| 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 | When apoptosis occurs, some DNA endonucleases will be activated. These endonucleases will cut off genomic DNA between nucleosomes and produce 180 bp-200 BP DNA fragments, which appear as a specific ladder pattern in agarose gel electrophoresis. When double strand or single strand breaks occurWhen apoptosis occurs, some DNA endonucleases will be activated. These endonucleases will cut off genomic DNA between nucleosomes and produce 180 bp-200 BP DNA fragments, which appear as a specific ladder pattern in agarose gel electrophoresis. When double strand or single strand breaks occur in genomic DNA, a large number of sticky 3'-oh ends will be generated, which can interact with YF under the catalysis of deoxyribonucleotide terminal transferase (TDT) ®/ CY dUTP binding can directly detect apoptotic cells by fluorescence microscopy or flow cytometry. This kind of method is called terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Because normal or proliferating cells have almost no DNA breaks, there is no 3'-oh formation and they can rarely be stained. TUNEL method can stain intact single apoptotic nuclei or apoptotic bodies in situ, can accurately reflect the typical biochemical and morphological characteristics of apoptosis, and can detect a very small number of apoptotic cells, so it is widely used in the study of apoptosis. This kit has a wide range of applications and can be used to detect apoptosis in frozen or paraffin sections, as well as cultured adherent cells or suspended cells. It can selectively detect apoptotic cells, but not necrotic cells or cells with DNA strand breaks caused by irradiation and drug treatment. This kit detects cell apoptosis with a short time-consuming, one-step staining reaction and can be detected after washing.Product parameters：555/565 nmComponent： Instruction： Experimental materials (self provided)PBS buffer (1 x, pH~7.4). 0.2% Triton X -100 (PBS formulation). 0.1% Triton X -100 (PBS formulation, containing 5 mg/mLBSA)4% paraformaldehyde (prepared with PBS)Immunohistochemical penDewaxing solvent (paraffin section sample)Related reagents for paraffin section processingAnti fluorescence quenching and sealing agent. ddH2Oexperimental design. A. Positive control:Prepare positive control slides using DNaseI treatment. DNaseI can digest single or double stranded DNA and expose the 3 '- OH end, artificially causing cell apoptosis. One experiment per time is sufficient. (To verify if there are any issues with the experimental operation and reagent kit)B. Negative control:Use TUNEL Reaction Buffer without TdT Enzyme and replace TdT Enzyme with ddH2O. (Mainly to exclude non-specific staining caused by cell apoptosis, operational processes, and other reasons; and to adjust the exposure intensity of the shooting.)C. Experimental processing group.The experimental group operated normally according to the instructions.D. Experimental control group.The experimental group operated normally according to the instructions.Experimental steps1. Sample preparation:(1) For adherent cells or cell smearsa. Clean once with PBS.Note: If you are concerned that the cells on the cell smear may not adhere firmly, you can dry the sample to make the cells adhere more firmly.b. Fixation: Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and fix at 4 ℃ for 30 minutes. Clean twice with PBS.c. Translucency: Add an appropriate amount of 0.2% Triton X -100 (prepared with PBS) and let it penetrate at room temperature for 20 minutes. Clean twice with PBS.d. Step 2: TUNEL reaction.(2) For suspended cells or cell suspensionsa. Collect cells (3-5 x 106 cells), centrifuge at 1000 rpm for 5 minutes, and wash twice with PBS.b. Fixation: Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and resuspend the cells thoroughly. Fix at 4 ℃ for 30 minutes. Centrifuge at 2000 rpm for 5 minutes and clean twice with PBS.c. Translucency: Add an appropriate amount of 0.2% Triton X -100 (prepared with PBS) and let it penetrate at room temperature for 20 minutes. Centrifuge at 2000 rpm for 5 minutes and clean twice with PBS.d. Step 2: TUNEL reaction.