| 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 | Annexin V ( annexin-V ) is a Ca2 + dependent phospholipid binding protein with a molecular weight of 35-36 KD, which can selectively bind to phosphatidylserine ( PS ). Phosphatidylserine ( PS ) is mainly distributed in the inner side of the cell membrane, that is, the side adjacent to the cytoplasm.Annexin V ( annexin-V ) is a Ca2 + dependent phospholipid binding protein with a molecular weight of 35-36 KD, which can selectively bind to phosphatidylserine ( PS ). Phosphatidylserine ( PS ) is mainly distributed in the inner side of the cell membrane, that is, the side adjacent to the cytoplasm. In the early stage of apoptosis, different types of cells will turn phosphatidylserine out to the cell surface and expose to the extracellular environment. At this time, using Annexin V labeled with fluorescent protein PE, that is, Annexin V-PE, combined with phosphatidylserine ( PS ), the eversion of phosphatidylserine, an important feature of apoptosis, can be directly detected by flow cytometry. Normal cells will not be stained by Annexin V-PE, apoptotic or necrotic cells will be stained by Annexin V-PE. Annexin V-PE can be used in combination with partially non-permeable nuclear dye ( 7-AAD / PI ) to distinguish cells at different stages of apoptosis. RedNucleus II provided in this kit is a far-red dye that belongs to an anthraquinone compound and cannot penetrate the intact cell membrane of living cells and early apoptotic cells. It is non-permeable, but can quickly stain the nucleus / dsDNA in dead and permeable cells. RedNucleus II is an ideal substitute for propidium iodide ( PI ) and 7-AAD.Combined with Annexin V-PE, it has better spectral characteristics without compensation regulation : it is not excited by ultraviolet light and does not overlap with PE / PE homologues, so it can be combined with FITC, PE and purple fluorescent dyes for multicolor analysis. When combined with Annexin V-PE, RedNucleus II was excluded from living cells and early apoptotic cells, while late apoptotic cells and dead cells were double-positive for Annexin V-PE and RedNucleus II. Annexin V-PE / RedNucleus II apoptosis detection kit can be detected by flow cytometry or other fluorescence detection equipment. Components: Components A598354(10T) A598354(50T) A598354(100T) A. 1×Annexin V Combining buffer solution 10 mL 50 mL 50 mL×2 B. Annexin V-PE 50 µL 250 µL 500 µL C. RedNucleus II 100 µL 500 µL 1 mLProduct parameters：Annexin v-pe:ex/em=488/578 nmrednucleus ii:ex/em=635/695 NMUsage method:1. Experimental design: Blank tube: Negative control group cells, without Annexin V-PE/RedNucleus II. Used to regulate voltage.Single staining tube: Positive control group cells were treated with Annexin V-PE alone/RedNucleus II alone. Used for adjusting compensation.Detection tube: Add Annexin V-PE/RedNucleus II to the processed cells. After adjusting the voltage compensation using blank tubes and single dye tubes, obtain the required flow data.2. Collect cells(1) For suspended cells:a. After inducing cell apoptosis, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, collect the cells, gently resuspend the cells in PBS, and count them.Note: PBS resuspension cannot be omitted. The process of PBS resuspension also serves to wash cells, ensuring the subsequent binding of Annexin V-PE.b. Take 5 × 104-1 × 105 resuspended cells, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, and add 100 µ L of 1 × Annexin V binding buffer to gently resuspend the cells. c. Add 5 µ L Annexin V-PE and mix gently.d. Add 5 µ L of RedNucleus II staining solution and mix gently.e. Incubate at room temperature (20-25 º C) in the dark for 15 minutes. Aluminum foil can be used to avoid light. During the incubation process, cells can be resuspended 2-3 times to improve staining efficiency.(2) For adherent cells:a. Suck out the cell culture medium into a suitable centrifuge tube, wash the adherent cells with PBS once, and add an appropriate amount of trypsin cell digestion solution (without EDTA) to digest the cells. Incubate at room temperature until gently blowing can remove the trypsin cell digestion solution when the adherent cells are blown down. Overdigestion of pancreatic enzymes should be avoided.Note: For adherent cells, the trypsin digestion step is crucial. If the trypsin digestion time is too short, cells need to be blown hard to detach, which can easily cause damage to the cell membrane and lead to false positives of cell necrosis; If the digestion time is too long, it can also cause cell membrane damage and false positives of cell necrosis, and even affect the binding of phosphatidylserine and Annexin V-PE on the cell membrane, thereby interfering with the detection of cell apoptosis.b. Add the cell culture