| Description | Animal liver and kidneys are the main organs for amino acid metabolism. Therefore, changes in urinary amino acids best reflect the physiological state of the liver and kidneys. Additionally, amino acid levels can indicate conditions such as burns and typhoid fever. The amino acid content in plants Animal liver and kidneys are the main organs for amino acid metabolism. Therefore, changes in urinary amino acids best reflect the physiological state of the liver and kidneys. Additionally, amino acid levels can indicate conditions such as burns and typhoid fever. The amino acid content in plants is significant for studying nitrogen metabolism changes under different conditions and during various growth and development stages, as well as for understanding nitrogen absorption, transport, assimilation, and nutritional status in plants.Detection Principle: The α-amino group of amino acids reacts with ninhydrin hydrate to produce a blue-purple compound with a characteristic absorption peak at 570 nm. The amino acid content is calculated by measuring the absorbance at 570 nm.Detection Range: 0.625 - 40 µmol/mLSensitivity: 0.5 µmol/mLApplicable Samples: Serum (plasma), animal/plant tissues, cells, cell culture supernatants, bacteria, urineG1501758Component96TStorageG1501758AExtraction Buffer100 mL2-8℃G1501758BAssay Buffer10 mL2-8℃G1501758CSubstrate1EA2-8℃. Store in the dark.G1501758DStandard (10mg Cysteine)1EA2-8℃. Store in the dark.User-Prepared Instruments and ReagentsMicroplate reader or visible spectrophotometer (capable of measuring absorbance at 570 nm)96-well plate or micro glass cuvettes, adjustable micropipettes and tipsRefrigerated centrifuge, water bathDeionized water, EthanolHomogenizer (for tissue samples)Experimental Procedure1. Reagent PreparationReagent NameReagent PreparationNotesExtraction 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. Toxic and irritant. Perform experiments in a fume hood.SubstrateToxic and irritant. Perform experiments in a fume hood.Working SubstratePrepare before use: Dissolve in 4 mL of 95% Ethanol.Unused dissolved substrate can be stored at 4°C protected from light for one week. For long-term storage, aliquot and store at -20°C protected from light for one month. Avoid repeated freeze-thaw cycles.StandardPrepare before use: Add 2.066 mL deionized water to dissolve completely, resulting in a 40 µmol/mL stock.Unused dissolved standard can be stored at 4°C for one week. For long-term storage, aliquot and store at -20°C for one month. Avoid repeated freeze-thaw cycles.2. Standard Curve SetupDilute the 40 µmol/mL standard stock solution with deionized water to concentrations of 20, 10, 5, 2.5, 1.25, and 0.625 µmol/mL as shown in the table below.TubeStandard VolumeDeionized Water Volume (µL)Standard Concentration (µmol/mL)Std.1200µL of 40µmol/mL040Std.2100µL of Std.110020Std.3100µL of Std.210010Std.4100µL of Std.31005Std.5100µL of Std.41002.5Std.6100µL of Std.51001.25Std.7100µL of Std.61000.625Note: The standard curve must be generated with 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 one month.3.1 Animal TissueWeigh approximately 0.1 g of tissue. Add 1 mL of Extraction Buffer and homogenize thoroughly at room temperature. Transfer the homogenate to a 1.5 mL microcentrifuge tube. Cap tightly (to prevent moisture loss) and incubate in a boiling water bath for 15 minutes. Cool with tap water. Centrifuge at 10,000 rpm for 10 minutes at room temperature. Collect the supernatant for assay.3.2 Plant TissueWeigh approximately 0.1 g of tissue. Add 1 mL of Extraction Buffer and grind. Sonicate for 5 minutes at room temperature (power 20% or 200W, pulse 3s on, 7s off, repeat 30 times). Transfer to a 1.5 mL microcentrifuge tube. Cap tightly (to prevent moisture loss) and incubate in a boiling water bath for 15 minutes. Cool with tap water. Centrifuge at 10,000 rpm for 10 minutes at room temperature. Collect the supernatant for assay.3.3 Cells or BacteriaCollect 5 million cells or bacteria into a centrifuge tube. Wash cells with cold