| Description | Phosphoenolpyruvate Carboxykinase (PEPCK, EC 4.1.1.32) is widely present in animals, plants, microorganisms, and cells. It catalyzes the conversion of oxaloacetate to phosphoenolpyruvate and is a key regulatory enzyme in the gluconeogenesis pathway.Assay PrinciplePEPCK catalyzes the conversion of Phosphoenolpyruvate Carboxykinase (PEPCK, EC 4.1.1.32) is widely present in animals, plants, microorganisms, and cells. It catalyzes the conversion of oxaloacetate to phosphoenolpyruvate and is a key regulatory enzyme in the gluconeogenesis pathway.Assay PrinciplePEPCK catalyzes the conversion of Oxaloacetate to Phosphoenolpyruvate and CO₂. Pyruvate Kinase and Lactate Dehydrogenase subsequently catalyze the sequential oxidation of NADH to NAD⁺. The rate of decrease in NADH absorbance at 340 nm is measured, which reflects PEPCK activity.Component100TStorageExtraction Buffer100 mL2-8℃Reagent 118 mL2-8℃Reagent 216.5 µL2-8℃Reagent 31EA-20℃Reagent 41EA-20℃Required Materials and Equipment (Not Provided)Spectrophotometer / Microplate reader, benchtop centrifuge, adjustable pipettes, micro quartz cuvette / 96-well plate, mortar and pestle, ice, and distilled water.Sample Preparation:1.Bacteria or Cultured Cells:Collect cells by centrifugation and discard the supernatant.Add Extraction Buffer at a ratio of 1 ml per 5-10 million cells (e.g., 1 ml for 5 million cells).Sonicate on ice (20% power or 200W, pulse 3s on/10s off, repeat 30 times).Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.2.Tissues:Homogenize tissue on ice in Extraction Buffer at a ratio of 1:5-10 (w/v) (e.g., 0.1 g tissue in 1 ml buffer).Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.3.Serum (or Plasma) Samples:Assay directly.Assay Procedure:1.Preheat the spectrophotometer or microplate reader for at least 30 minutes. Set the wavelength to 340 nm. Zero the instrument with distilled water.2.Preparation of Working Solution: Just before use, transfer and dissolve Reagent 2 and Reagent 3 into Reagent 1. Mix well. Aliquot and store any unused portions at -20°C. Avoid repeated freeze-thaw cycles.3.Preparation of Reagent 4: Just before use, dissolve the contents of the vial in 1 ml of distilled water. Mix well. Aliquot and store any unused portions at -20°C. Avoid repeated freeze-thaw cycles.4.Pre-warm the Working Solution and dissolved Reagent 4 at 37°C (for mammalian samples) or 25°C (for other species) for 5 minutes.5.In a micro quartz cuvette or a well of a 96-well plate, add:10 µl sample10 µl dissolved Reagent 4180 µl pre-warmed Working SolutionMix immediately and record the initial absorbance (A₁) at 340 nm. Record the absorbance again (A₂) after exactly 1 minute. Calculate ΔA = A₁ - A₂.Note: For this kit, if ΔA is greater than 0.1, dilute the sample with Extraction Buffer by an appropriate factor (account for this dilution factor 'n' in the calculations) so that ΔA is less than 0.1 to improve detection sensitivity.PEPCK Activity Calculation:1. Calculation for Micro Quartz Cuvette (d = 1.0 cm)General Parameters for Cuvette:Vₜₒₜₐₗ (Total reaction volume) = 0.0002 L (200 µL)ε (NADH molar extinction coefficient) = 6220 L/mol/cmd (Cuvette light path) = 1.0 cmVₛₐₘₚₗₑ (Sample volume in reaction) = 0.01 mL (10 µL)T (Reaction time) = 1 minVₛₐₘₚₗₑₜₒₜₐₗ (Total extract volume) = 1 mL (for tissues/cells)Cpr (Sample protein concentration, mg/mL)W (Sample mass, g)500 (Cell/Bacteria count in millions for example calculation: 5 million)a. For Serum (Plasma):Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per ml of serum.Calculation:PEPCK Activity (nmol/min/ml) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ Vₛₐₘₚₗₑ ÷ TSimplified Formula: PEPCK (nmol/min/ml) = 3215 × ΔAb. For Tissues, Bacteria, or Cells:Based on Sample Protein Concentration:Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per mg of protein.Calculation:PEPCK Activity (nmol/min/mg prot) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (Vₛₐₘₚₗₑ × Cpr) ÷ TSimplified Formula: PEPCK (nmol/min/mg prot) = 3215 × ΔA ÷ CprBased on Sample Fresh Weight:Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per gram of fresh tissue.Calculation:PEPCK Activity (nmol/min/g fresh