| Description | Product content： Component O66550510 preps O665505 50 preps Blocking Buffer 100 ml 500 ml Antibody Pretreat Solution（ HRP/Mouse ） 1 ml 5 × 1 ml Dilution Buffer 100 ml 500 ml Wash Buffer（ 10× ) 100 ml 500 mlProduct Introduction:The one-step rapid WB assay kit (Product content： Component O66550510 preps O665505 50 preps Blocking Buffer 100 ml 500 ml Antibody Pretreat Solution（ HRP/Mouse ） 1 ml 5 × 1 ml Dilution Buffer 100 ml 500 ml Wash Buffer（ 10× ) 100 ml 500 mlProduct Introduction:The one-step rapid WB assay kit (mouse) is the latest Western Blot detection kit developed by Kangwei Century, which can obtain high-quality Western Blot results in about 1 hour. It is easy to operate, has high detection sensitivity, low background, does not require the addition of secondary antibodies, and has strong system stability. The conventional Western Blot indirect detection process (blocking, primary antibody binding, and secondary antibody binding) requires a long time, a complex experimental process, and requires multi-step condition optimization. After transferring the protein on the gel to the carrier membrane, incubate it with the blocking solution in the reagent kit for 5 minutes, and then incubate the carrier membrane with the primary antibody treated with antibody reaction solution. After washing three times (5 minutes each time), luminescence or colorimetric detection can be performed. This reagent kit is designed for use in experimental systems where the target protein primary antibody is derived from mice.Notes:1. The customer prepares their own mouse source primary antibody.2. Before using Blocking Buffer blocking solution, Antibody Pretreat Solution (HRP/Mouse) antibody reaction solution (mouse), and Wash Buffer (10 x) rinse solution, please mix thoroughly.3. If there is precipitation in the rinsing solution when stored at 2-8 ℃, please restore it to room temperature, dissolve the precipitation, and use it normally. The 1x rinsing solution can be stored at room temperature for one month.4. It is recommended to stain the membrane with reagents such as spring red after the transfer is completed, and cut off any excess parts on the membrane to increase the efficiency of the reagents.5. The optimal dilution amount for primary antibody and antibody reaction solution HRP (mouse) needs to be determined through preliminary experiments.6. The antibody reaction solution HRP (mouse), antibody dilution solution, and antibody dosage can be increased or decreased proportionally according to the size of the membrane.7. The antibody dilution solution containing the first antibody can be recycled and reused once. It is recommended not to reuse antibodies with poor specificity and affinity. If the recovered antibody is used within 1-2 days and stored at 2-8 ℃ for long-term storage, please freeze it at -20 ℃ to avoid repeated freeze-thaw cycles.8. If there is a high background, please adjust the amount of antibodies and increase the number of times the film is washed.9. All reagents in the reagent kit should be stored at 2-8 ℃ to avoid freezing and thawing.Operation steps:This product is suitable for the sealing and antibody incubation steps after membrane transfer, taking a 5 cm x 8 cm membrane as an example:1. Preparation of rinsing solution: Dilute 10 ml of Wash Buffer (10 x) with distilled water to 100 ml, which is 1 x Wash Buffer. Set aside. Use 8-10 ml for each film wash.2. Sealing: After the membrane transfer is completed, immerse the membrane in 10 ml Blocking Buffer and seal at room temperature for 5 minutes.3. Rinse: Pour off the sealing solution, add 8-10 ml of 1 x Wash Buffer, and rinse at a high speed on a shaker for 1 minute.4. Prepare antibody incubation solution while washing the membrane: Take Antibody Pretreat Solution (HRP/Mouse) 100 µ Add mouse derived primary antibody 3-10 into the centrifuge tube µ g. Suck and beat the gun head until thoroughly mixed, and incubate at room temperature for 5 minutes. Add to 10 ml Dilution Buffer and mix well. Note: 1) The dosage of primary antibody can also be adjusted according to the dilution of the antibody. Taking the final dilution of antibodies at 1:1000 as an example, take 100 µ Add HRP (mouse) antibody reaction solution into the EP tube and add 10 µ Add the first antibody to 10 ml of antibody diluent, mix well, and incubate at room temperature for 5 minutes. 