PBS, centrifuge, and discard the supernatant. Add 1 mL of Extraction Buffer. Sonicate for 5 minutes at room temperature (power 20% or 200W, pulse 3s on, 7s off, repeat 30 times). Transfer to a 1.5 mL microcentrifuge tube. Cap tightly (to prevent moisture loss) and incubate in a boiling water bath for 15 minutes. Cool with tap water. Centrifuge at 10,000 rpm for 10 minutes at room temperature. Collect the supernatant for assay.3.4 Serum (Plasma), Cell Culture Supernatant, Urine, and Other LiquidsPipette 0.5 mL of the liquid sample and add 0.5 mL of Extraction Buffer. Cap tightly (to prevent moisture loss) and incubate in a boiling water bath for 15 minutes. Cool with tap water. Centrifuge at 10,000 rpm for 10 minutes at room temperature. Collect the supernatant for assay.Note: If protein concentration measurement is required, use Aladdin's BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648).4. Assay Steps4.1 Preheat the microplate reader or visible spectrophotometer for at least 30 minutes. Set the wavelength to 570 nm. For spectrophotometers, zero the instrument with deionized water.4.2 Sample Measurement (Add reagents sequentially into microcentrifuge tubes as below):ReagentBlank Tube (µL)Standard Tube (µL)Test Tube (µL)Deionized Water1000Standard (various conc.)0100Sample0010Working Substrate202020Assay Buffer5050504.3 Mix well and cap the tubes tightly (to prevent moisture loss). Incubate in a boiling water bath for 5 minutes. Cool in tap water for 10 seconds. Add 120 µL of 60% ethanol to each tube and invert several times to mix. Transfer 150 µL from each tube to the corresponding wells of a 96-well plate or micro glass cuvette. Measure the absorbance at 570 nm, recorded as A blank, A standard, and A test. Calculate ΔA test = A test - A blank and ΔA standard = A standard - A blank (The blank tube only needs to be prepared once). All measurements must be completed within 30 minutes after color development. Note:It is recommended to perform a preliminary test with 2-3 samples expected to have significant differences before the formal experiment. If A <sub> test </sub> is greater than 2.0, dilute the sample further with deionized water and multiply the result by the dilution factor.Proline and hydroxyproline do not produce an absorption peak at 570 nm when reacting with ninhydrin. Therefore, the results measured at 570 nm do not include these two amino acids.5. Calculation of ResultsNote: We provide two formulas, including the derived formula and a simplified version. They are equivalent. It is recommended to use the simplified formula in bold for final calculation.5.1 Standard Curve PlottingPlot the standard concentration (y-axis) against ΔA standard (x-axis) to generate the standard curve. Substitute ΔA test into the standard curve equation to calculate y (µmol/mL).5.2 Sample Amino Acid Content Calculation(1) Based on Sample WeightAmino Acid Content (µmol/g weight) = y ÷ (W ÷ V<sub>extraction</sub>) × n = y ÷ W × n(2) Based on Protein ConcentrationAmino Acid Content (µmol/mg prot) = y ÷ Cpr × n(3) Based on Bacterial or Cell CountAmino Acid Content (µmol/10⁴ cells) = y ÷ (Count ÷ V<sub>extraction</sub>) × n = y ÷ 500 × n = 0.002 × y × n(4) Based on Liquid VolumeAmino Acid Content (µmol/mL) = y × 2 × nParameter Definitions:W: Sample weight (g)V extraction : Volume of Extraction Buffer added (1 mL)n: Sample dilution factorCpr: Protein concentration of the supernatant (mg/mL)500: Total number of bacteria or cells (5 million)2: Dilution factor for liquid samples [(0.5 mL sample + 0.5 mL Buffer) / 0.5 mL sample = 2]6. Representative ResultsTypical Standard Curve: y = 20.349x - 0.423, R² = 0.9971 Figure 1: Total Amino Acid Standard Curve Precautions1. Biochemical reagents are generally irritating, biologically toxic, etc. For your safety and health, please use appropriate biosafety precautions throughout the experiment, including wearing lab coats, masks, gloves, head covers, etc. Perform experiments in a fume hood or biosafety cabinet.2. This product is for research use only. Not for