weight) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (W × Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ) ÷ TSimplified Formula: PEPCK (nmol/min/g fresh weight) = 3215 × ΔA ÷ WBased on Bacterial or Cell Density:Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per 10⁴ cells.Calculation (example for 5 million cells in 1 ml extract):PEPCK Activity (nmol/min/10⁴ cell) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (500 × Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ) ÷ TSimplified Formula: PEPCK (nmol/min/10⁴ cell) = 6.43 × ΔA2. Calculation for 96-Well Plate (d = 0.5 cm)General Parameters for 96-Well Plate:(All parameters remain the same except for the light path 'd')d (96-well plate light path) = 0.5 cma. For Serum (Plasma):Simplified Formula: PEPCK (nmol/min/ml) = 6430 × ΔAb. For Tissues, Bacteria, or Cells:Based on Sample Protein Concentration:Simplified Formula: PEPCK (nmol/min/mg prot) = 6430 × ΔA ÷ CprBased on Sample Fresh Weight:Simplified Formula: PEPCK (nmol/min/g fresh weight) = 6430 × ΔA ÷ WBased on Bacterial or Cell Density:Simplified Formula: PEPCK (nmol/min/10⁴ cell) = 12.86 × ΔAPrecautionsBefore formal assay, it is essential to perform a pilot test with 2-3 samples expected to have significant differences in activity... Read More | B669951 Component 50T Storage B669951A Buffer ATL 15 mL RT B669951B Buffer AL 15 mL RT B669951C Buffer AW1 (concentrate) 13 mL RT B669951D Buffer AW2 (concentrate) 15 mL RT B669951E Buffer EB 15 mL RT B669951F Proteinase K 1.25 mL RT B669951G Spin Columns DM with Collection Tubes 50 sets B669951 Component 50T Storage B669951A Buffer ATL 15 mL RT B669951B Buffer AL 15 mL RT B669951C Buffer AW1 (concentrate) 13 mL RT B669951D Buffer AW2 (concentrate) 15 mL RT B669951E Buffer EB 15 mL RT B669951F Proteinase K 1.25 mL RT B669951G Spin Columns DM with Collection Tubes 50 sets RTProductsThis kit is suitable for extracting high purity total DNA from Gram-negative and Gram-positive bacteria. 106-108 cells can be processed at a time, and up to 20 µg of total DNA can be obtained within one hour without the need for toxic solvents such as phenol or chloroform, and without the need for ethanol precipitation. The optimized buffer system enables the DNA in the lysate to be efficiently and specifically bound to the silica matrix centrifugal adsorption column, while other contaminants can flow through the membrane, and the inhibitors of PCR and other enzymatic reactions can be effectively removed through a two-step washing step, and finally washed off with low-salt buffer or water, so that high-purity DNA can be obtained.The purified DNA can be used for downstream experiments such as digestion, PCR, Real-Time PCR, library construction, Southern Blot and molecular labeling, molecular labeling and other downstream experiments. Self-contained reagents: anhydrous ethanol; Enzymatic Lysis Buffer is required for extraction of Gram-positive bacteria.Enzymatic Lysis Buffer was prepared by 20 mM Tris, pH 8.0; 2 mM Na2-EDTA, pH 8.0; and 1.2% Triton X-100. 121°C sterilization for 20 minutes, and the appropriate amount of Lysozyme was added at a final concentration of 20 mg/ml. Pre-experiment Preparation and Important Notes1. Add 1.25ml Proteinase K Storage Buffer to Proteinase K to dissolve it and store it at -20℃. Do not leave the prepared Proteinase K at room temperature for a long time, and avoid repeated freezing and thawing to avoid affecting its activity.2. Repeated freezing and thawing of the sample should be avoided, as this may result in smaller DNA fragments and a decrease in the amount of extracted DNA.3. If extracting genomes from bacterial cultures with high accumulation of secondary metabolites or thick cell walls, it is recommended that samples be collected early in the logarithmic phase.4. Anhydrous ethanol should be added to Buffer GW1 and Buffer GW2 according to the instructions on the label of the reagent bottle before first use.5. Before use, please check Buffer GTL and Buffer GL for crystallization or precipitation. If crystallization or precipitation occurs, please re-dissolve Buffer GL and Buffer GTL in a 56℃ water bath.6. If the downstream experiments are sensitive to RNA contamination, 4µl