| Description | Product content Q665687Component100 TStorageQ665687AQuick T4 DNA Ligase (15 U/µL)100 µL-20℃. Avoid freeze/thaw cycle.Q665687B2×Quick Ligation Reaction Buffer5×200 µL-20℃. Avoid freeze/thaw cycle. Product IntroductionThe Quick Ligation Reaction Kit allows ligationProduct content Q665687Component100 TStorageQ665687AQuick T4 DNA Ligase (15 U/µL)100 µL-20℃. Avoid freeze/thaw cycle.Q665687B2×Quick Ligation Reaction Buffer5×200 µL-20℃. Avoid freeze/thaw cycle. Product IntroductionThe Quick Ligation Reaction Kit allows ligation of DNA sticky or flush ends in 5 minutes at room temperature (25°C). The kit contains Quick T4 DNA Ligase and 2×Quick Ligation Reaction Buffer optimized for fast and efficient DNA ligation.The ligation efficiency of Quick Ligation is equivalent to 1 hour of conventional ligation with T4 DNA Ligase. The Quick Ligation products can be used directly in routine bacterial transformation experiments.matters needing attention1. This kit enables most of the linkage reactions to reach the reaction endpoint within 5 minutes or less at 25°C. Increasing the reaction time will not enhance the reaction efficiency. If you use the rapid connection reaction after 1 hour, the conversion efficiency will be significantly reduced; if the rapid connection reaction at 25 ℃ overnight, the conversion efficiency will drop to 75%.2. 2×Quick Ligation Reaction Buffer contains ATP, which should be thawed on ice and mixed thoroughly before use. It is recommended to freeze the buffer in small tubes for the first time, so as to avoid repeated freezing and thawing, which will affect the efficiency of DNA ligation.3. Since T4 DNA Ligase contains glycerol, which is sticky and easy to hang on the wall, it is recommended to collect the liquid to the bottom of the tube by centrifugation for a short period of time before use, and the tip of the lance should not go too deep into the liquid surface when taking samples to avoid sticking to the tip of the lance and causing losses.4. If the quick ligation product is used for electrotransformation, the PEG in the quick ligation reaction system will affect the efficiency of electrotransformation, and it is recommended to use a centrifugal column to purify the ligation product from DNA before electrotransformation.Usage1. The reaction solution was prepared according to the following system:*The amount of Insert DNA used: the molar ratio of Vector DNA and Insert DNA is generally 1:3-1:8, and the appropriate molar ratio of Vector DNA and Insert DNA can be selected according to the experimental situation.Calculation of DNA molar number: DNA molar number (nmol)=DNA mass (ng)/( 660daltons x number of inserted DNA bases bp).2. mix gently and centrifuge briefly. react at 25°C for 5 minutes.Note: The reaction time should not exceed 15 minutes, otherwise the connection efficiency will be reduced.3. Do not perform heat inactivation reactions. Centrifuge instantly and collect the solution from the wall to the bottom of the tube.Note: Heat inactivation significantly reduces transformation efficiency due to the presence of PEG in the buffer.4. After the reaction, store the DNA ligation product at 0-4℃, and then carry out transformation experiments; you can also store the DNA ligation product at -20℃.Note: When transforming by chemical method, do not add more than 10% of the volume of the receptor cell for the ligation product.5. Heat shock the ligation product to transform 50 µl of receptor cells or take 1-2 µl of ligation product to electroshock transform 50 µl of receptor cells.Note: 1) When transforming by chemical method, do not add more than 10% of the volume of the receptor cell for the ligation product.(2) If the quick ligation product is used for electrotransformation, it is recommended to use a centrifugal column to purify the ligation product from DNA before electrotransformation because the PEG in the quick ligation reaction system will affect the efficiency of electrotransformation... 