| Description | Inquire | This reagent kit is suitable for simultaneously isolating and purifying genomic DNA, total RNA, and total protein from the same cell or tissue sample. This product does not require dividing the sample into three parts to extract DNA, RNA, and protein separately, nor does it require dividing the This reagent kit is suitable for simultaneously isolating and purifying genomic DNA, total RNA, and total protein from the same cell or tissue sample. This product does not require dividing the sample into three parts to extract DNA, RNA, and protein separately, nor does it require dividing the purified total nucleic acid into two parts before purifying DNA and RNA separately. Therefore, it can maximize the recovery of DNA, RNA, and protein, and can be used for the purification of nucleic acid and protein in small and rare samples. The purified DNA, RNA, and protein can be eluted separately and directly applied to various downstream molecular biology operations. This reagent kit does not contain toxic substances such as phenol and chloroform, and does not require ethanol precipitation. The operation is simple and fast. The extracted genomic DNA can be used for PCR, Real time PCR, SouthBlot, Dot Blot, comparative genomic hybridization (CGH), gene analysis, and SNP analysis; Total RNA can be applied in experiments such as RT-PCR, cDNA synthesis, Northern Blot, Dot Blot, and gene chips; Total protein can be applied in electrophoresis and Western Blot, among others. A665492 Component 50 T Storage A665492A Buffer RL 35 mL RT A665492B Buffer RW1 40 mL RT A665492C Buffer RW2 (concentrate) 11 mL RT A665492D RNase-Free Water 10 mL RT A665492E Buffer GW1 (concentrate) 13 mL RT A665492F Buffer GW2 (concentrate) 15 mL RT A665492G Buffer GE 15 mL RT A665492H Buffer PZ 60 mL RT A665492I Buffer PLS 15 mL RT A665492J Spin Columns DM with Collection Tubes 50 sets RT A665492K Spin Columns RM with Collection Tubes 50 sets RT A665492L Collection Tubes 100 EA RT A665492M RNase-Free Centrifuge Tubes (1.5 mL) 100 EA RTSelf prepared reagents:β- Mercaptoethanol (for newly opened or RNA extraction), 70% ethanol (prepared with water without RNase), and anhydrous ethanol.Preparation and important precautions before the experiment:To prevent RNase pollution, attention should be paid to the following aspects:1) Use plastic products and gun heads without RNase 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) The solution should be prepared using water without RNase.4) Operators should wear disposable masks and gloves, and change gloves frequently during the experiment.2. The sample should avoid repeated freeze-thaw cycles, otherwise it will affect the quality of DNA, RNA, and protein extraction. The sample can be stored in Buffer RL at -70 ℃ for one month.3. Please add Buffer RL before use β- Mercaptoethanol, 1 ml Buffer RL with 10 µ L β- Mercaptoethanol. join β- The buffer RL room temperature of mercaptoethanol can be stored for one month.Before the first use, anhydrous ethanol should be added to Buffer RW2, Buffer GW1, and Buffer GW2 according to the instructions on the reagent bottle label.5. Before use, please check if there is any crystallization or precipitation in the Buffer RL. If there is any crystallization or precipitation, please dissolve it again in a 56 ℃ water bath.6. All centrifugation steps are performed using a desktop centrifuge at room temperature. Operation steps:1. Material processing1a The cells cultured on the wall should be first processed into cell suspension (maximum extraction amount of 107 cells), collected cells, discarded the culture medium, and added 600 cells µ L Buffer RL (check if it has been added before use) β- Mercaptoethanol), repeatedly blow and beat to fully decompose.Attention: It is necessary to discard the culture medium completely, otherwise it will affect the lysis and subsequent nucleic acid purification steps.1b Take no more than 30 mg of animal tissue, grind it into fine powder with liquid nitrogen, and add 600 µ Buffer RL (check if it has been added before use) β- Mercaptoethanol, or directly add 600 µ L Buffer RL (check if it