021] In some embodiments according to the present disclosure, the sample processing instrument includes a waste liquid pipeline connected to a cleaning station located at the sample needle and a waste liquid pump disposed in the waste liquid pipeline. The waste liquid pump is configured to discharge waste liquid in the cleaning station via the waste liquid pipeline.

[0022] In some embodiments of the present disclosure, the sample processing instrument includes an exhaust pipeline disposed downstream of the flow cell and a vacuum pump disposed in the exhaust pipeline, wherein the vacuum pump is configured to draw fluid in a cleaning station located at the sample needle into the flow cell via the sample pipeline.

[0023] According to another aspect of the present disclosure, a computer-readable medium is provided, on which a program is stored, and when the program is executed by a processor of the control device (for example, on an associated personal computing device, a dedicated device, etc.), the above method is implemented.

[0024] Technical Effects

[0025] According to the method and sample processing instrument disclosed in the present invention, the background of the sample pipeline of the sample processing instrument is detected by using sheath liquid, which can save the preparation of the detection agent for background detection, thereby significantly reducing costs, and can avoid the introduction of impurities and increase of background when the detection agent is loaded into the sample processing instrument. Therefore, the method and sample processing instrument disclosed in the present invention can ensure or improve the detection accuracy. In addition, the method and sample processing instrument disclosed in the present invention can also save the time of replacing the detection agent container and the sample container, thereby simplifying the operation process and improving efficiency.

[0026] According to the method and sample processing instrument disclosed in the present invention, the sheath liquid supplied to the cleaning station at the sample container is used to perform background detection, which can simplify the structure. The sheath liquid supplied to the cleaning station is used to clean the open end of the sample needle inserted into the sample container to aspirate the sample. Therefore, after cleaning the open end of the sample needle, the sheath liquid is clean and can be directly supplied to the flow cell via the sample needle and the sample pipeline for background detection, thereby avoiding the sample needle from moving up and down, thereby simplifying the operation process and shortening the running time. Therefore, according to the method and sample processing instrument disclosed in the present invention, efficiency can be improved and costs can be further reduced.

[0027] According to the method and sample processing instrument disclosed in the present invention, a nanometer filter is arranged in the sheath fluid detection pipeline, thereby ensuring that the background noise in the sheath fluid is sufficiently low.

[0028] The above and other objects, features and advantages of the present disclosure will be more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only and thus are not to be considered as limiting the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The features and advantages of one or more embodiments of the present disclosure will become more easily understood through the following description with reference to the accompanying drawings, in which:

[0030] Figure 1 is a functional block diagram of a sample processing instrument;

[0031] Figure 2 is a schematic diagram of a portion of a sample processing instrument according to an embodiment of the present disclosure;

[0032] Figure 3 for Figure 2 A schematic diagram of a variation of a sample processing apparatus;

[0033] Figure 4 for Figure 2 A schematic diagram of another variation of the sample processing instrument; and

[0034] Figure 5 The present invention is a flowchart of a method for background detection of a sample pipeline of a sample processing instrument according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] The present disclosure will be described in detail below by way of exemplary embodiments with reference to the accompanying drawings. In several figures, similar reference numerals represent similar parts and assemblies. The following detailed description of the present disclosure is for illustrative purposes only and is by no means a limitation of the present disclosure and its application or use. The embodiments described in this specification are not exhaustive, but are only some of a plurality of possible embodiments. The exemplary embodiments may be implemented in many different forms and should not be construed as limiting the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies may not be described in detail.

[0036] Before describing in detail at least one embodiment of the present invention, it should be understood that the present invention is not necessarily limited in its application to the details of the construction and the arrangement of parts set forth in the following description or illustrated in the accompanying drawings. The present invention is applicable to other embodiments and combinations of the disclosed embodiments that can be practiced or executed in various ways. In addition, it should be understood that the words and terms used herein are for descriptive purposes and should not be considered as limiting.

[0037] Unless otherwise clearly indicated from the following discussion, it should be understood that throughout the specification, discussions utilizing terms such as "control," "process," "compute," "determine / determine," and "obtain" refer to the actions and / or processes of a computer or computing system or similar electronic computing device that manipulate and transform data represented as physical, such as electronic, quantities within the computing system's registers or memories into other data similarly represented as physical quantities within the computing system's memories, registers, or other such information storage, transmission, or display devices.

