Carryover monitor for validation of flow cytometer cleaning cycle

Abstract

Systems and methods for operating a sample processing instrument. The method includes processing one or more samples through a fluidics system of the sample processing instrument, cleaning the fluidics system, measuring an amount of particles at an interrogation point the fluidics system by selectively supplying a flow to the fluidics system from one of a sample tube source and a sample line source, measuring the amount of particles in the flow, comparing the amount of particles measured against a predetermined target value, and determining, using the comparing, whether a cleaning requirement is met.

Description

CARRYOVER MONITOR FOR VALIDATION OF FLOW CYTOMETERCLEANING CYCLECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is being filed as a PCT International application and claims the benefit of and priority to U.S. Provisional Application No. 63 / 562,119, filed on March 06, 2024. the disclosure of which is hereby incorporated by reference in its entirety.BACKGROUND

[0002] A sample processing instrument is used to analyze a liquid sample which may include small suspended particles (e.g., biological particles such as extracellular vesicles, non-biological particles such as beads) or cells and / or to sort the particles or cells therein. The sample processing instrument generally processes multiple samples, and after a sample is processed, it needs to be cleaned to avoid inaccurate processing results for the next sample.

[0003] In order to prevent contamination between one sample and the next due to carryover of particles which may remain within the system after a sample is run, many sample processing instruments are equipped with a cleaning cycle to remove carry over particles and ensure the cleanliness of sample lines. However, it is not easy for users to accurately monitor and learn the result of cleaning with respect to traditional sample processing instruments. This is disadvantageous for detection of samples, especially, samples that contain small particles (e.g., nanoparticles) that are not easily cleaned.SUMMARY

[0004] Examples presented herein relate to a method for operating a sample processing instrument. The method including processing one or more samples through a fluidics system of the sample processing instrument, cleaning the fluidics system, measuring an amount of particles at an interrogation point the fluidics system by selectively supplying a flow to the fluidics system from one of a sample tube source and a sample line source, measuring the amount of particles in the flow, comparing the amount of particles measured against a predetermined target value, and determining, using the comparing, whether a cleaning requirement is met.

[0005] In other examples presented herein, the flow is supplied from the sample tube source and the cleaning requirement is determined to not be met, the method further includes supplying a second flow from the sample line source, measuring asecond amount of particles in the second flow, comparing the second amount of particles measured against the predetermined target value, and determining, using the comparing, whether the cleaning requirement is met. In still other examples presented herein, a source for the flow is determined based on a user input. In yet other examples presented herein, the predetermined target value is different based on whether the flow is supplied from the sample tube source or the sample line source. In further examples presented herein, the predetermined target value is higher for flow supplied from the sample tube source and lower for flow supplied from the sample line source.

[0006] In other examples presented herein, the sample line source comprises a sheath fluid. In further examples presented herein, the sheath fluid is 5 nanometer (nm) sheath fluid. In other examples presented herein, the sample tube source is a sample buffer. In yet other examples presented herein, the predetermined target value is 100 events.

[0007] Other example presented herein relate to a system for operating a sample processing instrument. The system includes a fluidics system including a flow cell, a sample tube source, a sample line source, a fluidics path to the flow cell, a source selection valve in communication with the fluidics path and in selective communication with each of the sample tube source and the sample line source, and a controller including a processor and a memory. The memory including instructions that, when executed by the processor, cause the processor to generate a display including a source selection operation, receive an input from the source selection operation, and operate the source selection valve, using the input, to provide flow to the flow cell from one of the sample tube source and the sample line source.

[0008] In other examples presented herein, the source selection operation is associated with determining whether a cleaning requirement is met based on a measured amount of particles at an interrogation point in the fluidics system. In further examples presented herein, the cleaning requirement comprises a predetermined threshold amount of particles. In other further examples presented herein, the predetermined threshold amount of particles is 100 events.

[0009] In yet other examples presented herein, the sample line source is a sheath fluid. In further examples presented herein, the sheath fluid is a 5 nm sheath fluid. In still other examples presented herein, the sample processing instrument is a flow cytometer.

[0010] Still other examples presented herein relate to a system for operating a sample processing instrument. The system including at least one processor, a memory, in communication with processor and including instructions which, when executed by the at least one processor, cause the processor to determine whether a fluidics systems of the sample processing instrument meets a cleaning requirement based on an amount of particles present in a measurement flow, and generate a graphical user interface including a source selection operation, wherein the source selection operation accepts input from a user selecting one of a sample tube source and a sample line source as a source for the measurement flow.

[0011] In other examples presented herein, the sample tube source is a sample buffer and a sample line source is a sheath fluid. In further examples presented herein, the sheath fluid is a 5 nm sheath fluid. In other further examples presented herein, the cleaning requirement comprises a threshold amount of particles and a first threshold amount of particles for the sample line source is a lower amount than a second threshold amount of particles for the sample tube source.

[0012] A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows:

[0014] FIG. 1 is a functional block diagram of an example sample processing instrument.

[0015] FIG. 2 is a schematic diagram of a fluidics systems of a sample processing instrument according to an embodiment of the present application.

[0016] FIG. 3 A is a first graph of a series of graphs demonstrating an example use case for using the sheath fluid as a monitoring fluid.

[0017] FIG. 3B is a second graph of the series of graphs of FIG. 3A demonstrating the example use case for using the sheath fluid as a monitoring fluid.

[0018] FIG. 3C is a third graph of the series of graphs of FIG. 3 A demonstrating the example use case for using the sheath fluid as a monitoring fluid.

[0019] FIG. 3D is a fourth graph of the series of graphs of FIG. 3A demonstrating the example use case for using the sheath fluid as a monitoring fluid.

[0020] FIG. 4 is a flowchart of an example method of operating the sample processing instrument.

[0021] FIG. 5 is a flowchart of an example method for measuring an amount of particles in the fluidics system.

[0022] FIG. 6 is an example user interface for enabling a user to define and execute cleaning and monitoring operations of the sample processing system.

[0023] FIG. 7 is an example graphical user interface of parameter setting element of FIG. 6.

