| Description | Glutathione is a tripeptide containing a γ-amide bond and a sulfhydryl group, composed of glutamate, cysteine, and glycine. It is widely found in animal and plant tissues and microorganisms. In living organisms, it helps maintain normal immune system function and has antioxidant and Glutathione is a tripeptide containing a γ-amide bond and a sulfhydryl group, composed of glutamate, cysteine, and glycine. It is widely found in animal and plant tissues and microorganisms. In living organisms, it helps maintain normal immune system function and has antioxidant and detoxifying effects. Glutathione exists in two forms: reduced (GSH) and oxidized (GSSG). GSSG, also known as glutathione disulfide, is formed by the oxidation of two glutathione molecules. GSSG can be reduced back to GSH by glutathione reductase; therefore, it exists primarily in the reduced form in organisms. The ratio of reduced to oxidized glutathione (GSH/GSSG) serves as a key dynamic indicator for assessing the cellular redox state. Detection Principle: Endogenous GSH in the sample is masked by 2-vinylpyridine. Under the catalysis of glutathione reductase (GR), GSSG is reduced to GSH. The generated GSH then reacts with 5,5'-Dithiobis-(2-nitrobenzoic acid) (DTNB) to produce yellow-colored 5-thio-2-nitrobenzoic acid (TNB), which has a characteristic absorption peak at 412 nm. The GSSG content is quantified by measuring the change in absorbance. Detection Range: 1-20 µM Sensitivity: 1 µM Applicable Samples: Animal/plant tissues, blood cells, cells, bacteria, serum (plasma).O1492795Component96TStorageO1492795AExtraction Buffer70 mL×22-8℃O1492795BInhibitor210 µL-20℃. Store in the dark.O1492795CAssay Buffer20 mL2-8℃O1492795DGR14 µL2-8℃. Store in the dark.O1492795EGR Cofactor2 EA-20℃. Store in the dark.O1492795FChromogen2 EA2-8℃. Store in the dark.O1492795GStandard1 EA2-8℃. Store in the dark.User-Provided Instruments and ReagentsTypeNameNotesInstrumentMicroplate ReaderCapable of measuring absorbance at 412 nm.Consumables96-well MicroplateStandard transparent plate.ReagentsPBS / Deionized WaterFor washing samples / Preparing reagents.OthersHomogenizer (for tissue samples), water bath, ice bucket, low-temperature centrifuge, adjustable pipettes and tipsUsing a multichannel pipette for large-scale detection can improve efficiency.Experimental Procedure1. Reagent PreparationReagent NameReagent PreparationPrecautionsExtraction BufferReady-to-use; equilibrate to room temperature before use.Store at 4°C.Diluted Extraction BufferAdd 500 µL Extraction Buffer to 4.5 mL deionized water.Obtained by 10-fold dilution of Extraction Buffer.InhibitorReady-to-use; equilibrate to room temperature before use.Store at -20°C protected from light. Toxic and irritant; recommended to handle in a fume hood.Assay BufferReady-to-use; equilibrate to room temperature before use.Store at 4°C.GR DilutionBefore use, prepare by adding 1 µL GR to 20 µL deionized water per sample.Prepare freshly before use.GR Cofactor DilutionBefore use, add 1.5 mL deionized water to each vial; equilibrate to room temperature protected from light.After dissolution, store at -20°C protected from light for up to 1 month.Chromogen DilutionBefore use, add 1.5 mL deionized water to each vial; equilibrate to room temperature protected from light.After dissolution, store at 4°C protected from light for up to 1 month.GSSG StandardDissolve in 1 mL of Diluted Extraction Buffer.20 mM; After dissolution, aliquot and store at -20°C protected from light for up to 1 month.2. Standard PreparationTake 100 µL of the 20 mM GSSG standard and dilute with 900 µL Diluted Extraction Buffer to obtain a 2 mM GSSG standard solution.Take 10 µL of the 2 mM GSSG standard and dilute with 990 µL Diluted Extraction Buffer to obtain a 20 µM GSSG standard solution.Further dilute the standard as shown in the table below. A standard curve must be prepared for each experiment. Diluted standard solutions are unstable and must be used within 4 hours.Standard Working Solution20µM Standard (µL)Diluted Extraction Buffer (µL)Concentration (µM)110002028020163604012440608520804610902759513. Sample PreparationNote: Fresh samples are recommended. If not used immediately, samples can be stored at -80°C for up to 10 days. Because the Extraction Buffer contains a protein precipitant, the supernatant cannot be used for protein concentration determination. If protein content needs to be measured, prepare