of DNase-Free RNase A (100mg/ml) can be added before adding Buffer GL. RNase A is not provided in this kit.If the extracted samples are Gram-positive bacteria, customers need to prepare their own Enzymatic Lysis Buffer to treat the bacteria, which requires the use of Lysozyme (lysozyme) at a concentration of 20 mg/ml, which is not provided in this kit.Procedurei Extraction of genomic DNA from Gram-negative bacteria1. Take 1-5 ml of bacterial culture (106-108 cells, maximum 2×109 cells) and put it into a centrifuge tube (provided), centrifuge it at 12,000 rpm (~13,400×g) for 1 minute, and aspirate the supernatant as much as possible.2. Add 180 µl Buffer GTL to the precipitate and shake to resuspend the bacteria.3. Add 20 µl of Proteinase K, vortex and mix well, incubate at 56°C until the solution becomes clear, and invert or shake the centrifuge tube at intervals during the incubation to disperse the sample.Note: If RNA removal is required, add 4 µl of RNase A solution at a concentration of 100 mg/ml after the above steps are completed, shake to mix, and leave for 5-10 minutes at room temperature.4. Add 200µl Buffer GL and mix well with vortexing and shaking. Add 200µl of anhydrous ethanol and mix well with vortexing and shaking.Centrifuge briefly so that the solution on the walls of the tube collects at the bottom.Note: 1) If multiple samples are manipulated together, Buffer GL and anhydrous ethanol can be mixed in equal proportions and then added together, shaking to mix.2) The addition of Buffer GL and anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.5. Add all of the solution obtained in step 4 (including the precipitate formed) to the Spin Columns DM in the collection tube, or if the solution cannot be added all at once, transfer it several times. centrifuge at 12,000 rpm for 1 minute, discard the waste solution, and return the column to the collection tube.6. Add 500 µl of Buffer GW1 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and return the adsorption column to the collection tube.7. Add 500 µl of Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.Note: Step 7 can be repeated if further DNA purity is required.8. Centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Leave the adsorbent column at room temperature for several minutes to dry thoroughly. Note: The purpose of this step is to remove residual ethanol from the adsorbent column; ethanol residue can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).9. Place the adsorption column in a new centrifuge tube, add 50-200 µl Buffer GE to the middle part of the adsorption column overhanging the center of the adsorption column, leave it at room temperature for 2-5 minutes, centrifuge it at 12,000 rpm for 1 minute, collect the DNA solution, and store the DNA at -20 ℃. note: 1) If the downstream experiments are sensitive to the pH or EDTA, the elution can be done with sterilized water. The pH of the elution solution has a great influence on the elution efficiency. If water is used as the elution solution it should be ensured that its pH is 7.0-8.5 (the pH of water can be adjusted to this range with NaOH), and the elution efficiency is not high when the pH is lower than 7.0.2) Incubation at room temperature for 5 minutes prior to centrifugation increases yield.3) Re-elution with an additional 50-200 µl Buffer GE or sterilized water can increase the yield.4) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 9 can be re-spiked onto the adsorbent membrane and step 9 repeated; if the elution volume is less than 200 µl, the final concentration of DNA can be increased, but the total yield may be reduced. If the amount of DNA is less than 1 µg, elution with 50 µl Buffer GE or sterilized water is recommended.