Enrichment and culture method based on immunomagnetic beads

Abstract

The invention discloses an enrichment and culture method based on immunomagnetic beads, which comprises the following steps: acquiring a to-be-enriched sample, and judging the bacterial concentration of the to-be-enriched sample; if the bacterial concentration is greater than a first preset threshold value, directly performing first operation on the to-be-enriched sample; if the bacterial concentration is smaller than a second preset threshold value, performing a second operation on the to-be-enriched sample; and if the bacterial concentration is greater than a second preset threshold value and less than a first preset threshold value, performing third operation on enrichment of the to-be-enriched sample. According to the present invention, with the method, the enriched bacteria characteristics are significant, the positive reporting rate is improved, the positive reporting time is substantially shortened, the immunomagnetic beads are adopted to enrich and culture the bacteria in the sample so as to shorten the time, reduce the false negative, improve the positive reporting rate, further improve the microbiological identification level, shorten the identification time, and improve the detection accuracy. And the clinical application is better realized.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial detection, and in particular relates to an enrichment and cultivation method based on immunomagnetic beads. Background Art

[0002] In microbiological research and applications, efficient and specific separation and enrichment of target microorganisms from complex samples is a crucial step.

[0003] In the existing technology, it takes a long time to culture and detect microorganisms in clinical samples. The microbiological testing capacity conflicts with the clinical demand for rapid testing. In addition, bacteria are generally dispersed in samples, which makes it possible for microbiological culture testing to detect positive samples as negative results. False negatives will not only affect the test results but also delay the treatment time of patients. Therefore, the existing technology not only takes a long time to test, but also has low detection accuracy. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides an enrichment and culture method based on immunomagnetic beads. The technical problem to be solved by the present invention is achieved by the following technical solution:

[0005] An immunomagnetic bead-based enrichment and culture method comprising:

[0006] Obtaining a sample to be enriched, and determining the bacterial concentration of the sample to be enriched;

[0007] If the bacterial concentration is greater than the first preset threshold, the first operation is directly performed on the sample to be enriched; if the bacterial concentration is less than the second preset threshold, the second operation is performed on the sample to be enriched; if the bacterial concentration is greater than the second preset threshold and less than the first preset threshold, the third operation is performed on the sample to be enriched, wherein the first operation is an enrichment operation, the second operation is a culture-first-then-enrichment operation, the third operation is an enrichment-first-then-culture operation, and the enrichment operation uses an immunomagnetic bead reagent for enrichment.

[0008] In one embodiment, the immunomagnetic bead reagent comprises: at least aerobic bacteria and / or anaerobic bacteria;

[0009] The aerobic bacteria include one or more of Escherichia, Staphylococcus, Klebsiella, Acinetobacter, Streptococcus, Pseudomonas, Enterococcus, and Proteus;

[0010] The anaerobic bacteria include one or more of Prevotella, Peptiphilus, Peptostreptococcus, Veillonella, Bifidobacterium, Clostridium, Bacteroides, and Lactobacillus.

[0011] In a specific embodiment, when the aerobic bacteria include multiple genera, the mass percentage of Escherichia is 5% to 50%, the mass percentage of Staphylococcus is 5% to 25%, the mass percentage of Klebsiella is 3% to 15%, the mass percentage of Acinetobacter is 3% to 20%, the mass percentage of Streptococcus is 5% to 25%, the mass percentage of Pseudomonas is 5% to 25%, the mass percentage of Enterococcus is 5% to 25%, and the mass percentage of Proteus is 5% to 25%.

[0012] In a specific embodiment, when the anaerobic bacteria include multiple genera, the mass percentage of Prevotella is 5% to 30%, the mass percentage of Peptophilus is 5% to 25%, the mass percentage of Peptostreptococcus is 5% to 30%, the mass percentage of Veillonella is 5% to 25%, the mass percentage of Bifidobacterium is 5% to 30%, the mass percentage of Clostridium is 5% to 30%, the mass percentage of Bacteroides is 5% to 30%, and the mass percentage of Lactobacillus is 5% to 30%.

