Automatic liquid mixing machine for virus titer detection based on plaque method

Abstract

The invention discloses an automatic liquid mixing machine for virus titer detection based on a plaque method. The automatic liquid mixing machine comprises a workbench, and a first constant temperature module, a second constant temperature module, a host cell liquid fixing module, a virus test sample fixing module and an execution module which are integrated on the workbench, a space interval is formed between the first constant-temperature module and the virus test sample fixing module; the execution module is provided with a first moving path, a second moving path and a third moving path; the virus test sample fixing module and the first moving path are arranged in a staggered manner, and the host cell sap fixing module and the second moving path are arranged in a staggered manner; the positions of all the modules are reasonably arranged, the execution module is used for automatically executing liquid relief, liquid separation and mixing operation, and the operation efficiency is improved while it is guaranteed that the proportion of mixed liquid obtained after mixing is accurate and the detection result is accurate.

Description

Technical Field

[0001] This invention relates to the field of virus detection technology, and in particular to an automated liquid mixing machine for virus titer detection based on plaque assay. Background Technology

[0002] In the processing of biopharmaceuticals, virus removal has become an essential step to meet viral safety requirements. The production of biopharmaceuticals requires virus inactivation and / or virus removal processes. A common method for virus removal is membrane filtration, and the virus removal capacity of the membrane directly determines the viral safety of the biopharmaceutical. Membrane separation technology uses a membrane as the separation medium. When a driving force exists across the membrane (such as pressure difference or concentration difference), the raw material components selectively permeate through the membrane, while viruses, due to their larger size than the membrane pores, are physically retained.

[0003] Plaque assay, which detects viral titers based on viral infectivity, is a classic viral titer detection technique. Its basic principle is as follows: after culturing host cells to a monolayer, an appropriately diluted virus is inoculated and cultured. The virus adsorbs and invades the host cells, uses enzymes within the host cells to synthesize its own components, causing the host cells to lyse and die, forming plaques. Each plaque represents a live viral particle.

[0004] For example, the Parenteral Drug Association (PDA) issued a guidance document, "Virus Filtration, Technical Report No. 41 (Revised 2008)," or TR41, for the testing methods and validation of viral filtration in biologics. TR41 specifies that the intercepted virus is either bacteriophage PR772 or PP7 (PR772 is a large virus, PP7 is a small virus, and the choice can be made as needed), and the material stream is immunoglobulin IVIG (or bovine serum albumin BSA). The titer detection of both PR772 and PP7 bacteriophages is achieved using the aforementioned plaque assay.

[0005] More specifically, Appendix III of TR41 clearly describes the small virus-retention filter-test protocol, which uses PP7 phage as the nominal challenge virus model, and human immunoglobulin (IVIG) is used to assess protein penetration. To calculate the virus rejection rate, the titer of PP7 phage in the challenge solution and filtrate needs to be detected separately. TR41 clearly describes the method for detecting the PP7 phage titer, which uses a double-layer plate counting method to culture and count the samples. The specific formulation of the detection system is 1 mL of a filtrate sample containing a specific concentration of PP7 phage and 2 mL of host cells (Pseudomonas aeruginosa), and 9 mL of warm agar; or approximately 0.1 mL of a filtrate sample containing PP7 phage, 1 mL of host cells, and 4.5 mL of agar solution.

[0006] Currently, the preparation and mixing of host cell fluid, bacteriophages, and soft agar are all done manually. The detection volume is limited by manual labor, the efficiency is extremely low, and it cannot meet the detection needs.

[0007] Furthermore, regarding the method for detecting virus titers in ultra-low virus titer systems disclosed in existing patents such as CN115181816B, since the titer of PP7 in the filtrate is below the detection limit, to ensure accurate detection results, the approach adopted is to accumulate a sufficiently large volume of filtrate for testing for a given volume of filtrate; that is, the amount of filtrate tested must be sufficiently large. For example, if the filtrate volume is 100ml and contains 20 PP7 molecules, if only 1ml is tested, the probability of detecting 0 PP7 molecules is relatively high, and the detection result is not statistically significant. Therefore, at least 30ml of filtrate must be tested, which requires mixing the solution 30 times, resulting in an extremely large workload.

[0008] Therefore, it is necessary to design an automated liquid mixing machine based on plaque detection for virus titer detection to improve detection efficiency and provide high-precision detection results. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide an automated liquid mixing machine for virus titer detection based on plaque assay, thereby solving the problem of low efficiency in existing virus titer detection based on plaque assay.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] An automated liquid mixing machine for virus titer detection based on plaque method includes: a workbench, and a first constant temperature module, a second constant temperature module, a host cell fluid fixation module, a virus test sample fixation module, and an execution module integrated thereon;

[0012] The first constant temperature module is used to keep the mixture inside the mixing tube placed therein at a constant temperature;

[0013] The second thermostatic module is used to keep the liquid agar in the agar bottle placed inside warm;

[0014] The host cell fluid fixation module is used to place the host cell fluid bottle;

[0015] The virus test sample fixing module is used to hold the container containing the virus test sample;

[0016] The first constant temperature module and the virus test sample fixing module are spatially separated;

[0017] The execution module has an execution end that can form a detachable sealed connection with the pipette tip, and controls the pipette tip to automatically pick up, carry and release host cell fluid or virus test sample or liquid agar.

[0018] The execution module has a first movement path, a second movement path, and a third movement path;

[0019] On the first moving path, the execution module is drawn by the host cell fluid fixation module through the suction tip and carried to the first constant temperature module, whereby the host cell fluid is injected into the mixing tube;

[0020] On the second moving path, the execution module is drawn by the virus test sample fixing module through the suction head and carried to the first constant temperature module, whereby the virus test sample is injected into the mixing tube;

[0021] The virus test sample fixation module is offset from the first movement path, and the host cell fluid fixation module is offset from the second movement path;

[0022] On the third moving path, the execution module is moved from the second constant temperature module by the suction head to the first constant temperature module, where the liquid agar is injected into the mixing tube.

[0023] The automatic mixing machine provided by this invention has the positions of each module reasonably set on the worktable, and uses the execution module to automatically perform pipetting, dispensing and mixing operations, which improves the operating efficiency while ensuring the accuracy of the mixed liquid ratio and the accuracy of the test results.

[0024] Specifically, each module is integrated on the workbench, with its position and distance determined, forming the basis for the automatic operation of the execution module.

[0025] The host cell fluid fixation module is used to place and position the host cell fluid bottle. A large amount of host cell fluid is stored in the host cell fluid bottle. Each time the execution module executes the first movement path, it uses a pipette tip to draw a quantitative amount of host cell fluid from the host cell fluid bottle, and then carries the host cell fluid from the host cell fluid fixation module to the first thermostatic module. The module then injects a quantitative amount of host cell fluid into the multiple mixing tubes on it in sequence, thereby completing the pipetting and dispensing operation of the host cell fluid. The first thermostatic module can ensure that the mixing tube and the liquid inside it are kept at a suitable temperature to ensure the activity of the host cells.

[0026] The virus test sample fixation module is used to place and position several containers containing virus test samples. Each container holds the same or different large doses of virus test samples. Each time the execution module executes the second movement path, it uses a pipette tip to draw a quantitative amount of virus test sample from the container containing the virus test sample. Then, it carries the virus test sample from the virus test sample fixation module to the first thermostatic module, and sequentially injects a quantitative amount of virus test sample into multiple mixing tubes already injected with host cell fluid. This completes the pipetting and separation of virus test samples, and also achieves the mixing of virus test samples and host cell fluid. The first thermostatic module can ensure that the mixing tube and the liquid inside it are kept at a suitable temperature to ensure the activity of the virus test sample. The virus test sample and host cell fluid are fully mixed in the mixing tube, avoiding the virus from being too close or even aggregating, and ensuring that only one virus invades a host cell as much as possible, thereby improving the accuracy of virus titer detection results based on plaque method.