(5) DNA stored in water will be affected by acidic hydrolysis. For long-term storage, it is recommended to elute with Buffer GE and store at -20℃.i. Extraction of genomic DNA from Gram-positive bacteria1. Take 1-5 ml of bacterial culture (106-108 cells, maximum 2×109 cells) and put it into a centrifuge tube (provided), centrifuge it at 12,000 rpm (~13,400×g) for 1 minute, and aspirate the supernatant as much as possible.2. Add 180µl Enzymatic Lysis Buffer (self-provided) to resuspend the bacteria.Enzymatic Lysis Buffer is prepared as described in the Self-Prepared Reagents section in the front of the manual.3. Incubate at 37°C for 30 minutes.4. Add 20µl Proteinase K and mix well. Add 200µl of Buffer GL and mix well with vortexing and shaking.Note: Do not add Proteinase K directly to Buffer GL.Incubate at 5.56°C for 30 minutes.Note: 1) If desired, incubation at 95°C for 15 minutes will inactivate the pathogen, but 95°C incubation will cause some DNA degradation.(2) If RNA removal is required, add 4µl of RNase A solution at a concentration of 100mg/ml after the above steps are completed, shake and mix well, and leave for 5-10 minutes at room temperature.6. Add 200µl of anhydrous ethanol and mix well with vortex shaking.Note: The addition of anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.7. Add all of the solution obtained in step 6 (including the precipitate formed) to the Spin Columns DM that have been loaded into the collection tube, and if the solution cannot be added all at once, it can be transferred in several times. centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid from the collection tube, and put the column back into the collection tube.8. Add 500 µl of Buffer GW1 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.9. Add 500 µl Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge the column at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the column back into the collection tube.Note: Step 9 can be repeated if further DNA purity is required.10. Centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Leave the adsorption column at room temperature for several minutes to dry thoroughly.Note: The purpose of this step is to remove residual ethanol from the adsorption column; ethanol residue can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).11. Place the adsorption column in a new centrifuge tube (self-provided), add 50-200 µl of Buffer GE to the center of the adsorption column overhanging the center of the adsorption column, let it stand at room temperature for 2-5 minutes, centrifuge at 12,000 rpm for 1 minute, collect the DNA solution, and store the DNA at -20℃.Note: 1) If the downstream experiment is sensitive to pH or EDTA, you can use sterilized water for elution. The pH of the eluent has a great influence on the elution efficiency, if water is used as the eluent should ensure that its pH is 7.0-8.5 (you can use NaOH to adjust the pH of the water to this range), and the elution efficiency is not high when the pH is lower than 7.0.2) Incubation at room temperature for 5 minutes prior to centrifugation increases yield.3) Re-elution with an additional 50-200 µl Buffer GE or sterilized water can increase the yield.4) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 11 can be re-spiked onto the adsorbent membrane and step 11 repeated; if the elution volume is less than 200 µl, the final concentration of DNA can be increased, but the total yield may be reduced. If the amount of DNA is less than 1 µg, elution with 50 µl Buffer GE or sterilized water is recommended.(5) DNA stored in water will be affected by acidic hydrolysis. For long-term storage, it is recommended to elute with Buffer GE and store at -20℃... Read More | Products contentN665730Component24 T96 TStorageN665730ATPS V50 144 µL576 µL-20℃. Avoid freeze/thaw cycle.N665730B5×FA Reaction Buffer144 µL576 µL-20℃. Avoid freeze/thaw cycle.N665730C2×HiFidelity PCR Mix600 µL2×1.2 mL-20℃. Avoid freeze/thaw Products contentN665730Component24 T96 TStorageN665730ATPS V50 144 µL576 µL-20℃. Avoid freeze/thaw cycle.N665730B5×FA Reaction Buffer144 µL576 µL-20℃. Avoid freeze/thaw cycle.N665730C2×HiFidelity PCR Mix600 µL2×1.2 mL-20℃. Avoid freeze/thaw cycle.N665730DPPM48 µL192 µL-20℃. Avoid freeze/thaw cycle.