| Description | Pyruvate Kinase (PK, EC 2.7.1.40) is widely present in animals, plants, microorganisms, and cultured cells. It catalyzes the final step of glycolysis and is one of the key rate-limiting enzymes in glycolysis, as well as a crucial enzyme for ATP production. Therefore, determining PK activity is of Pyruvate Kinase (PK, EC 2.7.1.40) is widely present in animals, plants, microorganisms, and cultured cells. It catalyzes the final step of glycolysis and is one of the key rate-limiting enzymes in glycolysis, as well as a crucial enzyme for ATP production. Therefore, determining PK activity is of significant importance.Detection Principle: PK catalyzes the conversion of phosphoenolpyruvate and ADP to ATP and pyruvate. Lactate dehydrogenase (LDH) further catalyzes the reaction of NADH and pyruvate to produce lactate and NAD⁺. The change in NADH absorbance at 340 nm is measured to calculate the PK activity in the sample.Applicable Samples: Animal/plant tissues, cells, bacteria, serum (plasma)A1501205Component48T96TStorageA1501205AExtraction Buffer60 mL60 mL×22-8℃A1501205BAssay Buffer12 mL24 mL2-8℃A1501205CSubstrate Mix1EA1EA-20℃. Store in the dark.A1501205DLDH10.2 µL20.4 µL2-8℃Please check the quantity of each component before the experiment.An additional 10% of each component is provided beyond the specified volume for standard curve preparation or preliminary experiments.User-Provided Instruments and ReagentsTypeNameNotesInstrumentMicroplate ReaderCapable of measuring absorbance at 340 nm.Consumables96-well UV PlateUV-transparent plate.ReagentsPBS (pH 7.4) / Deionized WaterFor washing cells/bacteria / Reagent preparation.OthersHomogenizer (for tissue samples), incubator, ice bucket, low-temperature centrifuge, adjustable pipettes and tipsUsing a multichannel pipette for large-scale detection can improve efficiency.Experimental Procedure1. Reagent PreparationReagent NameReagent PreparationPrecautionsExtraction BufferReady-to-use; equilibrate to room temperature before use.Store at 4°C.Assay BufferReady-to-use; equilibrate to room temperature before use.Store at 4°C.Substrate Mix Working ReagentPrepare before use: For 48T: Add 10.2 mL Assay Buffer and 0.6 mL deionized water to the vial. For 96T: Add 20.4 mL Assay Buffer and 1.2 mL deionized water to the vial. Dissolve thoroughly.After preparation, aliquot and store at -20°C for up to 6 months. Avoid repeated freeze-thaw cycles. Before use, incubate at 25°C (for general species) or 37°C (for mammals) for 5 min.LDH Working ReagentPrepare before use: For 48T: Add 0.6 mL deionized water to the LDH vial. For 96T: Add 1.2 mL deionized water to the LDH vial. Mix thoroughly.Keep on ice after preparation. The diluted reagent can be stored at 4°C for 1 month.2. Sample PreparationNote: Fresh samples are recommended. If not used immediately, samples can be stored at -80°C for up to 1 month.2.1 Animal/Plant Tissues: Weigh approximately 0.1 g of tissue, add 1 mL of Extraction Buffer, and homogenize on ice. Centrifuge at 8000 g, 4°C for 10 minutes. Collect the supernatant and keep on ice for detection.2.2 Cells/Bacteria: Collect 5×10⁶ cells or bacteria into a centrifuge tube. Wash with cold PBS, centrifuge, and discard the supernatant. Add 1 mL of Extraction Buffer. Disrupt by ultrasonic homogenization on ice (power 20% or 200 W, ultrasonicate for 3 s, interval 7 s, repeat 30 times). Centrifuge at 8000 g, 4°C for 10 minutes. Collect the supernatant and keep on ice for detection.2.3 Serum (Plasma) and other liquid samples: Detect directly.3. Assay Steps3.1 Microplate Reader Preparation: Preheat for at least 30 minutes. Set the wavelength to 340 nm.3.2 Assay System Setup: In a 96-well UV plate, add sequentially: 10 µL of sample, 10 µL of LDH Working Reagent, and 180 µL of Substrate Mix Working Reagent. Mix rapidly immediately after addition.3.3 Absorbance Measurement: Immediately after mixing, measure the absorbance at 340 nm at 20 seconds (A1) and