[0024] FIG. 8 schematically illustrates an example of the control unit of the sample processing instrument that can be used to implement aspects described herein.DETAILED DESCRIPTION

[0025] The present application is described in detail hereinafter by means of exemplary embodiments with reference to the accompanying drawings. In the several drawings, similar reference numerals indicate similar parts and components. The following detailed description of the present application is for explanation only and is by no means intended to limit the present application and the applications or usages thereof. The embodiments described in this specification are not exhaustive, but are only some of a number 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 application. In some exemplary embodiments, well-known processes, well- known device structures, and w ell-known technologies may not be described in detail.

[0026] Before at least one embodiment of the present application is explained in detail, it is to be understood that the present application is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments that may be practiced or carried out in various ways as well as to combinations of the disclosed embodiments. In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

[0027] The sample processing instrument according to the present disclosure will be described by taking a flow cytometer as an example. Flow cytometers are used to detect particles in a sample to determine one or more characteristics of the particles. However, it should be understood that the sample processing instrument according to the present disclosure is not limited to a flow cytometer, and may be any other suitable instrument for processing biological samples or non-biological samples. In some embodiments, the sample processing instrument may be a cell or particle sorter.

[0028] The sample processing instrument according to the present disclosure is suitable for automatically performing the cleaning process between processing different samples, for automatically performing the cleaning process using different cleaning agents, and for automatically performing the monitoring process of measuring the cleaning result after the cleaning process. The system may additionally automatically determine the next action according to the measurement result. For example, various monitoring agents are discussed herein with differing sensitivities for the measurement of particles at an interrogation point in the fluidics system. Additionally, the system may provide an interface to a user to enable to user to easily operate and intuitively observe the monitoring and cleaning process. For example, a user interface is provided enabling a user to select a monitoring agent to be used to measure carry over in the interrogation point of the fluidics system. As discussed herein, carryover refers to sample particles and other debris which may remain the fluidics system following a sample run and contaminate future sample analyses.

[0029] The main functional parts of the sample processing instrument 1 will be described below with reference to FIG. 1. The sample processed (for example, analyzed or sorted) by the sample processing instrument 1 may include biological particles such as exosomes or extracellular vesicles or non-biological particles such as beads. The disclosed system is optimized for detecting and measuring particles at the nano-level (e.g., nanoparticles, nanobeads, exosomes), but the disclosed system can also be used for larger particles.

[0030] FIG. 1 is a functional block diagram of the sample processing instrument 1. As shown in FIG. 1, the sample processing instrument 1 includes fluidics components 10, a flow cell 20, a sample processing unit 30 and a control unit 40.

[0031] The fluidics components 10 are configured to supply various fluids to the flow cell 20, which includes an interrogation point, and to discharge the fluid out of the flow cell 20. The fluids described herein may include samples to be analyzed, sorted orotherwise processed, sheath fluid, cleaning agents, waste fluids, and the like. The fluidics components 10 may include various pumps, valves, pressure regulating devices, sensors, etc., for delivering fluid or discharging fluid. Various fluids, particularly samples and sheath fluid are delivered to the flow cell 20.

[0032] FIG. 2 is a schematic diagram of a flow cell of a sample processing instrument according to an embodiment of the present application. Referring to FIG. 2, the flow cell 20 includes two opposite sheath ports 21 and 22, and the sheath fluid is delivered to the chamber 25 of the flow cell 20 through the sheath ports 21 and 22. The flow cell 20 further includes a sample needle 23 disposed therein, and the sample is transported into the chamber 25 through the sample needle 23. In the chamber 25, the sample is wrapped in sheath fluid and then flows through the cuvette 26 for processing. The cuvette 26 forms the processing area of the sample and may include an interrogation point. For example, the optical detection device focuses the light beam in the processing area (e.g., the interrogation point) of the cuvette 26. In case that the particles in the sample pass through the processing area of the cuvette 26, the characteristics of the particles are determined by measunng the light scattered or emitted from the particles.

[0033] The sample processing unit 30 processes the sample wrapped in the sheath fluid flowing through the cuvette 26. For example, the sample processing unit 30 may measure characteristics of parti cles / cells in the sample and quantify the parti cles / cells having particular characteristics, and / or the sample processing unit 30 may sort particles / cells in the sample based on their characteristics. The sample processing unit 30 may include various optical devices, electrical devices, and / or mechanical devices according to the aim of sample processing.

[0034] The control unit 40 controls the operation of the entire sample processing instrument 1. The various functions, actions, or steps of the various systems, devices, components, or methods of the sample processing instrument according to the present application are controlled by the control unit 40. The control unit 40 will be described in detail below.

[0035] An example of fluidics components according to an embodiment of the present application will be described below with reference to FIG. 2 showing a part of a system 100, which includes fluidics for controlling flow- of different fluids. As described above, the fluidic system 100 is used to supply various fluids to the flow cell20 and to discharge the fluid out of the flow cell 20. To this end, the fluidic system 100 includes fluid pipelines connecting various fluid sources to the flow cell 20.

[0036] These fluid sources may include a sample source 101, a sheath source (not shown), a waste reservoir, and other solution sources. The sample source 101 is used to supply samples. Generally, the sample source 101 includes multiple sample containers containing different samples, for example, a well plate, a test tube, and the like. The sheath fluid is stored in the sheath source. Sheath liquid is the matrix liquid that helps the sample flow to be detected normally, and may function to wrap around the sample flow and keep it in the center of the nozzle to ensure the accuracy of detection while preventing particles in the sample flow from approaching the nozzle wall and blocking the nozzle. In addition, the sheath fluid may also be used as a cleaning agent for cleaning the sample processing instrument (especially, the flow cell and the fluid pipelines) and / or as a monitoring solution for monitoring the system for the presence of carryover. Other solution sources include a fluid container 103 storing other cleaning agents (for example, water or another special cleaning solution) rather than the sheath fluid, and a separate container (not shown) storing a monitoring solution (for example, water or a buffer) for measuring the cleaning result of the sample processing instrument. The waste reservoir is used to collect the waste liquid after sample processing and cleaning of the sample processing instrument.