(3) Paraffin tissue sectioninga. Dewaxing and hydration: Place the sliced samples sequentially in xylene I (10 min) → xylene II (10 min) → 100% ethanol I (5 min) → 100% ethanol II (5 min) → 95% ethanol (5 min) → 90% ethanol (5 min) → 80% ethanol (5 min) → 70% ethanol (5 min) → ddH2O rinse for 5 min, rinse twice.Note: Xylene is toxic and volatile. Please perform this operation in a fume hood.b. Use filter paper to dry the liquid around the sliced sample, and circle the sample contour with an immunohistochemical pen for downstream transparency and labeling.Note: If it is found that the contour circle of immunohistochemistry strokes is damaged in subsequent experimental operations, it needs to be redrawn in a timely manner.c. Transparency: Dilute 2 mg/mL of ProteinaseK solution with PBS in a ratio of 1:100 to a final concentration of 20 µ g/mL. Add 100 µ L dropwise to each sample to cover all sample areas. Incubate at 20-37 ℃ for 20 minutes.Note: Protein K can penetrate the cell membrane and nuclear membrane, allowing subsequent staining reagents to fully enter the nucleus for reaction and improve labeling efficiency. An excessively long incubation time increases the risk of tissue slices falling off the carrier film during subsequent washing steps, while a too short incubation time may result in insufficient permeability treatment and affect labeling efficiency. To obtain better results, the concentration, incubation time, and temperature of Protein K need to be optimized according to different types of tissue samples.d. Wash the slices twice with PBS, each time for 5 minutes. Use filter paper to remove excess liquid, and place the processed sample in a wet box to keep it moist.Note: Protein K must be washed thoroughly in this step, otherwise it will seriously interfere with subsequent labeling reactions.e. Step 2: TUNEL reaction.(4) Frozen tissue sectionsa. Fixation: Take out frozen sections and warm them back to room temperature. Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and fix at room temperature for 30 minutes. Wash twice with PBS for 10 minutes each time.Note: If you are concerned that formaldehyde cleaning may not be clean enough, it may affect the final dyeing effect. After formaldehyde fixation is completed, an appropriate amount of 2 mg/mL glycine can be added and washed for 10 minutes to neutralize the residual fixing solution, and then PBS cleaning can be carried out.b. Use filter paper to dry the liquid around the sliced sample, and circle the sample contour with an immunohistochemical pen for downstream transparency and labeling.Note: If it is found that the contour circle of immunohistochemistry strokes is damaged in subsequent experimental operations, it needs to be redrawn in a timely manner.c. Transparency: Dilute 2 mg/mL of ProteinaseK solution with PBS in a ratio of 1:100 to a final concentration of 20 µ g/mL. Add 100 µ L dropwise to each sample to cover all sample areas. Incubate at 20-37 ℃ for 20 minutes.Note: Protein K can penetrate the cell membrane and nuclear membrane, allowing subsequent staining reagents to fully enter the nucleus for reaction and improve labeling efficiency. An excessively long incubation time increases the risk of tissue slices falling off the carrier film during subsequent washing steps, while a too short incubation time may result in insufficient permeability treatment and affect labeling efficiency. To obtain better results, the concentration, incubation time, and temperature of Protein K need to be optimized according to different types of tissue samples.d. Wash the slices twice with PBS, each time for 5 minutes. Use filter paper to remove excess liquid, and place the processed sample in a wet box to keep it moist.Note: Protein K must be washed thoroughly in this step, otherwise it will seriously interfere with subsequent labeling reactions.e. Step 2: TUNEL reaction.(5) Positive treatment (only the positive control is subjected to this step, and other samples are directly subjected to the TUNEL reaction step)a. Dilute 10 x DNase I Buffer with ddH2O in a ratio of 1:10 to 1 x DNase I Buffer for later use.b. Drip 100 µ L of 1xDNase I Buffer onto the processed sample, covering all sample areas, and equilibrate at room temperature for 5 minutes.c. Dilute DNase I (2 U) with 1 x DNase I Buffer at a ratio of 1:100/ µ L) A working solution with a final concentration of 20 U/mL.d. Discard the buffer and add 100 µ Incubate DNase I working solution with a concentration of 20 U/mL at room temperature for 10 minutes.e. Discard DNase I working solution and clean twice with PBS.f. Step 2: TUNEL reaction.2. TUNEL