2) If the membrane area is small, the amount of antibodies, reaction solution, and diluent can be reduced proportionally.5. After completing step 3, pour out the rinsing solution and add the antibody incubation solution mixed with primary antibody, Antibody Pretreat Solution (HRP/Mouse), and Dilution Buffer to the membrane (ensuring that the incubation solution completely submerges the surface of the membrane). Incubate at room temperature on a shaker at around 60 rpm for 40 minutes.6. Discard (recover) the antibody incubation solution and rinse 3-5 times with the prepared 1 x Wash Buffer, each time for 3 minutes. 7. Conduct subsequent testing. It is recommended to use ECL or DAB methods for testing.Application examples:Example 1 Antigen is 293T cell lysateA: Normal WB control: beta actin mouse monoclonal antibody (CW0096) 5 µ Incubate at room temperature for 40 minutes, wash the film and dilute the secondary antibody sheep anti mouse HRP (CW0102) 1:10000. Incubate at room temperature for 40 minutes and expose ECL (CW0049).B: One step method WB: beta actin mouse monoclonal antibody (CW0096) 5 µ Incubate at room temperature for 40 minutes and expose ECL (CW0049).Example 2 Antigen is E. coli multi label protein lysateC: Normal WB control: GST mouse monoclonal antibody (CW0084) 2.5 µ Incubate at room temperature for 40 minutes, wash the film and dilute the secondary antibody sheep anti mouse HRP (CW0102) 1:10000. Incubate at room temperature for 40 minutes and expose ECL (CW0049).D: One step method WB: GST mouse monoclonal antibody (CW0084) was incubated at room temperature with 2.5ug for 40 minutes, and ECL (CW0049) was exposed... Read More | Product content:ComponentG665836100 rxnsG665836100 rxnsG665836100 rxns2×GoldStar Probe One Step Buffer1.4 ml1.4 ml1.4 mlGoldStar Probe One Step EnzymeMix100 µl100 µl100 µl50×Low ROX-50 µl-50×High ROX--50 µlRNase-Free Water1.5 ml1.5 ml1.5 mlProduct IntroductionProduct content:ComponentG665836100 rxnsG665836100 rxnsG665836100 rxns2×GoldStar Probe One Step Buffer1.4 ml1.4 ml1.4 mlGoldStar Probe One Step EnzymeMix100 µl100 µl100 µl50×Low ROX-50 µl-50×High ROX--50 µlRNase-Free Water1.5 ml1.5 ml1.5 mlProduct Introduction：This product is a specialized reagent kit for one-step Real Time RTqPCR using probe methods (TaqMan, Molecular Beacon, etc.). When using this product for Real Time RT qPCR reaction, reverse transcription and quantitative PCR are requiredConducted in the same reaction system, there is no need to add reagents or open the tube cap during the reaction process, avoiding contaminationThis has improved the efficiency of the experiment. This product has high detection sensitivity, strong fluorescence signal, and high signal-to-noise ratio, making it very suitable forDetection of RNA viruses and other trace amounts of RNA. The special buffering system it contains can enable reverse transcriptase to interact with DNA polymeraseMaximize the effectiveness and improve reaction efficiency. By using this product, a wider linear range can be obtained, which is beneficial for the target base Due to more accurate quantification, good repeatability, and high reliability.ROX dye is used to correct the fluorescence signal error generated between wells in quantitative PCR instruments, and is generally used for ABIReal Time PCR amplification equipment from companies such as Stratagene. The excitation optical systems of different instruments vary, thereforeThe concentration of ROX dye must be matched with the corresponding fluorescence quantitative PCR instrument.matters needing attention：1. Before using the reagents in this reagent kit, please gently mix them upside down to avoid foaming as much as possible, and use them after brief centrifugation. 2. This product uses RNA as a template for one-step RT-PCR experiments, and RNase contamination should be avoided during the operation process,2.It is recommended to perform RNA operations in a dedicated area, using specialized instruments and consumables. Operators should wear masks and disposable gloves and frequently change gloves. Experimental consumables should be treated with a 0.1% DEPC (diethyl pyrocarbonate) aqueous solution at 37 ℃ for 12 hours and sterilized under high pressure for 30 minutes before use.3. Each reagent in this kit should avoid repeated freezing and thawing as much as possible, as repeated freezing and thawing may lead to a decrease in product performance.4. This reagent kit must use specific primers, and the selection of primers can be based on specific experiments. The quality of primer design directly affects the results of RT qPCR reaction. When designing primers, GC content, primer length, and primer should be considered