[0027] The second thermostatic module is used to keep the liquid agar in the agar bottle placed inside warm, ensuring that the agar remains liquid. Each time the execution module executes the third movement path, it uses a pipette tip to draw a certain amount of liquid agar from the agar bottle, and then carries the liquid agar from the second thermostatic module to the first thermostatic module. The first thermostatic module then sequentially injects a certain amount of liquid agar into the multiple mixing tubes already containing host cell fluid and virus test samples, thus completing the liquid agar transfer and separation operation. At the same time, it also achieves the mixing of liquid agar with virus test samples and host cell fluid to obtain the final mixture. The first thermostatic module can maintain the mixture at a suitable temperature to prevent the liquid agar from solidifying too early, ensuring that the agar is quickly and evenly dispersed in the mixture. The mixture is then poured into a plate, and after the liquid agar solidifies, it is inverted for incubation. Because the agar has high transparency, it is convenient for subsequent plaque counting.

[0028] Based on the three movement paths of the execution module, the automatic liquid transfer, separation and mixing operations of the corresponding three samples are realized, which greatly improves the efficiency of liquid mixing. Especially for detection tasks that require batch liquid preparation and mixing, it can greatly reduce the amount of manual work and save time and costs.

[0029] Meanwhile, when the first path and the third path are executed multiple times, there is no need to replace the pipette tip multiple times. When the second path is executed multiple times, the pipette tip only needs to be replaced when different virus samples are changed, which reduces the amount of pipette tip replacement compared with manual operation and can significantly improve the efficiency. Of course, each time the execution module sucks up different liquids with the pipette tip, the pipette tip needs to be replaced to ensure the purity of each liquid and avoid cross-contamination. In addition, if during the execution of the first moving path by the execution module, the hanging drop of the host cell fluid attached to the outer wall of the pipette tip falls into the container containing the virus test sample on the virus test sample fixing module, it may cause the virus in the virus test sample to invade the dropped host cells and replicate and proliferate, that is, the number of viruses increases, and finally the number of plaques obtained is more than the actual number, that is, the test result of the virus titer is on the high side; and when the execution module executes the second moving path, the hanging drop of the virus attached to the outer wall of the pipette tip falls into the host cell fluid bottle, contaminating the whole bottle of host cell fluid, and the fallen virus is likely to replicate and proliferate in the host cells, and the direct consequence is also that the test result of the virus titer is on the high side. Therefore, in the present application, the first moving path of the execution module is controlled to be misaligned with the virus test sample fixing module, and the second moving path of the execution module is controlled to be misaligned with the host cell fluid fixing module, so as to achieve physical isolation between the host cell fluid and the virus test sample before they are mixed in the mixing tube. Then, the execution module will not pass through the virus test sample fixing module during the execution of the first moving path, and the execution module will not pass through the host cell fluid fixing module during the execution of the second moving path, which can avoid cross-contamination between the host cell fluid and the virus test sample, thus ensuring the accuracy of the test result.

[0030] Further, the first constant temperature module and the virus test sample fixing module have a spatial interval, which makes the second moving path of the execution module long enough. The execution module needs a certain amount of time to execute the second moving path. Then, even if there may be hanging drops of the virus attached to the outer wall of the pipette tip, it is easier to fall off earlier before reaching the first constant temperature module, reducing the probability of the virus test sample accidentally falling into the mixing tube, ensuring that the volume of the virus test sample injected into the mixing tube is accurate and is the preset amount, and further improving the accuracy of the test result.

[0031] It can be understood that the so-called misalignment setting means that the module is not on the corresponding moving path. And having a spatial interval means that there is a certain spatial interval between the sample placement positions in the module, with a certain and preset path length, which does not mean that the outer edges of the contours of the modules must be close to each other.

[0032] Preferably, the minimum length of the first moving path is L1, and the minimum length of the second moving path is L2, satisfying L1 < L _{2}; and / or, 200 mm ≤ L2 ≤ 500 mm.

[0033] The first movement path starts at the host cell fluid fixation module and ends at the first isothermal module. The second movement path starts at the virus test sample fixation module and ends at the first isothermal module. Based on at least one host cell fluid bottle, at least one container containing a virus test sample, and several mixing tubes located in the first isothermal module, the lengths of the first and second moving paths are not fixed but ranges. Therefore, both the first and second moving paths have a minimum length. The straight-line distance between the closest host cell fluid bottle and the mixing tube of the first isothermal module is the minimum length L1 of the first moving path. If the containers are all cylindrical, the distance between their centers is L1 (the same applies below). The straight-line distance between the closest container containing a virus test sample and the mixing tube of the first isothermal module is the minimum length L2 of the second moving path. Controlling the minimum length L2 of the second moving path to be greater than the minimum length L1 of the first moving path can improve the efficiency of pipetting and separating the host cell fluid. On the other hand, it can ensure that the second moving path from all containers containing virus test samples to the mixing tube of the first isothermal module is long enough and the moving time is long enough. During the moving process, virus droplets that may be attached to the outer wall of the pipette tip can fall off before reaching the first isothermal module, reducing the probability of virus contamination of the mixing tube.

[0034] Similarly, the minimum length L2 of the second moving path satisfies 200mm≤L2≤500mm. Its purpose is to control the moving distance of the pipette tip carrying the virus test sample in the execution module. If the minimum length L2 is less than 200mm, the virus adhering to the outer wall of the pipette tip may drip into the mixing tube. If the minimum length L2 is greater than 500mm, the moving distance may be too long. With the moving speed of the execution module being constant, the moving time will be longer, which will reduce the mixing efficiency and also make the overall size of the automatic mixing machine too large. Therefore, controlling the minimum length L2 within the above range takes into account the mixing efficiency, the accuracy of the test results, and ensures that the size of the automatic mixing machine is reasonable.

[0035] Preferably, the host cell fluid fixation module and the virus test sample fixation module are located on opposite sides of the first constant temperature module.

[0036] With this setup, the host cell fluid fixation module and the virus test sample fixation module are separated by the first constant temperature module and kept at a considerable physical distance, further reducing the risk of cross-contamination, especially avoiding aerosol contamination during storage and improving detection accuracy.

[0037] Preferably, 30mm≤L1≤80mm. This setting avoids the first thermostat module and the host cell fluid fixation module being too short, which would be inconvenient for their installation on the workbench. It also avoids the first thermostat module and the host cell fluid fixation module being too far apart, which would reduce the efficiency of host cell fluid transfer. Thus, under the premise of avoiding mutual interference, the minimum length L1 of the first moving path is as short as possible, the distance between the first thermostat module and the host cell fluid fixation module is as small as possible, the efficiency of host cell fluid transfer is higher, the layout between modules is more compact, and the overall size of the equipment is reduced.

[0038] Preferably, the automatic mixing machine further includes a pipette tip recycling module for collecting used pipette tips, and the execution module also has a fourth movement path, on which the execution module moves from the first temperature control module to the pipette tip recycling module and puts the used pipette tips into the pipette tip recycling module;

[0039] The second constant temperature module, the host cell fluid fixation module, and the virus test sample fixation module are all misaligned with the fourth movement path.