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 | Product introduction：Product introduction：Cell Cycle Assay Kit Plus ( Cell Cycle Assay Kit Plus ) has certain applicability for live cells and fixed cell cycle detection. For different types of cells, whether it is applicable or not needs to be determined after testing. Cell Cycle Product introduction：Product introduction：Cell Cycle Assay Kit Plus ( Cell Cycle Assay Kit Plus ) has certain applicability for live cells and fixed cell cycle detection. For different types of cells, whether it is applicable or not needs to be determined after testing. Cell Cycle Assay Kit Plus ( Cell Cycle Assay Kit Plus ) uses RedNucleus I staining to detect cell cycle. RedNucleus I is a far-infrared nucleic acid dye with cell membrane permeability, which can quickly enter living cells, specifically bind to DNA, and perform cell cycle detection on living cells without RNase digestion. Compared with the traditional PI staining method, the cells do not need to be broken or fixed, and the operation is simpler. RedNucleus I is a fluorescent dye of double-stranded DNA, and the fluorescence intensity after binding to double-stranded DNA is proportional to the content of double-stranded DNA. The intracellular DNA content can be measured by flow cytometry, and then the cell cycle analysis can be carried out according to the distribution of DNA content. After RedNucleus I staining, assuming that the fluorescence intensity of G0 / G1 phase cells is 1, the theoretical value of the fluorescence intensity of G2 / M phase cells containing two copies of genomic DNA is 2, and the fluorescence intensity of S phase cells undergoing DNA replication is between 1-2. In addition, RedNucleus I is compatible with dyes such as Horizon BV / BUV, FITC and R-PE, and can be periodically detected after sample staining.The kit is usually used to detect the cell cycle of cultured adherent or suspended cells. If it is used for cell cycle detection of tissues, the tissues must be digested into a single cell state.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. this product is applicable to the detection of living cells and fixed cell cycle with certain limitations. Whether it is applicable to different types of cells needs to be determined after testing. If fixation is needed, it is recommended to use ice bath pre cooling 75-80% ethanol -20 ℃ to fix cells overnight. 3. fluorescent dyes have quenching problems. Please try to avoid light during storage and use to slow down fluorescence quenching. 4. for your safety and health, please wear experimental clothes and disposable gloves.Instruction： Experimental materials ( self-provided )：①cell lines or other cell samples ( self-prepared ) ；②This kit ; ③ trypsin ( self-prepared ) ;④ Cell culture medium containing FBS ( self-prepared ) ; Experimental procedure： 1.Preparation of cell samples : ( 1 ) ( This step is for adherent cells, if suspended cells, can be carried out directly step ( 2 ) ) Digest cells with trypsin, add cell culture medium, gently blow away cells, collected into the centrifuge tube. Note : The number of cells on the machine needs to reach 50,000 and above, so the initial number of cells collected needs to be sufficient. ( 2 ) Centrifuged about 1000 g for 3-5 min to precipitate cells. Carefully remove the supernatant, add about 1 mL of ice bath pre-cooled 1 × staining buffer ( 10 × staining buffer diluted with diH2O at 1 : 10 ), re-suspend the cells. Repeat once. ( 3 ) Centrifuged about 1000 g for 3-5 min to precipitate cells. After the supernatant was discarded, 1 mL of culture medium was added to re-suspend the cells ( for fixed cells, 1 × PBS can also be used to re-suspend ). Gently flick the bottom of the centrifuge tube to properly disperse the cells to avoid cell aggregation. 2.Staining : 4 µL of RedNucleus I staining solution was added to each tube of cell samples, slowly and fully mixed, and incubated at room temperature in dark for 20 min ( or incubated at 37 ° C in dark for 5-10 min ). The optimal incubation time of different cells is different, and the staining time can be adjusted and optimized according to the actual staining effect to obtain a more ideal staining effect. 