| Description | 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 | D-Lactate, typically present in the bloodstream at nanomolar concentrations, is produced by an intestinal source or via the methylglyoxal pathway. In mammals, D-Lactate metabolism requires D-Lactate hydrogenase and is metabolized slowly, thus an increase in blood concentration levels can lead to D-Lactate, typically present in the bloodstream at nanomolar concentrations, is produced by an intestinal source or via the methylglyoxal pathway. In mammals, D-Lactate metabolism requires D-Lactate hydrogenase and is metabolized slowly, thus an increase in blood concentration levels can lead to acidemia and acidosis. The severity of this D-lactic acidosis can be associated with neurotoxic symptoms. Significant D-Lactate accumulations in the body can also be related to impaired metabolism and excretion.D-Lactate Colorimetric Assay kit has been used to determine the stereospecificity of lactate produced.Suitability: Suitable for use with samples of serum, plasma, cells, culture and fermentation media.Principle: In this assay, D-Lactate is specifically oxidized by D-Lactate hydrogenase and generates a proportional colorimetric product measured at 450 nm. The useful concentration range in samples is 0.1-10 mM D-Lactate... Read More | FFPE DNA/RNA KitFixed Tissue DNA/RNA Extraction Kit Catalog number: F666120 (50 preps)Storage conditions: DNase I and 10×Reaction Buffer -20℃, Spin Columns DF and Spin Columns RS can be stored at room temperature for 2 months, 2-8℃ for 1 year, the rest of the components are stored FFPE DNA/RNA KitFixed Tissue DNA/RNA Extraction Kit Catalog number: F666120 (50 preps)Storage conditions: DNase I and 10×Reaction Buffer -20℃, Spin Columns DF and Spin Columns RS can be stored at room temperature for 2 months, 2-8℃ for 1 year, the rest of the components are stored at room temperature (15-30℃).Products Content:Products IntroductionThis kit is suitable for the effective purification of genomic DNA and total RNA from paraffin-embedded tissues, using specially optimized deparaffinizing agents and lysates to release DNA and RNA from tissue section samples, without the use of the organic reagent xylene, and without the need for overnight operation; the digested samples are incubated at higher temperatures to remove inhibitors caused by cross-linking, which can effectively improve nucleic acid yields and purity; and an optimized buffer system allows nucleic acids in the lysate to bind specifically to the adsorbent membrane, and inhibitors are effectively removed by a two-step rinsing procedure. The optimized buffer system enables the nucleic acids in the lysate to bind specifically to the adsorbent membrane, and the inhibitors are effectively removed by a two-step rinsing step, and finally eluted with low-salt buffer or water to obtain high purity DNA and RNA, and at the same time, equipped with a high-efficiency microsorbent column, the volume of the elution can be as low as 20 µl. The purified DNA and RNA can be directly used for PCR, Real-time PCR, SNP genotyping, STR genotyping, and so on. The purified DNA and RNA can be directly used for PCR, Real-time PCR, SNP genotyping, STR genotyping, second-generation sequencing, pharmacogenomics research and blot analysis.Self-contained reagent: anhydrous ethanolPre-experiment Preparation and Important Notes 1. After obtaining the sample, fix the sample as soon as possible, the fixation time of 14-24 hours is appropriate, too long a period of time will easily lead toDNA and RNA breaks, affecting downstream experiments. If the formaldehyde fixation time is too long or the sample is stored for too long(>1 year) is prone to compromise DNA integrity and failure to amplify long fragments.2. Ensure that samples are thoroughly dehydrated prior to embedding; residual formalin will inhibit Proteinase K action.3. Add 1.25 ml of Proteinase K Storage Buffer to Proteinase K to dissolve it, and store at -20℃. Do not leave the prepared Proteinase K at room temperature for a long period of time to avoid affecting its activity.4. Anhydrous ethanol should be added to Buffer RW2, Buffer GW1 and Buffer GW2 according to the label instructions on the vials before first use.5. Check Buffer GTL, Buffer GL and Buffer DS for crystallization or precipitation prior to use; if crystallization or precipitation occurs, redissolve Buffer GTL, Buffer GL and Buffer DS in a 37°C water bath.6. Preheat the water bath or thermostatic mixer to 56°C before starting the experiment.7. Use an ambient temperature centrifuge or set the centrifuge temperature to 25°C. Temperatures below 15°C may result in clogging of the adsorption column.8. To prevent RNase contamination, the following should be observed:1) Use RNase-free plastics and tips to avoid cross-contamination.(2) Glassware should be dry baked at 180°C for 4 hours before use, plasticware can be soaked in 0.5 M NaOH for 10 minutes, rinsed thoroughly with water and autoclaved.3) RNase-free water should be used to prepare the solution.