| Description | Glycogen is a macromolecular polysaccharide composed of glucose and serves as one of the primary storage forms of sugar. It is mainly stored in the liver and muscles as reserve energy, referred to as liver glycogen and muscle glycogen, respectively. Liver glycogen regulates blood glucose Glycogen is a macromolecular polysaccharide composed of glucose and serves as one of the primary storage forms of sugar. It is mainly stored in the liver and muscles as reserve energy, referred to as liver glycogen and muscle glycogen, respectively. Liver glycogen regulates blood glucose concentration; when blood sugar rises, glycogen can be synthesized in the liver, and when blood sugar decreases, liver glycogen is broken down into glucose to supplement blood sugar. Therefore, liver glycogen is crucial for maintaining the relative balance of blood glucose. Muscle glycogen is the storage form of sugar in muscles. During strenuous exercise that consumes large amounts of blood sugar, muscle glycogen cannot be directly broken down into blood sugar but must first decompose to produce lactic acid, which circulates to the liver via the bloodstream and is converted into liver glycogen and glucose through gluconeogenesis. Detection Principle: Glycogen is extracted using a strong alkaline extraction buffer. Under strong acidic conditions, it forms a blue compound with the anthrone chromogen, which has a characteristic absorption peak at 620 nm. Within a certain concentration range, the glycogen content is linearly related to the absorbance at 620 nm. The glycogen content in the sample can be calculated based on the standard curve. Detection Range: 0.003125 - 0.25 mg/mL Sensitivity: 0.003125 mg/mL Applicable Samples: Animal tissues, bacteria, cellsG1501748Component96TStorageG1501748AExtraction Buffer120 mL2-8℃G1501748BChromogen1EA2-8℃. Store in the dark.G1501748CStandard1 mL2-8℃Note: It is recommended to perform preliminary experiments using 2-3 samples expected to have significant differences before formal testing.User-Provided Instruments and Consumables1.Microplate reader or visible spectrophotometer (capable of measuring absorbance at 620 nm)2.Low-temperature centrifuge, Water bath3.96-well plate or micro glass cuvettes, Adjustable pipettes and tips, EP tubes4.Deionized water, Concentrated sulfuric acidExperimental Procedure1. Reagent PreparationReagent NameReagent PreparationPrecautionsExtraction BufferReady-to-use; equilibrate to room temperature before use.Store at 4°C. Corrosive; please take protective measures during handling.ChromogenFirst, dissolve the powder in 7.2 mL of deionized water. Then slowly add 28.8 mL of concentrated sulfuric acid. Mix thoroughly after complete dissolution.Store at 4°C protected from light; valid for one week. Toxic; please take protective measures during handling.StandardStore at 4°C.2. Standard Curve SetupDilute the 1 mg/mL standard with deionized water to prepare standard solutions of 0.25, 0.1, 0.05, 0.025, 0.0125, 0.00625, and 0.003125 mg/mL as shown in the table below.No.Standard VolumeDeionized Water Volume (µL)Concentration (mg/mL)Std.1100µL of 1mg/mL3000.25Std.2160µL of Std.12400.1Std.3200µL of Std.22000.05Std.4200µL of Std.32000.025Std.5200µL of Std.42000.0125Std.6200µL of Std.52000.00625Std.7200µL of Std.62000.003125Note: A standard curve must be prepared for each experiment. Diluted standard solutions are unstable and must be used within 4 hours.3. Sample PreparationNote: Fresh samples are recommended. If not used immediately, samples can be stored at -80°C for up to 1 month.3.1 TissuesWeigh 0.1 g of tissue and place it in a 10 mL test tube. Add 0.75 mL of Extraction Buffer. Boil in a water bath for 20 minutes (stopper the tube tightly to prevent water evaporation). Shake the tube every 5 minutes to mix thoroughly. After the tissue is completely dissolved, remove the tube and let it cool. Dilute to 5 mL with deionized water, mix well. Centrifuge at 8,000 g, 25°C for 10 minutes. Collect the supernatant for detection.3.2 Cells or BacteriaCollect 5 million bacteria or cells into an EP tube. Centrifuge and discard the supernatant. Add 0.75 mL of Extraction Buffer and disrupt the bacteria or cells by ultrasonication (power 200 W, ultrasonicate for 3 s, interval 10 s, repeat 30 times). Transfer to a 10 mL test tube. Boil in a water bath for 20 minutes (stopper the tube tightly to