| Description | This reagent kit is for research purposes only. Purpose of use: This reagent kit is used to determine the content of lactose in serum, plasma, and related liquid samples.Experimental principle:This kit applies enzyme-linked immunosorbent assay to determine the level of lactose in the sample. This reagent kit is for research purposes only. Purpose of use: This reagent kit is used to determine the content of lactose in serum, plasma, and related liquid samples.Experimental principle:This kit applies enzyme-linked immunosorbent assay to determine the level of lactose in the sample. Purified lactose antibodies were coated on a microplate to produce solid-phase antibodies. Lactose was added to the microplate of the coated monoclonal antibody, along with HRP labeled lactose antigens, to compete for binding. After thorough washing, the substrate TMB was added for colorimetry. The depth of sample color is negatively correlated with the content of lactose in the sample. Measure the absorbance (OD value) at a wavelength of 450nm using an enzyme-linked immunosorbent assay (ELISA) reader, and calculate the content of lactose in the sample through a standard curve.Kit composition:130times concentrated washing solution20ml×1 bottle8.1Standard S1（80µg/L）0.5ml×1bottle2Enzyme-linked immunosorbent assay6ml×1 bottle8.2Standard S2（40µg/L）0.5ml×1bottle3Enzyme labeling coated plate96 holes x 1 pieces8.3Standard S3（20µg/L）0.5ml×1bottle4Color reagent A solution6ml×1 bottle8.4Standard S4（10µg/L）0.5ml×1bottle5Color developer B solution6ml×1 bottle8.5Standard S5（5µg/L）0.5ml×1bottle6Stop solution6ml×1 bottle9Instructions1 copy7Sample Diluent6ml×1 bottle10Microplate Sealers2 sheetsSpecimen requirements:1. Specimen processing:(1) After collecting the water sample, it is repeatedly freeze-thawed three times at -20 ℃, and then filtered through glass fiber for future reference(2) The tissue samples should be extracted using butanol: methanol: water (5:25:70 V: V: V), or extracted according to relevant literature. The experiment should be conducted as soon as possible after extraction. If the experiment cannot be conducted immediately, the specimen can be stored at -20 ℃ for future reference2. Samples containing NaN3 cannot be detected as NaN3 inhibits the activity of horseradish peroxidase (HRP).Operation steps:1. Sample addition: Set up standard wells, blank wells (blank control wells do not include samples and enzyme-linked immunosorbent assay reagents, the other steps are the same), and sample wells to be tested. Add 50 microliters to the standard well on the enzyme-linked immunosorbent assay (ELISA) plate, and first add 40 diluents to the sample well to be tested µ l. Then add 10 more samples to be tested µ L (The final dilution of the sample is 5 times). Add the sample to the bottom of the enzyme-linked immunosorbent assay (ELISA) plate well, avoiding touching the well wall as much as possible. Gently shake and mix well.2. Enzyme addition: Add 50 enzyme labeled reagents to each well µ l. Excluding blank holes.3. Warm incubation: Seal the plate with a sealing film and incubate at 37 ℃ for 60 minutes.4. Solution preparation: Dilute 30 times the concentrated washing solution with distilled water and set aside for later use5. Washing: Carefully remove the sealing film, discard the liquid, shake dry, fill each well with washing solution, let it stand for 30 seconds, then discard. Repeat this process 5 times and pat dry.6. Color development: Add color development agent A50 to each well first µ l. Add color developer B50 again µ l. Gently shake and mix well, and develop color at 37 ℃ in the dark for 15 minutes7. Termination: Add 50% termination fluid to each hole µ l. Terminate the reaction (at this point, the blue color immediately turns yellow).8. Measurement: Zero the blank hole and sequentially measure the absorbance (OD value) of each hole at a wavelength of 450nm. The measurement should be conducted within 15 minutes after adding the termination solution.Calculation:Draw a standard curve on a coordinate paper with the concentration of the standard substance as the x-axis and the OD value as the y-axis. Based on the OD value of the sample, determine the corresponding concentration from the standard curve; Multiply it by the dilution factor; Alternatively, a linear regression equation can be used to calculate the standard curve using the concentration and OD value of the standard substance. The OD value of the sample can be substituted into the equation to calculate the sample concentration, which is then multiplied by the dilution factor to obtain the actual concentration of the sample.Notes:1. The kit should be balanced at room temperature for 15-30 minutes before use when taken out from the cold storage environment. If the enzyme coated plate is not used up after opening, the Flat noodles should be stored in a sealed