use in clinical diagnosis... Read More | DescriptionCAR10 is a kit that contains a selection of 10 carbohydrates/sugars: Arabinose, Fructose, Galactose, Glucose, α-Lactose, Maltose, Mannose, Ribose, Sucrose and Xylose, which may be used for general research, as reagents or as reference compounds in analytical procedures | Live & deadtm animal cell viability / toxicity detection kit (calcein am, ethd-i) is a kit that provides double fluorescent staining for the detection of animal cell death and survival. The two probes in the kit can respectively measure the activity of cellular lactonase and the integrity of Live & deadtm animal cell viability / toxicity detection kit (calcein am, ethd-i) is a kit that provides double fluorescent staining for the detection of animal cell death and survival. The two probes in the kit can respectively measure the activity of cellular lactonase and the integrity of plasma membrane to reflect cell viability. The kit can be used for fluorescence microscopy, flow cytometry, microplate reader and other fluorescence detection systems. This kit can be applied to most eukarYOtic mammalian cells, including some tissues with adherent nuclei, but it is not applicable to fungi and yeast. Compared with trypan blue, the kit is faster, safer and more sensitive.Component： Product parameters：Calcein am: ex/em = 494 / 517 nm; Ethd-i: ex/em = 528 / 617 nm (bound DNA)Usage:Fluorescence microscopy detection1. Prepare working fluidPreparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution: Remove the original solution of Calcein AM and EthD-I and restore them to room temperature. Add 20 µ L 2 mM EthD-I and 5 µ Mix 4 mM Calcein AM with 10 mL PBS or other serum-free buffer or culture medium, vortex well. The above working solution can be directly used for cell staining.Note: The aqueous solution of Calcein AM is easily hydrolyzed and should be used up every day. The concentration selection of Calcein AM and EthD-I varies depending on the type of cell used, with a recommended concentration range of 0.1-10 µ M.2. Prepare cells and conduct experiments(1) For adherent cells, they can be washed 2-3 times with 1 × PBS before staining. For suspended cells, centrifuge at room temperature of 250-1000 × g for 5 minutes and collect cells for staining.(2) Wash the cells thoroughly 2-3 times with 1 × PBS to remove residual esterase activity.(3) For adherent cells, add sufficient amount of Calcein AM/EthD-I staining solution. For suspended cells, add an appropriate amount of staining solution to control the cell density between 1-5 × 105/mL.(4) Incubate at room temperature in dark for 15-20 minutes (if the working solution concentration is high or the incubation temperature is high, the incubation time should be appropriately reduced).(5) Observe the labeled cells under a fluorescence microscope.Flow cytometry detection1. Remove the reagent and restore it to room temperature.2. Preparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution: Take out the original solution of Calcein AM and EthD-I, and restore to room temperature. Add 20 µ L 2 mMEthD-I and 5 µ Vortex mix 4 mM Calcein AM with 10 mL PBS or other serum-free buffer or culture medium. The working fluid can directly stain cells.3. Wash cells thoroughly 2-3 times with 1 × PBS.4. Suspend cells with 0.5 mL of staining solution and control the cell density to 1-5 × 105/mL.Note: It is recommended to prepare two additional cell samples, each containing only one dye (Calcein AM and EthD-I), for compensatory regulation of flow cytometry single staining; Prepare another cell sample containing only buffer solution (which should be consistent with the buffer used to prepare Calcein AM and EthD-I detection working solutions) as a negative control for flow cytometry analysis.5. Incubate at room temperature in dark for 15-20 minutes.6. Within 1-2 hours, cell activity was detected by flow cytometry. Calcein AM can be excited by a 488 nm laser, with fluorescence emission spectra detected at around 530 nm and EthD-I emission spectra at