prevent water evaporation). Shake the tube every 5 minutes to mix thoroughly. Remove the tube and let it cool. Dilute to 5 mL with deionized water, mix well. Centrifuge at 8,000 g, 25°C for 10 minutes. Collect the supernatant for detection.Note: For protein concentration determination, Aladdin BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648) are recommended.4. Assay Steps4.1 Instrument Preparation: Preheat the microplate reader or visible spectrophotometer for at least 30 minutes. Set the wavelength to 620 nm. For visible spectrophotometers, zero the instrument with deionized water.4.2 Sample Assay: Add reagents sequentially to EP tubes as follows:ReagentBlank Tube (µL)Standard Tube (µL)Test Tube (µL)Sample0060Standard0600Deionized Water6000Chromogen2402402404.3 Mix well. Incubate in a 95°C water bath for 10 minutes (cap tightly to prevent evaporation). Cool. Transfer 200 µL to a 96-well plate or micro glass cuvette. Measure the absorbance at 620 nm, recorded as A blank, A standard, and A test. Calculate ΔA test = A test - A blank and ΔA standard = A standard - A blank. Note: It is recommended to perform preliminary experiments with 2-3 samples expected to have significant differences before formal testing. If ΔA test is less than 0.001, appropriately increase the sample amount. If ΔA test is greater than 1.5, dilute the sample further with deionized water (multiply the result by the dilution factor) or reduce the amount of sample used for extraction. 5. Result Calculation Note: We provide both derived and simplified calculation formulas, which are equivalent. The simplified formulas in bold are recommended as the final calculation formulas. 5.1 Standard Curve Plotting Plot the standard curve with standard concentration as the y-axis and ΔA standard as the x-axis (using concentration as the y-axis facilitates calculation). Substitute ΔA test into x to calculate y (mg/mL). 5.2 Sample Glycogen Content Calculation (1) Based on sample mass: Glycogen (mg/g) = 1.11 × (y × V sample ) ÷ (W × V sample ÷ V total ) × n = 5.55 × y ÷ W × n (2) Based on sample protein concentration: Glycogen (mg/mg prot) = 1.11 × (y × V sample ) ÷ (V sample × Cpr) × n = 1.11 × y ÷ Cpr × n (3) Based on bacterial or cell count: Glycogen (mg/10⁴) = 1.11 × (y × V sample ) ÷ (Bacterial or Cell Count × V sample ÷ V total ) × n = 5.55 × y ÷ Bacterial or Cell Count × n Parameter Description: 1.11: Constant for converting glucose content measured by this method to glycogen content (i.e., 100 µg glucose color developed with anthrone reagent is equivalent to that of 111 µg glycogen). V sample : Volume of test sample added to the reaction system, 0.06 mL. W: Sample mass, g. V total : Total volume of the sample extract, 5 mL. n: Dilution factor. Cpr: Sample protein concentration, mg/mL. Bacterial or Cell Count: In units of 10⁴ (ten thousands)6. Result PresentationTypical Standard Curve: y = 0.1746x + 0.0027, R² = 0.9961(The following data and curve are for reference only; users must establish their own standard curve based on their experiment.)Precautions1. It is recommended to perform preliminary experiments using 2-3 samples expected to have significant differences before formal testing.2. This product is for scientific research use only and is not intended for clinical diagnosis. For your safety and health, please wear a lab coat and disposable gloves during operation... Read More | Products content Products IntroductionThis kit is a dedicated sample preparation solution for microbiome analysis and is suitable for the purification and enrichment of genomic DNA of pathogenic microorganisms such as bacteria and fungi from mixed samples such as swabs, blood, sputum, alveolar Products content Products IntroductionThis kit is a dedicated sample preparation solution for microbiome analysis and is suitable for the purification and enrichment of genomic DNA of pathogenic microorganisms such as bacteria and fungi from mixed samples such as swabs, blood, sputum, alveolar lavage, etc. During the purification process, differential lysis of the host cells and subsequent enzymatic digestion can effectively remove most of the host DNA while providing a comprehensive coverage of the bacterial and fungal DNA loci to a higher level. By differential lysis of host cells and subsequent enzymatic digestion, this kit can effectively remove most of the host DNA while maximizing