has been added before use) β- Mercaptoethanol, homogenization treatment.Attention: The homogenate should be sufficient, otherwise it will affect RNA production.2. Centrifuge the solution obtained in the previous step at 12000 rpm (~13400 × g) for 3-5 minutes. Carefully add the supernatant to the spin columns DM that have been loaded into the collection tube. Centrifuge at 12000 rpm for 30-60 seconds and collect the filtrate. Place the adsorption column DM in a new 2 ml collection tube at room temperature or 4 ℃ for DNA extraction. Attention: Ensure that there is no liquid residue on the adsorption column, and if necessary, repeat centrifugation until all liquids pass through the membrane of the adsorption column. Total RNA extraction3. Add 1 volume of 70% ethanol (prepared without RNase water) to the filtrate obtained in step 2, and mix well.4. Add all the solution obtained in the previous step to the spin columns RM that have been loaded into the collection tube. If the solution cannot be added completely at once, it can be transferred in stages. Centrifuge at 12000 rpm for 20 seconds and retain the liquid in the collection tube for protein extraction.5. Place the adsorption column RM into a new 2ml collection tube and add 700 to the adsorption column RM µ L Buffer RW1, centrifuge at 12000 rpm for 20 seconds, discard the waste liquid in the collection tube, and place the adsorption column RM into the recovery manifold.6. Add 500 to the adsorption column RM µ Buffer RW2 (check if anhydrous ethanol has been added before use), centrifuge at 12000 rpm for 20 seconds, discard the waste liquid in the collection tube, and place the adsorption column RM back into the 2 ml collection tube.7. Repeat step 6.Centrifuge at 8.12000 rpm for 2 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: The purpose of this step is to remove residual ethanol from the adsorption column, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).9. Place the adsorption column RM in a new 1.5 ml centrifuge tube without RNase, and add 30-50 to the middle of the adsorption column RM µ Place RNase Free Water at room temperature for 2-5 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 30 µ l. Small volume affects the recovery rate.2) If you want to increase RNA production, you can use 30-50 µ Repeat step 9 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 9.Genomic DNA extraction10. Add 500 to the adsorption column DM µ Buffer GW1 (check if anhydrous ethanol has been added before use), centrifuge at 12000 rpm for 20 seconds, discard the waste liquid in the collection tube, and place the adsorption column DM into the recovery tube.11. Add 500 to the adsorption column DM µ Buffer GW2 (check if anhydrous ethanol has been added before use), centrifuge at 12000 rpm for 2 minutes, discard the waste liquid in the collection tube, and place the adsorption column DM into the recovery tube. Attention: To further improve DNA purity, repeat step 11.Centrifuge at 12.12000 rpm for 2 minutes and discard the waste liquid from the collection tube. Place the adsorption column DM at room temperature for a few minutes to thoroughly dry the ethanol in the column. Attention: The purpose of this step is to remove residual ethanol from the adsorption column, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).13. Place the adsorption column DM in a new centrifuge tube and add 100 to the middle of the adsorption column DM by suspending it in the air µ L Buffer GE, leave at room temperature for 2-5 minutes, centrifuge at 12000 rpm for 2 minutes, collect DNA solution, and store DNA at -20 ℃.Attention:1) The volume of Buffer GE should not be less than 100 µ l. Small volume affects the recovery rate.2) If we want to increase DNA production, we will µ Add a new Buffer GE to the adsorption column and repeat step 13; If you want to increase the DNA concentration, you can add the DNA eluent obtained in step 13 back onto the adsorption column and repeat step 13.Protein extraction14. Add 1 volume of Buffer PZ to the RNA extraction effluent (i.e. the solution obtained in step 4), mix well, and let it stand at room temperature