around 610 nm.Note: When using the cell circle gate, attention should be paid to excluding cell debris and using a single staining tube to regulate compensation. Double staining tube flow cytometry should obtain two relatively independent cell populations: a live cell population displaying green fluorescence and a dead cell population displaying red fluorescence.ELISA reader detection1. Cultivate an appropriate amount of adherent or suspended cells in a 96 well black ELISA plate.Note: Dead cells can be obtained by treating cells with 1% saponin or 0.1-0.5% digitalis saponin for 10 minutes.2. Preparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution:Remove the original solutions of Calcein AM and EthD-I and restore them to room temperature. Add 20 µ L 2 mM EthD-I and 5 µ Mix 4 mM Calcein AM 10 mL PBS or other serum-free buffer or culture medium, vortex well.Note: (1) 10 mL of staining solution is sufficient to stain a 96 well plate, and the volume of the staining solution can be adjusted according to experimental needs. The concentrations of Calcein AM and EthD-I can range from 0.1 to 10 µ Explore between M.(2) The aqueous solution of Calcein AM is easily hydrolyzed and should be used up every day. EthD-I working solution can be stored at -20 ℃ for at least one year.3. Wash the cells thoroughly with 1 × PBS to remove residual esterase activity. For adherent cells, add 100 to each well µ Wash cells with PBS. For suspended cells, add 100 µ Resuspend cells with L PBS and centrifuge to remove the supernatant. Repeat the above operation.4. Add 100 to each hole µ L PBS.5. Add 100 to each hole µ L staining solution, making the total volume of each well 200 µ L. The final concentration of Calcein AM is 1 µ M. The final concentration of EthD-I is 2 µ M. Gently shake the culture plate to evenly cover the cells with the liquid.Incubate at room temperature in dark for 30-45 minutes.Note: The optimal incubation time varies for different cells, with 30 minutes as the initial incubation time. Subsequently, the staining time can be adjusted and optimized according to the actual staining effect to obtain a more ideal staining effect.7. Enzyme reader detection. When the ELISA reader is set to fluorescein, it can detect Calcein AM; When the ELISA reader is set to rhodamine or Texas Red, EthD-I can be detected. Select the optimal emission and excitation wavelengths based on spectral characteristics.Note: By comparing the relative fluorescence values (RFU) measured between the sample group and the control group, the changes in the number of dead and live cells can be obtained. Another method of data analysis is also provided below.The following method can calculate the ratio of live cells to dead cells in a certain region. The required samples include dead cell control group, live cell control group, and the sample group to be tested. Dead cells can be obtained by treating cells with 1% saponin or 0.1-0.5% digitalis saponin for 10 minutes.1. Prepare staining solution and follow the above steps to stain cells. Additionally, prepare 1 mL and 2 mL separately µ M Calcein AM and 4 µ M EthD-I solution, stain the control group according to the following instructions. For the following groups of cells or cell-free groups, it is necessary to maintain complete consistency in cell count, detection of working solution concentration, incubation time, and incubation temperature.2. Measurement of sample group and control group:A. The measured values of the sample group at 645 nm are denoted as Calcein AM and EthD-I=F (645) sam.B. The measured values of the sample group at 530 nm are denoted as Calcein AM and EthD-I=F (530) sam.C. The measurement value of dead cell EthD-I single staining control group at 645 nm is denoted as EthD-I=F (645) maxD. The measurement value of dead cell Calcein AM single staining control group at 645 nm is recorded as Calcein AM=F (645) minE. The measurement value of live cell EthD-I single staining control group at 530 nm is recorded as EthD-I=F (530) min.F. The measurement value of live