Due to factors such as location, secondary structure of PCR products, it is recommended to use professional primer design software for design.5. It is recommended to use specific probes in this reagent kit and use professional design software for design. Usage: The following examples are typical reaction systems and conditions. In practical operation, corresponding improvements and optimizations should be made based on the differences in template, primer structure, and target fragment size. (Please prepare the reaction solution on ice)1. Dissolve the RNA template, primers, 2xGoldStar Probe One Step Buffer, GoldStar Probe One Step EnzymeMix, and RNase Free Water and place them on ice for later use.2. PCR reaction system: reagent 25 µl Reaction system final concentration 2×GoldStar Probe One Step Buffer 12.5 µl 1× Forward Primer，10 µM 0.5 µl 0.2 µM 1） Reverse Primer，10 µM 0.5 µl 0.2 µM 1） Probe ，10 µM 0.5 µl 0.2 µM 2） GoldStar Probe One Step EnzymeMix 1.0 µl / RNA Template X µl 10 pg – 100 ng3） 50×Low ROX or High ROX （optional）4） 0.5 µl 1× RNase-Free Water up to 25 µl /Note: 1) Typically, the primer concentration is 0.2 µ M can achieve good results, ranging from 0.1 to 1.0 µ M serves as a reference for setting the range. 2) The concentration of the probe used is related to the fluorescent quantitative PCR instrument used, the type of probe, and the type of fluorescent labeling substance. Please refer to the instrument manual or the specific usage requirements of each fluorescent probe for concentration adjustment during actual use.3) The amount of RNA templates is usually based on 10 pg-100 ng as a reference. Due to the different copy numbers of target genes contained in templates of different species, gradient dilution can be applied to the templates to determine the optimal template usage.4) The excitation optical systems of different instruments vary, and depending on the instrument used for fluorescence quantification, 50 x Low ROX or 50 x High ROX can be added.3. Mix well, centrifuge briefly, and collect the solution to the bottom of the tube.4. RT-PCR reaction conditions steps temperature time / Reverse Transcription 45℃ 10 min / PCR pre denaturation 95℃ 10 min / denaturation 95℃ 15s 30-40cycle Annealing/Extension 60℃ 45s 30-40cycleAttention:1) The hot start enzyme used in this product must be activated under pre denaturation conditions of 95 ℃ and 5-10 minutes.2) It is recommended to use a two-step PCR reaction program. If good experimental results cannot be obtained due to the use of primers with lower Tm values, a three-step PCR amplification can be attempted. The annealing temperature should be set within the range of 56 ℃ -64 ℃ as a reference... Read More | DescriptionTruQuant IQQ is a high-quality quantitation system for making simultaneous accurate biological measurements on several hundred biochemicals in small quantities of biological samples. This is achieved by (1) spiking a complex Internal Standard (WORKFLOW-A) into a biological sample to a) DescriptionTruQuant IQQ is a high-quality quantitation system for making simultaneous accurate biological measurements on several hundred biochemicals in small quantities of biological samples. This is achieved by (1) spiking a complex Internal Standard (WORKFLOW-A) into a biological sample to a) quantify all the biochemicals in the sample relative to their counterparts in the Internal Standard, b) suppression-correct each compound and c) normalize sample to sample variances; and (2) injecting the same well characterized Long-Term Reference Standard (WORKFLOW-B) to create a daily retention time (RT) library of all compounds to be found in the Internal Standard for reproducible ID, and to measure day-to-day (QA/QC) to assure reproducible instrument performance. The system is completely automated using IROA ClusterFinder™software.IROA TruQuant IQQ Workflow Kit contains the materials and tools for the analysis of 90 experimental samples. The kit is intended to be used for mass spectrometry metabolomics applications... Read More | Live & deadtm animal cell viability / toxicity detection kit (calcein am, ethd-i) is a kit that provides double fluorescent staining for the detection of animal cell death and survival. The two probes in the kit can respectively measure the activity of cellular lactonase and the integrity of Live & deadtm animal cell viability / toxicity detection kit (calcein am, ethd-i) is a kit that provides double fluorescent staining for the detection of animal cell death and survival. The two