[0038] The following will refer to Figure 1 To describe the main functional parts of the sample processor 1. The sample processor according to the present disclosure can be any suitable instrument for processing (e.g., detecting or sorting) biological samples or non-biological samples. For example, in some embodiments, the sample processor can be a flow cytometer. The sample processed (e.g., analyzed or sorted) by the sample processor 1 can include biological particles such as exosomes or extracellular vesicles or non-biological particles such as beads. The sample processor 1 is optimized to detect and measure nanoscale particles (e.g., nanoparticles, nano-microspheres, exosomes), but the sample processor of the present disclosure can also be used for larger particles.

[0039] Figure 1 is a functional block diagram of the sample processing device 1. Figure 1 As shown, the sample processing instrument 1 includes a fluid system 10 , a flow cell 20 , a sample processing unit 30 and a control device 40 .

[0040] The fluid system 10 is used to supply various fluids to the flow cell 20 and discharge the fluid in the flow cell 20. The fluids described herein may include samples to be analyzed, sorted or otherwise processed, sheath fluids, cleaning agents, waste fluids, etc. The fluid system 10 may include various fluid components such as pipelines, pumps, valves, pressure regulating devices, sensors, etc. for conveying or discharging fluids.

[0041] Various fluids, in particular, samples and sheath fluids are delivered to the flow cell 20. Figure 2 The flow cell 20 includes two opposite sheath liquid ports 21 and 22, through which the sheath liquid is delivered to the chamber 25 of the flow cell 20. The flow cell 20 also includes a sample port 23, through which the sample is delivered to the chamber 25. In the chamber 25, the sample is wrapped by the sheath liquid and then flows through the cuvette 26 for processing. The cuvette 26 forms a processing area for the sample. For example, an optical detection device focuses a light beam into the processing area of ​​the cuvette 26, and when particles in the sample pass through the processing area of ​​the cuvette 26, the characteristics of the particles are determined by measuring the light scattered or emitted from the particles.

[0042] The sample processing unit 30 processes the sample wrapped by the sheath fluid flowing through the cuvette 26. For example, the sample processing unit 30 can measure the properties of particles / cells in the sample and quantify particles / cells with specific properties, and / or the sample processing unit 30 can sort the particles / cells in the sample based on their properties. The sample processing unit 30 can include various optical devices, electrical devices, and / or mechanical devices, etc., depending on the purpose of sample processing.

[0043] The control device 40 controls the operation of the entire sample processing instrument 1. The various functions, actions or steps of various systems, devices, components or methods of the sample processing instrument according to the present disclosure are implemented through the control of the control device 40. The control device 40 will be described in detail below.

[0044] See below Figure 2 A sample processing instrument according to an embodiment of the present disclosure is described. Figure 2 A part of the sample processing apparatus 1 , namely a part of the fluid system 10 and the flow cell 20 is shown.

[0045] See also Figure 2 The fluid system 10 includes a sample pipeline 11, a sheath liquid supply pipeline 13, a sheath liquid detection pipeline 15, a waste liquid pipeline 17 and a discharge pipeline 19.

[0046] The sample line 11 is used to connect a sample container (not shown) to the flow cell 20, and includes a sample needle 11a for aspirating a sample from the sample container and a sample needle 11b installed in a sample port 23 of the flow cell 20. The sample needles 11a and 11b are respectively located at the two ends of the sample line 11. A piston pump 12 and a three-way reversing valve 14 are provided in the sample line 11. The three-way reversing valve 14 can be switched between a first position in which the sample container is connected to the piston pump 12 and a second position in which the piston pump 12 is connected to the flow cell 20. When the three-way reversing valve 14 is in the first position, the piston pump 12 can aspirate a sample from the sample container. The three-way reversing valve 14 is switched to the second position, and the piston pump 12 pumps the aspirated sample to the flow cell 20. The piston pump 12 and the three-way reversing valve 14 are repeatedly operated in this way, so that the sample is transported to the flow cell 20 via the sample line 11 for processing.

[0047] When processing the sample, the sheath liquid is supplied from the sheath liquid container (not shown) to the flow cell 20 via the sheath liquid supply line 13. Generally, the flow cell 20 has two opposite sheath liquid ports 21 and 22, so the sheath liquid supply line 13 includes two branch lines 13a and 13b respectively connected to the sheath liquid ports 21 and 22. In the flow cell 20, the sample is wrapped by the sheath liquid so that the particles in the sample flow through the cuvette 26 in a linear manner, thereby facilitating the detection or processing of the particles.