bag.2. Concentrated detergent may precipitate crystals. When diluted, it can be heated in a water bath to aid in dissolution. Washing does not affect the results.3. A sampler should be used for each step of sample addition, and its accuracy should be regularly calibrated to avoid experimental errors. It is best to control the sample addition time within 5 minutes. If there are a large number of specimens, it is recommended to use a firing gun for sample addition.4. Please make a standard curve at the same time as each measurement, preferably with a re hole. If the content of the substance to be tested in the sample is too high (the OD value of the sample is greater than the OD value of the first well of the standard well), please dilute the sample diluent by a certain multiple (n times) before measurement. When calculating, please multiply the total dilution multiple (x n x 5).5. The sealing film is only for one-time use to avoid cross contamination.6. Please store the substrate in dark.7. Strictly follow the instructions and determine the test results based on the reading of the enzyme-linked immunosorbent assay (ELISA) reader8. All samples, washing liquids, and various waste should be treated as infectious substances.9. The components of this reagent with different batch numbers shall not be mixed.Detection range:two µ G/L-90 µ G/L... Read More | Glycogen and starch generate glucose-1-phosphate (1PG/G1P) during the process of phosphohydrolysis. This reagent kit provides a simple, sensitive, and rapid determination method: Glucose-1-phosphate (1PG/G1P) is reduced from NADP+to NADPH by the sequential action of phosphoglucose mutase and Glycogen and starch generate glucose-1-phosphate (1PG/G1P) during the process of phosphohydrolysis. This reagent kit provides a simple, sensitive, and rapid determination method: Glucose-1-phosphate (1PG/G1P) is reduced from NADP+to NADPH by the sequential action of phosphoglucose mutase and phosphoglucose dehydrogenase. The content of glucose-1-phosphate (1PG/G1P) in the sample can be calculated by detecting the increase in NADPH at 340nm.Composition and preparation of reagent kit: Reagent name Specifications Save requirements Remarks Extraction solution Liquid 100mL x 1 bottle 4 ℃ storage / Reagent 1 Powder mg x 1 tube 4 ℃ storage Shake or centrifuge the reagent a few times before use to make it fall to the bottom, then dissolve it in 1.2mL of distilled water for later use. Reagent 2 Powder mg x 1 tube Store at -20 ℃ Shake or centrifuge the reagent a few times before use to make it fall to the bottom, then dissolve it in 1.2mL of distilled water for later use. Reagent 3 Liquid 16mL x 1 bottle 4 ℃ storage / Reagent 4 Powder mg x 1 tube Store at -20 ℃ Shake or centrifuge the reagent a few times before use to make it fall to the bottom, then add 1 Dissolve 1mL of distilled water for later use. TRC 1 powder 4 ℃ storage Only used to identify whether the reagents in the kit are normal (not involved in result calculation). Usage: Use a pre standard tube (GIP) to shake the powder a few times until it falls to the bottom, then add 0.5mL of distilled water and mix well to dissolveDilute GIP with a concentration of 4mg/mL and then dilute it four times to 1mg/mL for later use: follow the instructions in the sample addition table for the measuring tube operationRequired instruments and supplies:ELISA reader, 96 well plate, desktop centrifuge, adjustable pipette, mortar, ice and distilled water.Determination of glucose-1-phosphate (1PG/G1P) content:1. Sample preparation① Organizational sample:Suggest weighing around 0 1g of tissue, add 1mL of extraction solution, and homogenize in an ice bath. Centrifuge at 12000rpm, 4 ℃ for 10 minutes, take the supernatant, and place it on ice for testing.[Note]: If the sample size is increased, it can be extracted in a ratio of tissue mass (g) to extraction solution volume (mL) of 1:5-10.② Bacterial/cellular samples:Collect bacteria or cells into a centrifuge tube first, centrifuge and discard the supernatant; Take about 5 million bacteria or cells and add them to 1mLExtract solution, sonicate bacteria or cells (ice bath, power 200W, sonication for 3s, interval 10s, repeated 30 times); Centrifuge at 12000rpm at 4 ℃ for 10 minutes, take the supernatant, and place it on ice for testing.[Note]: If the sample size is increased, extraction can be carried out in a ratio of 500-1000:1 of bacteria/cell quantity (104) to extraction solution (mL).③ Liquid sample: direct detection.2. Machine testing:① Preheat the enzyme-linked immunosorbent assay (ELISA) reader for at least 30 minutes and adjust the wavelength to 340nm.