| Description | NAD Kinase (NADK, EC 2.7.1.23) is widely present in animals, plants, microorganisms, and cultured cells. It is the only known enzyme that catalyzes the phosphorylation of NAD⁺ to NADP⁺ in vivo. It can utilize ATP or inorganic polyphosphate [poly(P)] as a phosphoryl donor to catalyze the NAD Kinase (NADK, EC 2.7.1.23) is widely present in animals, plants, microorganisms, and cultured cells. It is the only known enzyme that catalyzes the phosphorylation of NAD⁺ to NADP⁺ in vivo. It can utilize ATP or inorganic polyphosphate [poly(P)] as a phosphoryl donor to catalyze the phosphorylation of NAD(H), generating NADP(H). Therefore, NADK plays a crucial role in synthesizing NADP(H) and regulating the balance between NAD(H) and NADP(H).Assay PrincipleNADK catalyzes the phosphorylation of NAD⁺ to generate NADP⁺. The generated NADP⁺ is then reduced to NADPH by Glucose-6-Phosphate Dehydrogenase (G6PDH). The rate of increase in NADPH, measured by the rise in absorbance at 340 nm, reflects the activity of NADK.Component50TStorageExtraction Buffer50 mL2-8℃Reagent 125 mL2-8℃Reagent 250 mL2-8℃Reagent 31EA-20℃Reagent 41EA-20℃Required Materials and Equipment (Not Provided)UV spectrophotometer, benchtop centrifuge, adjustable pipettes, 1 ml quartz cuvette, mortar and pestle, ice, and distilled water.Sample Preparation1.Bacteria, Cells, or Tissues:Bacteria or Cultured Cells: Collect cells by centrifugation and discard the supernatant. Add Extraction Buffer at a ratio of 1 ml per 5-10 million cells (e.g., 1 ml for 5 million cells). Sonicate on ice (20% power or 200W, pulse 3s on/10s off, repeat 30 times). Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice.Tissues: Homogenize tissue on ice in Extraction Buffer at a ratio of 1:5-10 (w/v) (e.g., 0.1 g tissue in 1 ml buffer). Centrifuge the homogenate at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice.2.Serum (or Plasma) Samples: Assay directly.Assay Procedure:1.Preheat the spectrophotometer for at least 30 min. Set wavelength to 340 nm. Zero with distilled water.2.Pre-warm Reagent 1 and Reagent 2 at 37°C (for mammalian samples) or 25°C (for other species) for at least 15 min.3.Working Solution I Preparation: Add 12 mL of Reagent 1 to the contents of Reagent 3. Mix thoroughly. Aliquot and store unused portions at -20°C. Avoid repeated freeze-thaw cycles.Working Solution II Preparation: Add 45 mL of Reagent 2 to the contents of Reagent 4. Mix thoroughly. Aliquot and store unused portions at -20°C. Avoid repeated freeze-thaw cycles.4.Assay Setup:ReagentTest Tube (µL)Control Tube (µL)Sample100100Working Solution I400Reagent 1400Mix thoroughly. Incubate at 37°C (mammalian) or 25°C (other species) for 15 min.Immediately boil for 2 min (tighten caps to prevent evaporation).Cool on ice.Centrifuge at 10,000 g, 25°C for 10 min. Collect the supernatant.5.Detection:ReagentVolume (µL)Supernatant (from step 4)200Working Solution II800Add reagents to a new tube or cuvette. Mix thoroughly after addition.Let the reaction stand at room temperature for 15 min.Measure the absorbance at 340 nm.Calculate ΔA = ATest - AControl.NADK Activity Calculation:General Parameters:VTotal (Total reaction volume for detection step) = 5 × 10⁻⁴ L (0.5 mL = 500 µL)ε (NADPH molar extinction coefficient) = 6.22 × 10³ L/mol/cmd (Cuvette light path) = 1 cmVSample (Sample volume in initial reaction) = 0.1 mL (100 µL)VSample Total (Total extraction volume) = 1 mLT (Reaction time for NADK enzyme step) = 15 minCpr (Sample protein concentration, mg/mL)W (Sample mass, g)500 (Cell/Bacteria count in millions for example calculation: 5 million)1. For Serum (Plasma):Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADP⁺ per minute per ml of serum.Calculation:NADK Activity (nmol/min/ml) = [ΔA × VTotal ÷ (ε × d) × 10⁹] ÷ VSample ÷ TSimplified Formula: NADK (nmol/min/ml) = 53.59 × ΔA2. For Tissues, Bacteria, or Cells:a. Based on Sample Protein Concentration:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADP⁺ per minute per mg of protein.Calculation:NADK Activity (nmol/min/mg prot) = [ΔA × VTotal ÷ (ε × d) × 10⁹] ÷ (VSample × Cpr) ÷ TSimplified Formula: NADK (nmol/min/mg prot) = 53.59 × ΔA ÷ Cprb. Based on Sample Fresh