* This kit is suitable for human genomic DNA library construction with a starting template DNA input of 50 ng. We also have transposase library construction kits for human genomic DNA starting at 5 ng and 1 ng, so it is recommended to use different kits for different starting amounts of DNA in order to obtain higher quality libraries. Products IntroductionThis kit is developed for Illumina's high-throughput sequencing platform and provides the enzyme premix system and reaction buffer for genomic DNA library construction, including all components except PCR primers. Compared with the traditional library construction kits, this kit adopts the new transposase method for library construction, which can complete DNA fragmentation, end repair and junction reaction in one simple enzymatic reaction, significantly reducing the amount of template, reducing the number of experimental steps, and shortening the time of library construction; it adopts the high-fidelity DNA polymerase for library enrichment, and the preference-free PCR amplification can expand the coverage area of the sequence, which can be used for efficient and effective sequencing. The use of high-fidelity DNA polymerase for library enrichment and preference-free PCR amplification broadens the coverage area of the sequence and enables efficient preparation of DNA libraries for Illumina's second-generation sequencing platform. The kit is suitable for DNA libraries with a starting template of 50 ng, and all reagents in the kit have been subjected to strict quality control and functional validation to maximize the stability and reproducibility of library construction. Product Features ● DNA fragmentation and junction ligation in one step.● Ultra-fidelity amplification minimizes amplification-preferred steps.Provide your own instruments, kits and consumables1. Magnetic frame: DynaMagTM-2 is recommended.2. DNA purification and recovery kit: It is recommended to use DNA purification and recovery kit by magnetic bead method.3. Library PCR primer kits: transposase method for second-generation sequencing multi-sample primer kits are recommended. 4. Anhydrous ethanol, deionized water (pH between 7.0 and 8.0).5. Reaction tubes: It is recommended to use low adsorption PCR tubes and 1.5 ml centrifuge tubes. Tips: It is recommended to use high quality filter tips to prevent contamination of kits and library samples. Pre-experiment Preparation and Important Notes1. Avoid repeated freezing and thawing of reagents.2. PCR products are easily contaminated due to improper operation, resulting in inaccurate results. It is recommended to isolate the PCR reaction system preparation area from the PCR product purification area, and to use special pipettes to clean the experimental areas at regular intervals.3. Bead purification: the beads should be equilibrated to room temperature before use, all operations on the beads should be carried out at room temperature, 80% ethanol should be dispensed freshly, the beads should be rinsed and dried until the surface is free of liquid reflections and has a frosted appearance, insufficient drying of the beads will cause ethanol residue that will affect the subsequent experiments, and over-drying of the beads will affect the efficiency of DNA recovery.4. The kit is suitable for human genomic DNA library construction, if the DNA sample is a PCR product, it should be ensured that its length>.500 bp, since transposases do not work on DNA ends, it is recommended to extend the PCR product by 50-100 bp at each end of the PCR product to avoid low coverage of the ends for sequencing.Sample PreparationDNA purity requirements: A260/A280 = 1.8-2.0. Sample DNA: dissolve in ultrapure water. DNA Quantification: Too much or too little DNA will affect the quality of the library. It is recommended to use Nano to test the purity of the genomic DNA and then use Qubit to test the concentration of the genome (do not use any absorbance-based assay for template quantification).Schematic diagram of DNA banking processprocedureDNA fragmentation, junction reaction1. Add the following reagents to a 200 µl PCR tube: 2. Mix by gently blowing with a pipette and centrifuge briefly so that all components are collected at the bottom of the tube.3. Place the above PCR tubes in the PCR instrument with the hot cap on and program the reaction as follows:DNA should be purified immediately after the fragmentation reaction has been performed and the transposase is still in a high state of activity.to prevent smaller library fragments due to DNA over-fragmentation. Purification of