then at 2 minutes and 20 seconds (A2). Calculate ΔA = A1 - A2.4. Result Calculation4.1 Data ProcessingCalculate ΔA = A1 - A2.4.2 Sample PK Activity Calculation(1) Based on sample mass:Unit Definition: One unit of enzyme activity is defined as the consumption of 1 nmol NADH per minute per gram of tissue in the reaction system.Formula:PK (U/g) = [ΔA×Vtotal reaction÷ (ε × d) × 10⁹] ÷ (Vsample ÷ Vtotal extract×W) ÷ T = 3215 × ΔA ÷ W(2) Based on cell/bacterial count:Unit Definition: One unit of enzyme activity is defined as the consumption of 1 nmol NADH per minute per 10⁴ bacteria or cells in the reaction system.Formula:PK (U/10⁴) = [ΔA × Vtotal reaction ÷ (ε × d) × 10⁹] ÷ (Vsample ÷ Vtotal extract; × 500) ÷ T = 3215 × ΔA ÷ 500 = 6.431 × ΔA(3) Based on liquid volume:Unit Definition: One unit of enzyme activity is defined as the consumption of 1 nmol NADH per minute per mL of serum (plasma) in the reaction system.Formula:PK (U/mL) = [ΔA × Vtotal reaction; ÷ (ε × d) × 10⁹] ÷ Vsample ÷ T = 3215 × ΔA(4) Based on protein concentration:Unit Definition: One unit of enzyme activity is defined as the consumption of 1 nmol NADH per minute per mg of protein in the reaction system.Formula:PK (U/mg prot) = [ΔA × Vtotal reaction; ÷ (ε × d) × 10⁹] ÷ (Cpr × Vsample ) ÷ T = 3215 × ΔA ÷ CprParameter Description:Vtotal reaction; : Total reaction volume, 2 × 10⁻⁴ Lε: Molar extinction coefficient of NADH, 6.22 × 10³ L/mol/cmd: Light path of the 96-well plate, 0.5 cm10⁹: Conversion factor (1 mol = 1 × 10⁹ nmol)Vsample : Volume of sample added, 0.01 mLVtotal extract; : Volume of Extraction Buffer added, 1 mLT: Reaction time, 2 minCpr: Sample protein concentration, mg/mLW: Sample mass, g500: Cell or bacterial count (5 × 10⁶), converted to units of 1Precautions1. It is recommended to perform preliminary experiments using 2-3 samples expected to have significant differences before formal testing.2. This kit is compatible with spectrophotometer detection. Adjust the preparation volume of detection reagents proportionally according to the spectrophotometer's requirements.3. For tissue and cell samples, results can be normalized by measuring the protein concentration. Aladdin BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648) are recommended.4. Biochemical reagents are generally irritating and biologically toxic. For your safety and health, please implement appropriate biosafety precautions throughout the experiment. Wear personal protective equipment such as lab coats, masks, gloves, and hair caps. Perform experiments in a fume hood or biosafety cabinet.5. This product is for scientific research use only. Not intended for clinical diagnosis.Frequently Asked QuestionsQ: What should I do if the sample ΔA is too high or too low?A: If the sample ΔA is > 1.0, the PK activity in the sample is too high. Dilute the sample appropriately with Extraction Buffer or reduce the amount of sample used for extraction, and then re-assay. If the sample ΔA is < 0.005, extend the reaction time to 5 or 10 minutes, or appropriately increase the sample amount, and then re-assay.Q: Will testing multiple samples simultaneously affect the results?A: Appropriately extending the time by 3-5 minutes for this assay will not affect the results. When testing multiple samples, it is recommended to use a multi-channel pipette for operation... Read More | DescriptionUse in combination with the KitAlysis Bench Top Inertion Box (Z742064) or a glove box/glove bag to provide inert atmosphere for kit set-up.Designed to be used with KitAlysis High-Throughput Screening Kits.Components:24-Well Reaction BlockTorque ScrewdriverSmall screwdriver to easily DescriptionUse in combination with the KitAlysis Bench Top Inertion Box (Z742064) or a glove box/glove bag to provide inert atmosphere for kit set-up.Designed to be used with KitAlysis High-Throughput Screening Kits.Components:24-Well Reaction BlockTorque ScrewdriverSmall screwdriver to easily remove torqued screws after reaction is complete.10 Reaction Block Replacement Screws... Read More | Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 500ug of high-purity plasmid DNA from 120-300ml bacterial Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 500ug of high-purity plasmid DNA from 120-300ml bacterial culture for sequencing, in vitro transcription and translation, restriction enzyme digestion, bacterial transformation and other molecular biology experiments.Scope of application：Nucleic acid extraction and purification... 