cell Calcein AM single staining control group at 530 nm is denoted as Calcein AM=F (530) max.G. A blank control well without cells (with or without dye), the detection value at 530 nm is recorded as F (530) 0.H. A blank control well without cells (with or without dye), the detection value at 645 nm is recorded as F (645) 0.3. Calculate the ratio of dead cells to live cells based on measurement data:%Live Cells=(B-E) ÷ (F-E)%Dead Cells=(A-D) ÷ (C-D)Determine the ratio of live cells to dead cells in a certain areaBy creating fluorescence spectral standard curves at 530 nm and 645 nm, the number of dead and live cells can be determined, and the fluorescence intensity of each dye is linearly related to the number of dead or live cells in the sample.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. phenol red or serum may interfere with the detection of this kit. 3. fluorescent dyes have quenching problems. Please try to avoid light during experimental operation to slow down fluorescence quenching. 4. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Dead and live cell staining (animal)... Read More | R669988 Component 50T Storage R669988A DNase I 1000 U -20℃. Avoid freeze/thaw cycle. R669988B 10×Reaction Buffer 1000 µL -20℃. Avoid freeze/thaw cycle. R669988C Buffer RL 35 mL RT R669988D Buffer RLC 35 mL RT R669988E Buffer RW1 40 mL RT R669988F Buffer RW2 (concentrate) 11 mL R669988 Component 50T Storage R669988A DNase I 1000 U -20℃. Avoid freeze/thaw cycle. R669988B 10×Reaction Buffer 1000 µL -20℃. Avoid freeze/thaw cycle. R669988C Buffer RL 35 mL RT R669988D Buffer RLC 35 mL RT R669988E Buffer RW1 40 mL RT R669988F Buffer RW2 (concentrate) 11 mL RT R669988G RNase-Free Water 10 mL RT R669988H Spin Columns FL with Collection Tubes 50 sets RT R669988I Spin Columns RM with Collection Tubes 50 sets RT R669988J RNase-Free Centrifuge Tubes (1.5 mL) 50 EA RTProductsThis kit is used for the extraction and purification of high-quality total RNA from a variety of plants, and is also suitable for the extraction of fungal mycelial RNA. The unique separation column is used for homogenization and filtration of high viscosity plant or fungal lysates, while the silicon matrix membrane is used to adsorb the RNA for purification, so that various contaminants, such as polysaccharides, are effectively removed by washing, and the eluted RNA can be directly used in various downstream experiments. The molecular weight of RNA extracted by this kit is more than 200 bases, with high purity and almost no DNA residue. For RNA experiments that are very sensitive to trace DNA, the residual DNA can be removed by digestion on a column using RNase-free DNase. The extracted RNA can be used in Northern Blot, Dot Blot, RT-PCR and in vitro translation experiments.Self-contained reagents: β-mercaptoethanol, anhydrous ethanol (freshly opened or for RNA extraction).Pre-experiment Preparation and Important Notes1. To prevent RNase contamination, attention should be paid to the following aspects:1) Use RNase-free plastics and tips to avoid cross-contamination.2) RNase-free water should be used to prepare the solution.(3) Operators wear disposable masks and gloves, and change gloves diligently during the experiment.2. To prevent RNase contamination, attention should be paid to the following aspects:1) Use RNase-free plastics and tips to avoid cross-contamination.(2) Glassware should be dry-roasted at 180°C for 4 hours before use, and plasticware can be soaked in 0.5M 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.3. Avoid repeated freezing and thawing of the extracted samples, otherwise it will affect the amount and quality of RNA extraction.4. Please add β-mercaptoethanol to Buffer RL before use, add 10µl of β-mercaptoethanol to 1ml of Buffer RL, it can be stored for 1 month at room temperature. Buffer RL with β-mercaptoethanol can be stored at room temperature for 1 month. β-mercaptoethanol is not required for use of Buffer RLC.5. Anhydrous ethanol should be added to Buffer RW2 before first use according to the instructions on the reagent bottle label.6. If precipitation occurs in Buffer RL and Buffer RLC, heat to dissolve and leave at room temperature.7. All centrifugation steps are carried out at room temperature and all steps are performed quickly. Procedure1. 