| Description | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export | Product IntroductionBCIP (5-Bromo-4-chloro-3-indolyl phosphate) 5-bromo-4-chloro-3-indolyl-phosphate + NBT (tetrazolium nitro blue) is the best substrate for alkaline phosphatase (AP) One of the combination. Under the catalysis of alkaline phosphatase, BCIP will be hydrolyzed to produce a highly Product IntroductionBCIP (5-Bromo-4-chloro-3-indolyl phosphate) 5-bromo-4-chloro-3-indolyl-phosphate + NBT (tetrazolium nitro blue) is the best substrate for alkaline phosphatase (AP) One of the combination. Under the catalysis of alkaline phosphatase, BCIP will be hydrolyzed to produce a highly reactive product, which reacts with NBT to form an insoluble dark blue to blue-violet compound. This kit can be used for the enzymatic color development of IHC and Western Blot experiments of the AP system. Under AP catalysis, a dark blue precipitate is produced where AP conjugates are combined on tissue sections or blotting membranes. The location and expression of the target protein can be determined based on the color reaction.Product Components40×BCIP: 1 ml40×NBT: 1 mlBCIP/NBT Buffer: 40 mlPrecautions1. The working fluid should be prepared for immediate use, and the prepared working fluid will be effective within 1 hour.2. The amount of working fluid must be sufficient to ensure complete coverage of the tissue sheet or blotting membrane. To3. In order to obtain the best experimental results, be sure to optimize the experimental conditions.4. NBT is poisonous, please take necessary protective measures when using it.5. This product is only used for scientific research, not for human experiments or human treatment.Instructions1. BCIP/NBT color developing working solution preparation:According to the required amount, mix 40×BCIP, 40×NBT and BCIP/NBT Buffer in a volume ratio of 1:1:38 to form the BCIP/NBT color developing working solution.2. Color rendering:1) Blotting membrane color development: Drop the prepared working solution on the blotting membrane (or pour the blotting membrane into the BCIP/NBT color developing working solution), and incubate for 3-10 minutes at room temperature and dark. After the color development is completed, the film is immersed in water to terminate the reaction.2) Color development of tissue sections or cell slides: Drop an appropriate amount of BCIP/NBT color developing working solution on the tissue sections or cell slides that need color development, and incubate at room temperature for 3-10 minutes in the dark. Observe under the microscope to control the color development time. When the best color development effect is reached, rinse with tap water to stop the color development. After color development, the slices are counter-stained, dehydrated and transparent, and can be stored for a long time after mounting... Read More | 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 | Products contentN665954Component24 T96 TStorageN665954ATPS V136 µL144 µL-20℃. Avoid freeze/thaw cycle.N665954B5×FA Reaction Buffer96 µL384 µL-20℃. Avoid freeze/thaw cycle.N665954CTS Buffer72 µL288 µL-20℃. Avoid freeze/thaw cycle.N665954D2× Products contentN665954Component24 T96 TStorageN665954ATPS V136 µL144 µL-20℃. Avoid freeze/thaw cycle.N665954B5×FA Reaction Buffer96 µL384 µL-20℃. Avoid freeze/thaw cycle.N665954CTS Buffer72 µL288 µL-20℃. Avoid freeze/thaw cycle.N665954D2× PCR Mix600 µL2×1.2 mL-20℃. Avoid freeze/thaw cycle. * This kit is suitable for human genomic DNA library construction, the starting template DNA input amount is 1 ng, our company also has 50 ng and 5 ng of human genomic DNA starting transposase method library construction kit, in order to get a higher quality library, different starting amount of DNA is recommended to use different kits. Products IntroductionThis kit is developed for Illumina's high-throughput sequencing platform and provides the enzyme premix system and reaction buffer for genomic DNA library construction, including all components except PCR primers. Compared with the traditional library construction kits, this kit adopts the new transposase method for library construction, which can complete DNA fragmentation, end repair and junction reaction in one simple enzymatic reaction, significantly reducing the amount of template, reducing the number of experimental steps, and shortening the time of library construction; it adopts the high-fidelity DNA polymerase for library enrichment, and the preference-free PCR amplification can expand the coverage area of the sequence, which can be used for efficient and effective sequencing. The use of high-fidelity DNA polymerase for library enrichment and preference-free PCR amplification broadens the coverage area of the sequence and enables efficient preparation of DNA libraries for Illumina's second-generation sequencing platform. The kit is suitable for use with 1 ng of starting template DNA, and all reagents in the kit have been subjected to stringent quality control and functional validation to maximize the stability and reproducibility of library construction.Product Features● DNA fragmentation and junction ligation in one step.