reaction(1) Prepare TUNEL reaction solution (ready to use):/1 sample5 sample10 sampleTdT enzyme1 µL5 µL10 µLYF®488/555/594/640 TUNEL Reaction Buffer49 µL245 µL490 µLTUNEL Total volume of reaction solution50 µL250 µL500 µL(2) For adherent cells, cell smears, or tissue sectionsa. Add 50 to each sample µ L TUNEL reaction solution, evenly cover the sample with the reaction solution. The appropriate time for dark incubation at 37 ℃ (recommended staining time for cells is 30 minutes to 1 hour, and tissue staining time is 2 hours).Note: 50 µ L TUNEL reaction solution is suitable for smear, slicing, or 96 well plates (other different well plates can adjust the volume of TUNEL reaction solution appropriately to cover cells). If the sample to be tested is a smear, slice, or in a 24 well plate, 12 well plate, or 6 well plate, anti evaporation film can be used, or self sealing bags or other appropriate materials can be used to cut circular plastic sheets slightly smaller than the holes. After adding TUNEL reaction solution dropwise, cover the sample to prevent the evaporation of TUNEL reaction solution and make the TUNEL reaction solution evenly cover the sample.b. Discard the TUNEL reaction solution, wash twice with PBS, and then wash three times with 0.1% Triton X -100 (PBS preparation, containing 5 mg/mL BSA) for 5 minutes each time. This way, free unreacted markers can be removed cleanly.c. (Optional) Add an appropriate concentration of 5 to each sample µ DAPI staining solution with a concentration of g/mL, incubated at room temperature in dark for 5 minutes. After staining, discard DAPI staining solution and wash twice with PBS for 5 minutes each time.d. (Optional) Slice sealing: Add 50 drops to each sample µ L anti fluorescence quenching sealing agent (anti fluorescence quenching sealing agent may not be suitable for certain dyes, it is recommended to conduct pre experimental testing for compatibility before the experiment), cover the cover glass, gently tap the cover glass with the blunt end of tweezers to remove bubbles and ensure complete sealing.e. Use filter paper to remove excess liquid and add 100 to the sample area µ Keep the sample moist with PBS and immediately observe under a fluorescence microscope.(3) For suspended cells or cell suspensionsa. Add 50 to each sample tube µ Gently resuspend cells in LTUNEL reaction solution and incubate at 37 ℃ in the dark for 30-1 hour. Gently resuspend cells with a micropipette every 15 minutes.b. Centrifuge at 2000 rpm for 5 minutes, discard TUNEL reaction solution, and wash twice with 0.1% Triton X -100 (PBS preparation, containing 5 mg/mLBSA) for 5 minutes each time. This way, free unreacted markers can be removed cleanly.c. Add 100 to each sample tube µ L concentration is 5 µ DAPI staining solution with a concentration of g/mL, incubated at room temperature in dark for 5 minutes.d. Join 400 µ L PBS resuspended cells and immediately detected with a flow cytometer or observed under a fluorescence microscope after smearing.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. when the staining background is heavy or non-specific staining is obvious, the staining time can be appropriately reduced. 3. it is recommended to add negative control and positive control groups during the experiment. 4. please wear mask and gloves when using component A. if it contacts the skin, please wash it with plenty of water immediately. 5. fluorescent dyes have quenching problems. Please try to avoid light to slow down fluorescence quenching. 6. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Late apoptosis detection, TUNEL Kit... Read More | Inquire | Cell viability and cytotoxicity assays are usually used for drug screening and compound cytotoxicity testing. The CCK-8 kit uses highly water-soluble tetrazolium salt ( called WST-8 ) to produce water-soluble WST-8 for cell proliferation and cytotoxicity assays. Unlike MTT, WST-8 and WST-8 have no Cell viability and cytotoxicity assays are usually used for drug screening and compound cytotoxicity testing. The CCK-8 kit uses highly water-soluble tetrazolium salt ( called WST-8 ) to produce water-soluble WST-8 for cell proliferation and cytotoxicity assays. Unlike MTT, WST-8 and WST-8 have no cytotoxicity in cell culture medium, so multiple downstream experiments can be performed using the same detection plate. CCK-8 method is a convenient colorimetric method