[0048] A cleaning station 60 is provided at the sample needle 11a. The cleaning station 60 is configured to collect waste liquid for cleaning the sample pipeline 11 and to clean the end of the sample needle 11a. A sample container (not shown) can be placed below the cleaning station 60. When it is necessary to aspirate a sample, the sample needle 11a moves downward, enters the sample container and is immersed in the sample. When it is necessary to clean the sample needle, the sample needle 11a moves upward so that its end is located in the cleaning station, thereby cleaning the end of the sample needle.

[0049] The sheath liquid detection pipeline 15 is used to connect a sheath liquid container (not shown) to the cleaning station 60. The sheath liquid can be supplied to the cleaning station 60 through the sheath liquid detection pipeline 15 to clean the sample needle 11a, especially the outer periphery and end of the sample needle 11a. A valve 16 is provided on the sheath liquid detection pipeline 15 to control the on-off of the sheath liquid detection pipeline 15. For example, the valve 16 can be a switch valve.

[0050] The waste liquid pipeline 17 is connected to the washing station 60. Waste liquid washed from the sample pipeline 11 and waste liquid washed from the end of the sample needle 11a can be discharged through the waste liquid pipeline 17. A waste liquid pump 18 can be provided on the waste liquid pipeline 17.

[0051] After the sample line 11 and the sample needle 11a are cleaned, the sheath liquid supplied to the cleaning station 60 via the sheath liquid detection line 15 will also be clean. The inventor of the present application proposes to use the clean sheath liquid to perform background detection of the sample line 11. That is, the clean sheath liquid in the cleaning station 60 can be directly supplied from the end of the sample needle 11a to the flow cell 20 via the sample line 11, and background detection is performed when the sheath liquid flows through the cuvette 26 of the flow cell 20. The end of the sample needle 11a can be kept in the cleaning station without moving. In contrast, in the existing sample processing instrument, the sample needle needs to be moved downward and inserted into the detection agent container in order to aspirate the detection agent for background detection.

[0052] A filter 50 may also be provided on the sheath fluid detection pipeline 15. Impurities in the sheath fluid can be filtered out by the filter 50, thereby reducing the background noise of the sheath fluid itself. Preferably, the smaller the size of the particles or impurities that can be filtered out by the filter 50, the smaller the background noise of the sheath fluid itself. For example, the filter 50 can filter nano-scale particles or impurities, which is particularly suitable for nano-scale sample processing instruments, that is, the sample processing instrument can process nano-scale particles in the sample.

[0053] The filter 50 may be disposed in a common section of the sheath liquid detection pipeline 15 and the sheath liquid supply pipeline 13. In this way, a single filter 50 may meet the requirements of both background detection and sample detection.

[0054] A discharge pipeline 19 is provided at the downstream side of the flow cell 20 for discharging the fluid or waste liquid in the flow cell 20. The fluid or waste liquid in the flow cell 20 may be, for example, a processed sample, sheath fluid, or cleaning fluid.

[0055] It should be understood that the sample processing apparatus according to the present disclosure is not limited to Figure 2 The specific examples shown can be changed according to actual needs.

[0056] Figure 3 for Figure 2 Schematic diagram of a variation of a sample processing apparatus. Figure 3 In the variant shown, a peristaltic pump 32 is used to replace Figure 2 The piston pump 12 in the embodiment of the present invention is omitted. Figure 2 The three-way reversing valve 14 in the peristaltic pump 32 has the same function as Figure 2 The piston pump 12 and the three-way reversing valve 14 in the cleaning station 60 have the same functions. The fluid (sheath fluid) in the cleaning station 60 can be pumped into the flow cell 20 by the peristaltic pump 32 for background detection.

[0057] Figure 4 for Figure 2 A schematic diagram of another variation of a sample processing apparatus. Figure 4In the variant shown, the Figure 2 The waste liquid pipeline 17 and the waste liquid pump 18 in the exhaust pipeline 19 are provided with a vacuum pump 42 to replace Figure 2 The piston pump 12 and the three-way reversing valve 14 in the vacuum pump 42 are configured to draw the fluid in the cleaning station 60 located at the sample needle 11a through the sample pipeline 11 into the flow cell 20 for background detection, and then draw it from the flow cell 20 into the exhaust pipeline 19 for exhaust.

[0058] It should be understood that the sample processing instrument and its various components according to the present disclosure can be changed as needed, and are not necessarily limited to the specific examples shown in the figures and described herein. For example, additional components can be added, reduced or replaced as needed.