[0037] Referring to FIG. 2, the fluid pipeline includes sample pipelines 111. 112 and 1 13 that communicate the sample source 101 to the sample needle 23, a sheath pipeline 117 for communicating a sheath source (not shown) to the sheath ports 21 and 22 of the flow cell 20; a waste pipeline 116 for communicating the flow' cell 20 to a waste reservoir (not shown); sheath cleaning pipelines 153 and 154 for conveying sheath fluid for cleaning, and cleaning agent pipelines 142 and 144 for conveying a cleaning agent for cleaning.

[0038] Various pumps for pumping various fluids may be provided in the fluid pipeline. In the example shown in FIG. 2, there is a sample pump 121 for pumping samples, a sheath pump 125 for pumping sheath liquid for cleaning, and a cleaning pump 123 for pumping a cleaning agent. In the example of FIG. 2, the sample pump 121, the sheath pump 125, and the cleaning pump 123 are all piston pumps. However, it should be understood that the systems disclosed in the present application are not limited to the specific examples shown in the drawings, as long as it can realize the functions described herein. For example, the type of the pump may be varied. Inembodiments, the sheath pump 125 and the cleaning pump 123 may be other types of pumps such as peristaltic pumps. Similarly, the sample pump 121 may also adopt any other suitable type of pump, for example, a peristaltic pump. In some embodiments, the number of pumps may be changed. In some examples, the sheath pump is omitted.

[0039] Various switching devices may be provided in the fluid pipeline, for example, for switching the flowing direction of the fluid or for controlling the on-off state of the fluid. The switching device may include various types of valves. As shown in FIG. 2, the switching device includes three-way valves 131 and 132 and on-off valves 141, 151 and 152.

[0040] The three-way valve 132 is configured to selectively communicate the sample pipelines 111 to 113 with different pumps (for example, the sample pump 121 or the cleaning pump 123) to suck or pump different fluids (for example, the sample or the cleaning agent) to the flow cell 20 or the sample source 101. In the example of FIG. 2, the three-way valve 132 includes a first port 1321 connected to the sample pipeline 113, a second port 1322 connected to the sample pump 121, and a third port 1323 connected to the cleaning pump 123. In case that the first port 1321 is switched to communicate with the second port 1322, the sample pump 121 is allowed to suck a sample from the sample source 101 when the sample pipeline 113 is connected to the sample pipeline 111 or pump a fluid (e.g., a sample or sheath fluid) to the flow cell 20 when the sample pipeline 113 is connected to the sample pipeline 112. That is. the system may allow the sample pump 121 to suck a sample from the sample source 101 by switching the valve 132 to connect the sample pump 121 to the sample pipeline 113 and by switching the valve 131 to connect the sample pipeline 113 to the sample pipeline 111 (the sample or sheath fluid may alternatively be sent to the flow cell 20 by switching the valve 131 to connect the sample pipeline 113 to the sample pipeline 112). The system may allow the cleaning pump 123 to suck the cleaning agent from the fluid container 103 and pump it to the flow cell 20 by switching the valve 132 to connect the cleaning pipeline 144 to the sample pipeline 113 and by switching the valve 131 to connect the sample pipeline 113 to the sample pipeline 112 (the cleaning agent may alternatively be sent to the sample source 101 by switching the valve 131 to connect the sample pipeline 113 to the sample pipeline 111).

[0041] The three-way valve 131 is configured to selectively communicate a pump (e.g.. the sample pump 121 or the cleaning pump 123) with the sample source 101 or the flow cell 20 to selectively suck or pump fluid (e.g., the sample or the cleaningagent) to the flow cell 20 or the sample source 101. In the example of FIG. 2, the three- way valve 131 is provided between the sample pipelines 111. 112 and 113 for selectively communicating the sample pipeline 113 with the sample pipeline 111 or the sample pipeline 112. The three-way valve 131 has a first port 1311 connected to the sample pump 121 or the cleaning pump 123 via the three-way valve 132, a second port 1312 connected to the sample needle 23, and a third port 1313 connected to the sample source 101. The system may allow the fluid in the sample pipeline 113 (for example, the sample pumped by the sample pump 121 or the cleaning agent pumped by the cleaning pump 123) to be conveyed into the flow cell 20 by switching the valve 131 to connect the sample pipeline 113 to the sample pipeline 112, or alternatively allow fluid to be sucked from / pump into the sample source 101 by switching the valve 131 to connect the sample pipeline 113 to the sample pipeline 111.

[0042] By the three-way valves 131 and 132, it is possible to selectively pump the sample to the flow cell 20 to, for example, analyze the sample, or pump the cleaning agent to the sample source 101 or the flow cell 20 to clean the sample pipelines 111 to 1 13 or the flow cell 20.

[0043] The cleaning pump 123 is connected to the third port 1323 of the three-way valve 132 via a cleaning agent pipeline 144, and is connected to the fluid container 103 via a cleaning agent pipeline 142. An on-off valve 141 may be provided in the cleaning agent pipeline 142 to control the on-off state of the cleaning agent pipeline 142. In case of sucking the cleaning agent, the on-off valve 141 is in a closed state to allow communication of the cleaning agent pipeline 142. In case of no need to suck the cleaning agent, the on-off valve 141 is in an open state to interrupt the communication of the cleaning agent pipeline 142.