3.Flow cytometry detection and analysis : Excited at 638 nm by flow cytometry, it is recommended to detect in RL3 or FL4 channels, or use RL1 and RL2 channels. Cell DNA content analysis and light scattering analysis were performed using appropriate analysis software.Scope of application：Cell cycle detection... Read More | Product introduction： The MA qPCR live bacteria detection kit provides an effective means for detecting bacterial activity. The kit provides a mixture of PMA dye and qPCR based on SYBR Green dye. The optimal amount of dye and the number of samples that can be treated may vary depending on theProduct introduction： The MA qPCR live bacteria detection kit provides an effective means for detecting bacterial activity. The kit provides a mixture of PMA dye and qPCR based on SYBR Green dye. The optimal amount of dye and the number of samples that can be treated may vary depending on the type of sample. PMA is a high-affinity DNA-binding dye, especially with double-stranded DNA. The dye itself has weak fluorescence, but it can emit brighter fluorescence after binding to nucleic acids. PMA is impermeable to cell membranes, so it can selectively modify the DNA of dead cells with damaged membranes. After the PMA-modified DNA is photolyzed by blue light ( ~ 464 nm ), the photoreactive azide group on the PMA is converted into a highly reactive nitrene radical, which reacts with any hydrocarbon near the DNA binding site to form a stable covalent nitrogen-carbon bond, resulting in permanent DNA modification. This modification process will make DNA insoluble and lost with cell debris during the later genomic DNA extraction process. The unbound PMA remaining in the solution reacts with water molecules under strong light irradiation to decompose into hydroxylamine compounds without cross-linking activity, so that it can no longer covalently bind to DNA. Based on this feature of PMA, PMA was combined with qPCR technology to form a new detection method, PMA-qPCR, for the screening of live bacteria. At present, the method has been verified in a variety of bacterial strains, yeast, fungi, viruses and parasites. The treatment of complex samples, such as manure or soil, may require optimization of sample dilution, dye concentration, and light treatment time. The treatment of diluted samples, such as water testing, may require filtration or concentration prior to dye treatment. Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. the components of the kit contain fluorescent dyes. Avoid light during use and storage. 3. for your safety and health, please wear experimental clothes and disposable gloves.Product parameters:Spectral characteristics :PMA: Ex = 464 nm; Ex/Em = 510/610 nm (following photolysis and reaction with DNA/RNA)Component： PMA：Ex = 464 nm; Ex/Em = 510/610 nm (following photolysis and reaction with DNA/RNA) Instruction： Precautions before use： 1.This live bacteria detection kit distinguishes dead bacteria and live bacteria according to cell membrane permeability. Many methods of killing bacteria cause damage to the cell membrane and are therefore compatible with this kit. But some methods, such as ultraviolet irradiation, may not immediately cause cell membrane rupture. Therefore, before selecting this kit, it is necessary to carry out literature search and pre-experiment to determine whether the kit is suitable for the bacterial type and killing method you choose. 2.After PMA treatment, the bacteria need to be photolyzed to covalently bind the dye to dead cell DNA. Photolysis operations can use blue or white light sources. Generally speaking, the brighter the lamp, the higher the efficiency of the photolysis step. Non-LED lamps ( such as halogen lamps ) may heat your sample and have a negative impact on the analysis. Ice is required to cool the sample during irradiation. 3.Sample can be cryopreservation after photolysis. Frozen samples before PMA treatment photolysis may damage the cell membrane and produce false negative results. If the sample needs to be frozen before detection, it is recommended to perform a pre-experiment first. 4.Part of the mechanism of PMA is to remove PMA covalently modified DNA from the sample by precipitation ; therefore, when extracting genomic DNA, it is necessary to use the same volume of genomic DNA eluent for volume normalization. The positive control can use the genomic DNA of living cells. 