[0013] In a specific implementation, the first operation includes:

[0014] Selecting a corresponding immunomagnetic bead reagent according to the sample to be enriched;

[0015] The immunomagnetic bead reagent is placed in an enrichment container, and the supernatant is removed by magnetic suction using a magnetic sorting device;

[0016] Adding a sample to be enriched in an amount matching the amount of the immunomagnetic bead reagent into the enrichment container, and using a pipette or a vortex device to evenly mix the immunomagnetic bead reagent and the sample to be enriched;

[0017] Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution;

[0018] The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample.

[0019] In a specific embodiment, the second operation includes:

[0020] In a sterile environment, the sample to be enriched is injected into a culture container with a bacterial enrichment culture solution, and an antibiotic antagonist and a corresponding immunomagnetic bead reagent are added to the culture container;

[0021] When it is determined that the bacterial concentration in the culture container is greater than a first preset threshold, the culture in the culture container is placed in a sterile environment and transferred to an enrichment container;

[0022] Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution;

[0023] The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample.

[0024] In a specific implementation, the third operation includes:

[0025] Selecting a corresponding immunomagnetic bead reagent according to the sample to be enriched;

[0026] The immunomagnetic bead reagent is placed in an enrichment container, and the supernatant is removed by magnetic suction using a magnetic sorting device;

[0027] Adding a sample to be enriched in an amount matching the amount of the immunomagnetic bead reagent into the enrichment container, and using a pipette or a vortex device to evenly mix the immunomagnetic bead reagent and the sample to be enriched;

[0028] Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution;

[0029] The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample;

[0030] The enriched sample is added to a culture container with a bacterial enrichment culture solution, and an antibiotic antagonist is added to the culture container for culturing.

[0031] In one embodiment, after the reacted sample is subjected to magnetic separation, the method further comprises:

[0032] Remove all supernatant from the sample after magnetic separation;

[0033] After adding flushing liquid or physiological saline to the wall of the enrichment container for flushing, the enrichment container is fixed on the magnetic separation device for magnetic separation, and the above steps are repeated until the cleaning is completed.

[0034] Beneficial effects of the present invention:

[0035] The enrichment and cultivation method based on immunomagnetic beads of the present invention can select different enrichment and cultivation methods according to different use scene requirements, and directly enrich the sample, and the bacteria in the sample are concentrated and enriched, and then the plate is plated to obtain characteristic strains, which will be more effective than the dispersed bacteria for a long time culture bottle culture and finally plated to obtain characteristic strains; the sample is first enriched and then cultivated, and the bacteria in the sample are concentrated and enriched, and then the plate is finally plated to obtain characteristic strains, which will be higher than the sample detection rate of directly enriched; the sample is first cultivated and then enriched, and the bacteria in the sample are micro-cultured and concentrated again. Finally, the plate is plated to obtain characteristic strains, which will be higher than the sample detection rate of directly enriched. After enrichment, not only the bacterial characteristics are obvious, the positive rate of reporting is improved, and the positive time of reporting is greatly shortened. In addition, the present invention uses immunomagnetic beads to enrich and cultivate the bacteria in the sample to shorten the time, reduce false negatives, and improve the positive rate of reporting, and can further improve the level of microbial identification, shorten the identification time, and better serve the clinic.

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention provides a flow chart of an enrichment and culture method based on immunomagnetic beads. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0039] Embodiment 1

[0040] See also Figure 1 , Figure 1 The present invention provides a flow chart of an enrichment and culture method based on immunomagnetic beads, including:

[0041] Obtaining a sample to be enriched, and determining the bacterial concentration of the sample to be enriched;

[0042] If the bacterial concentration is greater than the first preset threshold, the first operation is directly performed on the sample to be enriched; if the bacterial concentration is less than the second preset threshold, the second operation is performed on the sample to be enriched; if the bacterial concentration is greater than the second preset threshold and less than the first preset threshold, the third operation is performed on the sample to be enriched, wherein the first operation is an enrichment operation, the second operation is a culture-first-then-enrichment operation, the third operation is an enrichment-first-then-culture operation, and the enrichment operation uses an immunomagnetic bead reagent for enrichment.