[0040] This configuration allows the execution module to deposit used pipette tips into the tip recycling module, preventing used tips from remaining on the execution module and increasing its workload. It also prevents residual host cell solution, virus test samples, or liquid agar from falling into non-target locations and causing contamination during subsequent movement of the execution module. Furthermore, by ensuring that the second isothermal module, host cell solution, and virus test samples are not on the fourth movement path, it prevents residual liquid on the pipette tips from dripping into the agar bottles, host cell solution bottles, or containers containing virus test samples in the second isothermal module during the fourth movement path, thus avoiding contamination.

[0041] Preferably, the second temperature control module is located between the first temperature control module and the virus test sample fixing module; or, the suction tip recovery module is located between the first temperature control module and the virus test sample fixing module.

[0042] Given the significant physical distance required between the first isothermal module and the virus test sample fixation module, placing a second isothermal module or a tip recovery module between the first isothermal module, the mixing solution isothermal module, and the virus test sample fixation module can improve space utilization. This allows for a more compact layout between modules and reduces the overall size of the equipment without compromising detection accuracy and mixing efficiency. In particular, when the second isothermal module is located between the first isothermal module and the virus test sample fixation module, the third movement path of the execution module is shortened, preventing liquid agar from cooling and solidifying during movement, thus ensuring it can be extruded from the tip and injected into the mixing tube. Alternatively, when the tip recovery module is located between the first isothermal module and the virus test sample fixation module, the fourth movement path of the execution module is shortened, allowing used tips to be quickly returned to the tip recovery module, further reducing the risk of cross-contamination. Furthermore, the execution module can perform the next pipetting operation as quickly as possible, improving pipetting efficiency.

[0043] It is particularly noteworthy that accidental dripping of the virus test sample during transport, whether into the host cell fluid or the mixed solution, will affect the titer test results. However, dripping into either the second isothermal module or the pipette tip recovery module will not adversely affect the results. This is because when dripping into the second isothermal module, the liquid agar inside has a relatively high temperature, which can inactivate the dripped virus due to the high temperature. Dripping into the pipette tip recovery module has even less impact.

[0044] Preferably, the second constant temperature module is located between the first constant temperature module and the virus test sample fixing module, and the minimum length of the third moving path is L3, wherein 30mm≤L3≤80mm.

[0045] With this configuration, the first and second isothermal modules are placed adjacent to each other, and the third moving path is as short as possible. This allows the execution module to quickly inject liquid agar into the mixing tube on the first isothermal module, minimizing the residence time of the agar in the pipette tip, preventing premature solidification, and ensuring that the agar is injected into the mixing tube in liquid form, allowing it to quickly and evenly disperse with the host cell fluid and virus test sample. If L3 < 30 mm, it is inconvenient to install the first and second isothermal modules. If L3 > 80 mm, with the execution module moving at a constant speed, it prolongs the time required for the execution module to execute the third moving path, increasing the possibility of the liquid agar solidifying during the movement. This could result in the agar not being injected smoothly into the mixing tube, leading to a lower injection volume than the preset value or inability to mix evenly with the host cell fluid and virus test sample, thus affecting the accuracy of the virus titer test results.

[0046] Preferably, the automatic mixing machine further includes a pipette tip module, the pipette tip module including a pipette tip holder and a plurality of unused pipette tips inserted in the pipette tip holder;

[0047] The execution module has a fifth movement path, on which the execution module moves from the suction head recycling module to the suction head module to obtain an unused suction head;

[0048] The suction head module is misaligned with the first moving path, the second moving path, and the fourth moving path.

[0049] With this setup, pipette tips do not need to be preloaded onto the execution module. The execution module can retrieve unused pipette tips before aspirating different liquids, reducing the workload on the execution module. A single test often involves at least dozens of tests, and a separate pipette tip module can hold more pipette tips, reducing the frequency of replacement. Furthermore, the pipette tip module is not on the execution module's first movement path carrying host cell fluid, the second movement path carrying viral test samples, or the fourth movement path for pipette tip retrieval. This achieves physical separation between unused pipette tips and liquids such as host cell fluid and viral test samples, preventing these liquids from accidentally falling into unused pipette tips and causing pipette tip contamination. This ensures the cleanliness of unused pipette tips and the accuracy of subsequent test results.

[0050] Preferably, the suction head module and the second constant temperature module are located on both sides of the first constant temperature module.

[0051] Since all the aforementioned modules are arranged around the first thermostatic module, placing the pipette tip module and the second thermostatic module on either side of the first thermostatic module allows for an adjacent arrangement between them. This minimizes the distance between the pipette tip module and the first thermostatic module, within installation limits, and consequently, also shortens the distance between the pipette tip module and other modules. This reduces the distance the execution module travels from obtaining a clean pipette tip to moving it to the host cell fixation module, the virus test sample fixation module, and the second thermostatic module. Considering the high frequency and number of pipette tip replacements, this arrangement significantly improves operational efficiency. It also increases the physical distance between the second thermostatic module and the pipette tip module, preventing liquid agar from accidentally dripping into unused pipette tips, solidifying, and clogging them, thus preventing the pipette tips from drawing liquid and interfering with the normal operation of the execution module.

[0052] Preferably, the suction head module and the suction head recovery module are located on the same side of the first constant temperature module.

[0053] Since the execution module needs to change pipette tips when acquiring different liquids, that is, it needs to put the used pipette tips into the pipette tip recycling module and then load the unused pipette tips, the pipette tip module and the pipette tip recycling module are located on the same side of the first constant temperature module. This makes it easier to reduce the distance between the pipette tip module and the pipette tip recycling module, thereby shortening the length of the fifth movement path of the execution module and improving the operating efficiency of the execution module.

[0054] Preferably, the suction tip module and the host cell fluid fixation module are located on the same side of the first thermostatic module.

[0055] Generally, the host cell fluid fixation module contains only one type of host cell fluid, which is relatively small in volume. Fixing the host cell fluid fixation module to one side of the first constant temperature module allows for a larger space on that side of the first constant temperature module. The pipette tip module is then placed within this space, making the layout of each module on the worktable more compact. This allows for a reasonable reduction in the size of the automatic mixing machine and also helps improve the movement efficiency of the execution module.

[0056] Preferably, a cabinet is provided above the workbench, and the first constant temperature module, the second constant temperature module, the host cell fluid fixation module, the virus test sample fixation module, and the execution module are all located within the space surrounded by the cabinet.

[0057] The cabinet can isolate the external environment, making it easier to create a sterile environment suitable for virus titer detection for some testing processes with high requirements for environmental cleanliness, thereby eliminating external interference and improving detection accuracy and precision.

[0058] Preferably, the execution module includes a pipette, a robotic arm, a linear actuator, and a controller. The pipette is disposed at the execution end of the robotic arm, the robotic arm is movably disposed on the linear actuator, the controller is used to control the execution module to perform various liquid retrieval operations and corresponding movement paths, and the linear actuator is fixed on the worktable.

[0059] In the execution module of the automatic mixing machine provided in this application, a linear actuator works in conjunction with a robotic arm. After the execution end of the robotic arm obtains a clean pipette tip, the robotic arm first moves linearly along the linear actuator to the position corresponding to the host cell fluid fixation module, the virus test sample fixation module, and the second isothermal module, ensuring that the execution end of the robotic arm can reach the host cell fluid bottle, the container containing the virus test sample, and the agar bottle. The robotic arm then rotates a certain angle so that the pipette tip is aligned with the host cell fluid bottle, the container containing the virus test sample, and the agar bottle in sequence, controlling the pipette tip to sequentially aspirate the host cell fluid, the virus test sample, and the liquid agar. The robotic arm then rotates a certain angle, and the execution module sequentially executes the first movement path, the second movement path, and the third movement path, so that its execution end moves from the host cell fluid fixation module, the virus test sample fixation module, and the second isothermal module to the first isothermal module, and sequentially injects the aspirated host cell fluid, the virus test sample, and the liquid agar into the mixing tube in the first isothermal module.