[0044] The sheath pump 125 is arranged between the sheath pipeline 117 connected to the sheath source and the sample pump 121 to deliver the sheath fluid to the sample source 101 or the flow cell 20 via the sample pump 121, so as to clean the sample pipelines 111-113 or the flow cell 20 with the sheath fluid. The sheath pump 125 is connected to the sheath pipeline 117 (or the sheath source) via the sheath cleaning pipeline 153, and is connected to the sample pump 121 via the sheath cleaning pipeline 154. An on-off valve 151 may be provided in the sheath cleaning pipeline 153 to control the on-off state of the sheath cleaning pipeline 153. In case that the sheath fluid is sucked for cleaning, the on-off valve 151 is in a closed (i.e., on) state to allow communication of the sheath cleaning pipeline 153. In case of no need to suck thesheath fluid, the on-off valve 151 is in an open (i.e., off) state to interrupt the communication of the sheath cleaning pipeline 153. Furthermore, an on-off valve 152 may be provided in the sheath cleaning pipeline 154 to control the on-off state of the sheath cleaning pipeline 154. In case of pumping the sheath fluid, the on-off valve 152 is in a closed (i.e., on) state to allow the communication of the sheath cleaning pipeline 154. In case of no need to pump the sheath fluid, the on-off valve 152 is in an open (i.e., off) state to interrupt the communication of the sheath cleaning pipeline 154.

[0045] In embodiments, this flow' path is also used to supply sheath fluid to be used as a monitoring fluid.

[0046] It should be understood that the system according to the present disclosure is not limited to the specific example shown in FIG. 2, but may be changed according to actual requirements. For example, the sheath pump and the cleaning pump may be peristaltic pumps, and accordingly, on-off valves may be omitted in the sheath cleaning pipelines and the cleaning agent pipeline. In another example, the sheath pump is omitted, and instead, only an on-off valve is provided in the sheath cleaning pipeline between the sheath pipeline (or the sheath source) and the sample pump. It should be understood that the system according to the present application is not limited to having the components described above. For example, it may also have a filter (for example, a filter 119 for filtering sheath fluid as shown in FIG. 2), a sensor for sensing temperature or pressure, a regulator for adjusting temperature or pressure, and the like. In some preferred embodiments, the filter 119 is a 5 nanometer (nm) filter.

[0047] An example process of conveying a sample through the fluidic system 100 during sample processing will be described below with reference to FIG. 2. When a sample is to be processed, the three-way valve 132 is switched such that the sample pump 121 is connected to the sample pipeline 1 13, and the three-way valve 131 is switched such that the sample pipeline 113 is connected to the sample pipeline 111, whereby the sample is sucked from the sample source 101 into the sample pipeline 113 by the sample pump 121 (for example, the piston of the sample pump 121 moves downward).

[0048] Then, the three-way valve 131 is switched such that the sample pipeline 113 is connected to the sample pipeline 112, and the sample in the sample pipeline 113 is pumped into the flow cell 20 by the sample pump 121 (for example, the piston of the sample pump 121 moves upward) for processing (for example, detection or sorting, etc.).

[0049] During the sample processing, the sample pump 121 is always connected to the sample pipeline 113. and the three-way valve 131 is repeatedly switched between the second port 1312 and the third port 1313 to repeatedly perform the processes of sucking and pumping samples until the sample processing is finished.

[0050] Following sample processing, cleaning of the sampling flowpath by the fluidic system is necessary to prevent contamination of future samples and to maintain proper system operation.

[0051] The process of cleaning the sample pipelines 111 to 113 and the flow cell 20 by the fluidic system 100 using the cleaning agent will be described below with continued reference to FIG. 2. When the sample processing instrument is to be cleaned with the cleaning agent, the on-off valve 141 is closed to communicate the cleaning agent pipeline 142, thereby allowing the cleaning pump 123 to suck the cleaning agent from the fluid container 103.

[0052] When the on-off valve 141 is switched to an open state, and the three-way valve 132 is switched such that the cleaning agent pipeline 144 is connected to the sample pipeline 113 to pump the cleaning agent into the sample pipeline 113. At this moment, the three-w ay valve 131 may be in a state where the sample pipeline 113 is connected to either of the sample pipeline 112 and the sample pipeline 111.

[0053] In the case that the sample pipeline 113 is connected to the sample pipeline111, the cleaning agent is pumped through the sample pipeline 111, thereby cleaning the sample pipelines 1 13 and 11 1. Next, the on-off valve 141 is repeatedly put in a closed state or an open state to suck or pump the cleaning agent until the sample pipeline 111 is cleaned.

[0054] In the case that the sample pipeline 113 is connected to the sample pipeline1 12, the cleaning agent is pumped through the sample pipeline 112 and the flow cell 20, thereby cleaning the sample pipelines 113 and 112 and the flow' cell 20. Next, the on-off valve 141 is repeatedly in the closed or open state to suck or pump the cleaning agent until the fluidics system, including the sample pipeline 112 and the flow cell 20, are cleaned.

[0055] The process of cleaning the sample pipelines 111 to 113 and the flow cell 20 by the fluidic system 100 using the sheath liquid will be described below with continued reference to FIG. 2. When the sample processing instrument is to be cleaned with sheath liquid, the on-off valve 151 is closed to allow communication of the sheathcleaning pipeline 153, thereby allowing the sheath pump 125 to suck the sheath liquid from a sheath source (not shown).

[0056] Then, the on-off valve 151 is put in an open state, and the on-off valve 152 is put in a closed state and the three-way valve 132 is switched such that the first port 1321 communicates with the second port 1322 to pump the sheath fluid into the sample pipeline 113 via the sample pump 121. The three-way valve 131 may be in a state where the sample pipeline 113 is connected to either of the sample pipeline 112 and the sample pipeline 111.

[0057] In the case that the sample pipeline 113 is connected to the sample pipeline 111, the sheath fluid is pumped through the sample pipeline 111, thereby cleaning the sample pipelines 113 and 111. Next, the on-off valve 151 and the on-off valve 152 are alternately in a closed state or an open state to suck or pump the sheath fluid until the sample pipeline is cleaned.

[0058] In the case that the sample pipeline 113 is connected to the sample pipeline 12, the sheath fluid is pumped through the sample pipeline 112 and the flow cell 20, thereby cleaning the sample pipelines 113 and 112 and the flow cell 20. Next, the on- off valve 151 and the on-off valve 152 are alternately in a closed state or an open state to suck or pump the sheath fluid until the sample pipeline and the flow cell 20 are cleaned.