another identical sample using deionized water instead of Extraction Buffer.3.1 Animal/Plant Tissue Samples:Use fresh tissue samples whenever possible. Weigh 0.1 g of tissue, add 1 mL of pre-cooled Extraction Buffer, and homogenize quickly on ice (pre-cool the homogenizer on ice). Centrifuge the homogenate at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection.3.2 Serum/Plasma Samples:Use fresh serum (plasma) whenever possible. Centrifuge the collected serum (plasma) at 600 g, 4°C for 10 min. Within 30 minutes, aspirate the supernatant into another tube. Add an equal volume of Extraction Buffer, mix, then centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection.3.3 Cell or Bacterial Samples:Use fresh cells (bacteria) whenever possible; avoid using frozen cells (bacteria). Collect 5×10⁶ cells (bacteria). Wash twice with 1 mL of pre-cooled PBS (resuspend in PBS, centrifuge at 600 g, 4°C for 10 min). Add 3 times the volume of Extraction Buffer relative to the cell (bacterial) pellet to resuspend the cells (bacteria). Disrupt by ultrasound on ice (power 20% or 200 W, ultrasonicate for 3 s, interval 7 s, repeat 30 times). Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection.Note: Cells can also be extracted using a freeze-thaw method (not suitable for bacteria): Resuspend cells and subject to 2-3 rapid freeze-thaw cycles (freeze in liquid nitrogen, thaw in a 37°C water bath). Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection.4. Assay Steps4.1 Microplate Reader Preparation: Preheat for at least 30 minutes, set wavelength to 412 nm.4.2 Assay System Setup (Step 1 - Pre-treatment): Perform the following operations in 1.5 mL EP tubes. This step must be done in EP tubes. Do not add Inhibitor directly to the 96-well plate as it may corrode the plate. Inhibitor is toxic and irritant; recommended to handle in a fume hood.ReagentBlank Tube (µL)Standard Tube (µL)Test Tube (µL)Sample003Deionized Water30027Standard0300Inhibitor1.51.51.54.3 Mix well and incubate at 37°C for 30 minutes. This becomes the "Mixture".4.4 Assay System Setup (Step 2 - Reaction): Perform the following operations in a 96-well plate.ReagentBlank Well (µL)Standard Well (µL)Test Well (µL)Mixture212121Assay Buffer140140140GR Dilution222GR Cofactor Dilution202020Chromogen Dilution2020204.5 Absorbance Measurement: Mix thoroughly after addition. Read the absorbance at 412 nm (A1), recorded as A1 blank, A1 standard, and A1 test. Then incubate at 37°C protected from light for 10 minutes. Quickly read the absorbance at 412 nm again (A2), recorded as A2 blank, A2 standard, and A2 test. 5. Result Calculation The following provides both the derived formula and the simplified calculation formula, which are completely equivalent. 5.1 Data Processing Calculate ΔA = A2 - A1 for each. Then calculate ΔΔA standard = ΔA standard - ΔA blank And ΔΔA test = ΔA test - ΔA blank 5.2 Standard Curve Plotting 5.2 Standard Curve Plotting Plot the standard curve with standard concentration as the y-axis and ΔΔA standard as the x-axis. Substitute ΔΔA test into the equation to obtain the y value (µM). 5.3 Sample GSSG Content Calculation (1) Based on sample mass: GSSG (nmol/g) = y × V standard ÷ V sample × V extract ÷ W × n = 10 × y ÷ W × n (2) Based on cell or bacterial count: GSSG (nmol/10⁴) = y × V standard ÷ V sample × V extract ÷ 500 × n = 0.02 × y × V extract × n (3) Based on liquid volume: GSSG (nmol/mL) = y × V standard ÷ V sample × 2 × n = 20 × y × n (4) Based on protein concentration: GSSG (nmol/mg prot) = y × V standard ÷ V sample ÷ Cpr × n = 10 × y ÷ Cpr × n Parameter Description: 1 µM = 1 nmol/mL; V standard : Volume of standard added, 30 µL; V sample : Volume of sample added, 3 µL; V extract : Volume of Extraction Buffer added, 1 mL (for cells/bacteria, use the actual volume used); W: Sample mass, g; n: Sample dilution factor; Cpr: Sample protein concentration, mg/mL; 500: Cell or bacterial count, in units of 10⁴; 2: Dilution factor for liquid samples (added equal volume of Extraction Buffer).6. Result PresentationTypical Standard Curve: y = 8.0042x + 0.212, R² = 0.9997Example-1: 0.1 g of rat liver tissue was processed and assayed according to the procedure using a 96-well plate. Measured: ΔA test = A2 test - A1 test = 0.386 - 0.120 = 0.266 ΔA blank = A2 blank - A1 blank = 0.132 - 0.097 = 0.035 ΔΔA test = ΔA test - ΔA blank = 0.266 - 0.035 = 0.231 Substituting ΔΔA test into the standard curve equation