medium collected in the previous step, gently blow down the cells, transfer them to a centrifuge tube, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, collect the cells, gently resuspend the cells in PBS and count them.Note: Adding the cell culture medium from the previous step is very important. On the one hand, it can collect cells that have already been suspended and undergone apoptosis or necrosis. On the other hand, the serum in the cell culture medium can effectively inhibit or neutralize residual trypsin. The residual trypsin will digest and degrade the subsequently added Annexin V-PE, leading to staining failure.c. Take 5 × 104-1 × 105 resuspended cells, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, and add 100 µ L of 1 × Annexin V binding buffer to gently resuspend the cells. d. Add 5 µ L Annexin V-PE and mix gently.e. Add 5 µ L of RedNucleus II staining solution and mix gently.f. Incubate at room temperature (20-25 º C) in the dark for 15 minutes. Aluminum foil can be used to avoid light. During the incubation process, cells can be resuspended 2-3 times to improve staining efficiency.3. Result analysis:(1) Flow cytometry detection:a. After incubation, 400 µ L of 1 × Annexin V binding buffer can be directly added to resuspend the cells, and immediately detected on the machine. Annexin V-PE is excited by 488 nm/566 nm laser, and the fluorescence emission spectrum is detected at 578 nm (BL2 (FL2)/YL1 channel), while the RedNucleus II channel emission spectrum is approximately at 695 nm (RL1 (FL4) channel).b. On the scatter plot of the bivariate flow cytometer, live cells are shown in the lower left quadrant, which is (Annexin V-PE -/RedNucleus II -); The lower right quadrant represents early apoptotic cells, which are (Annexin V-PE+/RedNucleus II -); The upper right quadrant represents necrotic and late stage apoptotic cells, which are (Annexin V-PE+/RedNucleus II+); The upper left quadrant displays naked nuclear cells, which are (Annexin V-PE -/RedNucleus II+).(2) Fluorescence microscopy detection:a. Centrifuge at 1000 rpm for 5 minutes, collect cells, and gently resuspend them in 400 µ L of 1 × Annexin V binding buffer. Transfer the cells to a 96 well plate and settle for a moment or perform cell smear, then observe under a fluorescence microscope.b. Annexin V-PE is compatible with PE filters. RedNucleus II can use a far red long pass filter.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. to reduce the process of apoptosis, the incubation process can be operated on ice, but the incubation time should be extended to at least 30 min. 3. as apoptosis is a rapid process, it is recommended that samples be analyzed within 1 h after staining. 4. for adherent cells, digestion is a key step. If there are floating cells when adherent cells induce apoptosis, the floating cells and adherent cells should be collected and stained. Handle adherent cells with care to avoid artificial damage to cells. The trypsin digestion time is too short, and the cells need to be blown hard to fall off, which is easy to cause damage to the cell membrane and excessive intake of rednucleus II; If the digestion time is too long, the cell membrane is also prone to damage, and even affect the binding of phosphatidylserine and annexin v-pe on the cell membrane. When digesting, spread pancreatin on the bottom of the well plate, fully contact the pancreatin with the cells when shaking gently, then pour out most of the pancreatin, use the remaining small amount of pancreatin to digest for a period of time, and terminate when the gap between cells increases and the bottom of the bottle is spotted. Try not to use EDTA in the digestive juice, which will affect the binding of annexin V to PS. 5. after the adherent cells are digested with trypsin, it is recommended to stain after recovering in the optimal culture conditions and medium for about 30 min to avoid false positives. 6. in order to avoid losing cells when washing cells, you can use a large tip over a small tip to aspirate. 7. the optimal concentration of dye is determined by the specific experimental requirements. 8. fluorescent dyes have quenching problems. Please try to avoid light during storage and use to slow down fluorescence quenching. 9. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Early apoptosis detection, annexin V Kit... Read More | Inquire | Product Characteristics Effect Diluents, Animal-free are effective buffers free of any animal components. They can be used for the dilution of serum, plasma, blood, stool or urine samples, as well as the dilution of primary and secondary antibodies. Effect Diluents, Animal-free efficiently minimize Product Characteristics Effect Diluents, Animal-free are effective buffers free of any animal components. They can be used for the dilution of serum, plasma, blood, stool or urine samples, as well as the dilution of primary and secondary antibodies. Effect Diluents, Animal-free efficiently minimize matrix effects, cross-reactions and unspecific binding in immunoassays like ELISA, Western blotting, Immunohistochemistry, protein arrays and immuno-PCR.The Effect Diluents, Animal-free are used alternatively to the standard sample or antibody dilution buffers: In ELISA for the dilution of specimen and detection antibodies. In Western Blotting for the dilution of primary and secondary antibodies. In Protein arrays for the dilution of specimen and detection antibodies. In immuno-PCR as a washing buffer.Three versions of the diluent are offered: Low, Medium and High for optimal discrimination between specific and unspecific reaction and for minimizing strong interference effects e.g., by RF (rheumatoid factors), HAMAs (human-a-mouse Abs) or by endogenous components that bind and mask the analyte.Composition & Properties The Effect Diluents, Animal free contain no animal components and are free of phosphates.Working Procedure 1.Mix thoroughly prior to use. 2.Dilution recommendations a.Dilute antibodies according to the instruction of the antibody b.Dilution of the specimen is recommended at 1:2 or higherTips & TricksEffect Diluents must not be considered as blocking buffers. Recommended blocking buffers are: Synthetic Blocking Buffer, ELISA (cat. no. S494401), Synthetic Blocking Buffer, Blotting (cat. no. S494457) and WellChampion (cat. no. W494467) for plate blocking and stabilization (preparation of pre-coated plates). Complex sample matrices, such as serum and plasma, may contain interfering factors that affect the ability of the assay to accurately quantify the target analyte. Strong interferences are often caused by RFs and HAMAs. This matrix effect can cause high background in the negative control or false negatives in the sample measurement. To reduce this effect the samples can be diluted in the Effect Diluents, Animalfree.Handling & Storage Store solution 2-8°C or -15 to -30°C (tolerates freezing and thawing cycles)... Read More | Product content N665859Component50 TStorageN665859ABuffer DS30 mLRTN665859BBuffer GTL15 mLRTN665859CBuffer GL15 mLRTN665859DBuffer GW1 (concentrate)13 mLRTN665859EBuffer GW2 (concentrate)15 mLRTN665859FBuffer TE10 mLRTN665859GProteinase K2×1.25 mLRTN665859HRNase A (100 mg/mL)0.4 Product content N665859Component50 TStorageN665859ABuffer DS30 mLRTN665859BBuffer GTL15 mLRTN665859CBuffer GL15 mLRTN665859DBuffer GW1 (concentrate)13 mLRTN665859EBuffer GW2 (concentrate)15 mLRTN665859FBuffer TE10 mLRTN665859GProteinase K2×1.25 mLRTN665859HRNase A (100 mg/mL)0.4 mLRTN665859ISpin Columns DF With Collection Tubes50 EA2-8℃N665859JCentrifuge Tubes (L-1.5 mL)50 EART Product IntroductionThis kit is suitable for the effective purification of genomic DNA from formalin-fixed, paraffin-embedded tissues.The product uses specially optimized dewaxing agent and lysis solution to release DNA from formalin-fixed or tissue sectioned samples, which does not involve the organic reagent xylene and does not need to be operated overnight; the digested samples are incubated at higher temperatures to remove formalin cross-linking of the free DNA, which can effectively improve the yield and purity of DNA; the optimized buffer system allows the inhibitors in the lysis solution to be specifically bound to the adsorbent membrane, which can be effectively removed by a two-step rinsing step. The optimized buffer system enables the DNA in the lysate to specifically bind to the adsorbent membrane, and the inhibitor is effectively removed by a two-step rinsing step, and finally eluted with low-salt buffer or water to obtain high-purity DNA.Meanwhile, configured with a high-efficiency microsorbent column, the elution volume can be as low as 20 µL.The purified DNA can be directly used for PCR, Real-time PCR, SNP Genotyping, STR genotyping, second-generation sequencing and pharmacogenomics research.The molecular weight of DNA isolated from formalin-fixed, paraffin-embedded samples is usually lower than that of DNA from fresh or frozen samples.The degree of DNA fragmentation depends on the type of sample, the duration of storage, and the conditions of fixation.Self-contained reagent: anhydrous ethanolPre-experiment Preparation and Important Notes1. After obtaining the sample, fix the sample in 4%-10% formalin as soon as possible, the fixation time should be 14-24 hours, too long a period of time will easily lead to genome breakage, affecting the downstream experiments. If the formaldehyde fixation time is too long or the sample has been stored for too long (> 1 year), it will easily lead to DNA integrity damage and unable to amplify long fragments.2. Ensure that the sample is thoroughly dehydrated before embedding; residual formalin will inhibit Proteinase K.3. 