probes in the kit can respectively measure the activity of cellular lactonase and the integrity of plasma membrane to reflect cell viability. The kit can be used for fluorescence microscopy, flow cytometry, microplate reader and other fluorescence detection systems. This kit can be applied to most eukarYOtic mammalian cells, including some tissues with adherent nuclei, but it is not applicable to fungi and yeast. Compared with trypan blue, the kit is faster, safer and more sensitive.Component： Product parameters：Calcein am: ex/em = 494 / 517 nm; Ethd-i: ex/em = 528 / 617 nm (bound DNA)Usage:Fluorescence microscopy detection1. Prepare working fluidPreparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution: Remove the original solution of Calcein AM and EthD-I and restore them to room temperature. Add 20 µ L 2 mM EthD-I and 5 µ Mix 4 mM Calcein AM with 10 mL PBS or other serum-free buffer or culture medium, vortex well. The above working solution can be directly used for cell staining.Note: The aqueous solution of Calcein AM is easily hydrolyzed and should be used up every day. The concentration selection of Calcein AM and EthD-I varies depending on the type of cell used, with a recommended concentration range of 0.1-10 µ M.2. Prepare cells and conduct experiments(1) For adherent cells, they can be washed 2-3 times with 1 × PBS before staining. For suspended cells, centrifuge at room temperature of 250-1000 × g for 5 minutes and collect cells for staining.(2) Wash the cells thoroughly 2-3 times with 1 × PBS to remove residual esterase activity.(3) For adherent cells, add sufficient amount of Calcein AM/EthD-I staining solution. For suspended cells, add an appropriate amount of staining solution to control the cell density between 1-5 × 105/mL.(4) Incubate at room temperature in dark for 15-20 minutes (if the working solution concentration is high or the incubation temperature is high, the incubation time should be appropriately reduced).(5) Observe the labeled cells under a fluorescence microscope.Flow cytometry detection1. Remove the reagent and restore it to room temperature.2. Preparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution: Take out the original solution of Calcein AM and EthD-I, and restore to room temperature. Add 20 µ L 2 mMEthD-I and 5 µ Vortex mix 4 mM Calcein AM with 10 mL PBS or other serum-free buffer or culture medium. The working fluid can directly stain cells.3. Wash cells thoroughly 2-3 times with 1 × PBS.4. Suspend cells with 0.5 mL of staining solution and control the cell density to 1-5 × 105/mL.Note: It is recommended to prepare two additional cell samples, each containing only one dye (Calcein AM and EthD-I), for compensatory regulation of flow cytometry single staining; Prepare another cell sample containing only buffer solution (which should be consistent with the buffer used to prepare Calcein AM and EthD-I detection working solutions) as a negative control for flow cytometry analysis.5. Incubate at room temperature in dark for 15-20 minutes.6. Within 1-2 hours, cell activity was detected by flow cytometry. Calcein AM can be excited by a 488 nm laser, with fluorescence emission spectra detected at around 530 nm and EthD-I emission spectra at around 610 nm.Note: When using the cell circle gate, attention should be paid to excluding cell debris and using a single staining tube to regulate compensation. Double staining tube flow cytometry should obtain two relatively independent cell populations: a live cell population displaying green fluorescence and a dead cell population displaying red fluorescence.ELISA reader detection1. Cultivate an appropriate amount of adherent or suspended cells in a 96 well black ELISA plate.Note: Dead cells can be obtained by treating cells with 1% saponin or 0.1-0.5% digitalis saponin for 10 minutes.2. Preparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution:Remove the original solutions of Calcein AM and EthD-I and restore them to room temperature. Add 20 µ L 2 mM EthD-I and 5 µ Mix 4 mM Calcein AM 10 mL PBS or other serum-free buffer or culture medium, vortex well.Note: (1) 10 mL of staining solution is sufficient to stain a 96 well plate, and the volume of the staining solution can be adjusted according to experimental needs. The concentrations of Calcein AM and EthD-I can range from 0.1 to 10 µ Explore between M.