Weight:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADP⁺ per minute per gram of fresh tissue.Calculation:NADK Activity (nmol/min/g fresh weight) = [ΔA × VTotal ÷ (ε × d) × 10⁹] ÷ (W × VSample / VSample Total) ÷ TSimplified Formula: NADK (nmol/min/g fresh weight) = 53.59 × ΔA ÷ Wc. Based on Bacterial or Cell Density:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADP⁺ per minute per 10⁴ cells.Calculation (example for 5 million cells in 1 ml extract):NADK Activity (nmol/min/10⁴ cell) = [ΔA × VTotal ÷ (ε × d) × 10⁹] ÷ (500 × VSample / VSample Total) ÷ TSimplified Formula: NADK (nmol/min/10⁴ cell) = 0.107 × ΔAPrecautionsBefore formal assay, it is essential to perform a pilot test with 2-3 samples expected to have significant differences in activity... 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 occur in 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 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. Component： 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 sample 5 sample 10 sample TdT enzyme 1 µL 5 µL 10 µL YF®488/555/594/640 TUNEL Reaction Buffer 49 µL 245 µL 490 µL TUNEL Total volume of reaction solution 50 µL 250 µL 500 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. Product parameters：590/617nm； Scope of application：Late apoptosis detection, TUNEL Kit... Read More | Product IntroductionBCIP (5-Bromo-4-chloro-3-indolyl phosphate) 5-bromo-4-chloro-3-indolyl-phosphate + NBT (tetrazolium nitro blue) is the best substrate for alkaline phosphatase (AP) One of the combination. Under the catalysis of alkaline phosphatase, BCIP will be hydrolyzed to produce a highly Product IntroductionBCIP (5-Bromo-4-chloro-3-indolyl phosphate) 5-bromo-4-chloro-3-indolyl-phosphate + NBT (tetrazolium nitro blue) is the best substrate for alkaline phosphatase (AP) One of the combination. Under the catalysis of alkaline phosphatase, BCIP will be hydrolyzed to produce a highly reactive product, which reacts with NBT to form an insoluble dark blue to blue-violet compound. This kit can be used for the enzymatic color development of IHC and Western Blot experiments of the AP system. Under AP catalysis, a dark blue precipitate is produced where AP conjugates are combined on tissue sections or blotting membranes. The location and expression of the target protein can be determined based on the color reaction.Product Components40×BCIP: 1 ml40×NBT: 1 mlBCIP/NBT Buffer: 40 mlPrecautions1. The working fluid should be prepared for immediate use, and the prepared working fluid will be effective within 1 hour.2. The amount of working fluid must be sufficient to ensure complete coverage of the tissue sheet or blotting membrane. To3. In order to obtain the best experimental results, be sure to optimize the experimental conditions.4. NBT is poisonous, please take necessary protective measures when using it.5. This product is only used for scientific research, not for human experiments or human treatment.Instructions1. BCIP/NBT color developing working solution preparation:According to the required amount, mix 40×BCIP, 40×NBT and BCIP/NBT Buffer in a volume ratio of 1:1:38 to form the BCIP/NBT color developing working solution.2. Color rendering:1) Blotting membrane color development: Drop the prepared working solution on the blotting membrane (or pour the blotting membrane into the BCIP/NBT color developing working solution), and incubate for 3-10 minutes at room temperature and dark. After the color development is completed, the film is immersed in water to terminate the reaction.2) Color development of tissue sections or cell slides: Drop an appropriate amount of BCIP/NBT color developing working solution on the tissue sections or cell slides that need color development, and incubate at room temperature for 3-10 minutes in the dark. Observe under the microscope to control the color development time. When the best color development effect is reached, rinse with tap water to stop the color development. After color development, the slices are counter-stained, dehydrated and transparent, and can be stored for a long time after mounting... Read More | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export | 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 |