● Ultra-fidelity amplification minimizes amplification preference.Provide your own instruments, kits and consumables1. Magnetic frame: DynaMagTM-2 is recommended.2. DNA purification and recovery kit: It is recommended to use Kangwei DNA purification and recovery kit by magnetic bead method.3. Library PCR primer kit: It is recommended to use Kangwei transposase method for second generation sequencing multi-sample primer kit.4. Anhydrous ethanol, deionized water (pH between 7.0 and 8.0).5. Reaction tubes: It is recommended to use low adsorption PCR tubes with 1.5 ml centrifuge tubes.Tip: It is recommended to use a high quality filter tip to prevent contamination of kits and library samples. Pre-experiment Preparation and Important Notes1. Avoid repeated freezing and thawing of reagents.2. PCR products are easily contaminated due to improper operation, resulting in inaccurate results. It is recommended to isolate the PCR reaction system preparation area from the PCR product purification area, and to use special pipettes to clean the experimental areas at regular intervals.3. Bead purification: the beads should be equilibrated to room temperature before use, all operations on the beads should be carried out at room temperature, 80% ethanol should be dispensed freshly, the beads should be rinsed and dried until the surface is free of liquid reflections and has a frosted appearance, insufficient drying of the beads will cause ethanol residue that will affect the subsequent experiments, and over-drying of the beads will affect the efficiency of DNA recovery.4. The kit is suitable for human genomic DNA library construction, if the DNA sample is a PCR product, it should be ensured that its length>.500 bp, since transposases do not work on DNA ends, it is recommended to extend the PCR product by 50-100 bp at each end of the PCR product to avoid low coverage of the ends for sequencing. Sample PreparationDNA purity requirement: A260/A280 = 1.8-2.0. Sample DNA: dissolved in ultrapure water.DNA quantification: Too much or too little DNA will affect the quality of the library. It is recommended to use Nano to test the purity of the genomic DNA and then use Qubit to test the concentration of the genome (do not use any absorbance-based assay for template quantification). Schematic diagram of DNA banking process procedureDNA fragmentation, junction reaction 1. Add the following reagents to a 200 µl PCR tube:2. Mix by gently blowing with a pipette and centrifuge briefly so that all components are collected at the bottom of the tube.3. Place the above PCR tubes in the PCR instrument with the hot cap on and program the reaction as follows:inactivation reactionAfter the DNA is fragmented, the enzyme is still in a high active state, so it should be removed from the PCR instrument immediately and terminated by adding the Reaction Termination Buffer, in order to prevent the DNA from being fragmented too much and resulting in smaller library fragments.1. Add 3 µl of TS Buffer to the PCR tube containing the fragmentation product.2. Mix by gently blowing with a pipette and centrifuge briefly so that all components are collected at the bottom of the tube.3. Incubate at room temperature for 5 min, or if the room temperature is too low, place the reaction on a PCR instrument at 25°C with the thermal cover closed.PCR amplification1. Add the following reagents to a 200 µl PCR tube.2. Mix by gently blowing with a pipette and centrifuge briefly so that all components are collected at the bottom of the tube. 3. Place the above PCR tubes in the PCR instrument with the thermal cap open, and the reaction program is as follows:Selective recovery of library DNA fragmentsIt is recommended to use CombiVision Magnetic Beads DNA Purification and Recovery Kit for selective recovery of DNA fragments. When different sizes of DNA fragments are required, the amount of magnetic beads used is different, please refer to the attached table for the specific amount of magnetic beads used.(If using other brands of magnetic beads, you need to figure out the optimal amount of magnetic beads by yourself).Note: Amplification products can also be fragment length sorted and purified using the Gum Recovery Kit. If there is no special requirement for library length distribution, amplification products can also be purified directly from DNA fragments without selective recovery of DNA fragments as described on page 4 of the manual.1. CMPure should be equilibrated at room temperature for 30 min after shaking and mixing before use.2. Transfer the PCR products to a 1.5 ml centrifuge tube, rehydrate to 100 µl, add several volumes of magnetic beads equilibrated to room temperature, vortex for 5 seconds, and let stand at room temperature for 5 minutes.3. Centrifuge briefly, place the tube on a magnetic rack to separate the beads from the supernatant until the solution is clear, and carefully aspirate the supernatant and transfer it to a new 1.5 ml centrifuge tube.Note: Do not discard the top clear.4. Add several volumes of magnetic beads to the supernatant, vortex and shake for 5 seconds, then let stand at room temperature for 5 minutes.5. Centrifuge briefly, place the tube on a magnetic rack to separate the beads from the supernatant until the solution is clear, carefully aspirate the supernatant and discard it, avoiding contact with the beads that have bound the target DNA.Note: Do not discard the beads.6. Continue to keep the centrifuge tube fixed on a magnetic rack and add 200 µl of freshly prepared 80% ethanol to the tube and allow to stand at room temperature for 30 seconds, carefully discarding the supernatant.Note: When adding ethanol, the liquid must not be blown directly onto the beads.7. Repeat step 6 once.8. Keep the centrifuge tube fixed on a magnetic rack and leave to dry at room temperature until the surface of the beads is slightly cracked, add 20 µl of ddH2O to solubilize.Note: Do not over-dry the beads as this may affect the elution efficiency.9. Remove the tube from the magnetic rack, vortex to completely resuspend the beads, and allow to stand at room temperature for 5 minutes. Centrifuge briefly, place the tube on the magnetic rack until the solution is clear, and transfer the supernatant solution to a new tube. Table: Suggested amount of magnetic beads for different segment selection recoveryLibrary DNA fragment purificationWe recommend the use of the Kangwei Century Magnetic Bead Method DNA Purification and Recovery Kit.1. CMPure should be equilibrated at room temperature for 30 min after shaking and mixing before use.2. 