② Thaw the reagent to room temperature (25 ℃);③ Add reagents to the 96 well plate in the following order according to the table:② Thaw the reagent to room temperature (25 ℃);③ Add reagents to the 96 well plate in the following order according to the table: Reagent name (µL） Measurement tube Blank tube (only done once) Reagent 1 10 10 Reagent 2 10 10 Reagent 3 150 170 Sample 20 / Mix well, incubate at room temperature (25 ℃) for 20 minutes, and then read A1 at 340nm (if the A value continues to increase, the incubation time needs to be extended until the absorbance value remains unchanged within 2 minutes). Reagent 4 10 10 Mix well, incubate at room temperature (25 ℃) for 20 minutes, and then read A2 at 340nm (if the A value continues to increase, the incubation time needs to be extended until the absorbance value remains unchanged within 2 minutes). Δ A=(A2-A1) measurement - (A2-A1) blank.[Note] 1 If the difference in Δ A is hovering around zero, the sample size V1 can be increased (such as increasing to 50 µ L, the three phases of the reagent should be reduced while keeping the total volume unchanged), or the sample sampling mass W can be increased. The changed V1 and W need to be substituted into the formula for recalculation.If the A2 value exceeds 1.2, the amount of sample added V1 can be reduced (such as to 10 µ L, the three-phase reagent should be increased while keeping the total volume unchanged), or the sample can be diluted with distilled water (keeping the sample addition system unchanged), and the changed V1 and D need to be substituted into the formula for recalculation.Result calculation:1. Calculated by sample weight:1PG/G1P content (µ g/g fresh weight)=[(Δ A ÷ (ε× d) × V2 × 106 × MR] ÷ (W × V1 ÷ V) × D=836 × Δ A ÷ W × D2. Calculated by the number of cells:1PG/G1P content (µ g/104 cell)=[(Δ A ÷ (ε× d) × V2 × 106 × MR] ÷ (500 × V1 ÷ V) × D=1.7 × Δ A × D. 3. Calculated by liquid volume:1PG/G1P content (µ g/mL)=[(Δ A ÷ (ε× d) × V2 × 106 × Mr] ÷ V1=836 × Δ A ε---NADPH Molar extinction coefficient，6.22×103 L/mol/cm； d---96 Orifice plate optical diameter，0.5cm； V---Add volume of extraction solution，1 mL； V1---Add sample volume，0.02mL V2---Total reaction volume；0.2mL=2×10-4L； W---Sample quality，g； Mr---Glucose-1-phosphate（1PG/G1P）Molecular weight；260； 500---Number of cells, in millions； D---Dilution ratio，Undiluted is 1。 /... Read More | This plant protein extraction kit can extract soluble plant proteins from fresh, frozen, or dried plant tissues. Suitable for protein extraction from various plants and different parts of plants (such as roots, stems, leaves, flowers, seeds, etc.), with high extraction efficiency, high protein yieldThis plant protein extraction kit can extract soluble plant proteins from fresh, frozen, or dried plant tissues. Suitable for protein extraction from various plants and different parts of plants (such as roots, stems, leaves, flowers, seeds, etc.), with high extraction efficiency, high protein yield, high activity, and fast speed. The extracted protein can be directly subjected to protein electrophoresis analysis, immunoprecipitation, Western Blot, protein activity determination, and protein purification experiments. The concentration of the extracted protein can be determined using the BCA protein quantification kit. P665757Component100 TStorageP665757APlant Protein Extraction Reagent100 mLRTP665757BProtease Inhibitor Cocktail (100×)1 mL-20℃. Avoid freeze/thaw cycle. Precautions：1. This product contains 1mM EDTA.2. To prevent protein degradation, all operations should be carried out on ice as much as possible.3. After extracting protein using this product, the BCA method can be used for protein quantification.4. To achieve the best experimental results, please adjust the optimal usage amount according to the experiment.Operation steps:1. Please remove the required Plant Protein Extraction Agent for pre cooling before protein extraction.2. Weigh the weight of the experimental plant tissue. Add 5 ml of Plant Protein Extraction Agent to 1 g of tissue (add Protein Inhibitor Cocktail in a 1:99 ratio before protein extraction).Attention:1) Before homogenization, cut large pieces of plant tissue into small pieces and homogenize them with a mechanical homogenizer for 10 seconds, with an interval of 10 seconds. Repeat the process three times and select the appropriate homogenization method according to the different tissue samples.2) The amount of lysate used is adjusted according to different parts of the plant. If concentrated protein extracts are needed, the amount of Plant Protein Extraction Agent used can be appropriately reduced.3. After homogenization, incubate on ice for 20-30 minutes.4.4 ℃ 13400 × g, centrifuge for 20 minutes.5. Collect soluble proteins from the supernatant for further purification or downstream analysis... Read More | Products R669890Component50 TStorageR669890ADNase I1000 U-20℃. Avoid freeze/thaw cycle.R669890B10×Reaction Buffer1mL-20℃. Avoid freeze/thaw cycle.R669890CBuffer RL35 mLRTR669890DBuffer RW140 mLRTR669890EBuffer RW2 (concentrate)11 mLRTR669890FRNase-Free Water10 mLRTR669890GSpin Products R669890Component50 