the full coverage of bacterial, fungal and other pathogenic microbial DNA sites, thus obtaining microbiome DNA enrichment products with a higher coverage. Microbial DNA purified with this kit is suitable for a variety of downstream applications, including whole genome sequencing analysis, 16S rDNA-based high sensitivity microbiome analysis, and macrogenomic birdshot sequencing analysis. Self-contained reagents and consumablesSterile pipette tips with aerosol barrier to prevent cross-contamination anhydrous ethanol Microcentrifuge tubes (2 ml/1.5 ml) PBS buffer (required for some samples only)Pre-experiment Preparation and Important Notes1. Add 1.25 ml Proteinase K Storage Buffer to Proteinase K and store at -20℃. Do not leave the prepared Proteinase K (20 mg/ml) at room temperature for a long time, and avoid repeated freezing and thawing to avoid affecting its activity.2. Dissolve Lysozyme (100 mg) in 10 ml Enzymatic Lysis Buffer to a final concentration of 10 mg/ml, dispense into sterile tubes and store at -20℃. Do not leave the prepared Lysozyme (10 mg/ml) at room temperature for a long time and avoid repeated freezing and thawing to avoid affecting its activity.3. Thaw Buffer GB1 and Buffer GB2 at room temperature or 2-8°C before use and mix thoroughly. Thawed Buffer GB1 and Buffer GB2 can be left at 2-8°C for 1-2 weeks without affecting their activity, and should be stored at -20°C for long term storage. To ensure optimal performance, do not freeze or thaw more than three times. If less than one bottle of Buffer GB1 and Buffer GB2 is required for a single extraction, ensure that it is used under sterile conditions such as an ultra-clean bench and avoid microbial contamination and growth in the remaining buffer.4. Before first use, anhydrous ethanol should be added to Buffer GW1 and Buffer GW2 according to the instructions on the vial label and labeled.5. Check Buffer GL for crystallization or precipitation before use, and if crystallization or precipitation occurs, redissolve Buffer GL in a 56°C water bath.6. If the downstream experiments are sensitive to RNA contamination, 4 µl of DNase-Free RNase A (100 mg/ml) can be added before adding Buffer GL. RNase A is not provided in the kit, but can be ordered separately from CW0601S.7. This kit is designed for the isolation of DNA from intact microbial cells. To ensure optimal recovery of microbial DNA, samples should be fresh. If storage or transportation is required, this should preferably be done at 2-8°C and not frozen or thawed, as freezing and thawing can damage the integrity of the microbial cells and therefore result in the loss of exposed microbial DNA during host DNA removal.8. To avoid false results due to contamination, keep the work area clean, wear protective clothing, and set up controls for quality control. Use appropriate measures to handle sample materials to minimize the risk of cross-contamination. During the extraction process, use DNA-free pipette tips and consumables, and cap reagents immediately after use to prevent contamination. procedure1. Sample pre-treatment: 1a: For swab samples, swirl the swab portion of the swab in 0.5 ml PBS for at least 20 s. Squeeze the swab several times against the wall of the tube before removing it so that as much of the bacterial fluid as possible can be squeezed out of the swab to minimize sample loss. 1b: For viscous samples, e.g. sputum, take ~500 µl of sample, add 1.5 times the volume (~750 µl) of Buffer GB1 and incubate at 37°C, 600 rpm for 15-30 min until the sample is completely liquefied.Note: The sample volume can be increased or decreased appropriately and the amount of Buffer GB1 added adjusted accordingly.1c: For alveolar lavage fluid containing a small amount of viscous sputum, centrifuge as much of the alveolar lavage fluid as possible, carefully remove the supernatant, and retain the lower viscous fraction (containing sputum, cells, and organisms), add 1.5 times the volume of Buffer GB1, and incubate for 15-30 min at 37°C, 600 rpm until the sample is completely liquefied.1d: For non-viscous body fluid samples such as blood and cerebrospinal fluid, liquefaction treatment is not required, and an appropriate amount of sample is taken directly, the operation of step 2 is carried out, and the cell precipitate is collected by centrifugation.2. Centrifuge at 10000 rpm for 5-10 min at room temperature