(2) The aqueous solution of Calcein AM is easily hydrolyzed and should be used up every day. EthD-I working solution can be stored at -20 ℃ for at least one year.3. Wash the cells thoroughly with 1 × PBS to remove residual esterase activity. For adherent cells, add 100 to each well µ Wash cells with PBS. For suspended cells, add 100 µ Resuspend cells with L PBS and centrifuge to remove the supernatant. Repeat the above operation.4. Add 100 to each hole µ L PBS.5. Add 100 to each hole µ L staining solution, making the total volume of each well 200 µ L. The final concentration of Calcein AM is 1 µ M. The final concentration of EthD-I is 2 µ M. Gently shake the culture plate to evenly cover the cells with the liquid.Incubate at room temperature in dark for 30-45 minutes.Note: The optimal incubation time varies for different cells, with 30 minutes as the initial incubation time. Subsequently, the staining time can be adjusted and optimized according to the actual staining effect to obtain a more ideal staining effect.7. Enzyme reader detection. When the ELISA reader is set to fluorescein, it can detect Calcein AM; When the ELISA reader is set to rhodamine or Texas Red, EthD-I can be detected. Select the optimal emission and excitation wavelengths based on spectral characteristics.Note: By comparing the relative fluorescence values (RFU) measured between the sample group and the control group, the changes in the number of dead and live cells can be obtained. Another method of data analysis is also provided below.The following method can calculate the ratio of live cells to dead cells in a certain region. The required samples include dead cell control group, live cell control group, and the sample group to be tested. Dead cells can be obtained by treating cells with 1% saponin or 0.1-0.5% digitalis saponin for 10 minutes.1. Prepare staining solution and follow the above steps to stain cells. Additionally, prepare 1 mL and 2 mL separately µ M Calcein AM and 4 µ M EthD-I solution, stain the control group according to the following instructions. For the following groups of cells or cell-free groups, it is necessary to maintain complete consistency in cell count, detection of working solution concentration, incubation time, and incubation temperature.2. Measurement of sample group and control group:A. The measured values of the sample group at 645 nm are denoted as Calcein AM and EthD-I=F (645) sam.B. The measured values of the sample group at 530 nm are denoted as Calcein AM and EthD-I=F (530) sam.C. The measurement value of dead cell EthD-I single staining control group at 645 nm is denoted as EthD-I=F (645) maxD. The measurement value of dead cell Calcein AM single staining control group at 645 nm is recorded as Calcein AM=F (645) minE. The measurement value of live cell EthD-I single staining control group at 530 nm is recorded as EthD-I=F (530) min.F. The measurement value of live cell Calcein AM single staining control group at 530 nm is denoted as Calcein AM=F (530) max.G. A blank control well without cells (with or without dye), the detection value at 530 nm is recorded as F (530) 0.H. A blank control well without cells (with or without dye), the detection value at 645 nm is recorded as F (645) 0.3. Calculate the ratio of dead cells to live cells based on measurement data:%Live Cells=(B-E) ÷ (F-E)%Dead Cells=(A-D) ÷ (C-D)Determine the ratio of live cells to dead cells in a certain areaBy creating fluorescence spectral standard curves at 530 nm and 645 nm, the number of dead and live cells can be determined, and the fluorescence intensity of each dye is linearly related to the number of dead or live cells in the sample.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. phenol red or serum may interfere with the detection of this kit. 3. fluorescent dyes have quenching problems. Please try to avoid light during experimental operation to slow down fluorescence quenching. 4. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Dead and live cell staining (animal)... Read More | Component Description T665563Component50 TStorageApplicationT665563AVNTR3820 1 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563BVNTR41201 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563CVNTR32321 mL-20℃. Avoid freeze/thaw Component Description T665563Component50 TStorageApplicationT665563AVNTR3820 1 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563BVNTR41201 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563CVNTR32321 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563DMarkerⅠ300 µL-20℃. Avoid freeze/thaw cycle.DNA Molecular Weight Standard IT665563EMarkerⅡ250 µL-20℃. Avoid freeze/thaw cycle.DNA Molecular Weight Standard IIProduct