TStorageR669890ADNase I1000 U-20℃. Avoid freeze/thaw cycle.R669890B10×Reaction Buffer1mL-20℃. Avoid freeze/thaw cycle.R669890CBuffer RL35 mLRTR669890DBuffer RW140 mLRTR669890EBuffer RW2 (concentrate)11 mLRTR669890FRNase-Free Water10 mLRTR669890GSpin Columns FL with Collection Tubes50 setsRTR669890HSpin Columns RM with Collection Tubes50 setsRTR669890IRNase-Free Centrifuge Tubes (1.5 mL)100 EART ProductsThis kit adopts centrifugal adsorption columns with high efficiency and specificbinding of nucleic acids and unique buffer system, which can rapidly extract totalRNA from bacteria or cultured animal cells.The reaction can be completed in 30-40minutes, and the extracted total RNA is extremely pure and free of protein and othercontaminants, which is suitable for RT-PCR, Real-Time RT-PCR, microarray analysis,in vitro translation and other experiments. Self-contained reagents: Lysozyme, β-mercaptoethanol, anhydrous ethanol (freshlyopened or for RNA extraction). Pre-experiment Preparation and Important Notes 1. To prevent RNase contamination, attention should be paid to the following aspects:1) Use RNase-free plastics and tips to avoid cross-contamination. 2) RNase-free water should be used to prepare the solution. 3) Operators wear disposable masks and gloves, and change gloves diligently duringthe experiment. 2. Add β-mercaptoethanol to Buffer RL before use to reach a final concentrationof 1%, e.g., add 10 µl of β-mercaptoethanol to 1 ml of Buffer RL. Buffer RL withβ-mercaptoethanol can be stored at 4℃ for 1 month, if precipitation occurs, pleaseheat to dissolve and use.3. Anhydrous ethanol should be added to Buffer RW2 before first use according tothe instructions on the reagent bottle label. 4. All centrifugation steps are carried out at room temperature if not otherwisespecified, and all steps should be performed quickly. Procedure 1. Centrifuge at 12,000 rpm (~13,400 x g) at 4°C for 2 minutes to collect theorganisms (maximum volume of organisms should not exceed 1 x 109) and carefullyremove all supernatants. Note: Supernatants that leave residues can interfere with the subsequent digestionprocess. 2. Thoroughly resuspend the organisms with 100 µl of TE buffer containing Lysozymeand incubate at room temperature. The specific formulation and incubation time areas follows:/The final concentration of Lysozyme in TE bufferincubation timeG-germ400µg/ml3-5minG+germ3mg/ml5-10min 3. Add 350 µl of Buffer RL (check that β-mercaptoethanol has been added beforeuse), vortex and shake to mix (insoluble precipitate may appear in this step), addall of the solution and the precipitate to the filter columns (Spin Columns FL) thathave been loaded into the collection tubes, and centrifuge at 12,000 rpm for 2minutes. 4. Add 250 µl of anhydrous ethanol to the filtrate obtained in the previous stepand mix well (a precipitate may appear at this point). Transfer the resulting solution together with the precipitate to a Spin Columns RM packed in a collectiontube, centrifuge at 12,000 rpm for 1 min, discard the waste solution and put thecolumn back into the collection tube.5. Add 350 µl Buffer RW1 to the adsorbent column, centrifuge at 12,000 rpm for1min, discard the waste liquid and put the adsorbent column back into the collectiontube.6. Preparation of DNase I mixture: Take 52µl of RNase-Free Water, add 8µl of 10×Reaction Buffer and 20µl of DNase I (1U/µl) to it, mix well, and make a finalvolume of 80µl of reaction solution.7. Add 80µl of DNase I mixture directly to the adsorption column and incubate at20-30°C for 15 minutes.8. Add 350 µl Buffer RW1 to the adsorbent column, centrifuge at 12,000 rpm for1min, discard the waste liquid and put the adsorbent column back into the collectiontube.9. Add 500 µl of Buffer RW2 to the column (check that anhydrous ethanol is addedbefore use), centrifuge at 12,000 rpm for 1 min, and discard the waste solution.10. Repeat step 9.11. Place the adsorbent column back into the collection tube and centrifuge at 12,000rpm for 2 minutes. Note: The purpose of this step is to remove residual ethanol from the adsorptioncolumn; ethanol residue can interfere with subsequent enzymatic reactions (zymography, PCR, etc.).12. Load the adsorption column into a new RNase-Free collection tube, add 30-50 µl of RNase-Free Water to the middle of the adsorption membrane, leave it at roomtemperature for 1 minute, centrifuge at 12,000 rpm for 1 minute, collect the RNAsolution, and store the RNA at -70°C to prevent degradation. Note: 1) The volume of RNase-Free Water should not be less than 30 µl, too smallvolume affects the recovery rate. 2) If you want to increase the RNA yield, repeat step 12 with 30-50 µl of freshRNase-Free Water. If the RNA concentration is to be increased, the resulting solution can be reintroduced into the adsorption column and step 12 repeated... 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 |