(4) Operators wear disposable masks and gloves, and change gloves diligently during the experiment.procedureParaffin-embedded samples1. Trim off excess paraffin from the tissue block to expose the tissue and cut into 5-10 µm slices.2. Place approximately 1 x 1 cm2 slices (1-5 slices in total) in a centrifuge tube (supplied), add 500 µl of Buffer DS and vortex for 10 s. Briefly centrifuge the sample to the bottom of the tube. Centrifuge briefly to collect the sample at the bottom of the tube, incubate at 56°C for 3 minutes, remove from the water bath and allow to cool to room temperature before proceeding.Note: If the surface of the sample is exposed to air, discard the initial 2-3 slices without using them.3. Centrifuge at 12,000 rpm for 2 minutes and carefully discard the supernatant thoroughly without aspirating the precipitate. The residual dewaxing solution can be carefully removed with a small tip (10 µl).4. Add 180 µl of Buffer GTL and 20 µl of Proteinase K to the above tube and mix well with vortexing.5. Incubate at 56°C for 15 minutes, then place on ice for 3 minutes. Centrifuge at 12,000 rpm for 15 minutes at room temperature.6. Transfer the supernatant to a new 1.5 ml centrifuge tube for RNA extraction, taking care not to aspirate undigested tissue. Use the precipitate for DNA extraction. RNA extraction7. Take the supernatant obtained in step 6 and incubate at 80°C for 15 minutes.8. Add 320 µl of Buffer GL, mix by vortexing and shaking, then add 720 µl of anhydrous ethanol and mix immediately by vortexing and shaking.9. Add all of the resulting solution to the Spin Columns RS in the collection tube; if the solution cannot be added all at once, it may be transferred in several passes. centrifuge the column at 12,000 rpm for 1 minute, pour off the waste solution from the collection tube, and place the column back into the collection tube. Note: If the columns are clogged, the sample size may be too large and consideration should be given to reducing the number of starting sections to 1-2.Optional step: If genomic DNA is to be removed, the following steps can be followeda. Add 350 µl of Buffer RW1 to the column, centrifuge at 12,000 rpm for 1 minute, discard the waste solution, and place the column back into the collection tube.b. Preparation of DNase I mixture: Take 52 µl of RNase-Free Water and add 8 µl of 10×Reaction to it.Buffer and 20 µl DNase I (1 U/µl), mix well, and prepare a final volume of 80 µl of reaction solution.c. Add 80 µl of DNase I Mix directly to the adsorption column and incubate at 20-30°C for 15 minutes.d. Add 350 µl of Buffer RW1 to the column, centrifuge at 12,000 rpm for 1 minute, discard the waste solution, and return the column to the collection tube.Add 500 µl of Buffer RW2 to the adsorbent column, 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.11. Repeat step 10. centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Place the column at room temperature for 5 minutes.minutes to dry thoroughly.12. Place the column in a new RNase-free centrifuge tube and add 20-50 µl to the center of the column.RNase-Free Water, left at room temperature for 5 minutes, centrifuged at 12,000 rpm for 1 minute, and collected RNA solution, the-80°C for storage.DNA extraction7. Take the precipitate obtained in step 6 and add 180 µl Buffer GTL and 20 µl Proteinase K to the precipitate. VortexResuspend the precipitate for 15 seconds.8. Incubate at 56°C for 1 hour until the sample is completely dissolved. 90°C for 1 hour.Add 200 µl Buffer GL, vortex and shake to mix and then add 200 µl anhydrous ethanol, vortex and shake to mix thoroughly. Centrifuge briefly so that the solution on the wall of the tube collects at the bottom of the tube. Add all of the solution from step 9 to the Spin Columns DF in the collection tube, or transfer the solution in several passes. centrifuge at 12,000 rpm for 1 minute, pour off the waste solution from the collection tube, and return the column to the 10. collection tube.Note: If the adsorption column is clogged, the sample size may be too large and consideration should be given to reducing the number of starting sections to 1-2.11. Add 500 µl of Buffer GW1 to the adsorbent column and centrifuge at 12,000 rpm for 1 minute. Pour off the waste liquid from the collection tube and put the column back into the collection tube.12. Add 500 µl of Buffer GW2 to the adsorbent column and centrifuge at 12,000 rpm for 1 minute. Pour off the waste liquid from the collection tube and place the column back into the collection tube.Note: Step 12 may be repeated if further purity is required.13. Centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Leave the adsorption column at room temperature for 5 minutes to dry thoroughly. Note: The purpose of this step is to remove residual ethanol from the adsorbent column; ethanol residue will affect the subsequent enzymatic reaction. 14. Place the column in a new 1.5 ml centrifuge tube, add 20-50 µl Buffer EB to the center of the column, leave at room temperature for 5 minutes, centrifuge at 12,000 rpm for 1 minute, collect the DNA solution, and store at -20℃... Read More | Product DescriptionOur Glycan Sequencing Kit includes the enzymes and buffer required to sequence ten N-linked oligosaccharides.ContentsNeuraminidase from Arthrobacter ureafaciens – 80 µlBeta-Galactosidase from Streptococcus pneumoniae – 60 µlN-Acetylglucosaminidase from Product DescriptionOur Glycan Sequencing Kit includes the enzymes and buffer required to sequence ten N-linked oligosaccharides.ContentsNeuraminidase from Arthrobacter ureafaciens – 80 µlBeta-Galactosidase from Streptococcus pneumoniae – 60 µlN-Acetylglucosaminidase from Streptococcus pneumoniae) – 40 µlAlpha-Mannosidase from Jack Bean – 20 µlCore Alpha-Mannosidase from X. manihotis) – 10 µl5X Reaction buffer – 400 µlAnalysisMany methods of analysis are available, including HPLC, gel electrophoresis, HPAEC, capillary electrophoresis, and mass spectrometry. For more information on these methods, please contact us.StabilityThe Glycan Sequencing Kit is stable at least 12 months when stored properly. Several days exposure to ambient temperatures will not reduce activity.PurityAll Enzymes are tested for contaminating protease by incubating 10 µg of denatured BSA with 2 µl of enzyme at 37°C for 24 hours. SDS-PAGE analysis of the treated BSA shows no evidence of degradation.The production host strains for our recombinant enzymes have been extensively tested and do not produce any detectable glycosidases. Enzymes purified from native sources are tested for contaminating exoglycosidases The absence of exoglycosidase contaminants is confirmed by extended incubations with the corresponding pNP-glycosides... 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 |