and carefully discard the supernatant.Note: Do not disturb the lower cell sediment to avoid sample loss.3. Add 500 µl Buffer GB2, vortex to mix, and incubate at room temperature, 600 rpm for 10 min. 4. Centrifuge at 12000 rpm for 2 min and carefully remove the supernatant.Note: Do not disturb the bacterial precipitate when removing the supernatant to avoid sample loss.5. Add 200 µl of Buffer GB2 to the precipitate, add 2 µl of Benzonase and incubate for 30 min at 37°C, 600 rpm. 6. Centrifuge at 12000 rpm for 2 min, discard the supernatant, add 500 µl of Buffer GB2, vortex and wash the precipitate. Repeat the procedure once.7. Centrifuge at 12000 rpm for 2 min, discard the supernatant, and finally aspirate the residual Buffer GB2 with a small-volume tip. 8. Add 180 µl Lysozyme (10 mg/ml), resuspend the bacterial precipitate and transfer the bacterial resuspension to a Lysis Tube.9. The Lysis Tube is incubated at 37°C, 600 rpm for 20-30 min, then vortexed for 10 min or processed on a thermostatic homogenizer for 10 min at maximum vibration speed (2500-2900 rpm).10. Centrifuge briefly, add 20 µl proteinase K, vortex to mix, add 200 µl buffer GL, vortex to mix, and incubate for 30 min at 56°C, 600 rpm. Note: 1) Do not add Proteinase K directly to Buffer GL.2）For RNA removal, add 4 µl DNase-Free RNase A (100 mg/ml) before adding Buffer GL, shake to mix, and let stand at room temperature for 5-10 minutes.11. Centrifuge at 12000 rpm for 1 min and carefully aspirate the supernatant into a new centrifuge tube. Note: Do not aspirate the glass beads.12. Add 200 µl of anhydrous ethanol, vortex to mix, and centrifuge momentarily to collect the solution to the bottom of the tube. Note: The addition of anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.13. Add all of the solution from step 12, including the precipitate, to the Spin Columns DM in the collection tube, or transfer the solution several times if it cannot be added all at once. centrifuge at 12,000 rpm for 1 minute, pour off the waste from the collection tube, and return the column to the collection tube.14. Add 500 µl Buffer GW1 to the adsorbent column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 min, pour off the waste liquid from the collection tube, and put the adsorbent column back into the collection tube.15. Add 500 µl Buffer GW2 to the adsorbent 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 adsorbent column back into the collection tube. Note: Step 15 can be repeated once if further improvement of DNA purity is required.16. Centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Leave the column at room temperature for a few minutes and dry thoroughly. Note: The purpose of this step is to remove residual ethanol from the adsorbent column; ethanol residue can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).17. Place the adsorbent column in a new centrifuge tube (supplied), add 50 µl of Buffer GE to the center of the adsorbent column overhang, let stand at room temperature for 5 minutes, centrifuge at 12,000 rpm for 1 minute, collect the DNA solution, and store the DNA at -20 °C. Attention:1）If the downstream experiments are sensitive to pH or EDTA, sterilized water can be used for elution. The pH value of the eluent has a great influence on the elution efficiency. If the eluent is made of water, the pH value should be 7.0-8.5 (the pH value of water can be adjusted to this range with NaOH), and the elution efficiency is not high when the pH value is lower than 7.0.2）Incubation at room temperature for 5 minutes prior to centrifugation increases yield.3）If the final concentration of DNA is to be increased, the DNA eluate obtained in step 17 can be re-spiked onto the adsorbent membrane and step 17 repeated. 