50-100 mg of plant tissue is quickly ground to a powder in liquid nitrogen and added to 600 µl of Buffer RL (check for addition of β-mercaptoethanol before use) or Buffer RLC. vortexing and oscillating to allow for adequate lysis.Note: 1) The main component of Buffer RL is guanidine isothiocyanate, which is suitable for lysis of most plant tissues. However, in some plant tissues (e.g. endosperm of corn), due to the special secondary metabolites, guanidine isothiocyanate causes precipitation of the sample, resulting in poor RNA extraction, in this case, Buffer RLC can be added instead of Buffer RL.2) Incubation at 56°C for 1-3 minutes helps tissue lysis, but do not incubate at high temperatures for plants with high starch content.2. Transfer all the liquid obtained in step 1 to an adsorption column (Spin Columns FL) that has been loaded into a collection tube, centrifuge at 12,000 rpm (~13,400 x g) for 2 minutes, and transfer the supernatant from the collection tube to a new centrifuge tube (supplied).Note: 1) The tip of the tip of the gun can be cut off when aspirating liquids to facilitate sampling.2) Spin Columns FL removes most of the debris, but a small portion will still flow out and a precipitate will form in the collection tube after centrifugation, so be careful to avoid aspirating the precipitate when proceeding to the next step.3. Add 0.5 times the volume of anhydrous ethanol to the clean lysate obtained in step 2 and mix rapidly.Note: Precipitation may occur upon addition of ethanol, but does not affect subsequent tests.4. Transfer the solution obtained in the previous step to the Spin Columns RM in the collection tube. If it is not possible to add all of the solution to the column at one time, centrifuge the column at 12,000 rpm for 15 seconds in two batches, discard the waste solution and put the column back into the collection tube.5. Add 350 µl Buffer RW1 to the adsorbent column, centrifuge at 12,000 rpm for 1 min, discard the waste liquid and put the adsorbent column back into the collection tube.6. Preparation of DNase I mixture: Take 52µl of RNase-Free Water, add 8µl of 10×Reaction Buffer and 20µl of DNase I (1U/µl) to it, mix well, and make a final volume of 80µl of reaction solution.7. Add 80µl of DNase I mixture directly to the adsorption column and incubate at 20-30°C for 15 minutes.8. Add 350 µl of Buffer RW1 to the adsorption column, centrifuge at 12,000 rpm for 1 minute, discard the waste liquid and put the column back into the collection tube.9. Add 500 µl of Buffer RW2 to the column (check that anhydrous ethanol is added before use), centrifuge at 12,000 rpm for 15 seconds, and discard the waste solution.10. Repeat step 9.11. Place the adsorbent column back into the collection tube, centrifuge at 12,000 rpm for 1 minute, and allow the column to come to room temperature for a few minutes to thoroughly dry out the anhydrous ethanol in the adsorbent column.Note: The purpose of this step is to remove residual ethanol from the adsorption column; ethanol residue can interfere with subsequent enzymatic reactions (zymography, PCR, etc.).12. Load the adsorption column into a new centrifuge tube, add 30-50 µl of RNase-Free Water to the middle of the adsorbent membrane, leave it at room temperature for 1 minute, centrifuge at 12,000 rpm for 1 minute, and store the resulting RNA solution at -70°C to prevent degradation.Note: 1) The volume of RNase-Free Water should not be less than 30 µl, too small volume affects the recovery rate.2) If you want to increase the RNA yield, repeat step 12 with 30-50 µl of fresh RNase-Free Water.3) If the RNA concentration is to be increased, the resulting solution can be reintroduced into the adsorption column and step 12 repeated... 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 |