[0060] Since different pipette tips are required to aspirate different samples, the robotic arm's actuator needs to change the pipette tip after transferring host cell fluid, virus test sample, and liquid agar. The specific operation of the robotic arm is as follows: the robotic arm first moves linearly along the linear actuator to the position corresponding to the pipette tip retrieval module. Then, the actuator executes the fourth movement path, that is, the robotic arm rotates a certain angle so that its actuator moves from the first thermostatic module to the pipette tip retrieval module and aligns with the pipette tip retrieval module. Then, the pipette tip used is accurately placed into the pipette tip retrieval module through the pipette tip at its actuator.

[0061] Then, the robotic arm moves linearly along the linear actuator to the position corresponding to the pipette tip module. The execution module then executes the fifth movement path, that is, the robotic arm rotates at a certain angle so that its execution end moves from the pipette tip retrieval module to the pipette tip module and aligns with the pipette tip module. Then, the clean pipette tip is picked up by the pipette at its execution end.

[0062] The linear actuator allows the robotic arm to move a certain distance linearly along the actuator before executing any movement path, bringing the actuator end closer to the corresponding target module. Then, the robotic arm rotates a small angle, allowing the actuator end to reach the target module from the starting module. Especially for starting and target modules that are close together, the angle of rotation of the robotic arm is very small, resulting in shorter first, second, and third movement paths, thus improving operational efficiency.

[0063] More importantly, during the execution of the first, second, and third movement paths, the pipette tip contains the aspirated host cell fluid, virus test sample, and liquid agar. The smaller the rotation angle of the robotic arm's execution end, the smoother the robotic arm's rotation, and thus the smoother the pipette tip and its contents. This prevents the liquid inside the pipette tip from being flung out due to the large angle rotation of the robotic arm, thereby preventing improper mixing or cross-contamination caused by the flung liquid. This ensures that the liquid volume injected into the mixing tube reaches the preset value, thus guaranteeing the accuracy of the test results.

[0064] In summary, compared with the prior art, the present invention has at least the following beneficial effects:

[0065] The automatic liquid mixing machine of this invention rationally positions each module on the worktable and automatically performs pipetting, dispensing, and mixing operations using the execution module. This ensures accurate proportions of the mixed solution and accurate test results while improving operational efficiency. Specifically, each module is integrated on the worktable, with its position and distance defined, forming the basis for the automatic operation of the execution module. Based on the three movement paths of the execution module, automatic pipetting, dispensing, and mixing operations for three different samples can be achieved, significantly improving mixing efficiency. Especially for testing tasks requiring batch preparation and mixing, it greatly reduces manual workload and saves time and costs.

[0066] Meanwhile, the execution module needs to change the pipette tip each time it draws a different liquid to ensure the purity of each liquid and avoid cross-contamination. Furthermore, in this application, the first movement path of the execution module is offset from the virus test sample fixation module, and the second movement path is offset from the host cell fluid fixation module. This achieves physical isolation between the host cell fluid and the virus test sample before they are mixed in the mixing tube. Therefore, the execution module will not pass through the virus test sample fixation module during the execution of the first movement path, nor will it pass through the host cell fluid fixation module during the execution of the second movement path, thus avoiding cross-contamination between the host cell fluid and the virus test sample and ensuring the accuracy of the test results.

[0067] Furthermore, the first temperature control module and the virus test sample fixing module are spatially separated, which makes the second movement path of the execution module long enough. The execution module needs a certain amount of time to execute the second movement path, so the virus droplets that may be attached to the outer wall of the pipette tip will fall off before reaching the first temperature control module, reducing the probability of the virus test sample accidentally falling into the mixing tube, ensuring that the volume of the virus test sample injected into the mixing tube is accurate and the preset amount, and further improving the accuracy of the test results.

[0068] In summary, the automated liquid mixing machine provided in this application integrates various functional modules on the worktable, with each module arranged in a reasonable and compact manner. By pre-setting three movement paths for the execution module corresponding to the samples to be pipetted and mixed, it provides the basis for automated liquid pipetting and mixing. At the same time, it ensures a reasonable spatial interval between the first constant temperature module and the virus test sample fixing module, reducing the probability of the virus test sample accidentally falling into the mixing tube. This significantly improves the efficiency of liquid pipetting and mixing operations and ensures the accuracy of the test results. Attached Figure Description

[0069] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0070] Figure 1 This is a schematic diagram showing the distribution of the various modules of the automatic mixing machine according to Embodiment 1 of the present invention;

[0071] Figure 2 This is a schematic diagram of the structure of the automatic mixing machine according to Embodiment 1 of the present invention;

[0072] Figure 3 This is a schematic diagram of the structure of each module of the automatic mixing machine according to Embodiment 1 of the present invention;

[0073] Figure 4 This is a schematic diagram showing the distribution of the various modules of the automatic mixing machine according to Embodiment 2 of the present invention;

[0074] Figure 5 This is a schematic diagram showing the distribution of the various modules of the automatic mixing machine according to Embodiment 3 of the present invention;

[0075] Figure 6 This is a schematic diagram showing the distribution of the various modules of the automatic mixing machine according to Embodiment 4 of the present invention;

[0076] Figure 7 This is a schematic diagram showing the distribution of the various modules of the automatic mixing machine according to Embodiment 5 of the present invention.

[0077] Explanation of reference numerals in the attached figures

[0078] 10. Workbench; 11. Cabinet;

[0079] 20. First thermostatic module; 21. Mixing tube;

[0080] 30. Second thermostat module; 31. Agar bottle;

[0081] 40. Host cell fluid fixation module; 41. Host cell fluid bottle;

[0082] 50. Virus test sample fixation module; 51. Container;

[0083] 60. Execution module; 61. Pipette; 62. Robotic arm; 63. Linear actuator; 64. First movement path; 65. Second movement path; 66. Third movement path; 67. Fourth movement path; 68. Fifth movement path;

[0084] 70. Suction head recycling module;

[0085] 80. Suction head module; 81. Suction head; 82. Suction head bracket. Detailed Implementation

[0086] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0087] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0088] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0089] Example 1

[0090] like Figure 1-3 As shown, the automated liquid mixing machine for virus titer detection based on plaque method in Embodiment 1 of the present invention includes: a workbench 10, and a first constant temperature module 20, a second constant temperature module 30, a host cell fluid fixation module 40, a virus test sample fixation module 50, an execution module 60, a pipette tip recovery module 70, and a pipette tip module 80 integrated thereon. Each module is integrated on the workbench 10, and their respective positions and distances are determined, forming the basis for the automatic operation of the execution module 60.

[0091] The first temperature control module 20 is used to keep the mixed liquid in the mixing tube 21 placed therein warm, and the set temperature of the first temperature control module 20 can be 38℃-42℃; the second temperature control module 30 is used to keep the liquid agar in the agar bottle 31 placed therein warm, and the set temperature of the second temperature control module 30 can be 45℃-60℃; the host cell fluid fixation module 40 is used to place the host cell fluid bottle 41, and a large dose of host cell fluid is stored in the host cell fluid bottle 41; the virus test sample fixation module 50 is used to place the container 51 containing the virus test sample, and each container 51 holds the same or different large doses of virus test sample, and the container 51 can be a test tube, centrifuge tube or centrifuge bottle, etc.