[0059] Figure 5 Flow chart of method S10 for background detection of a sample pipeline of a sample processing instrument according to an embodiment of the present disclosure. Method S10 is usually performed before sample processing so as to obtain a more accurate result when processing the sample.

[0060] like Figure 5 As shown, method S10 includes supplying sheath liquid to the flow cell (step S13) and performing background detection on the sheath liquid in the flow cell (step S14). According to the method S10 of the present disclosure, the sheath liquid is used for background detection, and the preparation of a detection agent (e.g., pure water) for background detection can be omitted, thereby significantly reducing costs.

[0061] In step S13, the sheath liquid is supplied to the flow cell via the sample line. In the existing sample processing instrument, it is necessary to replace the container containing the prepared detection agent with the processed sample container, which may introduce impurities. In contrast, according to the method S10 of the present disclosure, the step of replacing the container can be omitted, thereby avoiding the introduction of impurities during replacement and increasing the background. Therefore, the method according to the present disclosure can ensure or improve the processing precision and accuracy. Accordingly, according to the method S10 of the present disclosure, the time for replacing the container can also be saved, thereby simplifying the operation process and improving efficiency.

[0062] Before the sheath fluid is introduced into the sample pipeline, the method S10 may further include filtering the sheath fluid (step S12). Figures 2 to 4 As shown, before the sheath liquid is supplied to the cleaning station 60, the sheath liquid is made to flow through the filter 50, thereby filtering the sheath liquid. By filtering out larger particles (or impurities) in the sheath liquid through the filter, the background noise of the sheath liquid itself can be reduced. The sheath liquid with sufficiently low background noise can play a role substantially the same as the prepared detection agent (pure water). Therefore, the filter can be selected or designed according to the detection requirements.

[0063] In step S13, the sample container (not shown) may be supplied to a cleaning station (e.g. Figures 2 to 4 As described above, the sheath liquid is supplied to the cleaning station 60 via the sheath liquid detection pipeline 17 for cleaning the sample needle 11a, and after the sample needle 11a is cleaned, the sheath liquid is also clean and can be directly used for background detection.

[0064] Since the sheath liquid supplied to the cleaning station for cleaning the sample needle can be directly used for background detection, the position of the sample needle can remain unchanged, that is, the position of the sample needle when cleaning is maintained. When cleaning the sample needle, the open end of the sample needle is in the cleaning station, so the sheath liquid can be directly sucked through the open end of the sample needle for background detection. In this way, the sample needle can be prevented from moving up and down. In the existing sample processing instrument, after the container containing the detection agent (for example, pure water) replaces the sample container, the sample needle needs to move downward and immerse in the detection agent before the detection agent can be sucked. In contrast, the sample processing instrument according to the present disclosure can simplify the operation process and shorten the running time. Therefore, the method according to the present disclosure can further improve efficiency and reduce costs.

[0065] Before the background detection (ie, step S13) is performed, each pipeline and / or fluid component is usually cleaned (see step S11) to ensure that each pipeline and fluid component is clean to prepare for sample processing. These pipelines and fluid components include sample pipelines and sample needles.

[0066] Step S11 may be performed after the sample is processed in preparation for the processing of the next sample. In addition, step S11 may also be performed after determining that the background detection data cannot meet the requirements. Specifically, the background detection data obtained in step S14 may be compared with the predetermined background data. If the background detection data is greater than the predetermined background data, the process may return to step S11 to clean the sample line and / or sample needle again.

[0067] If the background detection data obtained in step S14 is less than or equal to the predetermined background data, it indicates that the background requirement has been met and the sample can be detected.

[0068] It is understandable that the predetermined background data may be determined according to sample processing requirements. Depending on the particles to be processed in the sample, the processing requirements and the predetermined background data may be different.

[0069] It should be understood that the method according to the present disclosure is not necessarily limited to the specific examples shown in the figures and described herein, but can be changed as needed. For example, a certain step can be additionally added or reduced as needed. In addition, the execution order of the various steps of the method can be changed without contradiction.

[0070] The above method can be implemented by the control device 40. The control device 40 in the present disclosure may include a processor implemented as a computer or a computing system. The method of running and cleaning the sample processing instrument described herein and the method of monitoring the cleaning of the sample processing instrument can be implemented by one or more computer programs executed by a computer processor. The computer program includes processor executable instructions stored on a non-transitory tangible computer-readable medium. The computer program may also include stored data. Non-limiting examples of non-transitory tangible computer-readable media are non-volatile memories, magnetic storage devices, and optical storage devices.