IntroductionThis kit is a genotyping product for human Mycobacterium tuberculosis based on the latest research progress in molecular epidemiology1) and optimized by process. It utilizes variable-number tandem repeats (VNTR) polymorphisms in the Mycobacterium tuberculosis genome for genotyping to differentiate clinical strains, and is a powerful tool for studying the molecular epidemiology of Mycobacterium tuberculosis and monitoring the status of tuberculosis transmission. Compared with other existing Mycobacterium tuberculosis VNTR typing systems based on the VNTR principle, this typing system has a stronger ability to discriminate strains prevalent in China1,2,3), and is therefore particularly suitable for the needs of Chinese users.By carefully optimizing the primer sequences of each PCR reaction and the composition of the premixed reaction solution, this product has a strong anti-interference power. Compared with the user's own reagents, this product significantly improves the signal intensity of specific bands and reduces the appearance of non-specific bands when using crude templates (boiling bacterial solution), which makes the experimental operation easier and quicker, and at the same time, improves the success rate of the test. The premixed reaction solution is chemically stable and can effectively withstand repeated freezing and thawing (10 times) and a longer period of time (one week) at room temperature, which is better adapted to the user's need for flexibility in the detection work.This kit is a companion product to the TB Genotyping Kit VNTR-9. For samples identified as clustered or identical strains by the VNTR-9 kit, this product can be used for finer further typing identification if necessary. The three high-resolution detection sites VNTR3820, VNTR4120 and VNTR3232 in this product can be used in combination with the nine detection sites in the VNTR-9 to increase the resolution index (Hunter-Gaston index (HGI) to 0.9931).References1) Luo T et al. Development of a hierarchical variable-number tandem repeat typing scheme for Mycobacterium tuberculosis in China. PLoS One. 2014 Feb 25. 9(2)2)Sun G et al. Discriminatory potential of a novel set of Variable Number of Tandem Repeats for genotyping Mycobacterium marinum. Vet Microbiol. 2011 Aug Vet Microbiol. 2011 Aug 26;152(1-2)3) Zhang L et al. Highly polymorphic variable-number tandem repeats loci for differentiating Beijing genotype strains of Mycobacterium tuberculosis in Shanghai, China. FEMS Microbiol Lett. 2008 May;282(1):22-31.matters needing attention1.This product is a companion to the TB genotyping kit VNTR-9. The strains to be tested should be tested by VNTR-9 typing test first, and then use this product for testing. And the results of this product should be integrated and analyzed with the results of VNTR-9.2.To avoid contamination, it is recommended that the preparation of the organisms be done within a different location than the preparation of the PCR Mix and that different pipettes be used.3.Care should be taken at all stages of sample DNA collection, extraction and amplification to ensure proper labeling and to prevent cross-contamination between different samples.4.Commonly used reagents and consumables need to be autoclaved before experimentation.5.Each tube of PCR Mix contains different primers and cannot be mixed. It can be dispensed into different amounts at once according to the experimental needs to avoid repeated freezing and thawing.6.To avoid splashing the reaction solution when opening the reaction tube, centrifuge briefly before opening the cap and collect the liquid at the bottom of the tube. In case of accidental splashing on gloves or table, change gloves immediately and wipe the table with 75% alcohol or dilute acid.7.Be careful not to cross-contaminate the PCR Mix when aspirating, and it is recommended that the pipette tip be wiped with 75% alcohol 2 times before taking Mix each time.8.Pre-experiment preparation: 1×TE buffer (PH=8.0), 0.5×TBE buffer, agarose, ethidium bromide (EB), normal PCR instrument, DNA electrophoresis equipment and gel imager, 0.2 ml PCR reaction tubes, octuplex or 96-well PCR tubes, pipettes of different sizes: 0.5-10 µl and 20-200 µl.Operation steps1. DNA template preparation:1.1. scrape a small amount (1-2 inoculation loops) of sample from solid medium, resuspend in 100ul TE and inactivate at 80°C for 30 minutes.1.2. The inactivated strain was taken out of the P3 laboratory as follows:Boil at 100°C for 10 minutes (be careful to avoid bursting the cap