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.4. Before use, please check Buffer GTL, Buffer GL and Buffer DS for any crystallization or precipitation. If there is any crystallization or precipitation, please re-dissolve Buffer GTL, Buffer GL and Buffer DS at 56℃ in a water bath.5. Preheat the water bath or thermostatic mixer to 56°C and keep the centrifuge at 25°C before starting the experiment.6. If downstream experiments are needed to reduce the low frequency of C>T:G>A transitions (artificial mutations) that occur to minimize the risk of false positives, 7 µL of UNG (1 U/uL) can be added after 1 hour of incubation at 90°C.Operation steps1. Sample processing:1a. Paraffin-embedded samples: Trim off excess paraffin from the tissue block with a scalpel to expose the tissue and then cut into 5-10µm slices. Take about 1×1cm2 slices (about 4-5 slices in total) and place them in a centrifuge tube (provided), add 160µL Buffer DS, vortex and shake for 10 seconds, then add 180µL Buffer GTL and 20µL Proteinase K, vortex and shake for 10 seconds. centrifuge the samples at 12,000rpm for 1 minute at 25℃.Note: 1) If the surface of the sample has been exposed to air, discard the 2-3 pieces that have been exposed to air and do not use them.2) DS will solidify below 18°C, and if it does it does not affect the following experiments.1b. Sample in formalin and other fixative: take about 20mg of sample, cut it into small pieces, place it in a centrifuge tube, add 500µL of 10mM PBS (PH7.4), vortex shaking, centrifuge at 12,000rpm for 1minute, discard the supernatant, and repeat 3 times. Add 180 µL Buffer GTL, 20 µL Proteinase K, vortex shaking to mix.2.56°C for 1 hour until the sample is completely dissolved. incubate at 90°C for 1 hour. centrifuge at 12,000 rpm, 25°C for 1 minute, and carefully pipette the lower aqueous phase (~180 µL) along the wall of the tube into a new centrifuge tube, trying to avoid aspirating the bottom precipitate and the upper layer of the wax solution.Note: 1) Samples can be left at room temperature after incubation at 56°C until the temperature of the water or dry bath reaches 90°C before placing the samples at 90°CIncubation.2) Optional step: add 7µL UNG (1U/µL), 50°C, 5min, no shaking. The purpose of this step is to minimize the risk of false positives by reducing the low-frequency occurrence of C>T:G>A transitions (artificial mutations) while effectively retaining the true occurrence of mutations.3. Optional step: If you need to remove RNA, you can lower the temperature of the sample to room temperature, then add 2µL of RNase A solution at a concentration of 100mg/mL, shake and mix well, and leave it at room temperature for 2 minutes.4. Add 20µL Proteinase K and incubate at 65℃, 450rpm for 15min.5. Add 200 µL of Buffer GL, mix well by vortexing and shaking, then add 200 µL of anhydrous ethanol and mix thoroughly by vortexing and shaking. Centrifuge briefly so that the solution on the wall of the tube collects at the bottom of the tube.Note: 1) Mix well immediately after adding Buffer GL and anhydrous ethanol.2) The addition of Buffer GL and anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.3) If more than one sample needs to be manipulated, the Buffer GL and anhydrous ethanol can be pre-mixed and spiked.6. Add all the solution obtained in step 5 to the adsorption columns (Spin Columns DF) that have been loaded into the collection tube, centrifuge at 25℃, 12000rpm for 2 minutes, pour out the waste liquid in the collection tube, and put the adsorption columns back into the collection tube.7. Add 500µL of Buffer GW1 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.8. Add 500µL of Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12000rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.Note: Step 8 can be repeated if further DNA purity is required.9.12 Centrifuge at 2000 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.10. Place the adsorption column in a new 1.5 mL collection tube, add 20-100 µL of Buffer TE or sterilized water to the middle of the adsorption column overhanging the column, let it stand at room temperature for 2-5 minutes, centrifuge it at 12,000 rpm for 1 minute, and collect the DNA solution.-20°C to preserve DNA.Note: 1) The pH value of the eluent has a great influence on the elution efficiency, if water is used as the eluent should ensure that its pH value is 7.0-8.5, the pH value is lower than 7.0 when the elution efficiency is not high.2) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 10 can be re-spiked onto the adsorbent membrane and left at room temperature for 2 minutes and centrifuged at 12,000 rpm for 1 minute... Read More |