fragmentation productsWe recommend the use of the Century Magnetic Bead Method DNA Purification and Recovery Kit.1. CMPure should be equilibrated at room temperature for 30 min after shaking and mixing before use.2. Add 50 µl of magnetic beads equilibrated to room temperature to the fragmentation product, vortex and shake for 5 seconds, then let stand at room temperature for 5 minutes.3. Centrifuge briefly, place the tube on a magnetic rack to separate the beads from the supernatant solution until the solution is clear (approximately 3-5 minutes), carefully aspirate the supernatant and discard, avoiding contact with the beads that have bound the target DNA. Note: Do not discard the beads.4. Continue to keep the centrifuge tube fixed on a magnetic rack and add 200 µl of freshly prepared 80% ethanol to the centrifuge tube and allow to stand at room temperature for 30 seconds, carefully discarding the supernatant.Note: When adding ethanol, the liquid must not be blown directly onto the beads.5. Repeat step 4.6. Keep the centrifuge tube fixed on a magnetic rack and leave to dry at room temperature until the surface of the beads is slightly cracked, then add 23 µlddH2O to solubilize.Note: Do not over-dry the beads as this may affect the elution efficiency.7. Remove the tube from the magnetic rack, vortex to completely resuspend the beads, and allow to stand at room temperature for 5 minutes. Centrifuge briefly, place the tube on the magnetic rack until the solution is clear, and transfer 21 µl of supernatant to a new 200 µl PCR tube.PCR amplification Add the following reagents to the 200 µl PCR tube: Mix by gently blowing with a pipette and centrifuge briefly so that all components are collected at the bottom of the tube.3. Place the above PCR tubes in the PCR instrument with the hot cap on and program the reaction as follows:Selective recovery of library DNA fragmentsIt is recommended to use CombiVision Magnetic Beads DNA Purification and Recovery Kit for selective recovery of DNA fragments. When different sizes of DNA fragments are required, the amount of magnetic beads to be used is different, please refer to the attached table for the specific amount of magnetic beads to be used (if other brands of magnetic beads are used, you need to find out the optimal amount of magnetic beads to be used on your own).Note: Amplification products can also be fragment length sorted and purified using the Gum Recovery Kit. If there is no special requirement for library length distribution, the amplification products can also be purified without selective recovery of DNA fragments as described on page 6 of the manual.1. CMPure should be equilibrated at room temperature for 30 min after shaking and mixing before use.2. Transfer the PCR product to a 1.5 ml centrifuge tube, rehydrate to 100 µl and add several volumes of magnetic beads equilibrated to room temperature, vortex for 5 seconds and let stand at room temperature for 5 minutes.3. Centrifuge briefly, place the tube on a magnetic rack to separate the beads from the supernatant until the solution is clear, and carefully aspirate the supernatant and transfer it to a new 1.5 ml centrifuge tube.Note: Do not discard the top clear.4. Add several volumes of magnetic beads to the supernatant, vortex and shake for 5 seconds, then let stand at room temperature for 5 minutes.5. Centrifuge briefly, place the tube on a magnetic rack to separate the beads from the supernatant until the solution is clear, carefully aspirate the supernatant and discard it, avoiding contact with the beads that have bound the target DNA.Note: Do not discard the beads.6. Continue to keep the centrifuge tube fixed on a magnetic rack and add 200 µl of freshly prepared 80% ethanol to the tube and allow to stand at room temperature for 30 seconds, carefully discarding the supernatant.Note: When adding ethanol, the liquid must not be blown directly onto the beads.7. Repeat step 6 once.8. Keep the centrifuge tube fixed on a magnetic rack and leave to dry at room temperature until the surface of the beads is slightly cracked, add 20 µl of ddH2O to solubilize.Note: Do not over-dry the beads as this may affect the elution efficiency.9. Remove the centrifuge tube from the magnetic rack, vortex and oscillate to completely resuspend the beads, and let stand at room temperature for 5 minutes. Leave brieflycentrifuge, place the tube on a magnetic rack until the solution is clear, and transfer the supernatant solution to a new centrifuge tube. Table: Suggested amount of magnetic beads for different segment selection recoveryLibrary DNA fragment purificationWe recommend the use of the Century Magnetic Bead Method DNA Purification and Recovery Kit.1. CMPure should be equilibrated at room temperature for 30 min after shaking and mixing before use.2. 