for the determination of cell viability. It does not need the solubilization process and only needs the least steps to provide the results. The CCK-8 method can be used for the determination of 96-well microplates and high-throughput screening of 384-well microplates. Advantage：At present, the commercially available liquid CCK-8 kits generally have defects such as harsh storage conditions ( -4C or -20 ), unstable use in different pH ranges, and easy deterioration ( discoloration or precipitation ). The solid instant CCK-8 kit adopts a new formula and Swiss process, which overcomes these shortcomings of the liquid CCK-8 kit. It can be stored at room temperature for a long time ( > 3 years ), ready to use, stable in a wide pH range, and the experimental results are more reliable. Compared with the liquid CCK-8 kit, the solid-soluble CCK-8 kit has higher sensitivity and the biological response time is shortened by half.Application scope:It can be used for drug screening, cell proliferation assay, cytotoxicity assay, tumor drug sensitivity test and activity detection of biological factors. Operating instructions:This reagent kit can be used for drug screening, cell proliferation assay, cytotoxicity assay, tumor drug sensitivity assay, and activity detection of biological factors.1. Carefully and slowly tear along the gap in the packaging bag;2. Pour all the powder in the bag into a clean container containing 10mL of ultrapure water, shake continuously for 1 minute, and use it when the solid is completely dissolved;3. Unused reagents must be stored at low temperatures below 4 ℃.Equipment required for testing:Enzyme reader 96 well plate with 450-490 nm filter;Carbon dioxide incubator;96 well plate, sterilized transparent plate for cell detection;Multi channel pipette (8 or 12 channels: 10-100 µ l);Blood cell counter or cell counter.Cell viability testing:1. Inoculate cell suspension (100 µ l/well) into a 96 well plate and pre culture the plate in a carbon dioxide incubator for 24 hours (37 ℃, 5% CO2);2. Add 10 µ l of CCK-8 solution to each well (be careful not to generate bubbles in the well as it may affect the reading of OD value);3. Incubate the culture plate in the incubator for 1-4 hours;4. Measure the absorbance at 450 nm using an enzyme-linked immunosorbent assay (ELISA) reader;5. If the OD value is not determined temporarily, 10 µ l of 0.1M HCI solution or 1% w/v SDS solution can be added to each well, and the culture plate can be covered and stored in the dark at room temperature. Within 24 hours of measurement, the absorbance will not change.Cell proliferation toxicity testing:1. Inoculate cell suspension (100 µ l/well) into a 96 well plate and pre culture the plate in an incubator for 24 hours (37 ℃, 5% CO2);2. Add 10ul of different concentrations of the substance to be tested to the culture plate;3. Incubate the culture plate in the incubator for an appropriate period of time (e.g. 6, 12, 24, or 48 hours);4. Add 10 µ l of CCK-8 solution to each well (be careful not to generate bubbles in the well as they may affect the reading of the OD value);5. Incubate the culture plate in the incubator for 1-4 hours;6. Measure the absorbance at 450nm using an enzyme-linked immunosorbent assay (ELISA) reader;7. If the OD value is not determined temporarily, 10 µ l of 0.1M HCI solution or 1% w/v SDS solution can be added to each well, and the culture plate can be covered and stored in the dark at room temperature. Within 24 hours of measurement, the absorbance will not change.Calculation method for cell survival rate/inhibition rate:Cell survival rate=[As Ab)/(Ac Ab)] x 100%Inhibition rate=[(Ac As)/(Ac Ab)] x 100%As: absorbance of experimental wells (including cells, culture medium, CCK-8 solution, and drug solution);Ac: absorbance of control wells (including cells, culture medium, CCK-8 solution, without drugs);Ab: Blank well absorbance (including culture medium and CCK-8 solution, excluding cells and drugs).Points for attention： 1.Unused reagents must be stored at low temperature below 4 °C, and stored in the dark at-20 °C for two years after unpacking, so as to avoid repeated thawing ; 2.The culture time of CCK-8 is generally 1-4 hours, but the naked eye can be taken out to observe the color degree in about 30 minutes. According to the cell type, the conditions need to be explored. The best reaction time of CCK-8 is based on