[0043] It should be noted that the advantages of choosing different operation modes are also different. The samples to be enriched are generally human body fluids, such as blood, saliva, urine, pus, etc. Due to the differences in the location and composition of the collection, it is necessary to select a suitable operation mode according to different situations. For example, the concentration of microorganisms such as bacteria in urine is generally high, which can be directly enriched; blood generally has a low content, so it is generally necessary to culture it, and it cannot be directly enriched, otherwise it will affect the detection rate. The concentration of sputum microorganisms is generally high, but there are also many impurities, and the situation of pus is more complicated, which needs to be determined according to the actual situation. Based on this, the first preset threshold and the second preset threshold of this embodiment can be set according to the actual detection requirements and the samples to be enriched. The first preset threshold is set according to the requirement of being able to be directly detected, and the second preset threshold is set according to the standard of being unable to be detected but culturable.

[0044] In one embodiment, the immunomagnetic bead reagent comprises: at least aerobic bacteria and / or anaerobic bacteria;

[0045] The aerobic bacteria include one or more of Escherichia, Staphylococcus, Klebsiella, Acinetobacter, Streptococcus, Pseudomonas, Enterococcus, and Proteus;

[0046] The anaerobic bacteria include one or more of Prevotella, Peptiphilus, Peptostreptococcus, Veillonella, Bifidobacterium, Clostridium, Bacteroides, and Lactobacillus.

[0047] In a specific embodiment, when the aerobic bacteria include multiple genera, the mass percentage of Escherichia is 5% to 50%, the mass percentage of Staphylococcus is 5% to 25%, the mass percentage of Klebsiella is 3% to 15%, the mass percentage of Acinetobacter is 3% to 20%, the mass percentage of Streptococcus is 5% to 25%, the mass percentage of Pseudomonas is 5% to 25%, the mass percentage of Enterococcus is 5% to 25%, and the mass percentage of Proteus is 5% to 25%.

[0048] In a specific embodiment, when the anaerobic bacteria include multiple genera, the mass percentage of Prevotella is 5% to 30%, the mass percentage of Peptophilus is 5% to 25%, the mass percentage of Peptostreptococcus is 5% to 30%, the mass percentage of Veillonella is 5% to 25%, the mass percentage of Bifidobacterium is 5% to 30%, the mass percentage of Clostridium is 5% to 30%, the mass percentage of Bacteroides is 5% to 30%, and the mass percentage of Lactobacillus is 5% to 30%.

[0049] Through the above ratio, the impact between different antigens and antibodies can be minimized, the capture efficiency of each can be balanced, and cross-reactions can be reduced.

[0050] It should be noted that some of the bacterial antigens currently used are expressed in different bacteria. The proteins expressed by the conserved sequences caused by biological evolution will make the specificity of the antibodies used poor, making it difficult to achieve the enrichment of a single bacterial species, resulting in the disadvantage of incomplete separation in existing separation technologies. In this example, there are multiple bacteria to be enriched. Using antibodies prepared by the above-mentioned homology between bacteria, magnetic beads can be enriched in different bacterial genera in a targeted manner, ensuring the specificity of each magnetic bead to a specific bacterial subpopulation and selectivity between different genera.

[0051] Based on this, the present embodiment combines the above-mentioned multiple antibodies with each other, and realizes the broad-spectrum enrichment of the target microorganism in the sample by the selection and proportioning of magnetic beads. The enriched microbial sample has higher purity and richer species, which provides ideal materials for subsequent cultivation, identification or further analysis. Since there may be binding site conflicts when using different types of immunomagnetic beads, after mixing different immunomagnetic beads, the best ratio that can minimize the impact between different antigen antibodies can be found. By mixing different types of immunomagnetic beads and adjusting their ratios, the capture efficiency of each can be balanced and cross-reactions can be reduced. In order to better utilize the paramagnetism of magnetic beads, the present embodiment preferably adopts nanomagnetic beads, such as magnetic beads with a particle size less than 80nm, which can specifically be biological immune magnetic beads.

[0052] In a specific implementation, the first operation includes:

[0053] Selecting a corresponding immunomagnetic bead reagent according to the sample to be enriched;

[0054] The immunomagnetic bead reagent is placed in an enrichment container, and the supernatant is removed by magnetic suction using a magnetic sorting device;

[0055] Adding a sample to be enriched in an amount matching the amount of the immunomagnetic bead reagent into the enrichment container, and using a pipette or a vortex device to evenly mix the immunomagnetic bead reagent and the sample to be enriched;

[0056] Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution;

[0057] The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample.