for 10-30 minutes.Centrifuge at 15.12000 rpm for 10 minutes and discard the supernatant.16. Add 500 µ Centrifuge at 12000 rpm for 1 minute with 70% ethanol, and try to absorb the supernatant as much as possible.17. Place the centrifuge tube at room temperature for a few minutes to dry the precipitate.Attention: The purpose of this step is to remove residual ethanol. Excessive drying can make protein precipitation difficult to dissolve, and incomplete drying of residual ethanol can affect protein loading.18. Add 100 µ L Buffer PLS to obtain protein solution.Attention:1) The protein samples obtained by dissolving with Buffer PLS are suitable for SDS-PAGE and Western Blot detection, but not for Bradford method for protein quantification. If Bradford method is needed for protein quantification, 5% SDS can be used to dissolve the protein, or suitable protein dissolution buffer can be selected based on downstream experiments.2) The amount of dissolved protein buffer added is determined based on the initial sample size and specific downstream test requirements.3) The dissolved protein can be stored at -20 ℃ for several months and at 2-8 ℃ for several days.If protein samples require SDS-PAGE electrophoresis, the following operations can be performed:19. Add protein loading buffer to the protein sample, denature at 95 ℃ for 5-10 minutes, and cool the sample to room temperature. Centrifuge at 20.12000 rpm for 1 minute, extract the supernatant for downstream SDS-PAGE or Western blot tests... Read More | G665573 Component 10 T Storage G665573A Buffer P1 30 mL RT G665573B Buffer P2 30 mL RT G665573C Buffer E3 30 mL RT G665573D Buffer PS 15 mL RT G665573E Buffer PW (concentrate) 10 mL RT G665573F Endo-Free Buffer EB 30 mL RT G665573G RNase A (10 mg/mL) 600 碌L RT G665573H Endo-Remover FX 10 EA G665573 Component 10 T Storage G665573A Buffer P1 30 mL RT G665573B Buffer P2 30 mL RT G665573C Buffer E3 30 mL RT G665573D Buffer PS 15 mL RT G665573E Buffer PW (concentrate) 10 mL RT G665573F Endo-Free Buffer EB 30 mL RT G665573G RNase A (10 mg/mL) 600 碌L RT G665573H Endo-Remover FX 10 EA RT G665573I Plungers 10 EA RT G665573J Spin Columns DX with Collection Tubes 10 EA RT G665573K Centrifuge Tubes (15 mL) 10 EA RTProduct IntroductionThis kit is specially designed for the efficient and rapid extraction of plasmids from 15-50 ml of bacterial fluids. On the basis of cell lysis by alkaline lysis method, it adopts unique silicon matrix membrane adsorption technology to bind plasmid DNA efficiently and exclusively, and each adsorption column can adsorb up to 250 µg of plasmid DNA; at the same time, it adopts a special buffer system and endotoxin removal filter to effectively remove endotoxin, genomic DNA, RNA, protein and other impurities. The plasmids obtained from this kit are of high purity and stable quality, and can be used for cell transfection, as well as DNA sequencing, PCR, in vitro transcription, endonuclease digestion and other experiments.Self-contained reagents: anhydrous ethanol, isopropanol.Pre-experiment Preparation and Important Notes1. All components are stable for 1 year in a dry, room temperature (15-30°C) environment, and longer by placing the adsorption columns at 2-8°C. Buffer P1 with RNase A is stable for 6 months at 2-8°C.2. Before the first use, add all of the RNase A solution to Buffer P1, mix well, and store at 2-8°C. Before use, it needs to be left at room temperature for a period of time, return to room temperature and then use.3. Anhydrous ethanol should be added to Buffer PW before the first use according to the instructions on the reagent bottle label.4. Please check Buffer P2 and Buffer E3 for crystallization or precipitation before use. If there is any crystallization or precipitation, the clarification can be restored by taking a water bath at 37℃ for a few minutes.5. Be careful not to touch Buffer P2 and Buffer E3 directly, and tighten the lid immediately after use.6. The amount and purity of extracted plasmid is related to the concentration of bacterial culture, strain type, plasmid size, plasmid copy number and other factors.7. The adsorption columns