of the EP tube during boiling to avoid letting water into the tube), place immediately on ice for 2 minutes, centrifuge at 12,000 rpm (~13,400 × g) for 10 minutes, take the supernatant and place in another sterile EP tube, label it, and store at -20°C.2. Testing procedures:2.1. Remove the TB Genotyping Kit HV-3, allow the liquid to equilibrate to room temperature, mix by shaking slightly 3-4 times, and then centrifuge at 12,000 rpm (~13,400 x g) for 5 seconds to allow the capped liquid to fall back into the tube.2.2.Three-locus VNTR typing: strains with identical results at 12 loci need to be further VNTR typed, i.e., the following four loci are added for comparison.1）PCR amplification: the reaction system was 20 µl. 19 µl of PCR Mix of VNTR3820, VNTR4120, and VNTR3232 were added to each PCR tube, 1 µl of DNA template was added, and mixed well.2）Amplification conditions:3) Gel preparation and electrophoresis:a: Notes:Important! Positive (H37Rv strain DNA) and negative controls (deionized water) need to be set up for each experiment.Key! This experiment is based on agarose gel electrophoresis to interpret the genotype of VNTR locus, therefore, in order to make the results accurate, it is necessary to follow the unified standard operation in this step of electrophoresis, and the following points should be noted:a-1: The comb used for glue making is 18 holes.a-2: The two wells on the left and right sides of the gel were discarded due to the tendency to distort the bands during electrophoresis, affecting the interpretation of the results, or a negative control was spotted in one of the wells. The remaining 16 wells were divided into 12 samples, 3 DNA Markers and 1 positive control. The order of spotting was "1, 2, M, 3, 4, 5, 6, M, 7, 8, 9, 10, M, 11, 12, H37Rv", the numbers represent samples, and M represents DNA Marker.a-3: When PCR amplification products are subjected to the first electrophoresis and Marker I is used, the gel concentration is 1%, the voltage is 150 V, and the time is 100-120 min.a-4: If the amplification product fragment is too large (>1000bp) and needs to be electrophoresed again and Marker II is used, the gel concentration is 0.8%, the voltage is 150V and the time is 150 minutes.b: Gluing as well as the electrophoresis process:PCR amplification products were electrophoresed using a 1% agarose gel.To prepare 1% agarose gel, 12×12 cm gel tray was used to make the gel, each gel was 80 ml.b-1: Weigh 0.8g of agarose, add 80ml of 0.5×TBE, weigh it on the balance and put it into the microwave oven, heat it on high for 2-3 minutes to make the agarose dissolve completely, shake it well, and observe it as a homogeneous and transparent solution without particles, then weigh it again on the balance and make up the appropriate amount of double-distilled water to keep the concentration of the gum unaffected.b-2: When the melted gel was cooled to about 55°C add 4 µl of ethidium bromide (10ug/ml) and gently swirl to mix well. The gel was made with an 18-tooth comb and the warm gel was poured into a 12 × 12 cm gel tray.b-3: Allow the gel to completely set (40 minutes at room temperature), carefully pull out the comb, remove the tray, and place it in the electrophoresis tank. Add 0.5× TBE buffer to the electrophoresis tank, not exceeding the gel surface by 1-2mm.b-4: Sample electrophoresis: add 12 samples to each gel (the topmost wells are not sampled), add 3-5µl PCR products to each well, and at the same time add three 5µl DNA MarkerⅠ to each gel. The voltage is 150V and the electrophoresis time is 100-120 minutes. This step is the key to the accuracy of the final readings of each point, and needs to be operated uniformly according to this standard.b-5: Some loci have amplification products greater than 1000bp in clinical strains, and these amplification products were then electrophoresed using 0.8% agarose gel, with DNA Marker II added as a control for the band size, voltage 150V, electrophoresis time 150 minutes.4) Results display:5) Analysis of results:a. If the genotypes of the three highly variable loci are also the same in different strains, they can be identified as clustered strains;b. If the high variant readings are highly similar, i.e., only 1-2 high variant sites are different, they need to be combined with epidemiologic data to identify if they are clustered strains;c. If all 3 high variant loci are genotypically discordant, identify as a single strain.Appendix 1: Rules for reading VNTR lociAppendix 2: VNTR locus repeat unit readout table... Read More |