gives y = 2.061 µM. Calculated based on sample mass: GSSG (nmol/g) = y × V standard ÷ V sample × V extract ÷ W × n = 10 × y ÷ W × n = 206.1 nmol/g.Precautions1. It is recommended to perform preliminary experiments using 2-3 samples expected to have significant differences before formal testing.2. The samples extracted with this kit are suitable for the detection of oxidized glutathione (GSSG). Because the extraction buffer contains a protein precipitant, the supernatant cannot be used for protein concentration determination. If protein content needs to be measured, prepare another identical sample using deionized water instead of the extraction buffer. For protein concentration determination, Aladdin BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648) are recommended.3. This kit is compatible with spectrophotometer detection. Adjust the preparation volume of detection reagents proportionally according to the spectrophotometer's requirements.4. It is recommended to establish your own standard curve for improved accuracy. If not, you may refer to the typical standard curve formula provided in the results section for calculation.5. Biochemical reagents are generally irritating and biologically toxic. For your safety and health, please wear appropriate personal protective equipment (lab coat, mask, gloves, hair cap, etc.) throughout the experiment and perform experiments in a fume hood or biosafety cabinet.6. This product is for scientific research use only. Not intended for clinical diagnosis.Frequently Asked Questions Q: What should I do if the sample ΔA test is too high or too low? Frequently Asked Questions Q: What should I do if the sample ΔA test is too high or too low? A: If the sample ΔA test is greater than the ΔA standard of the 20 µM standard, the GSSG content in the sample is too high. Dilute the sample appropriately with deionized water (multiply by the dilution factor in the calculation). If the sample ΔA test is less than 0.005, increase the sample amount.Q: Can blood cell samples be detected?A: Yes, blood cell samples can be detected. Centrifuge the collected anticoagulated blood at 600 g, 4°C for 10 min. Discard the upper plasma and wash the pellet 2-3 times with 3 volumes of PBS (resuspend blood cells in PBS, centrifuge at 600 g, 4°C for 10 min). Add an equal volume of Extraction Buffer, mix, and let stand at 4°C for 10 min. Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep on ice for detection... Read More | Description：Acetylcholinesterases (AChEs) are enzymes that hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline. AChE is located at the synaptic cleft and functions to terminate synaptic transmission by catalyzing the breakdown of ACh allowing cholinergic neurons to Description：Acetylcholinesterases (AChEs) are enzymes that hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline. AChE is located at the synaptic cleft and functions to terminate synaptic transmission by catalyzing the breakdown of ACh allowing cholinergic neurons to return to a resting state after activation. It is also found in membranes of red blood cells, motor and sensory fibers, muscles, nerves and central and peripheral tissues. Changes in AChE activity may result from exposure to certain insecticides, which act as cholinesterase inhibitors. Inhibitors of AChE are also used to treat certain conditions such as dementia.Acetylcholinesterase activity assay kit has been used to determine the activity of acetylcholinesterase in a rat organophosphate model and in brain tissue homogenates.Principle：Acetylcholinesterase can catalyze the hydrolysis of acetylcholine to choline, and the reaction of choline with disulfide p-nitrobenzoic acid to produce 5-merhydryl-nitrobenzoic acid (TNB). The product has a characteristic absorption peak at 412 nm, and the activity of acetylcholinesterase can be characterized by the change of light absorption valueThe Dilution Calculator EquationConcentration (start)xVolume (start)= Concentration (final)× Volume (final)This equation is commonly abbreviated as: C1V1 = C2V2... Read More | Products contentN665978Component384 TStorageN665978AIndex N502-N522 Primers for Illumina 16×24 µL-20℃. Avoid freeze/thaw cycle.N665978BIndex N701-N729 Primers for Illumina24×16 µL-20℃. Avoid freeze/thaw cycle. Products IntroductionThis kit is a companion to the Products contentN665978Component384 TStorageN665978AIndex N502-N522 Primers for Illumina 16×24 