[0092] The execution module 60 has an execution end that can form a detachable sealed connection with the pipette tip 81, and controls the pipette tip 81 to automatically pick up, carry and release host cell fluid or virus test sample or liquid agar.

[0093] Based on the above module distribution, the execution module 60 has a first movement path 64, a second movement path 65, and a third movement path 66. On the first movement path 64, the execution module 60 is drawn from the host cell fluid fixation module 40 by the pipette tip 81 and moved to the first constant temperature module 20. The host cell fluid is injected into the mixing tube 21. A quantitative amount of host cell fluid is drawn from the host cell fluid bottle 41 by the pipette tip 81 and then moved from the host cell fluid fixation module 40 to the first constant temperature module 20. A quantitative amount of host cell fluid is then injected into the multiple mixing tubes 21 thereon in sequence, thereby completing the pipetting and separation operation of the host cell fluid. The first constant temperature module 20 can ensure that the mixing tube 21 and the liquid inside it are kept at a suitable temperature to ensure the activity of the host cells.

[0094] On the second moving path 65, the execution module 60, through the virus test sample fixation module 50, picks up and carries the virus test sample to the first constant temperature module 20 via the pipette tip 81, and injects the virus test sample into the mixing tube 21. The virus test sample fixation module 50 is used to place and position several containers 51 containing the virus test sample. When the execution module 60 executes the second moving path 65, it picks up a quantitative amount of virus test sample from the container 51 containing the virus test sample using the pipette tip 81, and then carries the virus test sample from the virus test sample fixation module 50 to the first constant temperature module 20 and injects a quantitative amount of virus test sample into the mixing tube 21 thereon. This completes the pipetting and separation operation of the virus test sample, and also realizes the mixing of the virus test sample and the host cell fluid. The first constant temperature module 20 can ensure that the mixing tube 21 and the liquid inside it are kept at a suitable temperature to ensure the activity of the virus test sample. The virus test sample and the host cell fluid are fully mixed in the mixing tube 21, so as to ensure that only one virus invades a host cell as much as possible, thereby improving the accuracy of virus titer detection results based on plaque method.

[0095] On the third moving path 66, the execution module 60, via the suction head 81, draws and carries liquid agar from the second temperature-controlled module 30 to the first temperature-controlled module 20, injecting the liquid agar into the mixing tube 21. The second temperature-controlled module 30 is used to keep the liquid agar in the agar bottle 31 warm, ensuring that the agar remains liquid. Each time the execution module 60 executes the third moving path 66, it draws a fixed amount of liquid agar from the agar bottle 31 using the suction head 81, and then carries the liquid agar from the second temperature-controlled module 30 to the first temperature-controlled module 20 and injects it into the mixing tube 21. Multiple mixing tubes 21, already containing host cell fluid and virus test samples, are injected with a measured amount of liquid agar, thus completing the liquid agar transfer and separation operations. At the same time, the liquid agar is mixed with the virus test samples and host cell fluid to obtain the final mixture. The first thermostat module 20 can maintain the mixture at a suitable temperature to prevent the liquid agar from solidifying too early and ensure that the agar is quickly and evenly dispersed in the mixture. Then, the mixture is poured into a plate, and after the liquid agar solidifies, it is inverted for incubation. Because the agar has high transparency, it is convenient for subsequent plaque counting.

[0096] The virus sample fixation module 50 is offset from the first moving path 64 to prevent host cell fluid drips that may be attached to the outer wall of the pipette tip 81 from falling into the container 51 containing the virus sample on the virus sample fixation module 50 during the execution of the first moving path 64. Similarly, the host cell fluid fixation module 40 is offset from the second moving path 65 to prevent virus drips that may be attached to the outer wall of the pipette tip 81 from falling into the host cell fluid bottle 41 during the execution of the second moving path 65. This arrangement achieves physical isolation between the host cell fluid and the virus sample before they are mixed in the mixing tube 21. The execution module 60 will not pass through the virus sample fixation module 50 during the execution of the first moving path 64, nor will it pass through the host cell fluid fixation module 40 during the execution of the second moving path 65, thus avoiding cross-contamination between the host cell fluid and the virus sample and ensuring the accuracy of the test results.

[0097] Based on the three movement paths of the execution module 60, automatic liquid transfer, separation and mixing operations of the corresponding three samples are realized, which greatly improves the efficiency of liquid mixing. Especially for detection tasks that require batch liquid preparation and mixing, it can greatly reduce the amount of manual work, improve the efficiency of operation, and save time and cost.

[0098] Furthermore, the first constant temperature module 20 and the virus test sample fixing module 50 are spatially separated, which makes the second movement path 65 of the execution module 60 sufficiently long. The execution module 60 needs a certain amount of time to execute the second movement path 65. Therefore, any virus droplets that may be attached to the outer wall of the pipette tip 81 will fall off before reaching the first constant temperature module 20, reducing the probability of the virus test sample accidentally falling into the mixing tube 21. This ensures that the volume of the virus test sample injected into the target mixing tube 21 is accurate and the preset amount, thus ensuring the accurate proportion of each liquid in the mixture and further improving the accuracy of the test results.

[0099] The pipette tip retrieval module 70 is used to collect used pipette tips 81. The execution module 60 can put the used pipette tips 81 into the pipette tip retrieval module 70, avoiding the use of used pipette tips 81 being stored on the execution module 60 indefinitely, thus reducing the burden on the execution module 60. At the same time, it also prevents any residual host cell fluid, virus test samples, or liquid agar on the used pipette tips 81 from falling into non-target locations and causing contamination when the execution module 60 moves subsequently. Based on this, the execution module 60 also has a fourth movement path 67, on which the execution module 60 moves from the first temperature control module 20 to the pipette tip retrieval module 70 and puts the used pipette tips 81 into the pipette tip retrieval module 70.

[0100] Meanwhile, the second constant temperature module 30, the host cell fluid fixation module 40, and the virus test sample fixation module 50 are all offset from the fourth moving path 67 to avoid residual liquid on the pipette tip 81 dripping into the agar bottle 31, the host cell fluid bottle 41, and the container 51 containing the virus test sample during the process of moving the used pipette tip 81 to the pipette tip recycling module 70 (i.e., the execution module 60 executes the fourth moving path 67), causing contamination.

[0101] The pipette tip module 80 includes a pipette tip holder 82 and a plurality of unused pipette tips 81 inserted in the pipette tip holder 82. This configuration allows the pipette tips 81 to be removed from the execution module 60 without preloading, enabling the execution module 60 to retrieve unused pipette tips 81 before aspirating different liquids, thus reducing the workload on the execution module 60. Based on this, the execution module 60 has a fifth movement path 68, along which the execution module 60 moves from the pipette tip retrieval module 70 to the pipette tip module 80 to retrieve unused pipette tips 81. Similarly, the pipette tip module 80 is staggered from the first moving path 64, the second moving path 65, the third moving path 66, and the fourth moving path 67. That is, the pipette tip module 80 is not on the first moving path 64 where the execution module 60 carries the host cell fluid, the second moving path 65 where the execution module 60 carries the virus test sample, the third moving path 66 where the execution module 60 carries liquid agar, or the fourth moving path 67 where the execution module 60 retrieves the pipette tip 81. This achieves a physical separation between the unused pipette tip 81 and liquids such as the host cell fluid, the virus test sample, and liquid agar, preventing these liquids from accidentally falling into the unused pipette tip 81 and causing contamination or blockage of the pipette tip 81. This ensures the cleanliness of the unused pipette tip 81 and the accuracy of subsequent test results.

