| Description | Lactic acid is an important intermediate product in the metabolic processes of organisms, closely related to carbohydrate metabolism, lipid metabolism, protein metabolism, and intracellular energy metabolism. Lactic acid concentration is a key indicator for evaluating glycogen metabolism and aerobicLactic acid is an important intermediate product in the metabolic processes of organisms, closely related to carbohydrate metabolism, lipid metabolism, protein metabolism, and intracellular energy metabolism. Lactic acid concentration is a key indicator for evaluating glycogen metabolism and aerobic metabolism. Abnormally high concentrations of lactic acid are associated with pathological conditions such as cancer, diabetes, and lactic acidosis.The detection principle of this kit is as follows: Lactate dehydrogenase catalyzes the conversion of L-lactate to pyruvate, simultaneously reducing NAD+ to NADH and H+. Further, through the hydrogen transfer action of 1-mPMS, WST-8 reacts to form a yellow, soluble formazan. The absorbance at 450 nm is measured to calculate the L-lactate content in the sample.Detection Range: 0.03-2 mMSensitivity: 0.03 mMApplicable Samples: Animal and plant tissues, cells, bacteria, serum (plasma), or other liquids.L1501211Component48T96TStorageL1501211ALactate Assay Buffer70 mL70 mL×22-8℃L1501211BLactate Dehydrogenase0.7 mL1.4 mL-20℃L1501211CLactate Dehydrogenase Cofactor0.5 mL1 mL-20℃L1501211DWST-8350 µL700 µL-20℃. Store in the dark.L1501211EEnhancer70 µL140 µL-20℃. Store in the dark.L1501211FL(+)-Lactate Standard (100 mM)50 µL100 µL-20℃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 450 nm.Consumables96-well MicroplateStandard transparent plate.ReagentsPBS (pH 7.4)For washing samples.OthersHomogenizer (for tissue samples), incubator, ice machine, low-temperature centrifuge, adjustable pipettes and tipsUsing a multichannel pipette for large-scale detection can improve efficiency.Experimental Procedure1. Reagent PreparationReagent NameReagent PreparationPrecautionsLactate Assay BufferReady-to-use; equilibrate to room temperature before use.4℃保存 Store at 4°C.Lactate DehydrogenaseReady-to-use;Keep on ice during the experiment; store aliquots at -20°C.Lactate Dehydrogenase CofactorReady-to-use;Keep on ice during the experiment; store aliquots at -20°C.WST-8Ready-to-use;Keep on ice during the experiment; store aliquots at -20°C.EnhancerReady-to-use;Keep on ice protected from light during the experiment; store aliquots at -20°C protected from light.L(+)-Lactate Standard (100 mM)Equilibrate to room temperature before use.100 mM, store aliquots at -20°C.2. Standard PreparationAdd 20 µL of the 100 mM standard to 980 µL of Lactate Assay Buffer to prepare a 2 mM standard stock solution. Aliquot and store at -20°C for up to 6 months. Dilute the 2 mM standard stock solution sequentially with Lactate Assay Buffer to prepare standard working solutions with final concentrations of 1 mM, 0.5 mM, 0.25 mM, 0.125 mM, 0.0625 mM, and 0.03125 mM. Use Lactate Assay Buffer as the blank.Standard Working SolutionStandard (µL)Lactate Assay Buffer (µL)Concentration (mM)1200 µL of 2 mM022200 µL of 2 mM20013200 µL of 1 mM2000.54200 µL of 0.5 mM2000.255200 µL of 0.25 mM2000.1256200 µL of 0.125 mM2000.06257200 µL of 0.0625 mM2000.03125Blank020003. Sample PreparationNote: Fresh samples are recommended. If not used immediately, samples can be stored at -80°C for up to 1 month. NADH or NADPH present in cell or tissue extracts can create background for lactate assay. To remove NADH or NADPH background, an equal amount of sample can be assayed without lactate dehydrogenase, and the background reading should be subtracted from the lactate reading. Endogenous lactate dehydrogenase (LDH) can degrade lactate. Samples containing LDH (e.g., cell culture medium, cell or tissue lysates) should be processed using a 10 kDa MW cutoff ultrafiltration tube (centrifuge at 12,000 g, 4°C for 10 min; follow the filter instructions) to remove all proteins. Use the filtrate for detection, then store at -80°C.3.1 Animal/Plant Tissues: Weigh approximately 0.1 g of tissue sample, add 1 mL of Lactate Assay Buffer, and homogenize on ice. Centrifuge at 12,000 g, 4°C for 5 min. Transfer the supernatant to a new tube and keep on ice for detection.3.2 Cells or Bacteria: Collect 5×10^6 cells. Wash the cells or bacteria with pre-cooled PBS. Centrifuge at 800 g for 2 min, discard the supernatant. Add 1 mL of Lactate Assay Buffer, and disrupt using an ultrasonic homogenizer on ice for 5 min (power 20% or 200 W, ultrasonic 3 s, interval 7 s, repeat 30 times). Centrifuge at 12,000 g, 4°C for 5 min. Collect the supernatant and keep on ice for detection.3.3 Plasma and Serum (Other Biological Fluids): Detect directly.4. Experimental Steps4.1 Microplate Reader Preparation: Preheat for at least 30 minutes, set wavelength to 450 nm.4.2 Working Reagent Preparation: 50 µL of Working Reagent is required per well. To avoid loss, prepare for 55 µL per single well system: Pipette 31 µL Lactate Assay Buffer, 8 µL Lactate Dehydrogenase Cofactor, 5 µL WST-8, 1 µL Enhancer, and 10 µL Lactate Dehydrogenase. Mix well. The Working Reagent must be prepared freshly and used immediately.4.3 Assay System Setup: Set up the detection system in the microplate according to the table below. The standard curve generally needs to be performed only once.ReagentStandard Well (µL)Test Well (µL)Sample050Standard Working Solution500Working Reagent50504.4 Absorbance Measurement: Mix well and incubate at 37°C protected from light for 30 min. Read the absorbance at 450 nm, recorded as Ablank, Astandard, and Atest. 