4）DNA stored in water will be affected by acidic hydrolysis. For long-term storage, it is recommended to elute with Buffer GE and store at -20℃... Read More | RAFT Agent Kit for controlling polymerizations at the molecular level detailed list of products: Catalog Number Product Name Component Catalog Number Component Name Component CAS Specification&Purity R396714 RAFT Agent Kit for controlling polymerizations at the molecular level C139356-500mg 4-RAFT Agent Kit for controlling polymerizations at the molecular level detailed list of products: Catalog Number Product Name Component Catalog Number Component Name Component CAS Specification&Purity R396714 RAFT Agent Kit for controlling polymerizations at the molecular level C139356-500mg 4-Cyano-4-(dodecylsulfanylthiocarbonyl)sulfanylpentanoic acid 870196-80-8 See Component Catalog Number R396714 RAFT Agent Kit for controlling polymerizations at the molecular level C396701-500mg Cyanomethyl dodecyl trithiocarbonate 796045-97-1 See Component Catalog Number R396714 RAFT Agent Kit for controlling polymerizations at the molecular level C396703-500mg Cyanomethyl methyl(phenyl)carbamodithioate 76926-16-4 See Component Catalog Number R396714 RAFT Agent Kit for controlling polymerizations at the molecular level C168358-500mg 2-Cyano-2-propyl benzodithioate 201611-85-0 See Component Catalog Number R396714 RAFT Agent Kit for controlling polymerizations at the molecular level C396706-500mg 2-(2-Cyanoprop-2-yl)-S-dodecyltrithiocarbonate 870196-83-1 See Component Catalog Number R396714 RAFT Agent Kit for controlling polymerizations at the molecular level C132316-500mg 4-Cyano-4-(phenylcarbonothioylthio)pentanoic Acid 201611-92-9 See Component Catalog Number R396714 RAFT Agent Kit for controlling polymerizations at the molecular level S396708-500mg S,S-Dibenzyl trithiocarbonate 26504-29-0 See Component Catalog Number R396714 RAFT Agent Kit for controlling polymerizations at the molecular level D396711-500mg 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid 461642-78-4 See Component Catalog Number... Read More | Product DescriptionAcetyl esterase (sialate-O-acetylesterase) is a recombinant protein from Tannerella forsythia, ATCC 43037 strain, expressed in Escherichia coli. The enzyme removes acetyl groups attached via an O- group, mainly 9-, 8- and 7-. It can be used for monitoring of diacetylation of Product DescriptionAcetyl esterase (sialate-O-acetylesterase) is a recombinant protein from Tannerella forsythia, ATCC 43037 strain, expressed in Escherichia coli. The enzyme removes acetyl groups attached via an O- group, mainly 9-, 8- and 7-. It can be used for monitoring of diacetylation of sialic acids on products such as erythropoietin (EPO).The Zyme Acetyl Esterase Kit removes 9-, 8- and 7-O-acetyl groups from released sialic acids, released glycans or glycoproteins. It is commonly used for the characterization of highly-sialylated biotherapeutics such as EPO, FSH and blood clotting factors.Molecular Weight76.3 kDContentsAcetyl esterase – PBS pH7.5 buffer containing 10 mM Tris-HClReaction Buffer – 500 mM sodium acetate pH5.5Number of SamplesSufficient for up to 50 samples.Amount of SampleUp to 10 µg glycoprotein, up to 2.5 µg released glycans and up to 1 µg free sialic acid per digestion.Suitable SamplesAcetyl esterase (sialate-O-acetylesterase) can act upon complex glycoprotein samples, such as erythropoietin (EPO), bovine submaxillary mucin and oral epithelial cell-bound glycans, and on N- and O-glycans released from a glycoprotein. Either fluorescently labelled or unlabelled glycans are suitable. It can also be used on released sialic acids.Unit DefinitionOne unit (U) of acetyl esterase is defined as the amount of enzyme required to produce 300 µmole of 4-nitrophenol and acetate in 1 minute at 30°C in a buffer containing 50 mM Tris-HCl, 140 mM NaCl, pH 8.5, from 4-nitrophenyl acetate, a chromogenic esterase substrateStorageProtect from sources of heat and light. When stored correctly, the enzyme should be stable for 24 months from date of purchase. Exposure to ambient temperatures (20 – 26°C) over 3 days does not result in a reduction of enzymatic activity.ShippingThe product should be shipped at 4°C.HandlingEnsure that any glass, plastic ware or solvents used with this item are free of environmental carbohydrates. Use powder-free gloves for all sample handling procedures and avoid contamination with environmental carbohydrate.SafetyPlease read the Safety Data Sheets (SDSs) for all chemicals used. All processes involving labelling reagents should be performed using appropriate personal safety protection – safety glasses, chemically resistant gloves (e.g. nitrile), lab coat, and when appropriate, in a laboratory fume cupboard.For research use only. Not for human or drug use ApplicationAcetyl esterase (sialate-O-acetylesterase) can be used to remove 9-, 8- and 7-O-acetyl groups from released sialic acids, released glycans or glycoproteins... Read More | 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 |