[0102] The automatic loading and unloading of the execution module 60 and the suction head 81 is existing technology. The connection end of the execution module 60 and the suction head 81 forms a detachable sealed connection, which will not be described in detail here.

[0103] It should be noted that in the accompanying drawings of this embodiment and other embodiments, the black arrows indicate the range and direction of the first moving path 64, the yellow arrows indicate the range and direction of the second moving path 65, the orange arrows indicate the range and direction of the third moving path 66, the green arrows indicate the range and direction of the fourth moving path 67, and the blue arrows indicate the range and direction of the fifth moving path 68.

[0104] It should be noted that in this embodiment, based on at least one host cell fluid bottle 41, at least one container 51 containing a virus test sample, and several mixing tubes 21 located in the first constant temperature module 20, the lengths of the first moving path 64, the second moving path 65, and the third moving path 66 are not fixed, but rather a range.

[0105] like Figure 1 As shown, the double arrows indicate the first direction and the second direction respectively, and the first direction and the second direction are perpendicular to each other, representing the length direction and the width direction of the workbench 10 respectively. The host cell fluid fixation module 40, the first constant temperature module 20, the second constant temperature module 30 and the virus test sample fixation module 50 are arranged side by side and spaced apart along the first direction. The host cell fluid fixation module 40 and the virus test sample fixation module 50 are located on both sides of the first constant temperature module 20 respectively.

[0106] The second temperature control module 30 is located between the first temperature control module 20 and the virus test sample fixing module 50, and the three are arranged side by side with intervals in the first direction. Since the first temperature control module 20 and the virus test sample fixing module 50 require a relatively large physical distance, placing the second temperature control module 30 between the first temperature control module 20 (mixing solution temperature control module) and the virus test sample fixing module 50 can improve space utilization. Without affecting detection accuracy and mixing efficiency, the layout between modules is more compact, reducing the overall size of the equipment.

[0107] The pipette tip recovery module 70, pipette tip module 80, and host cell fluid fixation module 40 are located on the same side of the first thermostatic module 20, arranged side by side and spaced apart in the second direction. This is because, generally speaking, the host cell fluid fixation module 40 contains only one type of host cell fluid, which is relatively small in volume, thus allowing for a larger space on one side of the first thermostatic module 20. The pipette tip recovery module 70 and pipette tip module 80 are placed in this space. In contrast, the virus test sample fixation module 50 generally contains several different types of virus test samples, which are relatively large in volume. This distribution makes the total space occupied by each module more regular and closer to a rectangle. As a result, the minimum and maximum lengths of the movement path of the execution module 60 will not differ too much, and each module is distributed within the movement range of the execution module 60, which is beneficial to improving the movement efficiency of the execution module 60. Furthermore, the suction head module 80 and the second constant temperature module 30 are located on both sides of the first constant temperature module 20. Since all the above modules are arranged around the first constant temperature module 20, the concentration is high and the overall size of the device is small, which is conducive to improving the operating efficiency of the execution module 60. Since all the modules are basically located on the same side of the execution module 60, the rotation angle of the execution module 60 is small, and the liquid in the suction head 81 is less swirling, making it less likely to be thrown out of the suction head 81 during movement, thus ensuring that the amount of liquid injected into the mixing tube 21 reaches the preset value.

[0108] When the pipette tip module 80 and the second thermostat module 30 are located on either side of the first thermostat module 20, the pipette tip module 80 and the first thermostat module 20 can be arranged adjacent to each other. Under the condition that the installation allows, the distance between the pipette tip module 80 and the first thermostat module 20 can be shortened as much as possible. Correspondingly, the distance between the pipette tip module 80 and other modules can also be shortened to a certain extent. This shortens the distance that the execution module 60 needs to travel from the pipette tip module 80 to the host cell fluid fixation module 40, the virus test sample fixation module 50, and the second thermostat module 30 after obtaining a clean pipette tip 81, thereby greatly improving the operating efficiency. It also increases the physical distance between the second thermostat module 30 and the pipette tip module 80, preventing the liquid agar in the second thermostat module 30 from accidentally dripping into the unused pipette tip 81 and solidifying, clogging the pipette tip 81, causing the pipette tip 81 to be unable to draw liquid, and interfering with the normal operation of the execution module 60.

[0109] As shown Figure 1 and 3 The minimum length L1 of the first moving path 64 can be the straight-line distance from the center of the host cell fluid bottle 41 in the host cell fluid fixing module 40 to the center of the mixing tube 21 on the first constant temperature module 20 closest to the host cell fluid fixing module 40; the minimum length L2 of the second moving path 65 can be the straight-line distance between the center of the container 51 of the closest virus test sample fixing module 50 and the center of the mixing tube 21 of the first constant temperature module 20; the minimum length L3 of the third moving path 66 can be the straight-line distance from the center of the closest agar bottle 31 to the center of the mixing tube 21. Controlling the minimum length L2 of the second moving path 65 to be greater than the minimum length L1 of the first moving path 64, i.e., L1 < L2, can, on the one hand, improve the pipetting and liquid separation efficiency of the host cell fluid, and on the other hand, ensure that the second moving path 65 from all the containers 51 containing the virus test samples to the mixing tube 21 of the first constant temperature module 20 is long enough and the moving time is long enough. During the moving process, the virus hanging drops that may adhere to the outer wall of the pipette tip 81 can fall off in advance before reaching the first constant temperature module 20, reducing the probability of virus contamination of the mixing tube 21.

[0110] Preferably, the minimum length L1 of the first moving path 64 satisfies 30 mm ≤ L1 ≤ 80 mm. With this setting, it avoids the distance between the first constant temperature module 20 and the host cell fluid fixing module 40 being too short, which is not convenient for their installation on the workbench 10, and also avoids the distance between the first constant temperature module 20 and the host cell fluid fixing module 40 being too far, which reduces the pipetting efficiency of the host cell fluid. Thus, the minimum length of the first moving path 64 is as short as possible, the distance between the first constant temperature module 20 and the host cell fluid fixing module 40 is as small as possible, the pipetting efficiency of the host cell fluid is higher, the layout between the modules is more compact, and the overall size of the equipment is reduced.

[0111] Preferably, the minimum length of the second moving path 65 satisfies 200 mm ≤ L2 ≤ 500 mm. The purpose is to control the moving distance of the pipette tip 81 of the execution module 60 carrying the virus test sample. If the minimum length is less than 200 mm, it may cause the virus hanging drops adhering to the outer wall of the pipette tip 81 to fall into the non-target mixing tube 21. If the minimum length is greater than 500 mm, it may cause the moving distance to be too long. When the moving speed of the execution module 60 is constant, the moving time is long, reducing the mixing efficiency and also resulting in an overly large overall size of the automatic liquid mixer. Therefore, controlling the minimum length L2 within the above range takes into account the mixing efficiency, test accuracy, and ensures a reasonable size of the automatic liquid mixer.

[0112] Preferably, the minimum length of the third moving path 66 satisfies 30mm≤L3≤80mm. The execution module 60 can quickly inject liquid agar into the mixing tube 21 on the first thermostatic module 20, minimizing the residence time of the agar in the pipette tip 81, preventing premature solidification of the agar, and ensuring that the agar is injected into the mixing tube 21 in liquid form, so that it can be quickly and evenly dispersed with the host cell fluid and virus test sample. If L3<30mm, it is not convenient to install the first thermostatic module 20 and the second thermostatic module 30. If L3>80mm, under the condition that the moving speed of the execution module 60 is constant, it prolongs the time required for the execution module 60 to execute the third moving path 66, increasing the possibility that the liquid agar will solidify during the movement, causing the agar to fail to be injected into the mixing tube 21 smoothly, resulting in the injection volume being lower than the preset value or failing to mix evenly with the host cell fluid and virus test sample, affecting the accuracy of the virus titer test results.