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 | Products contentProducts IntroductionThis kit is suitable for simple, rapid and efficient isolation and purification of DNA/RNA from whole blood, tissue homogenates, swabs, serum, plasma and other cell-free body fluids, etc. The unique buffer system enables the viral nucleic acids in the lysate to Products contentProducts IntroductionThis kit is suitable for simple, rapid and efficient isolation and purification of DNA/RNA from whole blood, tissue homogenates, swabs, serum, plasma and other cell-free body fluids, etc. The unique buffer system enables the viral nucleic acids in the lysate to bind to the silica gel centrifugal adsorbent columns in a highly efficient manner, and the viral nucleic acids obtained are of high purity and stable quality, free of protein, nuclease and other impurities, and can be used in a variety of routine operations, including PCR, fluorescence quantitative PCR and other experiments. It can be used for a variety of routine operations, including PCR, fluorescence quantitative PCR and other experiments.Bring your own instrumentsThermostatic mixer.Pre-experiment Preparation and Important Notes1. Read these instructions carefully before experimenting.2. If Proteinase K is to be stored for a long period of time, please keep it at -20℃.3. Check Buffer RLC for crystallization or precipitation prior to use, and if crystallization or precipitation occurs, redissolve Buffer RLC in a 56°C water bath.4. Pre-treatment of tissue samples: Take 20 mg of tissue samples into 1.5 mL centrifuge tubes (self-provided), add 500 µL of Buffer RLC, and after the tissue homogenizer breaks up, centrifuge the samples for 1 minute at 12,000 rpm (~13,400×g), and take 200 µL of supernatant as samples. procedure1. Take a 1.5 mL centrifuge tube (provided), add 500 µL of Buffer RLC, 200 µL of sample, 20 µL of Proteinase K, vortex for 5 s, and then place it in a thermostatic mixer at 1200 rpm for 10 min at room temperature. Note: For wet swab samples, 200 µL of sample was taken after sufficiently shaking and mixing. Note: For wet swabs, 200 µL was taken from the sample after it was soaked in 400 µL of saline, shaken and mixed thoroughly for 5 minutes, and then centrifuged at 12,000 rpm for 1 minute, and 200 µL was taken for extraction.2. Instantly remove the centrifuge tube and add the solution from step 1 to the Spin Columns DM in the collection tube. centrifuge at 12,000 rpm (~13,400 x g) for 1 minute, pour off the waste liquid from the collection tube, and return the column to the collection tube.3. Add 500 µL of Buffer PGWT to the adsorbent column, centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid from the collection tube, and return the column to the collection tube.4. Add 500 µL of Buffer GWT2 to the adsorbent column, centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid from the collection tube, and return the column to the collection tube.5. Centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Place the adsorption column at room temperature for 2 minutes and allow to dry.6. Place the column in a new collection tube (RNase-Free Centrifuge Tube), add 40-100 µL of RNase-Free Water to the center of the column membrane, let it stand at room temperature for 2 minutes, and then centrifuge at 12,000 rpm for 1 minute to collect the nucleic acid solution. Store at -80℃ for a long time... Read More |