5.In order to verify the effectiveness of PMA in the test sample, the Ct ( dCt ) changes between- / + PMA can be compared. Experimental materials ( self-provided )：①Light source ( for the photolysis step after PMA modification of DNA ) ; ② Bacterial genomic DNA extraction kit ; ③ effective qPCR primers corresponding to the sample type Experimental procedure： 1.Suck 10 µL of E.coli bacterial solution in liquid LB medium, and culture E.coli in the bacterial incubator overnight or longer to the logarithmic growth phase ( OD600 ≈ 1.0 ) ; Note : The culture time is adjusted according to the experiment. 2.Two portions of live E.coli, 400 µL each, were placed in a clean centrifuge tube ; 3. ( Recommended ) Preparation of dead E.coli. If the dead E.coli is needed as a control, the dead E.coli can be obtained by heating the living E.coli in a water bath at 95 °C for 5 min, or at 58 °C for 3 h. the subsequent operation of the dead E. coli is the same as that of the living E. coli ; 4.Two copies of live E.coli, one without PMA treatment, and one with 25 µM PMA treatment ( the optimal PMA concentration for treating different types or different sources of bacteria needs to be consulted in the relevant literature ) ; 5.The PMA-treated samples were placed on a shaker at room temperature and incubated in the dark for 10 min to fully mix the dye with the sample ; 6.Exposure of the sample, you can use blue or white light source, irradiation time to explore their own. For example, a 60 W blue light can be used for 15 min. Note : 1 If a halogen lamp is used, we recommend that the PMA-treated sample tube be placed on an ice block 20 cm away from the light source. Ice should be placed in a transparent tray. Adjust the light source to point directly to the sample, photolysis for 5-15 min ; if the bacteria obtained from the environment are directly used for experiments, due to the complexity or turbidity of the environmental samples, the photolysis time needs to be prolonged appropriately. 7.Treated and untreated live E.coli 5000 × g, centrifuged for 10 min, remove the supernatant ; 8.Select the appropriate genomic DNA extraction kit according to the sample type, and use the same elution volume for each group of samples when elution DNA. Note : DNA extraction steps refer to the instructions of the kit used. Part of the mechanism of action of PMA is to remove PMA-bound DNA from the sample by precipitation ; therefore, when extracting genomic DNA, each group should use the same volume of genomic DNA eluent for volume normalization ( the amount of genomic DNA extracted from dead bacteria and live bacteria is inconsistent, so the concentration of the two is significantly different ). 9.Preparation of reaction mixture according to the following system : Note : 1 For the DNA extracted by commercial DNA extraction kit, the qPCR template was optimized with 2 µL as the initial volume ; 2 The template volume should not exceed 10 % of the final reaction volume ; 3 Template concentration : gDNA as template, usually 1-10 ng ; the final concentration of PCR primers is usually 0.4µM, which can get better results. When the reaction performance is poor, the primer concentration can be adjusted in the range of 0.2-1µM. 10.Slightly vortex the reaction mixture, transfer the fixed volume to the PCR tube. 11. Test procedure Note : 1 The extension time is adjusted according to the instrument ; the Taq enzyme in mix can be activated within 2 min, but the genomic DNA may require longer denaturation time, which can be increased at this time, and the specific denaturation time can be adjusted according to the sample type.12. ( Optional ) Data analysis Using live bacteria and dead bacteria as controls, the number of live cells in the sample was analyzed and calculated. It is recommended to verify the suitability of primers and PCR procedures before starting PMA qPCR detection of live bacteria. Calculation of dead and living bacteria control dCt ( 1 ) After the end of qPCR, the Ct value of each sample was calculated by instrument software ; ( 2 ) By calculating the dCt of each control bacteria, it was judged whether PMA successfully inhibited the amplification of dead bacterial DNA. The calculation is as follows : dCt live = Ct ( live, PMA treated ) -Ct ( live, PMA untreated ) dCt die = Ct ( die, PMA treated ) -Ct ( die, PMA untreated ) ( 3 ) The dCt expectation of living bacteria is close to 0 ± 1, which indicates that PMA does not affect the amplification of living cell DNA ;( 4 ) The expected value of dCt of dead bacteria is greater than 4 ( dCt is 4 means that it is reduced by about 16 times, that is, 94 % of dead bacterial DNA is removed ; a dCt of 8 indicated a decrease of about 250 times, that is, 99.6 % of the dead bacterial DNA was removed ).