5. Result CalculationThe following provides both the derived formula and the simplified calculation formula, which are completely equivalent.5.1 Data ProcessingCalculate ΔAstandard= Astandard- Ablank, ΔAtest = Atest - Ablank.5.2 Standard Curve PlottingPlot the standard curve with standard concentration as the y-axis and ΔAstandard as the x-axis. Substitute ΔAstandard into the equation to obtain the y value (mM).5.3 Sample L-Lactate Content Calculation① Calculated based on sample weight:L-Lactate (µmol/g) = y × Vsample ÷ (W × Vsample ÷ Vtotal) × n = y ÷ W × n② Calculated based on cell or bacterial count:L-Lactate (µmol/10⁴ cells) = y × Vsample ÷ (500 × Vsample ÷ Vtotal) × n = y ÷ 500 × n③ Calculated based on liquid volume:L-Lactate (mM) = y × Vsample ÷ Vsample × n = y × n④ Calculated based on protein concentration:L-Lactate (µmol/mg prot) = y × Vsample ÷ (Vsample × Cpr) × n = y ÷ Cpr × nParameter Description:1 mM = 1 mmol/L;Vsample : Volume of sample added, 0.05 mL;n: Sample dilution factor;Cpr: Sample protein concentration, mg/mL;W: Sample weight, g;Vtotal: Total volume of sample extract, 1 mL;500: Cell or bacterial count, 5×10⁶, converted to units of 10⁴.Result Presentation Using Previous Standard CurveTypical Standard Curve: y = 2.2613x - 0.0531Example-1: 50 µL of chicken serum was taken and processed according to the assay steps using a 96-well plate. The measured ΔAtest = Atest - Ablank= 0.435 - 0.096 = 0.339. Substituting into the standard curve, y = 0.713 mM. Calculated based on liquid volume: Lactate content (mM) = y × n = 0.713 × 5 = 3.565 mM.PrecautionsIt is recommended to perform preliminary experiments using 2-3 samples expected to have significant differences before formal testing.For tissue and cell samples, results can be normalized by measuring the protein concentration.This kit is compatible with spectrophotometer detection. Adjust the preparation volume of detection reagents proportionally according to the spectrophotometer's requirements.It is recommended to establish your own standard curve for improved accuracy. If not, you may refer to the typical standard curve formula provided in the results section for calculation.Biochemical reagents are generally irritating and biologically toxic. For your safety and health, please wear appropriate personal protective equipment (lab coat, mask, gloves, hair cap, etc.) throughout the experiment and perform experiments in a fume hood or biosafety cabinet.This product is for scientific research use only. Not intended for clinical diagnosis.Frequently Asked QuestionsWhat should I do if the sample ΔAtest is too high or too low?If the sample ΔAtest is >1.0, the lactate content in the sample is too high. Dilute the sample appropriately with Lactate Assay Buffer (multiply by the dilution factor in the calculation). If the sample ΔAtest is <0.13, increase the sample amount... Read More | Product introduction：This kit uses uniqcell lysis and heme / protein precipitation technology, combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of purifying genomic DNA.Scope of application：Nucleic acid extraction and purification | Product content: G665990Component200 TStorageG665990ABuffer PG100 mLRTG665990BBuffer PS60 mLRTG665990CBuffer PW (concentrate)50 mLRTG665990DBuffer EB30 mLRTG665990ESpin Columns DM with Collection Tubes200 EART Product Introduction:This kit uses a new silicon-based plasma membrane technology and Product content: G665990Component200 TStorageG665990ABuffer PG100 mLRTG665990BBuffer PS60 mLRTG665990CBuffer PW (concentrate)50 mLRTG665990DBuffer EB30 mLRTG665990ESpin Columns DM with Collection Tubes200 EART Product Introduction:This kit uses a new silicon-based plasma membrane technology and reagent formulation. Through the unique centrifugal adsorption column and the DNA washing elution step, 100 bp-10 kb DNA fragments can be recovered and purified from ordinary or low melting point agarose gel. The sol speed is fast and the recovery rate is high. The sol solution contains a pH indicator, which can be used to determine whether the sol recovery has reached the optimal state based on its color. Each adsorption column can adsorb up to 10 µ G DNA, while effectively removing impurities such as primers, enzymes, mineral oil, and agarose. The purified and recovered DNA has high purity and concentration, good integrity, and can be directly used for molecular biology experiments such as sequencing, linking and transformation, labeling, and in vitro transcription.Self prepared reagents: anhydrous ethanol, isopropanol.Preparation and important precautions before