[0113] Based on the above structure, the execution module 60 of this embodiment further includes the following movement paths: a sixth movement path from the suction head module 80 to the host cell fluid fixation module 40 so that the suction head 81 can draw host cell fluid from the host cell fluid bottle 41, and a seventh movement path from the first constant temperature module 20 to the host cell fluid fixation module 40 to draw host cell fluid again.

[0114] The eighth movement path from the suction head module 80 to the virus test sample fixing module 50, so that the suction head 81 can pick up one of the virus test samples, and the ninth movement path from the first constant temperature module 20 to the virus test sample fixing module 50 to pick up the virus test sample again.

[0115] The tenth moving path from the suction head module 80 to the second thermostatic module 30, so that the suction head 81 can draw liquid agar from the agar bottle 31, and the eleventh moving path from the first thermostatic module 20 to the second thermostatic module 30 to draw liquid agar again.

[0116] The aforementioned paths can be interleaved with the first moving path 64, the second moving path 65, the third moving path 66, the fourth moving path 67, and the fifth moving path 68. Each moving path is executed several times in a pre-set sequence during a complete pipetting and mixing process, thereby automating the entire pipetting and mixing process. The sixth to eleventh moving paths are not shown in the diagram. The execution module 60 can determine and execute moving paths based on the positions of each module. Specifically, each module and its components have their own coordinates on the workbench 10. That is, each unused pipette tip 81, each mixing tube 21, each host cell fluid bottle 41, each agar bottle 31, and each container 51 containing a virus test sample all have unique coordinates on the workbench 10. The execution module 60 executes the first to eleventh moving paths according to a preset sequence and the unique coordinates of each component.

[0117] It should be noted that when the automatic mixing machine is started for the first time, the execution module 60 can execute the movement path from the starting position directly to the pipette tip module 80 to obtain the unused pipette tip 81, instead of executing the fifth movement path 68. Of course, in some application scenarios, the starting position of the execution module 60 is the pipette tip recovery module 70, in which case the execution module 60 can execute the fifth movement path 68 when the automatic mixing machine is started for the first time.

[0118] like Figure 2 As shown, a cabinet 11 is provided above the workbench 10. The first constant temperature module 20, the second constant temperature module 30, the host cell fluid fixation module 40, the virus test sample fixation module 50, and the execution module 60 are all located in the space surrounded by the cabinet 11. The cabinet 11 can isolate the external environment. For some detection processes with high environmental cleanliness requirements, it is easier to form a sterile environment suitable for virus titer detection, thereby eliminating external interference and improving detection accuracy and precision.

[0119] In addition to the titer detection of PR772 bacteriophage and PP7 bacteriophage mentioned in the background art, the automatic mixing machine of this embodiment can also be used to determine the titer of PhiX174 bacteriophage, MS2 bacteriophage, and all other viruses whose titer can be detected by plaque assay.

[0120] like Figure 2 and Figure 3 As shown, the execution module 60 includes a pipette 61, a robotic arm 62, a linear actuator 63, and a controller (not shown). The pipette 61 is located at the execution end of the robotic arm 62, and the robotic arm 62 is movably mounted on the linear actuator 63. The controller is used to control the execution module 60 to perform various liquid picking operations and corresponding movement paths. The linear actuator 63 is fixed on the worktable 10.

[0121] The linear actuator 63 works in conjunction with the robotic arm 62. After the actuator of the robotic arm 62 obtains a clean pipette tip 81, the robotic arm 62 first moves linearly along the linear actuator 63 to the position corresponding to the host cell fluid fixation module 40, the virus test sample fixation module 50, and the second constant temperature module 30, ensuring that the actuator of the robotic arm 62 can reach the host cell fluid bottle 41, the container 51 containing the virus test sample, and the agar bottle 31. The robotic arm 62 then rotates a certain angle so that the pipette tip 81 is sequentially aligned with the host cell fluid bottle 41, the container 51 containing the virus test sample, and the agar bottle 31. The device 51 and agar bottle 31 are used to control the pipette tip 81 to sequentially aspirate host cell fluid, virus test sample and liquid agar. The robotic arm 62 then rotates at a certain angle, and the execution module 60 sequentially executes the first movement path 64, the second movement path 65 and the third movement path 66, so that its execution end moves from the host cell fluid fixation module 40, the virus test sample fixation module 50 and the second constant temperature module 30 to the first constant temperature module 20, and sequentially injects the aspirated host cell fluid, virus test sample and liquid agar into the mixing tube 21 in the first constant temperature module 20.

[0122] Since different pipette tips 81 are required to aspirate different samples, the actuator of the robotic arm 62 needs to replace the pipette tip 81 after transferring host cell fluid, virus test sample and liquid agar. The specific operation of the robotic arm 62 is as follows: the robotic arm 62 first moves linearly along the linear actuator 63 to the position corresponding to the pipette tip recovery module 70. Then the actuator module 60 executes the fourth movement path 67, that is, the robotic arm 62 rotates a certain angle so that its actuator moves from the first constant temperature module 20 to the pipette tip recovery module 70 and aligns with the pipette tip recovery module 70. Then, the pipette tip 81 used at its actuator end is accurately placed into the pipette tip recovery module 70 through the pipette 61.

[0123] Then, the robotic arm 62 moves linearly along the linear actuator 63 to the position corresponding to the pipette tip module 80. The execution module 60 then executes the fifth movement path 68, that is, the robotic arm 62 rotates a certain angle so that its execution end moves from the pipette tip retrieval module 70 to the pipette tip module 80 and is aligned with the pipette tip module 80. Then, the clean pipette tip 81 is picked up by the pipette 61 at its execution end.

[0124] The linear actuator 63 allows the robotic arm 62 to move a certain distance linearly along the linear actuator 63 before executing any movement path, bringing the execution end of the robotic arm 62 closer to the corresponding target module. Then, the robotic arm 62 rotates a small angle, allowing the execution end to reach the target module from the starting module. Especially for starting and target modules that are close to each other, the rotation angle of the robotic arm 62 is very small. Consequently, the first movement path 64, the second movement path 65, and the third movement path 66 are all shorter, improving operational efficiency.

[0125] More importantly, during the execution of the first movement path 64, the second movement path 65, and the third movement path 66, the pipette tip 81 contains the aspirated host cell fluid, virus test sample, and liquid agar. The smaller the rotation angle of the execution end of the robotic arm 62, the smoother the rotation of the robotic arm 62, and thus the smoother the pipette tip 81 and the liquid inside it. This prevents the liquid inside the pipette tip 81 from being thrown out due to the large angle rotation of the robotic arm 62, thereby preventing improper mixing or cross-contamination caused by the thrown-out liquid. This ensures that the liquid volume injected into the mixing tube 21 reaches the preset value, thereby guaranteeing the accuracy of the test results.

[0126] Preferably, the pipette 61 in this embodiment is a pipetting air pump to improve the accuracy of the pipette tip 81 when drawing in and releasing liquid, ensure that the amount of liquid injected into the mixing tube 21 reaches the preset value, and ensure that the ratio of the mixed liquid is accurate, which is beneficial to improving the accuracy of the detection structure; and it is also convenient to cooperate with the robotic arm 62 to improve the degree of automation and work efficiency.

