| Description | Polyphenol Oxidase (PPO, EC1.10.3.1) is widely found in the plastids of plants, fungi, and insects. It is a copper-containing oxidase that can oxidize monophenols and diphenols to produce quinones, leading to browning. It is closely related to fruit and vegetable processing, tea quality, and Polyphenol Oxidase (PPO, EC1.10.3.1) is widely found in the plastids of plants, fungi, and insects. It is a copper-containing oxidase that can oxidize monophenols and diphenols to produce quinones, leading to browning. It is closely related to fruit and vegetable processing, tea quality, and tissue culture. The Plant Polyphenol Oxidase (PPO) Activity Assay Kit (Catechol, Micro method) provides a simple method to detect the activity level of polyphenol oxidase (PPO) in plant tissue samples.Detection Principle: Polyphenol oxidase (PPO) in the sample catalyzes the oxidation of catechol to produce quinones, which have a characteristic absorption peak at 410 nm. The rate of increase in absorbance at 410 nm is measured to calculate PPO activity.P1501774Component48T96TStorageP1501774AExtraction Buffer60 mL120 mL2-8℃P1501774BReagentⅠ24 mL48 mL2-8℃P1501774CReagentⅡ6 mL12 mL2-8℃. Store in the dark.Note: Before formal testing, it is recommended to perform a preliminary test with 2-3 samples expected to have significant differences.User-Prepared Instruments and ReagentsMicroplate reader or visible spectrophotometer (capable of measuring absorbance at 410 nm)96-well plate or micro glass cuvettes, adjustable micropipettes and tipsRefrigerated centrifuge, ice maker, constant temperature water bathDeionized waterHomogenizerExperimental Procedure1. Reagent PreparationReagent NameReagent PreparationNotesExtraction BufferReady-to-use; Equilibrate to room temperature before use.Store at 4°C.ReagentⅠReady-to-use; Equilibrate to room temperature before use.Store at 4°C.ReagentⅡReady-to-use; Equilibrate to room temperature before use.Store at 4°C protected from light; Toxic, handle with care.2. Sample PreparationNote: Fresh samples are recommended. If not used immediately, samples can be stored at -80°C for one month.2.1 Preparation of Crude Enzyme ExtractHomogenize the plant sample in ice-cold Extraction Buffer with a mass (g) to volume (mL) ratio of 1:5 to 1:10 (recommended: 0.1 g tissue + 1 mL Extraction Buffer). Centrifuge the homogenate at 8,000 g, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.2.2 Boiled Sample ControlTake an appropriate amount of the crude enzyme extract and heat it in a boiling water bath for 5 minutes (seal to prevent moisture loss). Cool to room temperature.3. Assay Steps3.1 Preheat the microplate reader or visible spectrophotometer for at least 30 minutes. Set the wavelength to 410 nm. For spectrophotometers, zero the instrument with deionized water.3.2 Sample Measurement (Add reagents sequentially into 1.5 mL microcentrifuge tubes):ReagentControl Tube (µL)Test Tube (µL)Boiled Sample500Sample (supernatant)050ReagentⅠ200200ReagentⅡ50503.3 Mix thoroughly. Incubate in a 25°C water bath for 10 minutes, then immediately transfer to a boiling water bath for 10 minutes. After mixing, centrifuge at 5,000 g, 25°C for 10 minutes. Collect the supernatant. Transfer 200 µL of the supernatant to a micro glass cuvette or 96-well plate. Measure the absorbance of both the Test tube and Control tube at 410 nm. Calculate ΔA = Atest - Acontrol.Note:Each test tube requires a corresponding control tube.It is recommended to perform a preliminary test with 2-3 samples expected to have significant differences before the formal experiment.The optimal reaction temperature for PPO may vary slightly among different samples and can be adjusted between 25-37°C.If the sample absorbance is less than 0.02, consider increasing the sample volume appropriately. If the sample absorbance is greater than 1, it is advisable to dilute the sample before assay.4. Calculation of ResultsNote: We provide both the derived formula and a simplified formula. They are equivalent. It is recommended to use the simplified formula in bold for final calculation.4.1 Calculation Formula when using a 96-well plate:Unit Definition: One unit of enzyme activity is defined as the amount that causes a change of 0.005 in absorbance at 410 nm per minute per gram of tissue per mL of reaction mixture.PPO Activity (U/g fresh weight) = ΔA × Vtotal reaction÷ (W × Vsample / Vtotal sample ) ÷ 0.005 ÷ T = 120 × ΔA / W4.2 Calculation Formula when using a micro glass cuvette:Unit Definition: One unit of enzyme activity is defined as the amount that causes a change of 0.01 in absorbance at 410 nm per minute per gram of tissue per mL of reaction mixture.PPO Activity (U/g fresh weight) = ΔA × Vtotal