[0058] In a specific embodiment, the second operation includes:

[0059] In a sterile environment, the sample to be enriched is injected into a culture container with a bacterial enrichment culture solution, and an antibiotic antagonist and a corresponding immunomagnetic bead reagent are added to the culture container;

[0060] When it is determined that the bacterial concentration in the culture container is greater than a first preset threshold, the culture in the culture container is placed in a sterile environment and transferred to an enrichment container;

[0061] Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution;

[0062] The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample.

[0063] In a specific implementation, the third operation includes:

[0064] Selecting a corresponding immunomagnetic bead reagent according to the sample to be enriched;

[0065] The immunomagnetic bead reagent is placed in an enrichment container, and the supernatant is removed by magnetic suction using a magnetic sorting device;

[0066] Adding a sample to be enriched in an amount matching the amount of the immunomagnetic bead reagent into the enrichment container, and using a pipette or a vortex device to evenly mix the immunomagnetic bead reagent and the sample to be enriched;

[0067] Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution;

[0068] The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample;

[0069] The enriched sample is added to a culture container with a bacterial enrichment culture solution, and an antibiotic antagonist is added to the culture container for culturing.

[0070] In one embodiment, after the reacted sample is subjected to magnetic separation, the method further comprises:

[0071] Remove all supernatant from the sample after magnetic separation;

[0072] After adding flushing liquid or physiological saline to the wall of the enrichment container for flushing, the enrichment container is fixed on the magnetic separation device for magnetic separation, and the above steps are repeated until the cleaning is completed.

[0073] This example takes a specific enrichment operation as an example:

[0074] Step 1: Take 50ul of enriched magnetic beads and place them in an EP tube. Use a magnetic separation device to remove the supernatant by magnetic suction.

[0075] Step 2: Add 1 mL of the sample to be enriched into the ep tube and mix by repeatedly pipetting (at least 10 times) or using a vortex device (15 seconds);

[0076] Step 3, place the ep tube on a constant temperature mixing device, set the incubation temperature to 37°C, adjust the mixing speed (1200r) until the enriched magnetic beads can be evenly dispersed in the solution, and set the incubation time to 30min;

[0077] Step 4: After the reaction, the sample is separated by magnetic attraction for 30s-60s, and part of the supernatant is removed to the amount of liquid required for subsequent experiments.

[0078] If the clinical specimen has complex components (such as blood, pus, etc.), a cleaning step is required. The specific cleaning method is as follows: after the reaction in step 3 is completed, the sample is magnetically separated for 1min-2min, and all supernatant is removed; 1mL PBS buffer or saline is added along the tube wall to rinse, and the tube is blown slowly and gently twice, and the ep tube is fixed on the magnetic separation device. After complete magnetic attraction again, all supernatant is removed; repeat the above steps 3 times; add the PBS buffer or saline required for subsequent detection to the ep tube for resuspending and enrichment.

[0079] The enrichment and cultivation method based on immunomagnetic beads of the present embodiment can select different enrichment and cultivation methods according to different use scenario requirements, directly enrich the sample, concentrate the bacteria in the sample and then plate it to obtain characteristic strains, which will be more effective than the dispersed bacteria for a long time culture bottle culture and finally plate it to obtain characteristic strains; enrich the sample first and then cultivate it, concentrate the bacteria in the sample and then micro-cultivate it to finally plate it to obtain characteristic strains, which will be higher than the detection rate of the sample directly enriched; cultivate the sample first and then enrich it, micro-cultivate the bacteria in the sample and then concentrate it and finally plate it to obtain characteristic strains, which will be higher than the detection rate of the sample directly enriched. After enrichment, not only the bacterial characteristics are obvious, the positive rate is improved, and the positive time is greatly shortened. In addition, the present invention uses immunomagnetic beads to enrich and cultivate the bacteria in the sample to shorten the time, reduce false negatives, and improve the positive rate, which can further improve the level of microbial identification, shorten the identification time, and better serve the clinic.

[0080] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0081] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0082] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0083] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. An enrichment and culture method based on immunomagnetic beads, characterized in that: include: Obtaining a sample to be enriched, and determining the bacterial concentration of the sample to be enriched; If the bacterial concentration is greater than the first preset threshold, the first operation is directly performed on the sample to be enriched; if the bacterial concentration is less than the second preset threshold, the second operation is performed on the sample to be enriched; if the bacterial concentration is greater than the second preset threshold and less than the first preset threshold, the third operation is performed on the sample to be enriched, wherein the first operation is an enrichment operation, the second operation is a culture-first-then-enrichment operation, the third operation is an enrichment-first-then-culture operation, and the enrichment operation uses an immunomagnetic bead reagent for enrichment.