50 µl of magnetic beads equilibrated to room temperature were added to the PCR product, vortexed and shaken for 5 seconds, and then left to stand at room temperature for 5 minutes.3. Centrifuge briefly, place the tube on a magnetic rack to separate the beads from the supernatant solution until the solution is clear (approximately 3-5 minutes), carefully aspirate the supernatant and discard it, avoiding contact with the beads that have bound the target DNA. Note: Do not discard the beads.4. Continue to keep the centrifuge tube fixed on a magnetic rack and add 200 µl of freshly prepared 80% ethanol to the centrifuge tube and allow to stand at room temperature for 30 seconds, carefully discarding the supernatant.Note: When adding ethanol, the liquid must not be blown directly onto the beads.5. Repeat step 4.6. Keep the centrifuge tube fixed on a magnetic rack and leave to dry at room temperature until the surface of the beads is slightly cracked, add 25 µl of ddH2O to solubilize.Note: Do not over-dry the beads as this may affect the elution efficiency.7. Remove the tube from the magnetic rack, vortex to completely resuspend the beads, and allow to stand at room temperature for 5 minutes. Centrifuge briefly, place the tube on the magnetic rack until the solution is clear, and transfer the supernatant solution to a new tube. Library quality controlDetermination of library concentrationIn order to obtain high-quality sequencing results, accurate quantification of DNA libraries is required, and the first recommendation is to use Real-timePCR methods are used for absolute quantification of DNA libraries. Additionally, fluorescent dye methods such as the Qubit method or the fluorescent dye picogreen method can be used; do not use quantification methods based on absorbance measurements here. The following approximate formula can be used to convert the molar concentration of the DNA library.Library fragment distributionThe prepared DNA libraries can be detected by agarose gel electrophoresis or Agilent 2100 Bioanalyzer.Range of segment length distributions... Read More | Product introduction：PMA qPCR live bacteria detection kit provides an effective means to detect bacterial activity. This kit provides a mixture of PMA dye and SYBR green dye based qPCR. The optimal amount of dye and the number of samples that can be processed may vary depending on the type ofProduct introduction：PMA qPCR live bacteria detection kit provides an effective means to detect bacterial activity. This kit provides a mixture of PMA dye and SYBR green dye based qPCR. The optimal amount of dye and the number of samples that can be processed may vary depending on the type of sample. PMA is a DNA binding dye with high affinity, especially with double stranded DNA. The dye itself has weak fluorescence, but it can emit brighter fluorescence after binding with nucleic acids. PMA is impermeable to the cell membrane, so it can selectively modify the DNA of dead cells with damaged membrane. After bllight (~464 nm) photolysis of PMA modified DNA, the photoreactive azido group on PMA is converted into highly reactive azene radical, which reacts with any hydrocarbon moiety near the DNA binding site to form a stable covalent nitrogen carbon bond, resulting in permanent DNA modification. This modification process will make the DNA insoluble, and it will be lost together with cell debris in the later genomic DNA extraction process. The unbound PMA remaining in the solution reacts with water molecules under strong light irradiation and decomposes into hydroxylamine compounds without cross-linking activity, so that it can no longer covalently bind DNA. Based on this characteristic of PMA, our company combines PMA and qPCR technology to form a new detection method - PMA qPCR, which is used for the screening of live bacteria. At present, the method has been validated in a variety of bacterial strains as well as yeast, fungi, viruses and parasites. The treatment of complex samples, such as feces or soil, may require optimization of sample dilution, dye concentration, and light treatment time. Treatment of diluted samples, such as water testing, may require filtration or concentration prior to dye treatment. Component： 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 ( used for the photolysis step after PMA modified DNA ) ;② Bacterial genomic DNA extraction kit ; 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 procedureNote : 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. 3. 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 : Product parameters：Pma: ex = 464 nm; Ex/em = 510/610 nm (following photolysis and reaction with dna/rna)Scope of application：Live bacteria detection Matters needing attention：1.Please instantaneously centrifuge the product to the bottom of the tube before use, and then carry out subsequent experiments ; 2.the kit components contain fluorescent dyes, and attention should be paid to avoiding light during use and preservation ; 3.For your safety and health, please wear experimental clothes and disposable gloves... Read More |