[0059] In addition to the sample processing and cleaning processes described above, the system may also be used for monitoring the cleaning of the sample processing instrument. Following a system cleaning, the monitoring operation is used to ensure adequate removal of debris and contaminants from the system. In embodiments, multiple monitoring fluids are available to the sample processing system. One or more monitoring fluids may be used to perform the monitoring operation. In example, one or more monitoring fluids may be used in sequence, automatically, or one or more monitoring fluids may be used in response to a user selection.

[0060] In some embodiments, sample source 101 may be filled with a monitoring solution (e.g., water, a buffer, the sheath fluid), instead of a sample, in between analyses of two different samples. For example, a first sample in a sample source 101 may be analyzed by the system 100, the system 100 may be cleaned with a cleaning agent from the fluid container 103, and then sample source 101 may be switched for a different sample source 101 filled with a monitoring solution for monitoring the flowcell 20 for the presence of carryover. In some cases, the monitoring solution and the cleaning agent may be the same fluid, for example, water.

[0061] In some embodiments, the cleaning agent may be the monitoring solution, in which case the fluid container 103 may be used as the source of the monitoring solution as well as the cleaning agent. In this case, the process of feeding the monitoring solution through the flow cell 20 and other parts of the fluidics system during the monitoring process may be similar to the process of feeding the cleaning agent through the flow cell 20 and fluidics system during the cleaning process.

[0062] In some embodiments, a separate fluid container (i.e., a container other than the sample source 101 and the fluid container 103) may be provided to contain the monitoring solution. In this case, the same pump as other fluids or an additional pump may be used to pump the monitoring solution through the interrogation point, e.g., the flow cell 20, of the fluidics system. The fluid pipeline for the monitoring solution may be integrated into other fluid pipelines like the sheath cleaning pipeline, or may be an independent fluid pipeline from the fluid container containing the monitoring solution to the flow cell 20. Similarly, the sheath cleaning pipeline may also be formed as an independent fluid pipeline from the sheath source to the flow cell 20 and the sample pipeline, that is, it does not pass through the sample pump 121.

[0063] In some preferred embodiments, the sheath liquid serves as the monitoring solution. In this case, the sheath pump 125 or an additional pump may be used to pump the monitoring solution through the flow cell 20. Sheath line 117 may also or alternatively be used to supply sheath liquid to the flow cell to serve as the monitoring solution.

[0064] FIGS. 3A-D is a series of graphs demonstrating an example use case for using the sheath fluid as a monitoring fluid. Graphs 202, 206, and 208 (of FIGS. 3A, 3C, and 3D respectively) depict carryover readings from a flow cytometer taken with a monitoring fluid from the sample tube, such as sample source 101 of FIG. 2. In each case, some significant carryover is seen to be measured. However, graphs 204 of FIG. 3B depict carryover readings taken with a monitoring fluid from the sample line, such as the sheath fluid, which may be a 5 nm sheath fluid. In this case, substantially less carry over is measured. With common equipment and settings used to collect the readings for each column, differences in the carryover measurement are attributable to the different monitoring fluid selected.

[0065] With advances in the sensitivity of the sample processing instruments, buffers and other sample tube fluids may themselves carry to high an amount of particulates and other debris to provide an accurate measure of the cleanliness of the instrument. In other word, debris within the buffer itself may provide a deceptively high carryover reading. By using another, cleaner, monitoring fluid, such as a sheath fluid, e.g., a 5 nm sheath fluid, a truer measure of carryover in the instrument may be achieved. In this way, cleanliness of the instrument can be verified despite a user’s limited ability to control or verify the cleanliness of sample buffers and other fluids which may be introduced via the sample tube.

[0066] As described above, the structure of the disclosed systems and their fluidics components are not limited to the specific examples described and shown above, but can be varied as long as it can realize automatic cleaning / monitoring processes or automatic cleaning process with different cleaning agents. Furthermore, since the structure of the disclosed systems can be changed, the operation method of the disclosed systems can be changed accordingly.

[0067] FIG. 4 is a flowchart of an example method 300 of operating the sample processing instrument. The method 300 may be performed by a sample processing instrument, such as the sample processing instrument 1 of FIG. 1, which may be a flow cytometer. In embodiments, the method 300 may be an automated process executed by a control unit, such as control unit 40 of FIG. 1.

[0068] At operation 302, one or more samples are processed through the fluidics system of the sample processing instrument. For example, a first sample, which may contain a number of particles, is fed through to a flow cell via a flow path of the fluidics system, such as those discussed above, and processed. The particles of the first sample are detected or sorted by the instrument. The particles are, for example, biological nanoparticles.

[0069] After the first sample has been processed, there may be a need to process an additional sample. For accurate results, the flow cell and one or more pipelines of the system may need to be washed in between successive samples to prevent particles from the first sample from affecting the results of processing the second sample. It is generally difficult to remove these leftover particles, referred to herein as carry over, especially when the particles are of a small size. Therefore, in order to ensure the accurate processing of the second sample, the sample processing instrument must beadequately cleaned. In embodiments, the flow cell and sample flow path of the fluidics system may be of particular concern.

[0070] At operation 304, the fluidics system is cleaned. A suitable cleaning agent (e.g., sheath fluid, water, and / or any other suitable cleaning solution), cleaning parameters (e.g., duration of one cleaning cycle, number of cleaning cycles, maximum number of cleaning cycles, etc.), monitoring solution (e.g., water or sheath fluid) and / or monitoring parameters may be selected or set. The monitoring parameters may include parameters associated with the monitored solution (e.g., delivery time or volume, etc.), populations associated with monitored particles or monitoring parameters (e.g., monitoring criteria indicating that cleaning requirements are met). In embodiments, one or more of the cleaning agent, cleaning parameters, monitoring solution, and the monitoring parameters may be set according to known or identified characteristics of the particles in the first sample. The monitoring standard may be embodied in various forms, for example, the target carry over count within a predetermined time, the target carryover concentration / concentration percentage, the target carryover rate (number / second), and so on. Example settings of cleaning parameters and monitoring parameters and criteria may be seen in PCT Publication No. 2023 / 065796, the entirety of which is incorporated herein by reference.