reaction ÷ (W × V sample / Vtotal sample ) ÷ 0.01 ÷ T = 60 × ΔA / WParameter Definitions:Vtotal reaction: Total volume of the reaction system (0.3 mL)Vsample : Volume of sample added to the reaction (0.05 mL)Vtotal sample : Volume of Extraction Buffer added during homogenization (1 mL)T: Reaction time (10 minutes)W: Sample weight (g)PrecautionsThis product is for research use only. Not for use in clinical diagnosis. For your safety and health, please wear lab coats and disposable gloves during operation... Read More | Format:2-ComponentEnzyme:Horseradish peroxidase | This reagent kit is for research purposes only. Purpose of use: This reagent kit is used to determine the content of lactose in serum, plasma, and related liquid samples.Experimental principle:This kit applies enzyme-linked immunosorbent assay to determine the level of lactose in the sample. This reagent kit is for research purposes only. Purpose of use: This reagent kit is used to determine the content of lactose in serum, plasma, and related liquid samples.Experimental principle:This kit applies enzyme-linked immunosorbent assay to determine the level of lactose in the sample. Purified lactose antibodies were coated on a microplate to produce solid-phase antibodies. Lactose was added to the microplate of the coated monoclonal antibody, along with HRP labeled lactose antigens, to compete for binding. After thorough washing, the substrate TMB was added for colorimetry. The depth of sample color is negatively correlated with the content of lactose in the sample. Measure the absorbance (OD value) at a wavelength of 450nm using an enzyme-linked immunosorbent assay (ELISA) reader, and calculate the content of lactose in the sample through a standard curve.Kit composition:130times concentrated washing solution20ml×1 bottle8.1Standard S1（80µg/L）0.5ml×1bottle2Enzyme-linked immunosorbent assay6ml×1 bottle8.2Standard S2（40µg/L）0.5ml×1bottle3Enzyme labeling coated plate96 holes x 1 pieces8.3Standard S3（20µg/L）0.5ml×1bottle4Color reagent A solution6ml×1 bottle8.4Standard S4（10µg/L）0.5ml×1bottle5Color developer B solution6ml×1 bottle8.5Standard S5（5µg/L）0.5ml×1bottle6Stop solution6ml×1 bottle9Instructions1 copy7Sample Diluent6ml×1 bottle10Microplate Sealers2 sheetsSpecimen requirements:1. Specimen processing:(1) After collecting the water sample, it is repeatedly freeze-thawed three times at -20 ℃, and then filtered through glass fiber for future reference(2) The tissue samples should be extracted using butanol: methanol: water (5:25:70 V: V: V), or extracted according to relevant literature. The experiment should be conducted as soon as possible after extraction. If the experiment cannot be conducted immediately, the specimen can be stored at -20 ℃ for future reference2. Samples containing NaN3 cannot be detected as NaN3 inhibits the activity of horseradish peroxidase (HRP).Operation steps:1. Sample addition: Set up standard wells, blank wells (blank control wells do not include samples and enzyme-linked immunosorbent assay reagents, the other steps are the same), and sample wells to be tested. Add 50 microliters to the standard well on the enzyme-linked immunosorbent assay (ELISA) plate, and first add 40 diluents to the sample well to be tested µ l. Then add 10 more samples to be tested µ L (The final dilution of the sample is 5 times). Add the sample to the bottom of the enzyme-linked immunosorbent assay (ELISA) plate well, avoiding touching the well wall as much as possible. Gently shake and mix well.2. Enzyme addition: Add 50 enzyme labeled reagents to each well µ l. Excluding blank holes.3. Warm incubation: Seal the plate with a sealing film and incubate at 37 ℃ for 60 minutes.4. Solution preparation: Dilute 30 times the concentrated washing solution with distilled water and set aside for later use5. Washing: Carefully remove the sealing film, discard the liquid, shake dry, fill each well with washing solution, let it stand for 30 seconds, then discard. Repeat this process 5 times and pat dry.6. Color development: Add color development agent A50 to each well first µ l. Add color developer B50 again µ l. Gently shake and mix well, and develop color at 37 ℃ in the dark for 15 minutes7. Termination: Add 50% termination fluid to each hole µ l. Terminate the reaction (at this point, the blue color immediately turns yellow).8. Measurement: Zero the blank hole and sequentially measure the absorbance (OD value) of each hole at a wavelength of 450nm. The measurement should be conducted within 15 minutes after adding the termination solution.Calculation:Draw a standard curve on a coordinate paper with the concentration of the standard substance as the x-axis and the OD value as the