( 5 ) The dCt of dead bacteria depends on many factors, including : strain / cell type ; the way bacteria are killed ; the concentration of PMA used ; amplified sequence length. 13. Calculation of the proportion of viable ( optional ) bacteria If the control results of dead and live bacteria are normal, the proportion of live bacteria in the sample can be calculated.( 1 ) Calculate the dCt value of the sample : dCt sample = Ct ( sample, PMA treated ) -Ct ( sample, PMA untreated ) ( 2 ) Conversion of dCt value to live bacteria ratio : PMA inhibition multiple = 2 ( sample dCt ) Viable bacteria % = 100 / PMA inhibition multiple 14. ( Optional ) Calculate the absolute number of live bacteria If you want to calculate the absolute number of viable bacteria in the sample, you need to use a known number of target bacteria genomic DNA to make a standard curve. It is recommended that the diluted concentrations of several groups of genomes are within the range of the qPCR analysis system.( 1 ) qPCR was performed with the appropriate genome, and the Ct value was used as the ordinate, and the number of cells was used as the abscissa. The R2 value is calculated to determine the linearity, and the slope and y-axis intercept are displayed. ( 2 ) Calculate the copy number of the experimental samples : Ct = slope * cell number + y axis intercept ( y = mx + b ) Bacterial count sample = ( Ct-y axis intercept ) / slope Note : The live bacterial DNA was not lost during the purification process. Examples : Scope of application：Live bacteria detection... Read More | This product is a cDNA first strand synthesis kit specially prepared for the first step experiment of two-step RT-PCR. The reverse transcriptase used in this kit is a novel and efficient reverse transcriptase that utilizes E. coli engineered bacteria for recombination and expression. It removes This product is a cDNA first strand synthesis kit specially prepared for the first step experiment of two-step RT-PCR. The reverse transcriptase used in this kit is a novel and efficient reverse transcriptase that utilizes E. coli engineered bacteria for recombination and expression. It removes RNase H activity and enhances its thermal stability. It can synthesize cDNA first strands using extremely low amounts of total RNA or mRNA, with an initial sample size as low as pg level. SuperRT reverse transcriptase has strong affinity for RNA and can read RNA templates with high GC content and complex secondary structures, obtaining high yields of cDNA. This product contains all the reagents required for reverse transcription from RNA templates to cDNA first strand, including Super RT efficient reverse transcriptase, reaction buffer, primers, dNTP, etc. It is simple and convenient to use. This system has high compatibility with subsequent PCR and quantitative PCR experiments, and is suitable for various DNA polymerase reactions. S665657 Component 100 T Storage S665657A SuperRT, 200 U/µL 100 µL -20℃. Avoid freeze/thaw cycle. S665657B 5×SuperRT Buffer 500 µL -20℃. Avoid freeze/thaw cycle. S665657C Primer Mix 240 µL -20℃. Avoid freeze/thaw cycle. S665657D dNTP Mix, 2.5 mM Each 500 µL -20℃. Avoid freeze/thaw cycle. S665657E RNase-Free Water 1 mL -20℃. Avoid freeze/thaw cycle.Product features:·Efficient reverse transcription: It has a high affinity for RNA templates, with a reverse transcription efficiency of up to 90%, and can recognize pg level templates.