[0071] The sample processing instrument is cleaned by the selected cleaning agent according to the set cleaning parameters. In a cleaning cycle, the selected cleaning agent may be one, two or more. Correspondingly, cleaning parameters may be set for each cleaning agent. The cleaning parameters may be determined based on experimental data, historical data or experimental data.

[0072] At operation 306, an amount of particles at an interrogation point of the fluidics system is measured. A monitoring solution is pumped through the fluidics system by the fluidics components. The sample processing instrument then analyzes the interrogation point, which may generally be within a flow cell, including the monitoring solution during the monitoring period.

[0073] FIG. 5 is a flowchart of an example method 400 for measuring an amount of particles in the fluidics system. The method 400 may7be performed by a sample processing instrument, such as the sample processing instrument 1 of FIG. 1, which may be a flow cytometer. In embodiments, the method 400 may be an automated process executed by a control unit, such as control unit 40 of FIG. 1.

[0074] At operation 402, flow is selectively supplied to the fluidics system from one of the sample tube source and the sample line source. As discussed herein, the sample line source refers to a sheath fluid, such as a 5 nm sheath fluid, and the sample tube source is a sample buffer. In embodiments, a source for the flow is determined based on a user input.

[0075] At operation 404, the amount of particles in at an interrogation point of the fluidics system is measured. A measurement value related to the carryover or the monitoring solution during the monitoring period is obtained, for example, the amount of the cany' over and / or the flow7rate of the monitoring solution. The flow7rate of the monitoring solution may be measured by one or more sensors. For example, for a sample processing instrument that is a flow cytometer, the measurement may be performed by measuring light scattered from the interrogation point, which may reside within a flow' cell of the fluidics system, in response to one or more laser beams directed at the interrogation point. In this example, the cany7over may be counted by. for example, an optical detection system based on the detected light scattered or emitted from the particles. In the same monitoring time, the low er the amount of carryover (e g., a count or approximate count of the number of carryover particles remaining in the flow cell during the monitoring period), the better the cleaning results. Of course, as the monitoring time is longer, the amount of carryover detected is greater. If the measured value is not sufficient to indicate the cleaning level, a value that accurately indicates the cleaning level may be calculated. For example, the value may be a cany7over rate (number / second) (carry7over particles detected during monitoring divided by monitoring time), a carryover concentration (number / microliter) (number of carryover particles detected during monitoring divided by volume of monitoring solution), or a carryover concentration percentage (ratio of carryover concentration to concentration of the first particle in the first sample).

[0076] At operation 406, the amount of particles measured is compared against a predetermined target value. In some embodiments, the target value may be based on the first sample, the second sample, or the type of processing that is occurring. For example, different samples or different sample processing / analyses may have different target values.

[0077] In embodiments, the predetermined target value is different based on whether the flow is supplied from the sample tube source or the sample line source. For example, the predetermined target value is higher for flow supplied from the sampletube source and lower for flow supplied from the sample line source. In embodiments, the predetermined target value is 100 events.

[0078] At operation 408, a result of the comparison is used to determine whether a cleaning requirement has been met. In the case that the measured or calculated value (actual value) is less than or equal to the target value, it indicates that the cleaning requirement has been met, and the monitoring process may end at operation 420. In this case, ending the monitoring process includes an indication that the cleanliness of the machine is satisfactory for further sample runs.

[0079] In the case that the measured or calculated value (actual value) is greater than the target value, it indicates that the cleaning requirement has not been met, and then proceed to operation 410. If, at operation 408, it is determined that the cleaning requirement has not been met, an additional determination may be made, at operation 410, whether the sample line was used to supply the monitoring fluid, e.g., whether the monitoring fluid was the sheath fluid. If it is determined that the sample tube source was used to supply the flow, an additional verification measurement may be taken.

[0080] If, at operation 410. it is determined that the sample line was used as the monitoring fluid, then the monitoring process ends with an unsatisfactory result at operation 422. An unsatisfactory' result may indicate that further cleaning or other maintenance is necessary before any further sample runs.

[0081] If, at operation 410, it is determined that the sample tube was used as the monitoring fluid, than an additional monitoring measurement may be taken using the sample line, at operation 412. As the sheath fluid, and in particular a 5 nm sheath fluid, has a known level of cleanliness as compared with a buffer that might be supplied from the sample tube, the sample line can be used to assess whether measured carryover is present in the instrument or in the monitoring fluid. At operation 412, an additional flow of sheath fluid is supplied to the interrogation point of the fluidics system from the sample line. At operation 414, a second measurement is taken of the amount of the particles in the additional flow of the sheath fluid. At operation 416, the second measurement is compared with the predetermined target value.

[0082] At operation 418, a result of the comparison is used to determine whether a cleaning requirement has been met. If the measured values is less than the threshold value, the monitoring operation may end with a satisfactory status for the cleanliness of the system, at operation 420. This may indicate the system is ready to run additional samples. In embodiments, a user may be notified that the cleaning requirement hasbeen met. In some cases, a additional sample may be then automatically transported through the fluidics system and processed at the interrogation point.

[0083] If the measured values is equal to or greater than the threshold value, the monitoring operation may end with an unsatisfactory status for the cleanliness of the system, at operation 422. This may indicate further cleaning or other maintenance of the system is called for prior to running additional samples. In embodiments, a further determination may be made whether a maximum cleaning limit has been reached, for example, a set maximum cleaning duration limit (e.g., a maximum limit on the total amount of time spent in one or more cleaning cycles) or a maximum cleaning cycle number limit (e.g., a maximum limit placed on the number of cleaning cycles performed). In some embodiments, the maximum cleaning limit may be set by the user. In some embodiments, the maximum cleaning limit may be based on the first sample, an additional or next sample, or the type of processing that is occurring. For example, different samples or different sample processing / analyses may have different maximum cleaning limits. If the maximum cleaning limit is not reached, the system may continue the cleaning process until the cleaning requirement is met or the maximum cleaning limit is reached. If the maximum cleaning limit is reached, the cleaning process is stopped. A message or warning may be issued to the user, so that the user may take appropriate measures, such as troubleshooting.