y-axis. Based on the OD value of the sample, determine the corresponding concentration from the standard curve; Multiply it by the dilution factor; Alternatively, a linear regression equation can be used to calculate the standard curve using the concentration and OD value of the standard substance. The OD value of the sample can be substituted into the equation to calculate the sample concentration, which is then multiplied by the dilution factor to obtain the actual concentration of the sample.Notes:1. The kit should be balanced at room temperature for 15-30 minutes before use when taken out from the cold storage environment. If the enzyme coated plate is not used up after opening, the Flat noodles should be stored in a sealed bag.2. Concentrated detergent may precipitate crystals. When diluted, it can be heated in a water bath to aid in dissolution. Washing does not affect the results.3. A sampler should be used for each step of sample addition, and its accuracy should be regularly calibrated to avoid experimental errors. It is best to control the sample addition time within 5 minutes. If there are a large number of specimens, it is recommended to use a firing gun for sample addition.4. Please make a standard curve at the same time as each measurement, preferably with a re hole. If the content of the substance to be tested in the sample is too high (the OD value of the sample is greater than the OD value of the first well of the standard well), please dilute the sample diluent by a certain multiple (n times) before measurement. When calculating, please multiply the total dilution multiple (x n x 5).5. The sealing film is only for one-time use to avoid cross contamination.6. Please store the substrate in dark.7. Strictly follow the instructions and determine the test results based on the reading of the enzyme-linked immunosorbent assay (ELISA) reader8. All samples, washing liquids, and various waste should be treated as infectious substances.9. The components of this reagent with different batch numbers shall not be mixed.Detection range:two µ G/L-90 µ G/L... Read More | Product contentN666081Component50 TStorageN666081ANc-Buffer A50 mL2-8℃N666081BNc-Buffer B3 mL2-8℃N666081CNc-Buffer C25 mL2-8℃N666081DProtease Inhibitor Cocktail750 µL-20℃. Avoid freeze/thaw cycle.ProductsThe Nc-Nucleus/Plasma Protein Extraction Kit is a simple and rapid Product contentN666081Component50 TStorageN666081ANc-Buffer A50 mL2-8℃N666081BNc-Buffer B3 mL2-8℃N666081CNc-Buffer C25 mL2-8℃N666081DProtease Inhibitor Cocktail750 µL-20℃. Avoid freeze/thaw cycle.ProductsThe Nc-Nucleus/Plasma Protein Extraction Kit is a simple and rapid method for extracting nucleus and plasma proteins from mammalian cells and tissues, and the extracted proteins remain biologically active. The kit first cleaves the cell membrane and releases plasma proteins using the plasma protein extraction reagent, and then centrifuges the nucleus to obtain a nucleus precipitate. Finally, the nuclear proteins are extracted by the nuclear protein extraction reagent. The extracted nuclear and plasma proteins are of high purity, effectively avoiding cross-contamination of nuclear and plasma proteins, and can be used for subsequent operations such as Western, Gel Shift, reporter gene detection and enzyme activity determination.Caveat1. If phosphorylated proteins are to be extracted, add a phosphatase inhibitor to the extraction reagent.2. All sample handling should be done on ice.3. The amount of reagents can be adjusted according to the specific experimental situation to ensure that the ratio of each reagent used is Nc-Buffer A:Nc-Buffer B:Nc-Buffer C = 100:5.5:50.4. Higher speeds can be used for centrifugation.ProcedureI Extraction of cytoplasmic and cytosolic proteins from cells1. Please remove the extraction reagents Nc-Buffer A and Nc-Buffer C for pre-cooling before protein extraction.2. Collect the cells and count them. Centrifuge to remove supernatant.3. 1×107 cells were added with 1 ml of Nc-Buffer A (added to Protease Inhibitor Cocktail at a ratio of 1:99 within 2-3 minutes prior to protein pumping), vortexed for 5 seconds to mix well, and incubated on ice for 20 minutes.Note: The characteristics of various cells are different, and the amount of Nc-Buffer A needs to be adjusted according to the characteristics of different cells. If the protein concentration is small, reduce the amount of Nc-Buffer A and subsequent Nc-Buffer B and Nc-Buffer C proportionally.4. Add 55 µl of Nc-Buffer B, vortex for 5 seconds to mix thoroughly, and incubate on ice for 1 minute.5. Centrifuge at 12,000 rpm (~13,400 x g) for 15 minutes at 4°C, collect the supernatant (as clean as possible) into a new centrifuge tube