50 µl of magnetic beads equilibrated to room temperature were added to the PCR product, vortexed and shaken for 5 seconds, and then left to stand at room temperature for 5 minutes.3. Centrifuge briefly, place the tube on a magnetic rack to separate the beads from the supernatant solution until the solution is clear (approximately 3-5 minutes), carefully aspirate the supernatant and discard it, avoiding contact with the beads that have bound the target DNA. Note: Do not discard the beads.4. Continue to keep the centrifuge tube fixed on a magnetic rack and add 200 µl of freshly prepared 80% ethanol to the centrifuge tube and allow to stand at room temperature for 30 seconds, carefully discarding the supernatant.Note: When adding ethanol, the liquid must not be blown directly onto the beads.5. Repeat step 4.6. Keep the centrifuge tube fixed on a magnetic rack and leave to dry at room temperature until the surface of the beads is slightly cracked, add 25 µl of ddH2O to solubilize.Note: Do not over-dry the beads as this may affect the elution efficiency.7. Remove the tube from the magnetic rack, vortex to completely resuspend the beads, and allow to stand at room temperature for 5 minutes. Centrifuge briefly, place the tube on the magnetic rack until the solution is clear, and transfer the supernatant solution to a new tube.Library quality controlDetermination of library concentrationIn order to obtain high-quality sequencing results, accurate quantification of DNA libraries is required, and the first recommendation is to use Real-timePCR methods are used for absolute quantification of DNA libraries. Additionally, fluorescent dye methods such as the Qubit method or the fluorescent dye picogreen method can be used; do not use quantification methods based on absorbance measurements here. The following approximate formula can be used to convert the molar concentration of the DNA library. Average total length of librariesApproximate conversion formula Library fragment distributionThe prepared DNA libraries can be detected by agarose gel electrophoresis or Agilent 2100 Bioanalyzer.Range of segment length distributions... Read More | This reagent kit uses an adsorption column that can specifically bind to viral RNA and a unique buffer system, suitable for isolating viral RNA from cell-free body fluids such as serum, plasma, urine, cerebrospinal fluid, and cell culture supernatants. The viral RNA specifically binds to the siliconThis reagent kit uses an adsorption column that can specifically bind to viral RNA and a unique buffer system, suitable for isolating viral RNA from cell-free body fluids such as serum, plasma, urine, cerebrospinal fluid, and cell culture supernatants. The viral RNA specifically binds to the silicon substrate membrane, and pollutants flow through the membrane. Completely remove impurities such as proteins through two efficient washes, and then wash high-purity viral RNA with RNase free water or RNase Free Water provided by the reagent kit. The virus RNA extracted by this kit can be directly used for experiments such as RT-PCR, Real time RT-PCR, and Western blot analysis. R666005Component50 TStorageR666005ABuffer GL15 mLRTR666005BBuffer RW140 mLRTR666005CBuffer RW2（concentrate）11 mLRTR666005DProteinase K12.5 mgRTR666005EProteinase K Storage Buffer1.25 mLRTR666005FRNase-Free Water10 mLRTR666005GSpin Columns RS with Collection Tubes50 setsRTR666005HRNase-Free Centrifuge Tubes（1.5 mL）50 EART Self prepared reagent: anhydrous ethanol, 0.9% NaCl.Preparation and important precautions before the experiment1. Add 1.25 ml of