the best time of specific color development.3. It is recommended to do a few holes to explore the number of inoculated cells and the culture time after adding CCK-8 reagent ; 3.The WST-8 in this kit will react with reducing agents ( such as some antioxidants ) to interfere with the detection. Before the cell proliferation-toxicity test, the background OD can be checked to confirm whether there is a reducing agent in the substance to be tested. If the effect of reducing agent needs to be removed, the fresh medium can be replaced before adding CCK-8 ( remove the medium, wash the cells twice with the medium, and then add the new medium ) ; 4.Phenol red in the medium does not affect the experimental results, and the absorbance of phenol red can be eliminated by deducting the absorbance of the background in the blank hole during calculation, so it will not affect the detection. 5.It is recommended to use a multi-channel pipette to reduce the difference between parallel holes. When adding CCK-8 reagent, it is recommended to add it obliquely to the wall of the culture plate, not to insert it under the liquid surface of the medium, which is easy to produce bubbles and interfere with OD determination. 6.If the drug contains metal, it has an effect on the color of CCK-8. The final concentration of 1mM lead chloride, ferric chloride and copper sulfate will inhibit the color reaction of 5 %, 15 % and 90 %, and reduce the sensitivity. If the final concentration is 10mM, the color reaction will be 100 % inhibited ; 7.When using a 96-well plate for detection, if the cell culture time is long, attention should be paid to the evaporation problem. On the one hand, because a circle around the 96-well plate is the easiest to evaporate, the method of discarding the surrounding circle can be adopted, and the same amount of PBS, water or culture medium can be added. On the other hand, the 96-well plate can be placed near the water source in the incubator to alleviate evaporation ; 8.When using standard 96-well plates, the minimum inoculation amount of adherent cells is at least 1,000 cells / well ( 100µl medium ). The sensitivity of detecting white blood cells is relatively low, so it is recommended that the inoculation amount should not be less than 2,500 cells / well ( 100 µl medium ). If you want to use a 24-well plate or a 6-well plate experiment, first calculate the corresponding inoculation amount per well, and add the CCK-8 solution according to 10 % of the total volume of the medium per well ; 9.Cell culture time varies according to the type and number of cells ( per well ), usually the color of white blood cells is weak, requiring a longer culture time ( 4 hours ) and a large number of cells ( ~ 105 cells / well ) ; 10.CCK-8 reagent is very low toxic to cells. The continuous reaction between it and dehydrogenase in living cells makes the color of the solution deepen and the OD value increase. The following methods can terminate the CCK-8 reaction ( 96-well plate ) : a ) After the color reaction, the culture plate was placed in a refrigerator at 4 ° C ; b ) 10µL 0.1MHCL solution was added to each well ; c ) 10 µL 1 % ( w / v ) SDS ( sodium dodecyl sulfate ) solution was added to each well. After the reaction stopped, the OD value should be measured within 24 hours. 11.To determine the specific number of cells, it is recommended to do the standard curve at the same time... Read More | V669947 Component 50T Storage V669947A Buffer GL 15 mL RT V669947B Buffer GW1 (concentrate) 13 mL RT V669947C Buffer GW2 (concentrate) 15 mL RT V669947D Buffer RE 10 mL RT V669947E Proteinase K 12.5 mg RT V669947F Proteinase K Storage Buffer 1.25 mL RT V669947G Spin Columns RS with Collection Tubes V669947 Component 50T Storage V669947A Buffer GL 15 mL RT V669947B Buffer GW1 (concentrate) 13 mL RT V669947C Buffer GW2 (concentrate) 15 mL RT V669947D Buffer RE 10 mL RT V669947E Proteinase K 12.5 mg RT V669947F Proteinase K Storage Buffer 1.25 mL RT V669947G Spin Columns RS with Collection Tubes 50 RT V669947H RNase-Free Centrifuge Tubes (1.5 mL) 50 RTProductsThis kit is suitable for the extraction of viral RNA and DNA from fresh or frozen plasma, serum and cell-free body fluids. It is easy to operate as it does not require the use of organic solvents such as phenol and chloroform for extraction. The kit uses a unique buffer system to enable efficient and specific