and store at -20°C (this extract is cytoplasmic protein).6. Add 500 µl of Nc-Buffer C (add Protease Inhibitor Cocktail at a ratio of 1:99 before use) to the precipitate obtained in the previous step, vortex for 5 seconds to mix thoroughly, resuspend the precipitate and incubate on ice for 40 minutes, vortexing and mixing at 10-minute intervals for about 15-30 seconds each time.7. Centrifuge at 12,000 rpm for 15 minutes at 4°C, collect the supernatant (as clean as possible) into a new centrifuge tube and store at -20°C (this extract is for cytosolic proteins).II Extraction of cytoplasmic and cytosolic proteins from tissues1. Sampling and preservation of tissues.2. Remove the extraction reagents Nc-Buffer A and Nc-Buffer C for pre-cooling before protein extraction.3. Weigh the tissue and add 1 ml of Nc-Buffer A per 100 mg of tissue (add Protease Inhibitor Cocktail 2-3 minutes before protein extraction at a ratio of 1:99), homogenize well on ice with a homogenizer, and incubate on ice for 20 minutes.Note: The characteristics of various tissues are different, and the amount of Nc-Buffer A needs to be adjusted according to different tissues. If the protein concentration is small, reduce the amount of Nc-Buffer A and subsequent Nc-Buffer B and Nc-Buffer C proportionally.4. Add 55 µl of Nc-Buffer B, vortex for 5 seconds to mix thoroughly, and place on ice for 1 minute of incubation.5. Centrifuge at 12,000 rpm for 15 minutes at 4°C, collect the supernatant (as clean as possible) into a new centrifuge tube and store at -20°C (this extract is cytoplasmic protein).6. Add 500 µl of Nc-Buffer C (add Protease Inhibitor Cocktail at a ratio of 1:99 before use) to the precipitate obtained in the previous step, vortex for 5 seconds to mix thoroughly, resuspend the precipitate and incubate on ice for 40 minutes, vortexing and mixing at 10-minute intervals at, each time for about 15-30 seconds.7. Centrifuge at 12,000 rpm for 15 minutes at 4°C, collect the supernatant (as clean as possible) into a new centrifuge tube and store at -20°C (this extract is cytosolic protein)... Read More | The Succinic Acid (Succinate) assay kit is suitable for the specific assay of succinic acid in wine, cheese, eggs, sauce and other food products. Succinic acid (or succinate) is found in all plant and animal materials as a result of the central metabolic role played by this dicarboxylic acid in the The Succinic Acid (Succinate) assay kit is suitable for the specific assay of succinic acid in wine, cheese, eggs, sauce and other food products. Succinic acid (or succinate) is found in all plant and animal materials as a result of the central metabolic role played by this dicarboxylic acid in the Citric Acid Cycle. Succinic acid concentrations are monitored in the manufacture of numerous foodstuffs and beverages, including wine, soy sauce, soy bean flour, fruit juice and dairy products (e.g. cheese).Product Description： Succinic acid is found in all plant and animal materials as a result of the central metabolic role played by this dicarboxylic acid in the Citric Acid Cycle. Succinic acid concentrations are monitored in the manufacture of numerous foodstuffs and beverages, including wine, soy sauce, soy bean flour, fruit juice and dairy products (e.g. cheese). The ripening process of apples can be followed by monitoring the falling levels of succinic acid. The occurrence of > 5 mg/kg of this acid in egg and egg products is indicative of microbial contamination. Apart from use as a flavouring agent in the food and beverage industries, succinic acid finds many other non-food applications, such as in the production of dyes, drugs, perfumes, lacquers, photographic chemicals and coolants. Preparation Instructions：Suitable for succinate determination in food, beverage, agricultural products, and other biological samples.Note for Content：The number of manual tests per kit can be doubled if all volumes are halved. This can be readily accommodated using the MegaQuantTM Wave Spectrophotometer (D-MQWAVE).Browse all of our organic acid assay kits.Principle：The Succinate Assay Kit provides a simple, one step assay for measuring succinate. In this assay succinate is converted to pyruvate which reacts with specific reagents and dye to form a colored product. The color intensity at 570 nm or fluorescencAdvantages：Extended cofactors stability. Dissolved cofactors stable for > 1 year at 4oC.Very competitive price (cost per test)All reagents stable for > 2 years as suppliedVery rapid reaction (even at room temperature)Mega-Calc™ software tool is available from our website for hassle-free raw data processingStandard includedSuitable for manual, microplate and auto-analyser formats... Read More |