[0127] The workbench 10 has an electrical space (not shown) underneath, where controllers and other circuit structures can be installed to achieve electrical isolation and improve the cleanliness of the environment inside the cabinet 11.

[0128] Example 2

[0129] like Figure 4 As shown, the difference between this embodiment and Embodiment 1 is that the suction tip recovery module 70 is located between the first constant temperature module 20 and the virus test sample fixing module 50; moreover, the suction tip module 80 and the suction tip recovery module 70 are located on the same side of the first constant temperature module 20 and are arranged side by side at intervals along the second direction.

[0130] With this configuration, replacing the suction tip 81 does not require moving it over the first temperature control module 20, which reduces the distance between the suction tip module 80 and the suction tip retrieval module 70, thereby shortening the length of the fifth movement path 68 of the execution module 60 and improving the operational efficiency of the execution module 60. Furthermore, the suction tip module 80 and the suction tip retrieval module 70 are on the same side of the first temperature control module 20 as the virus test sample fixing module 50. This is because the virus test sample fixing module 50 generally contains several different virus test samples, and the suction tip needs to be replaced before drawing different virus test samples. 81. After injecting the previous virus test sample into the target mixing tube 21 in the first constant temperature module 20, the execution module 60 executes the fourth movement path 67 to put the used pipette tip 81 into the pipette tip recycling module 70, and then executes the fifth movement path 68 to retrieve the unused pipette tip 81 in the pipette tip module 80. Then it can move a shorter distance to the virus test sample fixing module 50 to retrieve a new virus test sample, thereby shortening the total path length of the above steps and improving the operation efficiency. The efficiency improvement is more obvious when there are many types of virus test samples.

[0131] The suction tip retrieval module 70, suction tip module 80, and virus test sample fixing module 50 can be arranged in a "7" shape to improve space utilization. The suction tip module 80 and the second temperature control module 30 are located on either side of the first temperature control module 20. Since all the modules are arranged around the first temperature control module 20, placing the suction tip module 80 and the second temperature control module 30 on either side of the first temperature control module 20 allows for an adjacent arrangement of the suction tip module 80 and the first temperature control module 20. Therefore, within the limits of installation, the distance between the suction tip module 80 and the first temperature control module 20 can be minimized. Correspondingly, a certain amount of space can be allocated to the suction tip module 80. This also shortens the distance between the pipette tip module 80 and other modules, thereby reducing the distance the execution module 60 travels from obtaining a clean pipette tip 81 to moving from the pipette tip module 80 to the host cell fluid fixation module 40, the virus test sample fixation module 50, and the second thermostat module 30, thus significantly improving operational efficiency. It also increases the physical distance between the second thermostat module 30 and the pipette tip module 80, preventing liquid agar in the second thermostat module 30 from accidentally dripping into unused pipette tips 81 and solidifying, clogging pipette tips 81, causing pipette tips 81 to be unable to draw liquid, and interfering with the normal operation of the execution module 60.

[0132] Example 3

[0133] like Figure 5 As shown, the difference between the automatic liquid mixer in this embodiment and the first embodiment is that, in this embodiment, the automatic liquid mixer does not have a pipette tip recovery module 70 and a pipette tip module 80. Several pipette tips 81 are pre-loaded on the execution module 60, and the pipette tips 81 need to be replaced each time a different liquid is drawn to ensure the purity of each liquid and avoid cross-contamination. The replaced pipette tips 81 are moved to other positions of the execution module 60 without interfering with the normal drawing, carrying and injecting of liquid by the execution module 60; or, the pipette tips 81 can be manually loaded or replaced by the staff.

[0134] Example 4

[0135] like Figure 6 As shown, the difference between the automatic mixing machine in this embodiment and the third embodiment is that in this embodiment, the execution module 60, the first constant temperature module 20 and the virus test sample fixing module 50 are arranged side by side and spaced apart along the second direction, and the distance between the first constant temperature module 20 and the virus test sample fixing module 50 is relatively large, while the execution module 60 is located on the side of the first constant temperature module 20 away from the virus test sample fixing module 50.

[0136] Example 5

[0137] like Figure 7As shown, the difference between the automatic mixing machine in this embodiment and Embodiment 3 is that the host cell fluid fixation module 40 and the virus test sample fixation module 50 are located on both sides of the first constant temperature module 20, but are at least partially offset from the first constant temperature module 20 in the second direction. With this arrangement, the host cell fluid fixation module 40 and the virus test sample fixation module 50 can still maintain a relatively large physical distance, reducing the risk of cross-contamination. Moreover, the multiple modules form a semi-circular distribution, and the space therein can be used to set up the execution module 60. Thus, each module is set around the execution module 60, shortening the moving distance from the execution module 60 to each module, and further improving the operating efficiency.

[0138] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. An automated liquid mixing machine for virus titer detection based on plaque assay, characterized in that, Comprising: A workbench, and a first constant temperature module, a second constant temperature module, a host cell liquid fixing module, a virus test sample fixing module and an execution module integrated thereon; The first constant temperature module is used for insulating the liquid mixture in the mixing tube placed therein; The second constant temperature module is used for insulating the liquid agar in the agar bottle placed therein; The host cell liquid fixing module is used for placing the host cell liquid bottle; The virus test sample fixing module is used for placing the container containing the virus test sample; There is a spatial interval between the first constant temperature module and the virus test sample fixing module; The execution module has an execution end that can form a detachable sealed connection with the pipette tip, and controls the pipette tip to automatically aspirate, carry and release the host cell liquid or virus test sample or liquid agar; The execution module has a first movement path, a second movement path and a third movement path; On the first movement path, the execution module aspirates and carries the host cell liquid from the host cell liquid fixing module through the pipette tip to the first constant temperature module, and injects the host cell liquid into the mixing tube; On the second movement path, the execution module aspirates and carries the virus test sample from the virus test sample fixing module through the pipette tip to the first constant temperature module, and injects the virus test sample into the mixing tube; The virus test sample fixing module is arranged out of alignment with the first movement path, and the host cell liquid fixing module is arranged out of alignment with the second movement path; ​ 2. The automatic mixing machine as described in claim 1, characterized in that, ​ 3. The automatic mixing machine as described in claim 2, characterized in that, ​ 4. The automatic mixing machine as described in any one of claims 1-3, characterized in that, ​ ​ 5. The automatic mixing machine as described in claim 4, characterized in that, ​ 6. The automatic mixing machine as described in claim 1, characterized in that, ​ 7. The automatic mixing machine as described in claim 4, characterized in that, ​ The execution module has a fifth movement path, on which the execution module moves from the suction head recycling module to the suction head module to obtain an unused suction head; The suction head module is misaligned with the first moving path, the second moving path, and the fourth moving path.

8. The automatic mixing machine as described in claim 7, characterized in that, The suction head module and the second constant temperature module are located on both sides of the first constant temperature module.

9. The automatic mixing machine as described in claim 7, characterized in that, The pipette tip module and the pipette tip recovery module are located on the same side of the first thermostatic module; and / or, the pipette tip module and the host cell fluid fixation module are located on the same side of the first thermostatic module.

10. The automatic mixing machine as described in claim 1, characterized in that, A cabinet is provided above the workbench, and the first temperature control module, the second temperature control module, the host cell fluid fixation module, the virus test sample fixation module, and the execution module are all located within the space enclosed by the cabinet; and / or, The execution module includes a pipette, a robotic arm, a linear actuator, and a controller. The pipette is disposed at the execution end of the robotic arm, the robotic arm is movably disposed on the linear actuator, and the controller is used to control the execution module to perform various liquid retrieval operations and corresponding movement paths. The linear actuator is fixed on the worktable.

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