µL-20℃. Avoid freeze/thaw cycle.N665978BIndex N701-N729 Primers for Illumina24×16 µL-20℃. Avoid freeze/thaw cycle. Products IntroductionThis kit is a companion to the transposase-based rapid DNA library construction kit, designed for Illumina platform library construction. It contains 16 N5 primers and 24 N7 primers, which can be used to prepare 384 different bipartite Index libraries. All reagents provided in the kit have been subjected to stringent quality control and functional validation to maximize the stability and reproducibility of library construction. The libraries can be used for sequencing on Illumina platforms such as HiSeq X-10/4000/2500/2000 and MiSeq.Provide your own instruments, reagents and consumables1. Magnetic frame: DynaMagTM-2 is recommended.2. DNA purification and recovery kit: It is recommended to use Kangwei DNA purification and recovery kit by magnetic bead method.3. DNA building kit: It is recommended to use the Kangwei Century transposase method second-generation sequencing rapid DNA building kit.4. Anhydrous ethanol.5. Reaction tubes: It is recommended to use low adsorption PCR tubes with 1.5 ml centrifuge tubes; Tip: It is recommended to use a high quality filter tip to prevent contamination of kits and library samples. Pre-experiment Preparation and Important NotesPlease centrifuge briefly before opening the cap so that the liquid collects at the bottom of the tube to avoid cross-contamination between different primers.procedure For the use of the CombiVision Second Generation Sequencing Multisample Primer Kit, please follow the CombiVision Second Generation Sequencing Rapid DNA Library Kit protocol. Index N502-N522 Primers for Illumina Index N701-N729 Primers for Illumina... Read More | Product content N665859Component50 TStorageN665859ABuffer DS30 mLRTN665859BBuffer GTL15 mLRTN665859CBuffer GL15 mLRTN665859DBuffer GW1 (concentrate)13 mLRTN665859EBuffer GW2 (concentrate)15 mLRTN665859FBuffer TE10 mLRTN665859GProteinase K2×1.25 mLRTN665859HRNase A (100 mg/mL)0.4 Product content N665859Component50 TStorageN665859ABuffer DS30 mLRTN665859BBuffer GTL15 mLRTN665859CBuffer GL15 mLRTN665859DBuffer GW1 (concentrate)13 mLRTN665859EBuffer GW2 (concentrate)15 mLRTN665859FBuffer TE10 mLRTN665859GProteinase K2×1.25 mLRTN665859HRNase A (100 mg/mL)0.4 mLRTN665859ISpin Columns DF With Collection Tubes50 EA2-8℃N665859JCentrifuge Tubes (L-1.5 mL)50 EART Product IntroductionThis kit is suitable for the effective purification of genomic DNA from formalin-fixed, paraffin-embedded tissues.The product uses specially optimized dewaxing agent and lysis solution to release DNA from formalin-fixed or tissue sectioned samples, which does not involve the organic reagent xylene and does not need to be operated overnight; the digested samples are incubated at higher temperatures to remove formalin cross-linking of the free DNA, which can effectively improve the yield and purity of DNA; the optimized buffer system allows the inhibitors in the lysis solution to be specifically bound to the adsorbent membrane, which can be effectively removed by a two-step rinsing step. The optimized buffer system enables the DNA in the lysate to specifically bind to the adsorbent membrane, and the inhibitor is effectively removed by a two-step rinsing step, and finally eluted with low-salt buffer or water to obtain high-purity DNA.Meanwhile, configured with a high-efficiency microsorbent column, the elution volume can be as low as 20 µL.The purified DNA can be directly used for PCR, Real-time PCR, SNP Genotyping, STR genotyping, second-generation sequencing and pharmacogenomics research.The molecular weight of DNA isolated from formalin-fixed, paraffin-embedded samples is usually lower than that of DNA from fresh or frozen samples.The degree of DNA fragmentation depends on the type of sample, the duration of storage, and the conditions of fixation.Self-contained reagent: anhydrous ethanolPre-experiment Preparation and Important Notes1. After obtaining the sample, fix the sample in 4%-10% formalin as soon as possible, the fixation time should be 14-24 hours, too long a period of time will easily lead to genome breakage, affecting the downstream experiments. If the formaldehyde fixation time is too long or the sample has been stored for too long (> 1 year), it will easily lead to DNA integrity damage and unable to amplify long fragments.2. Ensure that the sample is thoroughly dehydrated before