the experiment:1.Before the first use, anhydrous ethanol should be added to the Buffer PW according to the instructions on the reagent bottle label.2. Before use, please check the Buffer PG. If crystallization or precipitation occurs, it can be left in a 37 ℃ water bath for 3-5 minutes to restore clarity.3. It is best to use a new electrophoresis buffer during electrophoresis to avoid affecting the electrophoresis and recovery efficiency; The following experiment requires high requirements, please use TAE electrophoresis buffer as much as possible.4.When cutting glue, the UV irradiation time should be as short as possible to avoid damage to DNA.5. The recovery rate is related to the initial amount of DNA and the elution volume. The smaller the initial amount, the smaller the elution volume, and the lower the recovery rate.6. Preheat the water bath to 50 ℃.7. Buffer PG contains a pH indicator. When the pH is ≤ 7.5, the color of the solution is yellow, and DNA can effectively bind to the membrane. When the pH is too high, the color of the solution turns orange red and purple, which needs to be adjusted.8. All centrifugation steps can be performed at room temperature.Operation steps:1. Cut the single purpose DNA strip from the agarose gel (try to cut the excess), put it into a clean centrifuge tube (self prepared), and weigh and calculate the weight of the gel (record the weight of the centrifuge tube in advance).Attention: If the volume of the adhesive block is too large, it can be cut into small pieces.2. Add one time of the volume of Buffer PG (if the gel weighs 100 mg, its volume can be regarded as 100 µ l. And so on.3.50 ℃ water bath and gently invert the centrifuge tube every 2-3 minutes until the sol turns yellow to ensure full dissolution of the gel block. If there are still unsolved glue blocks, you can add some more sol solution or continue to let it stand for a few minutes until the glue blocks are completely dissolved.Note: 1) After the gel is completely dissolved, the gel solution is yellow, and subsequent operations can be carried out; If the glue solution is orange red or purple, 10-30 can be added to the glue solution µ 3 M sodium acetate (pH 5.0), adjust the color of the solution to yellow before proceeding with subsequent operations.2) After the gel block is completely dissolved, it is best to lower the temperature of the gel solution to room temperature before loading the column. The adsorption column has a weaker ability to bind DNA at higher temperatures.4. (Optional step) When the recovered fragment is less than 300 bp, add 1/2 of the gel volume of isopropanol, and mix it upside down (if the gel weighs 100 mg, add 50 µ Isopropanol of L.5. Column balance: Add 200 to the spin columns DM that have been loaded into the collection tube µ Centrifuge at 13000 rpm (~16200 × g) for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.6. Add the solution obtained from steps 3 or 4 to the adsorption column that has been loaded into the collection tube, let it stand at room temperature for 2 minutes, centrifuge at 13000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column in the collection tube.Attention: The volume of the adsorption column is 750 µ l. If the sample volume is greater than 750 µ L can be added in batches.7. Add 450 to the adsorption column µ LBuffer PW (please check if anhydrous ethanol has been added before use), centrifuge at 13000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column in the collection tube.Note: If purified DNA is used for salt sensitive experiments (such as flat end ligation or direct sequencing), it is recommended to add Buffer PW and let it stand for 2-5 minutes before centrifugation.8. Repeat step 7.9.13000 rpm for 1 minute and discard the waste liquid from the collection tube.Note: 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.).10. Place the adsorption column into a new 1.5 ml centrifuge tube (provided by oneself), and add 50 drops to the middle position of the adsorption membrane in the air µ L Buffer EB, leave at room temperature for 2 minutes. Centrifuge at 13000 rpm for 1 minute and collect DNA solution- Store DNA at 20 ℃.Attention:1) To improve the recovery of DNA, the solution obtained by centrifugation can be re dropped onto the adsorption column, left at room temperature for 2 minutes, and centrifuged at 13000 rpm for 1 minute.2) The elution volume should not be less than 30 µ l. A small volume will affect the recovery efficiency.3) When recovering DNA fragments larger than 10 kb, Buffer EB should be preheated in a 50 ℃ water bath to increase recovery efficiency.Note: This reagent kit is also suitable for the purification and recovery of PCR products. Add an equal volume of Buffer PG to the PCR reaction solution and mix thoroughly (for small fragments with a recovery of less than 150bp, the solution volume can be increased to three times to improve the recovery rate). Follow step 5 above for further operations... Read More | The content of this cell is too long for an XLSX file (more than 32767 characters). 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