| Description | 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 | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export | This kit is used to extract miRNAs from various animal tissues, plant tissues and cells. The extracted miRNA molecule is complete and high purity, which is suitable for various molecular biology experiments such as Northern blot, real timepcr, miRNA microarray chip, in situ hybridization, This kit is used to extract miRNAs from various animal tissues, plant tissues and cells. The extracted miRNA molecule is complete and high purity, which is suitable for various molecular biology experiments such as Northern blot, real timepcr, miRNA microarray chip, in situ hybridization, RNase protection assay, etcComposition:Scope of application：Nucleic acid extraction and purificationInstruction：1.Experimental preparation：1.1.All reagents were prepared with DEPC-treated solvents. Please use RNase-free tip and centrifuge tube to avoid RNA degradation by RNase during extraction.1.2.70 % ethanol, -20C pre-cooling.2.Operational procedure：There is a slight difference in the operation of miRNA extraction from different samples. The specific steps are as follows :【 Extraction of miRNA from animal tissues】1.Take 20-40 mg tissue, transfer to a pre-cooled mortar, and add liquid nitrogen to grind into powder.Please click below to describe the amount of organization used :①RNA-rich tissue ( e.g. liver ) : no more than 30 mg②Tissues with low RNA content ( e.g., muscle ) : no more than 100 mg③When the amount of tissue used was less than 20 mg : the amount of R-I, R-II and isopropanol used was halved.④When the amount of tissue used was more than 40 mg : the use of R-I, R-II and isopropanol increased proportionally.2.Add 400 ul Buffer R-I, repeatedly aspirate 8-10 times with a syringe equipped with a 21-25 needle, and transfer to a 1.5 m : centrifuge tube ( provided in the kit ). 3.Add 150 µl BufferR-1l, swirl for 15-30 s, centrifuge at 12,000 X g for 5 min. [ Centrifugation at 4 °C is recommended ] 4.Take the supernatant to 1.5ml centrifuge tube, add 180 u anhydrous ethanol, mix evenly.5.The preparation tube was placed in a 2 m : centrifuge tube ( provided in the kit ), the mixture in step 4 was transferred to the preparation tube, and 12,000 X g was centrifuged for 1 min. [ 1 Centrifugation at 4 °C is recommended ; 2 miRNA in the filtrate, pay attention to preserve the filtrate. ]6.Abandon the preparation tube, add 500µl isopropanol to the filtrate, and mix evenly.7.12,000Xg centrifuged for 10 min, discard the supernatant.8.Add 700µl 70 % ethanol ( pre-cooled at -20 °C ), centrifuged at 12,000Xg for 5min.9.The supernatant was discarded and dried at room temperature for 5-10 min.10.70 ul Buffer TE ( nucdease-free ) or RNase-free water was added to the centrifuge tube to elute miRNA.【 Extraction of miRNA from plant tissue 】1.Take 30-150 mg tissue, transfer to a pre-cooled mortar, and add liquid nitrogen to grind into powder.Please click below to describe the amount of organization used :①Plant leaves : usually 10-80 mg② Plant fiber tissue : usually 100-150 mg③When the amount of plant leaf tissue was less than 30 mg : the amount of R-I, R-II and isopropyl alcohol used was halved.④When the amount of plant leaf tissue was more than 80 mg : the use of R-I, R-II and isopropanol increased proportionally.⑤When the amount of plant fiber tissue was more than 150 mg : the use of R-I, R-II and isopropanol increased proportionally.2.Add 400 ul BufferR-I, use a syringe with a 21-25 needle to repeatedly suck 8-10 times, and transfer to a 1.5mI centrifuge tube ( provided in the kit ). 3.Add 150 ul Buffer R-1I, vortex oscillation 15-30 s, 12.000 x g centrifugation 5 min. [ Centrifugation at 4 °C is recommended ]4.Take the supernatant to 1.5ml centrifuge tube, add 180 mountain anhydrous ethanol, mix evenly.The preparation tube was placed in a 2 mI centrifuge tube ( provided in the kit ), the mixture in step 4 was transferred to the preparation tube, and 12.000 xg was centrifuged for 1 min. It is recommended to centrifuge at 4 °C ; 2 miRNA in the filtrate, pay attention to preserve the filtrate. ]Abandon the preparation tube, add 500µl isopropanol to the filtrate, and mix evenly.7.12,000xg high heart for 10 min, discard the supernatant.8.Add 700 ul 70 % ethanol ( -20 °C precooling ), 12,000 xg centrifuge for 5 min.9.The supernatant was discarded and dried at room temperature for 5-10 min.10.70 ul Buffer TE ( nucdease-free ) or RNase-free water was added to the centrifuge tube to elute miRNA.