treated with Buffer PS should be used immediately to avoid leaving them for too long.Operation steps1.Take 15-50 ml of fresh bacterial solution from the overnight culture, add it to a centrifuge tube (self-prepared) and centrifuge at 5000 × g for 10 minutes to collect the bacteria, and aspirate all the supernatant as much as possible.2.Add 2.5 ml of Buffer P1 to the centrifuge tube in which the bacterial precipitate has been left (please check that RNase A has been added first) and suspend the bacterial precipitate by mixing thoroughly using a pipette or vortex shaker. Note: If the bacterial mass is not thoroughly mixed, it will affect the lysis effect and make the extraction amount and purity low.3.Add 2.5 ml of Buffer P2 to the centrifuge tube, mix gently up and down 8-10 times to fully lyse the organisms, and leave at room temperature for 3-5 minutes. At this point the solution should become clear and viscous. Note: Mix gently, do not shake vigorously, so as not to interrupt the genomic DNA and cause genomic DNA fragments to be mixed in the extracted plasmid. If the solution does not become clear, it suggests that the amount of bacteria may be too large and the lysis is not complete, and the amount of bacteria should be reduced.4.Add 2.5 ml of Buffer E3 to the centrifuge tube and mix immediately by turning up and down 8-10 times, at which time a white flocculent precipitate appears. Note: Buffer E3 should be mixed immediately after addition to avoid localized precipitation.5.Install the cap of the filter (Endo-Remover FX), transfer the solution obtained in step 4 to the filter, wait until the white flocculent precipitate floats on the upper layer of the solution, remove the cap of the filter, align the filter with a clean 15 ml centrifuge tube (supplied), and slowly push the handle (Plungers) to filter, so that as much as possible of the solution passes through, and the filtrate is collected in the centrifuge tube.6.Add 1/3 solution volume of isopropanol to the filtrate and mix upside down.7.Column Equilibrium: Add 1ml Buffer PS to the adsorption column (Spin Columns DX) that has been loaded into a 15ml centrifuge tube, centrifuge for 2 minutes at 2500 x g. Pour off the waste liquid from the centrifuge tube and put the adsorption column back into the centrifuge tube.8.The mixture of filtrate and isopropanol from step 6 was transferred to the equilibrated adsorption column (which had been loaded into a collection tube).9.Centrifuge at 2500 x g for 1 minute, pour off the waste solution in the collection tube and put the adsorption column back into the collection tube. Note: The maximum volume of the adsorption column is 4 ml, so the solution obtained in step 8 is passed through the column in 2 times.10.Add 2 ml of Buffer PW to the adsorption column (please check that anhydrous ethanol has been added first), centrifuge at 2500 × g for 1 min, and pour off the waste liquid in the collection tube.11.Repeat step 10.12.The adsorbent column was put back into the collection tube and centrifuged at 2500 × g for 2 min, the waste liquid was poured off, and the column was left to dry at room temperature for 5 min.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can interfere with subsequent enzymatic reactions (digestion, PCR, etc.)13. Place the adsorption column in a new 15 ml centrifuge tube, add 0.5-1 ml Endo-Free Buffer EB to the middle of the adsorbent membrane, leave it at room temperature for 2-5 minutes, centrifuge it at 2500 × g for 2 minutes, and collect the plasmid solution into the centrifuge tube. -20°C to store the plasmid.Note: 1) In order to increase the recovery efficiency of the plasmid, the obtained solution can be reintroduced into the adsorption column, left at room temperature for 2-5 minutes, centrifuged at 2500 x g for 2 minutes, and the plasmid solution can be collected into a centrifuge tube.2) When the plasmid copy number is low or >10kb, Endo-Free Buffer EB can increase the extraction efficiency by preheating at 65-70°C in a water bath... 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 | 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 |