Protein K Storage Buffer to Protein K to dissolve it and store at -20 ℃. The prepared Protein K should not be left at room temperature for a long time to avoid repeated freeze-thaw cycles, which may affect its activity.2. To prevent RNase pollution, attention should be paid to the following aspects:1) Use RNase free plastic products and gun heads to avoid cross contamination.2) Glassware should be dry baked at a high temperature of 180 ℃ for 4 hours before use, while plastic containers can be soaked in 0.5 M NaOH for 10 minutes, thoroughly rinsed with water, and then sterilized under high pressure.3) Prepare the solution using water without RNase.4) Operators should wear disposable masks and gloves, and change gloves frequently during the experiment.3. Serum or plasma should avoid repeated freeze-thaw cycles that may cause protein denaturation or precipitation, reduce viral titers, and thus affect the yield of extracted viral nucleic acids.4. Before the first use, anhydrous ethanol should be added to Buffer RW2 according to the instructions on the reagent bottle label.5. If buffer GL precipitates, it can be heated at 56 ℃ to dissolve and then placed at room temperature.6. All centrifugation steps should be carried out at room temperature unless otherwise specified, and all operation steps should be carried out quickly.Operation steps1. Take 200 at room temperature µ Add serum or plasma to a 1.5 ml centrifuge tube (self provided). Attention: Less than 200 µ 0.9% NaCl (provided by the customer) can be added to make up for it.2. Add 20 to the solution in the previous step µ Protein K, mix well.3. Add 200 µ L Buffer GL, vortex oscillation for 15 seconds. Note: Do not directly add Protein K to Buffer GL. 4. Incubate at 56 ℃ for 15 minutes, briefly centrifuge, and collect the solution on the tube wall to the bottom of the tube.5. Add 250 µ Anhydrous ethanol, vortex for 15 seconds, incubate at room temperature for 5 minutes, briefly centrifuge, and collect the solution from the tube wall to the bottom of the tube.6. Add all the solution obtained in step 5 to the Spin Columns RS that have been loaded into the collection tube. If it is not possible to add all the solution to the adsorption column at once, please transfer it in two batches, centrifuge at 12000 rpm (~13400 × g) for 1 minute, discard the waste liquid in the collection tube, and put the adsorption column back into the collection tube.7. Add 500 to the adsorption column µ Centrifuge at 12000 rpm for 1 minute, discard the waste liquid from the collection tube, and place the adsorption column back into the collection tube.8. Add 500 to the adsorption column µ Buffer RW2 (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.9. Add 500 to the adsorption column µ Centrifuge anhydrous ethanol at 12000 rpm for 1 minute, discard the waste liquid from the collection tube, and place the adsorption column back into the collection tube. 10. Centrifuge at 12000 rpm for 3 minutes and discard the waste liquid from the collection tube. Place the adsorption column at room temperature for a few minutes to thoroughly air dry.Attention:1) The purpose of this step is to remove residual ethanol from the adsorption column, which will affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).2) Recommended steps: Place the adsorption column into a new 1.5 ml centrifuge tube (provided), open the tube cover, and incubate in a 56 ℃ oven for 3 minutes to thoroughly dry the membrane of the adsorption column.11. Place the adsorption column in a new RNase free centrifuge tube and add 20-50 to the middle of the adsorption column in the air µ Place RNase Free Water at room temperature for 5 minutes, centrifuge at 12000 rpm for 1 minute, collect RNA solution, and store RNA at -70 ℃ to prevent degradation.Attention:1) The volume of RNase Free Water should not be less than 20 µ l. Small volume affects the recovery rate.2) If you want to increase RNA production, you can use 20-50 µ Repeat step 11 for the new RNase Free Water.3) If you want to increase the RNA concentration, you can add the obtained solution back to the adsorption column and repeat step 11... 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 |