·Free response to complex templates: Even templates with high GC content and complex secondary structures can achieve good results without high-temperature denaturation.Notes:1. During the operation process, RNase contamination should be avoided to prevent RNA degradation or cross contamination during experiments. It is recommended to perform RNA operations in specialized areas, use specialized instruments and consumables, and have operators wear masks and disposable gloves, and frequently change gloves.2. Disposable plastic containers should be used as much as possible for experiments. If glass containers are used, they should be treated with a 0.1% DEPC (diethyl pyrocarbonate) aqueous solution at 37 ℃ for 12 hours, and sterilized under high pressure at 120 ℃ for 30 minutes before use. Alternatively, glass containers should be sterilized under dry heat at 180 ℃ for 60 minutes before use. The sterile water used in the experiment should be treated with 0.1% DEPC and then subjected to high-pressure sterilization.3. All reagents in this reagent kit should be gently mixed upside down before use, avoiding foaming as much as possible, and used after brief centrifugation. The enzymes involved should be returned to -20 ℃ as soon as possible after use to avoid repeated freeze-thaw cycles.If the initial amount of RNA is less than 50 ng, it is recommended to add RNA enzyme inhibitors (RNAsin). This kit is not provided.Usage:Note: 1 ng -5 µ g of total RNA can establish a 20 µ l reaction system. If the total RNA amount is greater than 5 µ g, please expand the reaction system proportionally.Steps for reverse transcription:1. Dissolve the RNA template, Primer Mix, dNTP Mix, SuperRT Buffer, SuperRT, and RNase Free Water and place them on ice for later use.2. Prepare a reaction system according to the following table, with a total volume of 20 µ L. Reagent 20 µlReaction system Final concentration dNTP Mix，2.5 mM Each 4 µl 500 µM Each Primer Mix 2 µl / RNA Template X µl 50 pg-5 µg SuperRT，200 U/µl 1 µl / RNase-Free Water up to 20 µl / Attention:1) If the initial amount of RNA is less than 50 ng, it is recommended to add RNA enzyme inhibitors (RNAsin). This kit is not provided.2) Primer Mix is formulated from Oligo (dT) and Random Primer. Oligo dT Primer or Gene Specific Primer can be used according to experimental needs, with a recommendation of 20 µ The reaction system Oligo dT Primer is 50 pmol, or Gene Specific Primer is 2 pmol.3. Vortex shake and mix well, briefly centrifuge to collect the solution on the pipe wall to the bottom of the pipe.Incubate at 4.42 ℃ for 30-50 minutes and 85 ℃ for 5 minutes. After the reaction is complete, centrifuge briefly and cool on ice.5. Reverse transcripts can be directly used for PCR reactions and fluorescence quantitative PCR reactions, or stored at -20 ℃ for a long time. Reagent 20 µ Final concentration of reaction system dNTP Mix, 2.5 mM Each 4 µ L 500 µ M Each Primer Mix 2 µ RNA Template X µ L 50 pg-5 µ g 5 x SuperRT Buffer 4 µ 1 x SuperRT, 200 U/ µ L 1 µ RNase Free Water up to 20 µ Lii If the reverse transcription efficiency is low, or the RNA template secondary structure is complex and the GC content is high, the following steps are recommended:1. Dissolve the RNA template, Primer Mix, dNTP Mix, SuperRT Buffer, SuperRT, and RNase Free Water and place them on ice for later use.2. Configure the reaction system according to the following table, with a total volume of 15 µ L. Reagent 20 µlReaction system Final concentration dNTP Mix，2.5 mM Each 4 µl 500 µM Each Primer Mix 2 µl / RNA Template X µl 50 pg-5 µg RNase-Free Water up to 15 µl / Note: Primer Mix is formulated from Oligo (dT) and Random Primer. Oligo dT Primer or Gene Specific Primer can be used according to experimental needs. 3. Incubate at 70 ℃ for 10 minutes and quickly ice bath for 2 minutes.4. Centrifuge briefly to collect the solution on the tube wall to the bottom of the tube.5. Continue to add the following reagents to the above reaction solution: Reagent 20 µlReaction system Final concentration 5×SuperRT Buffer 4 µl 1× SuperRT，200 U/µl 1 µl / Note: If the initial amount of RNA is less than 50 ng, it is recommended to add RNA enzyme inhibitors (RNasins). This kit is not provided. 6. Incubate at 42 ℃ for 30-50 minutes and 85 ℃ for 5 minutes.7. After the reaction is complete, centrifuge briefly and cool on ice.8. Reverse transcripts can be directly used for PCR reactions and fluorescence quantitative PCR reactions, or stored at -20 ℃ for a long time... Read More |