binding of viral nucleic acids in lysate to silica gel centrifugal adsorption columns. Inhibitors of PCR and enzyme reactions as well as residual impurities can be efficiently removed in a two-step effective rinsing step, and finally high purity viral nucleic acids can be obtained by using a low-salt buffer or water for elution. The purified viral nucleic acid is free of protein, nuclease and other impurities, and can be used directly in PCR, RT-PCR, Real-Time PCR, blotting experiments and so on.Self-contained reagent: anhydrous ethanol.Pre-experiment and Important Notes1. Add 1.25ml Proteinase K Storage Buffer to Proteinase K to dissolve it and store it at -20℃. Do not leave the prepared Proteinase K at room temperature for a long time, and avoid repeated freezing and thawing to avoid affecting its activity. Do not add Proteinase K directly into Buffer GL.2. Repeated freezing and thawing of the sample should be avoided, as this may result in smaller DNA fragments and a decrease in the amount of extracted DNA.3. Avoid repeated freezing and thawing of serum or plasma, which can lead to protein denaturation or precipitation, reducing the viral titer and thus affecting the yield of extracted viral nucleic acids.4. Anhydrous ethanol should be added to Buffer GW1 and Buffer GW2 according to the label instructions of the reagent bottle before first use.5. Check Buffer GL for crystallization or precipitation before use. If crystallization or precipitation occurs, redissolve Buffer GL in a water bath at 56℃.Procedure1. Take a 1.5 ml centrifuge tube (self-provided) and add 20 µl Proteinase K.2. Add 200 µl serum or plasma to the centrifuge tube. Add 200µl Buffer GL and vortex and shake for 15 seconds.Note: 1) Sample volume less than 200 µl can be made up by adding 0.9% NaCl (self-provided). 2) In order to ensure effective lysis of the sample, the sample needs to be mixed well with Buffer GL after adding Buffer GL.3. Incubate at 56°C for 15 minutes, centrifuge briefly, and collect the solution from the wall of the tube to the bottom of the tube.4. 250 µl of anhydrous ethanol was added, vortexed and shaken for 15 seconds, left at room temperature for 5 minutes, centrifuged briefly, and the solution on the wall of the tube was collected at the bottom of the tube.Note: If the ambient temperature exceeds 25°C, anhydrous ethanol should be used after pre-cooling on ice.5. Add the solution obtained in step 4 to the adsorbent column (RNase-Free Columns RS) that has been loaded into the collection tube, and if the solution cannot be added at one time, it can be transferred in several times. centrifuge the column at 12,000 rpm (~13,400 × g) for 1 min, pour off the waste liquid in the collection tube, and put the column back into the collection tube.6. Add 500 µl of Buffer GW1 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.7. Add 500 µl of Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.Note: Step 7 can be repeated if further DNA purity is required.8. Add 500 µl of anhydrous ethanol to the adsorbent column and centrifuge at 12,000 rpm for 1 min. Pour off the waste liquid in the collection tube and put the adsorbent column back into the collection tube.9. Centrifuge at 12,000 rpm for 3 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 the removal of residual ethanol from the adsorbent column; ethanol residue can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).10. Place the adsorption column in a new collection tube (RNase-Free Centrifuge Tube), add 20-150 µl of Buffer RE or sterilized water overhanging the middle of the adsorption column membrane, leave it at room temperature for 2-5 minutes, and then centrifuge it at 12,000 rpm for 1 minute to collect the nucleic acid solution.Note: 1) If the downstream experiment is sensitive to pH or EDTA, you can use sterilized water for elution. The pH of the eluent has a great influence on the elution efficiency, if water is used as the eluent it should be ensured that its pH is 7.0-8.5 (the pH of water can be adjusted to this range with NaOH), and the elution efficiency is not high when the pH is lower than 7.0.(2) For long-term storage, please store the DNA solution at -20℃ and the RNA solution at -70℃.3) If the final concentration of DNA/RNA is to be increased, the DNA/RNA eluate obtained in step 10 can be re-spiked onto the adsorbent membrane and step 10 repeated... Read More |