2. The immunomagnetic bead-based enrichment and culture method according to claim 1, characterized in that: The immunomagnetic bead reagent comprises: at least aerobic bacteria and / or anaerobic bacteria; The aerobic bacteria include one or more of Escherichia, Staphylococcus, Klebsiella, Acinetobacter, Streptococcus, Pseudomonas, Enterococcus, and Proteus; The anaerobic bacteria include one or more of Prevotella, Peptiphilus, Peptostreptococcus, Veillonella, Bifidobacterium, Clostridium, Bacteroides, and Lactobacillus.

3. The immunomagnetic bead-based enrichment and culture method according to claim 2, characterized in that: When the aerobic bacteria include multiple genera, the mass percentage of Escherichia is 5% to 50%, the mass percentage of Staphylococcus is 5% to 25%, the mass percentage of Klebsiella is 3% to 15%, the mass percentage of Acinetobacter is 3% to 20%, the mass percentage of Streptococcus is 5% to 25%, the mass percentage of Pseudomonas is 5% to 25%, the mass percentage of Enterococcus is 5% to 25%, and the mass percentage of Proteus is 5% to 25%.

4. The immunomagnetic bead-based enrichment and culture method according to claim 2, characterized in that: When the anaerobic bacteria include multiple genera, the mass percentage of Prevotella is 5% to 30%, the mass percentage of Peptophilus is 5% to 25%, the mass percentage of Peptostreptococcus is 5% to 30%, the mass percentage of Veillonella is 5% to 25%, the mass percentage of Bifidobacterium is 5% to 30%, the mass percentage of Clostridium is 5% to 30%, the mass percentage of Bacteroides is 5% to 30%, and the mass percentage of Lactobacillus is 5% to 30%.

5. The immunomagnetic bead-based enrichment and culture method according to claim 1, characterized in that: The first operation includes: Selecting a corresponding immunomagnetic bead reagent according to the sample to be enriched; The immunomagnetic bead reagent is placed in an enrichment container, and the supernatant is removed by magnetic suction using a magnetic sorting device; Adding a sample to be enriched in an amount matching the amount of the immunomagnetic bead reagent into the enrichment container, and using a pipette or a vortex device to evenly mix the immunomagnetic bead reagent and the sample to be enriched; Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution; The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample.

6. The immunomagnetic bead-based enrichment and culture method according to claim 1, characterized in that: The second operation includes: In a sterile environment, the sample to be enriched is injected into a culture container with a bacterial enrichment culture solution, and an antibiotic antagonist and a corresponding immunomagnetic bead reagent are added to the culture container; When it is determined that the bacterial concentration in the culture container is greater than a first preset threshold, the culture in the culture container is placed in a sterile environment and transferred to an enrichment container; Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution; The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample.

7. The immunomagnetic bead-based enrichment and culture method according to claim 1, characterized in that: The third operation includes: Selecting a corresponding immunomagnetic bead reagent according to the sample to be enriched; The immunomagnetic bead reagent is placed in an enrichment container, and the supernatant is removed by magnetic suction using a magnetic sorting device; Adding a sample to be enriched in an amount matching the amount of the immunomagnetic bead reagent into the enrichment container, and using a pipette or a vortex device to evenly mix the immunomagnetic bead reagent and the sample to be enriched; Place the enrichment container on a constant temperature mixing device, set the incubation temperature and mixing speed, and incubate the reaction until the immunomagnetic beads are evenly dispersed in the solution; The sample after the reaction is subjected to magnetic separation, and at least a portion of the supernatant is removed to a preset usage amount to obtain an enriched sample; The enriched sample is added to a culture container with a bacterial enrichment culture solution, and an antibiotic antagonist is added to the culture container for culturing.

8. The immunomagnetic bead-based enrichment and culture method according to any one of claims 5 to 7, characterized in that: After the reacted samples are separated by magnetic absorption, the following steps are also included: Remove all supernatant from the sample after magnetic separation; After adding flushing liquid or physiological saline to the wall of the enrichment container for flushing, the enrichment container is fixed on the magnetic separation device for magnetic separation, and the above steps are repeated until the cleaning is completed.

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