[0084] In order to facilitate user operations and obtain information, the method of the present application may be carried out with a user interface. FIG. 6 is an example user interface 500 for enabling a user to define and execute cleaning and monitoring operations of the sample processing system.

[0085] Referring to FIG. 6, the user interface 500 may include a menu 510, a parameter setting element 520, a monitoring element 540, a setting-applicable-sample element 530, a historical data viewing element 550 and a control element 560. The menu 510 may include one or more next activity element that enable the user to interact with the sample processing instrument by configuring the processing of samples and the cleaning of the sample processing instrument or monitoring such processing or cleaning. The parameter setting element 520, the monitoring element 540, the setting- applicable-sample element 530 and the historical data viewing element 550 may be displayed on the user interface in response to the selection or operation of the corresponding next- activity element of the menu 510, so that the user can input information or information is displayed to the user.

[0086] The parameter setting element 520 is used to receive user input related to cleaning, monitoring and carryover (which will be described in detail below with reference to FIG. 7). The monitoring element 540 is configured to display information related to cleaning or monitoring status, monitoring data, monitoring results, monitoring standards, etc., to the user. The setting-applicable-sample element 530 includes samples to be monitored, and the user may select samples to which the settings at the parameter setting element 520 are applied, so that the sample processing instrument may automatically and continuously process multiple samples. The historical data viewing element 550 may retrieve or view7historical monitoring data according to user request. The control element 560 allows the user to control various elements displayed on the user interface or display contents of various elements.

[0087] As shown in FIG. 6, the menu 510, the parameter setting element 520, the setting- applicable-sample element 530, the monitoring element 540, the historical data viewing element 550 and the control element 560 may be displayed simultaneously on one screen, for example, within the corresponding boxes. It should be understood that the user interface according to the present application should not be limited to the specific example shown in FIG. 6, but may be changed as required. In some embodiments, any subset of these interface elements may be displayed simultaneously on the user interface. For example, in some cases, only the menu 510 and the parameter setting element 520 may be displayed simultaneously on the user interface 500. In some embodiments, the interface elements displayed on the user interface may be selected based on a user input. For example, the user may select the setting-applicable-sample element 530, and in response, the user interface may show7an enlarged setting- applicable-sample element 530 and none (or only a subset) of the other interface elements. For example, the historical data viewing element 550 is optional.Furthermore, the layout of various elements on the user interface may be changed. The content and display form of each element may also be changed as required.

[0088] FIG. 7 is an example graphical user interface 600 of parameter setting element 520 of FIG. 6. As shown in FIG. 7. a parameter setting element may display a number of menu items to establish parameters for cleaning and monitoring of the instrument. A monitoring fluid selection source 602 may provide options for selecting either the sample tube or the sample line as a source. Acceptance criteria selection 604 may provide for setting a threshold value for comparing to a measured number (or rate) of particles. Cleaning cycle settings 606 may provide for establishing, for example, anumber of times a cleaning cycle may be repeated trying to obtain a satisfactory outcome.

[0089] FIG. 8 schematically illustrates an example of the control unit 40 of the sample processing instrument 1 that can be used to implement aspects described herein, such as control unit 40 of FIG. 1. As shown in FIG. 8, the control unit 40 includes one or more processing devices 802. a memory storage device 804, and a system bus 806 that couples the memory storage device 804 to the one or more processing devices 802. The one or more processing devices 802 can include central processing units (CPU). In some instances, the one or more processing devices 802 are part of a processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to perform the various aspects, features, and functionalities described herein.

[0090] As shown in FIG. 8, the memory storage device 804 can include a randomaccess memory' (“RAM’') 808 and a read-only memory (“ROM”) 810. Basic input and output logic having basic routines that help to transfer information between elements within the control unit 40. such as during startup, can be stored in the ROM 810.

[0091] The control unit 40 can also include a mass storage device 812 that can include an operating system 814 and store softw are instructions and data 816. The mass storage device 812 is connected to the processing device 802 through the system bus 806. The mass storage device 812 and associated computer-readable data storage media provide non-volatile, non-transitory storage for the control unit 40.

[0092] Although the description of computer-readable data storage media contained herein refers to the mass storage device 812, it should be appreciated by those skilled in the art that computer-readable data storage media can be any available non-transitory, physical device or article of manufacture from which the control unit 40 can read data and / or instructions. The computer-readable storage media can be comprised of entirely non-transitory media. The mass storage device 812 is an example of a computer-readable storage device.

[0093] Computer- readable data storage media include volatile and non-volatile, removable, and non-removable media implemented in any method or technology7for storage of information such as computer-readable software instructions, data structures, program modules or other data. Example types of computer-readable data storage media include, but are not limited to, RAM. ROM, EPROM, EEPROM, flash memoryor other solid-state memory technology, or any other medium which can be used to store information, and which can be accessed by the device.

[0094] The control unit 40 can operate in a networked environment using logical connections to the other devices through the network 820. The control unit 40 connects to the network 820 through a network interface unit 818 connected to the system bus 806. The network interface unit 818 can also connect to additional types of communications networks and devices, including through Bluetooth. Wi-Fi, and cellular telecommunications networks including 4G and 5G networks. The network interface unit 818 can connect the control unit 40 to additional networks, systems, and devices. The control unit 40 also includes an input / output unit 822 for receiving and processing inputs and outputs from peripheral devices.

[0095] The mass storage device 812 and the RAM 808 can store software instructions and data. The software instructions can include an operating system 814 suitable for controlling the operation of the sample processing instrument 1. The mass storage device 812 and / or the RAM 808 can also store the software instructions and data 816. which when executed by the processing device 802, provide the functionality of the sample processing instrument 1 discussed herein.

[0096] Illustrative examples of the systems and methods described herein are provided below . An embodiment of the system or method described herein may include any one or more, and any combination of. the clauses described below.

[0097] Clause 1 . A method for operating a sample processing instrument, the method including: processing one or more samples through a fluidics system of the sample processing instrument; cleaning the fluidics system; measuring an amount of particles at an interrogation point the fluidics system by: selectively supplying a flow to the fluidics system from one of a sample tube source and a sample line source; and measuring the amount of particles in the flow: comparing the amount of particles measured against a predetermined target value; and determining, using the comparing, whether a cleaning requirement is met.