【miRNA extraction from cells】Steps 1-3 According to the different ways of cell culture, two experimental methods, a or b, can be selected.a. Suspension cultured animal cells or cell suspension obtained from petri dishes or culture flasks or freshly isolated animal tissue single cell suspension :1a.Collect 2X 10 * -1X 10 ' cells, centrifuge 2,000Xg for 5 min, discard the supernatant ;2a. Add 400 µl Buffer R-I, repeatedly draw 8-10 times with a syringe containing 21-25 needles, and transfer to a 1.5 mI centrifuge tube ( provided in the kit ) ;3a. Add 150µl Buffer R1I, vortex oscillation 15-30s, 12.000Xg centrifugal 5min. [ build at 4 °C centrifugal ].b. Cells cultured on 96-well L, 24-well, 12-well or 6-well plates :Cells were collected from 96-well, 24-well, 12-well or 6-well culture plates, and the medium was discarded as much as possible, and 400 u / well Buffer R-I was added to each well, and the pipette gun was used to blow up and down 8-10 times ;2b.Transfer the above cell suspension to a 1.5ml centrifuge tube ( provided in the kit ), and repeatedly draw 8-10 times with a syringe containing 21-25 needles ;3b. Add 150 µl Bufflr R-II, swirl for 15-30 s, centrifuge for 5 min at 12,000 × g. [ Recommended at 4 °C ]4.Take the supernatant to 1.5ml centrifuge tube, add 180 mountain anhydrous ethanol, mixing evenly.5.The preparation tube was placed in a 2 ml centrifuge tube ( provided in the kit ), the mixture in step 4 was transferred to the preparation tube, and centrifuged at 12.000 Xg for 1 min. [ 1 Centrifugation at 4 °C is recommended ; 2 miRNA in the filtrate, pay attention to preserve the filtrate. ]6.Abandon the preparation tube, add 500 u of isopropanol to the filtrate, and mix evenly.7.12,000Xg high heart for 10 min, discard the supernatant.8.Add 700µ70 % ethanol ( pre-cooled at − 20 °C ), centrifuged at 12,000 × g for 5 min.9.Abandon the supernatant, dry at room temperature for 5 - 10 min.10.70 ul Bufer TE ( nucdease-free ) or RNase-free water was added to the centrifuge tube to elute mRNA.3.Flow chartMatters needing attention：Buffer R-I contains irritating compounds, when operating to wear latex gloves and glasses, to avoid contamination of the skin, eyes and clothes, be careful not to inhale the nose and mouth. If the skin, eyes, to immediately rinse with a lot of water or saline, if necessary, seek medical advice... Read More | Product introduction：Reporter gene detection is an important tool for analyzing the interaction between potential cis elements (such as promoters, enhancers and silencers) and trans acting factors in the flanking region of structural genes in the field of modern molecular biology. Firefly Product introduction：Reporter gene detection is an important tool for analyzing the interaction between potential cis elements (such as promoters, enhancers and silencers) and trans acting factors in the flanking region of structural genes in the field of modern molecular biology. Firefly luciferase is widely used in gene regulation and drug screening. Firefly luciferase is a protein with a molecular weight of about 61 KD. In the presence of ATP, magnesium ions and oxygen, it can catalyze the production of oxyluciferin from luciferin. In the process of luciferin oxidation, it will produce a light signal. The optical signal of this kit is a kind of instantaneous light, which needs to be detected immediately after adding the working solution. The half-life of optical signal is about 5 min.Instruction：1.Working fluid configuration ( 1 ) Restore all components to room temperature. ( 2 ) The component B ( stock solution ) was fully diluted with component A to prepare a 0.2 mg / mL firefly luciferase working solution, which was vortexed and shaken to ensure full mixing. Note : The firefly luciferase working solution cannot be repeatedly frozen and thawed. If the dosage of a single experiment is small, it is recommended to subpackage according to a single dosage. At room temperature, the activity decreased by about 10 % after the working solution was configured for 3 h, and the activity decreased by about 25 % after 5 h. 2.chemiluminescence value detection ( 1 ) The cell culture plate was taken out from the incubator and incubated at room temperature for 20 min to restore it to room temperature ( 22-25 ° C ). ( 2 ) Add the same volume of firefly luciferase working solution with the medium to the culture plate and mix well. ( 3 ) Incubation at room temperature for 5 min. Note : The incubation time can be adjusted according to cell type and cell number. ( 4 ) The values were read by multifunctional microplate reader or chemiluminescence instrument ( instrument parameters : the determination time was 10 s, the determination interval was 2 s ).Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. the strongest wavelength of bioluminescence catalyzed by firefly luciferase is 560 nm. 3. to prevent interference between holes, it is recommended to use white opaque orifice plate.Recommendation：Component B is recommended to use sterile water in advance to configure 2 mg / mL storage solution, A component and B component configured as storage solution, and small batch packaging according to the experimental requirements. The detection working fluid is recommended to be used now to avoid repeated freezing and thawing. Component：One-Step Firefly Luciferase Assay Buffer；D-Luciferin Scope of application：Mainly used for ADCC detection... Read More | V669947 Component 50T Storage V669947A Buffer GL 15 mL RT V669947B Buffer GW1 (concentrate) 13 mL RT V669947C Buffer GW2 (concentrate) 15 mL RT V669947D Buffer RE 10 mL RT V669947E Proteinase K 12.5 mg RT V669947F Proteinase K Storage Buffer 1.25 mL RT V669947G Spin Columns RS with Collection Tubes V669947 Component 50T Storage V669947A Buffer GL 15 mL RT V669947B Buffer GW1 (concentrate) 13 mL RT V669947C Buffer GW2 (concentrate) 15 mL RT V669947D Buffer RE 10 mL RT V669947E Proteinase K 12.5 mg RT V669947F Proteinase K Storage Buffer 1.25 mL RT V669947G Spin Columns RS with Collection Tubes 50 RT V669947H RNase-Free Centrifuge Tubes (1.5 mL) 50 RTProductsThis kit is suitable for the extraction of viral RNA and DNA from fresh or frozen plasma, serum and cell-free body fluids. It is easy to operate as it does not require the use of organic solvents such as phenol and chloroform for extraction. The kit uses a unique buffer system to enable efficient and specific binding of viral nucleic acids in lysate to silica gel centrifugal adsorption columns. Inhibitors of PCR and enzyme reactions as well as residual impurities can be efficiently removed in a two-step effective rinsing step, and finally high purity viral nucleic acids can be obtained by using a low-salt buffer or water for elution. The purified viral nucleic acid is free of protein, nuclease and other impurities, and can be used directly in PCR, RT-PCR, Real-Time PCR, blotting experiments and so on.Self-contained reagent: anhydrous ethanol.Pre-experiment 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. Do not add Proteinase K directly into Buffer GL.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. Avoid repeated freezing and thawing of serum or plasma, which can lead to protein denaturation or precipitation, reducing the viral titer and thus affecting the yield of extracted viral nucleic acids.4. Anhydrous ethanol should be added to Buffer GW1 and Buffer GW2 according to the label instructions of the reagent bottle before first use.5. Check Buffer GL for crystallization or precipitation before use. If crystallization or precipitation occurs, redissolve Buffer GL in a water bath at 56℃.Procedure1. Take a 1.5 ml centrifuge tube (self-provided) and add 20 µl Proteinase K.2. Add 200 µl serum or plasma to the centrifuge tube. Add 200µl Buffer GL and vortex and shake for 15 seconds.Note: 1) Sample volume less than 200 µl can be made up by adding 0.9% NaCl (self-provided). 2) In order to ensure effective lysis of the sample, the sample needs to be mixed well with Buffer GL after adding Buffer GL.3. Incubate at 56°C for 15 minutes, centrifuge briefly, and collect the solution from the wall of the tube to the bottom of the tube.4. 250 µl of anhydrous ethanol was added, vortexed and shaken for 15 seconds, left at room temperature for 5 minutes, centrifuged briefly, and the solution on the wall of the tube was collected at the bottom of the tube.Note: If the ambient temperature exceeds 25°C, anhydrous ethanol should be used after pre-cooling on ice.5. Add the solution obtained in step 4 to the adsorbent column (RNase-Free Columns RS) that has been loaded into the collection tube, and if the solution cannot be added at one time, it can be transferred in several times. centrifuge the column at 12,000 rpm (~13,400 × g) for 1 min, pour off the waste liquid in the collection tube, and put the column back into 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 put the adsorption column back into 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. Add 500 µl of anhydrous ethanol to the adsorbent column and centrifuge at 12,000 rpm for 1 min. Pour off the waste liquid in the collection tube and put the adsorbent column back into the collection tube.9. Centrifuge at 12,000 rpm for 3 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 the removal of residual ethanol from the adsorbent column; ethanol residue can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).10. Place the adsorption column in a new collection tube (RNase-Free Centrifuge Tube), add 20-150 µl of Buffer RE or sterilized water overhanging the middle of the adsorption column membrane, leave it at room temperature for 2-5 minutes, and then centrifuge it at 12,000 rpm for 1 minute to collect the nucleic acid solution.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 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) For long-term storage, please store the DNA solution at -20℃ and the RNA solution at -70℃.3) If the final concentration of DNA/RNA is to be increased, the DNA/RNA eluate obtained in step 10 can be re-spiked onto the adsorbent membrane and step 10 repeated... Read More |