[0071] The term computer-readable medium does not include transient electrical or electromagnetic signals propagated through the medium (e.g., on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of non-transitory tangible computer-readable media are non-volatile memory (e.g., flash memory, erasable programmable read-only memory, or mask read-only memory), volatile memory (e.g., static random access memory circuits or dynamic random access memory), magnetic storage media (e.g., analog or digital tapes or hard drives), and optical storage media (e.g., CDs, DVDs, or Blu-ray discs).

[0072] Although the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the specific embodiments described and shown in detail herein. Those skilled in the art may make various changes to the exemplary embodiments without departing from the scope defined by the claims. In the absence of contradiction, the features of the various embodiments may be combined with each other. Alternatively, a feature in the embodiment may be omitted.

Claims

1. A method for background detection of a sample pipeline of a sample processing instrument, wherein: The sample line connects the sample needle used to draw the sample from the sample container to the flow cell. The method comprises executing the following steps by a control device: supplying a sheath fluid to the flow cell via the sample line; and The sheath fluid flowing through the flow cell is detected to obtain background detection data.

2. The method according to claim 1, further comprising: Prior to introducing the sheath fluid into the sample line, the sheath fluid is filtered by flowing the sheath fluid through a filter.

3. The method according to claim 2, wherein: The filter is configured to filter nano-sized particles.

4. The method according to claim 2, wherein: A cleaning station is provided at the sample needle, a sheath liquid detection pipeline is provided between the cleaning station and the sheath liquid container, and the filter is provided in the sheath liquid detection pipeline. The method further comprises: supplying the sheath fluid in the sheath fluid container to the cleaning station via the sheath fluid detection pipeline; and The sheath fluid in the washing station is supplied to the flow cell via the sample line to perform background detection.

5. The method according to claim 4, wherein: The method further comprises: Before introducing the sheath fluid into the sample line for background detection, cleaning the sample needle in the cleaning station; and The waste liquid after washing is discharged through a waste liquid pipeline connected to the washing station by a waste liquid pump, or is discharged from the flow cell through the sample pipeline by a vacuum pump.

6. The method according to claim 5, wherein: During sheath fluid washing of the sample needle and during the background detection, the open end of the sample needle is maintained in the washing station.

7. The method according to claim 4, wherein: A valve is provided in the sheath fluid detection pipeline for controlling the connection or interruption of the sheath fluid detection pipeline.

8. The method according to any one of claims 1 to 7, wherein: The method further comprises: Before the sheath fluid is introduced into the sample line for background detection, the sample line is cleaned.

9. The method according to any one of claims 1 to 7, wherein: The method further comprises: comparing the background detection data with predetermined background data; If the background detection data is greater than the predetermined background data, the method further includes cleaning the sample pipeline; and If the background detection data is less than or equal to the predetermined background data, the sample is prepared to be detected.

10. A sample processing apparatus comprising a control device for implementing the method according to any one of claims 1 to 9.

11. The sample processing apparatus according to claim 10, wherein: A peristaltic pump is disposed in the sample pipeline, and the peristaltic pump is configured to pump sheath fluid or sample from the sample needle to the flow cell.

12. The sample processing apparatus according to claim 10, wherein: A piston pump and a reversing valve are provided in the sample pipeline. The reversing valve can switch between a first position connecting the sample needle to the piston pump and a second position connecting the piston pump to the flow cell. The sheath fluid or sample is pumped from the sample needle to the flow cell by switching the piston pump and the reversing valve.

13. The sample processing apparatus according to claim 11 or 12, wherein: The sample processing instrument comprises a waste liquid pipeline connected to a cleaning station located at the sample needle and a waste liquid pump arranged in the waste liquid pipeline. The waste liquid pump is configured to discharge the waste liquid in the cleaning station via the waste liquid pipeline.

14. The sample processing apparatus according to claim 10, wherein: The sample processing instrument comprises an exhaust pipeline arranged downstream of the flow cell and a vacuum pump arranged in the exhaust pipeline. The vacuum pump is configured to draw the fluid in the cleaning station located at the sample needle into the flow cell via the sample pipeline. 15 . A computer-readable medium having a program stored thereon, wherein the program, when executed by a processor of a control device, implements the method according to claim 1 .

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