[0098] Clause 2. The method of clause 1. wherein the flow is supplied from the sample tube source and the cleaning requirement is determined to not be met, the method further including: supplying a second flow from the sample line source; measuring a second amount of particles in the second flow; comparing the second amount of particles measured against the predetermined target value; and determining, using the comparing, whether the cleaning requirement is met.

[0099] Clause 3. The method of clause 1 or 2, wherein a source for the flow is determined based on a user input.

[0100] Clause 4. The method of any one of clauses 1-3, wherein the predetermined target value is different based on whether the flow is supplied from the sample tube source or the sample line source.

[0101] Clause 5. The method of clause 4. wherein the predetermined target value is higher for flow supplied from the sample tube source and lower for flow supplied from the sample line source.

[0102] Clause 6. The method of any one of clauses 1-5, wherein the sample line source includes a sheath fluid.

[0103] Clause 7. The method of clause 6. wherein the sheath fluid is 5 nanometer sheath fluid.

[0104] Clause 8. The method of any one of clauses 1-7, wherein the sample tube source is a sample buffer.

[0105] Clause 9. The method of any one of clauses 1-8, wherein the predetermined target value is 100 events.

[0106] Clause 10. A system for operating a sample processing instrument, the system including: a fluidics system including: a flow cell; a sample tube source; a sample line source; a fluidics path to the flow cell; a source selection valve in communication with the fluidics path and in selective communication with each of the sample tube source and the sample line source; and a controller including a processor and a memory, the memory including instructions that, when executed by the processor, cause the processor to: generate a display including a source selection operation; receive an input from the source selection operation; and operate the source selection valve, using the input, to provide flow to the flow cell from one of the sample tube source and the sample line source.

[0107] Clause 11. The system of clause 10, wherein the source selection operation is associated with determining whether a cleaning requirement is met based on a measured amount of particles at an interrogation point in the fluidics system.

[0108] Clause 12. The system of clause 11, wherein the cleaning requirement includes a predetermined threshold amount of particles.

[0109] Clause 13. The system of clause 12. wherein the predetermined threshold amount of particles is 100 events.

[0110] Clause 14. The system of any one of clauses 10-13, wherein the sample line source is a sheath fluid.

[0111] Clause 15. The system of clause 14, wherein the sheath fluid is a 5 nanometer sheath fluid.

[0112] Clause 16. The system of any one of clauses 10-15, wherein the sample processing instrument is a flow cytometer.

[0113] Clause 17. A system for operating a sample processing instrument, the system including: at least one processor; a memory, in communication with processor and including instructions which, when executed by the at least one processor, cause the processor to: determine whether a fluidics systems of the sample processing instrument meets a cleaning requirement based on an amount of particles present in a measurement flow; and generate a graphical user interface including a source selection operation, wherein the source selection operation accepts input from a user selecting one of a sample tube source and a sample line source as a source for the measurement flow.

[0114] Clause 18. The system of clause 17. wherein the sample tube source is a sample buffer and a sample line source is a sheath fluid.

[0115] Clause 19. The system of clause 18, wherein the sheath fluid is a 5 nanometer sheath fluid.

[0116] Clause 20. The system of clause 18 or 19. wherein the cleaning requirement includes a threshold amount of particles and a first threshold amount of particles for the sample line source is a lower amount than a second threshold amount of particles for the sample tube source.

[0117] Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.

Claims

What is claimed is:1 . A method for operating a sample processing instrument, the method comprising: processing one or more samples through a fluidics system of the sample processing instrument; cleaning the fluidics system; measuring an amount of particles at an interrogation point the fluidics system by: selectively supplying a flow to the fluidics system from one of a sample tube source and a sample line source; and measuring the amount of particles in the flow; comparing the amount of particles measured against a predetermined target value; and determining, using the comparing, whether a cleaning requirement is met.

2. The method of claim 1, wherein the flow is supplied from the sample tube source and the cleaning requirement is determined to not be met. the method further compnsing: supplying a second flow from the sample line source; measuring a second amount of particles in the second flow; comparing the second amount of particles measured against the predetermined target value; and determining, using the comparing, whether the cleaning requirement is met.

3. The method of claim 1 or 2, wherein a source for the flow is determined based on a user input.

4. The method of any one of claims 1-3, wherein the predetermined target value is different based on whether the flow is supplied from the sample tube source or the sample line source.

5. The method of claim 4, wherein the predetermined target value is higher for flow supplied from the sample tube source and lower for flow supplied from the sample line source.

6. The method of any one of claims 1 -5. wherein the sample line source comprises a sheath fluid.

7. The method of claim 6, wherein the sheath fluid is 5 nanometer sheath fluid.

8. The method of any one of claims 1-7, wherein the predetermined target value is 100 events.

9. A system for operating a sample processing instrument, the system comprising: a fluidics system including: a flow cell; a sample tube source: a sample line source; a fluidics path to the flow cell; a source selection valve in communication with the fluidics path and in selective communication with each of the sample tube source and the sample line source; and a controller including a processor and a memory, the memory including instructions that, when executed by the processor, cause the processor to: generate a display including a source selection operation; receive an input from the source selection operation; and operate the source selection valve, using the input, to provide flow to the flow cell from one of the sample tube source and the sample line source.

10. The system of claim 9, wherein the source selection operation is associated with determining whether a cleaning requirement is met based on a measured amount of particles at an interrogation point in the fluidics system.

11. The system of claim 10, wherein the cleaning requirement comprises a predetermined threshold amount of particles.

12. The system of claim 11 , wherein the predetermined threshold amount of particles is 100 events.

13. The system of any one of claims 10-12, w herein the sample line source is a sheath fluid.

14. The system of claim 13, wherein the sheath fluid is a 5 nanometer sheath fluid.

15. The system of any one of claims 10-14, wherein the sample processing instrument is a flow cytometer.

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