embedding; residual formalin will inhibit Proteinase K.3. Anhydrous ethanol should be added to Buffer GW1 and Buffer GW2 according to the instructions on the label of the reagent bottle before first use.4. Before use, please check Buffer GTL, Buffer GL and Buffer DS for any crystallization or precipitation. If there is any crystallization or precipitation, please re-dissolve Buffer GTL, Buffer GL and Buffer DS at 56℃ in a water bath.5. Preheat the water bath or thermostatic mixer to 56°C and keep the centrifuge at 25°C before starting the experiment.6. If downstream experiments are needed to reduce the low frequency of C>T:G>A transitions (artificial mutations) that occur to minimize the risk of false positives, 7 µL of UNG (1 U/uL) can be added after 1 hour of incubation at 90°C.Operation steps1. Sample processing:1a. Paraffin-embedded samples: Trim off excess paraffin from the tissue block with a scalpel to expose the tissue and then cut into 5-10µm slices. Take about 1×1cm2 slices (about 4-5 slices in total) and place them in a centrifuge tube (provided), add 160µL Buffer DS, vortex and shake for 10 seconds, then add 180µL Buffer GTL and 20µL Proteinase K, vortex and shake for 10 seconds. centrifuge the samples at 12,000rpm for 1 minute at 25℃.Note: 1) If the surface of the sample has been exposed to air, discard the 2-3 pieces that have been exposed to air and do not use them.2) DS will solidify below 18°C, and if it does it does not affect the following experiments.1b. Sample in formalin and other fixative: take about 20mg of sample, cut it into small pieces, place it in a centrifuge tube, add 500µL of 10mM PBS (PH7.4), vortex shaking, centrifuge at 12,000rpm for 1minute, discard the supernatant, and repeat 3 times. Add 180 µL Buffer GTL, 20 µL Proteinase K, vortex shaking to mix.2.56°C for 1 hour until the sample is completely dissolved. incubate at 90°C for 1 hour. centrifuge at 12,000 rpm, 25°C for 1 minute, and carefully pipette the lower aqueous phase (~180 µL) along the wall of the tube into a new centrifuge tube, trying to avoid aspirating the bottom precipitate and the upper layer of the wax solution.Note: 1) Samples can be left at room temperature after incubation at 56°C until the temperature of the water or dry bath reaches 90°C before placing the samples at 90°CIncubation.2) Optional step: add 7µL UNG (1U/µL), 50°C, 5min, no shaking. The purpose of this step is to minimize the risk of false positives by reducing the low-frequency occurrence of C>T:G>A transitions (artificial mutations) while effectively retaining the true occurrence of mutations.3. Optional step: If you need to remove RNA, you can lower the temperature of the sample to room temperature, then add 2µL of RNase A solution at a concentration of 100mg/mL, shake and mix well, and leave it at room temperature for 2 minutes.4. Add 20µL Proteinase K and incubate at 65℃, 450rpm for 15min.5. Add 200 µL of Buffer GL, mix well by vortexing and shaking, then add 200 µL of anhydrous ethanol and mix thoroughly by vortexing and shaking. Centrifuge briefly so that the solution on the wall of the tube collects at the bottom of the tube.Note: 1) Mix well immediately after adding Buffer GL and anhydrous ethanol.2) The addition of Buffer GL and anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.3) If more than one sample needs to be manipulated, the Buffer GL and anhydrous ethanol can be pre-mixed and spiked.6. Add all the solution obtained in step 5 to the adsorption columns (Spin Columns DF) that have been loaded into the collection tube, centrifuge at 25℃, 12000rpm for 2 minutes, pour out the waste liquid in the collection tube, and put the adsorption columns back into the collection tube.7. Add 500µL of Buffer GW1 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.8. Add 500µL of Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12000rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.Note: Step 8 can be repeated if further DNA purity is required.9.12 Centrifuge at 2000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Leave the adsorption column at room temperature for several minutes to dry thoroughly.Note: The purpose of this step is to remove residual ethanol from the adsorption column; ethanol residue can interfere with subsequent enzymatic reactions.10. Place the adsorption column in a new 1.5 mL collection tube, add 20-100 µL of Buffer TE or sterilized water to the middle of the adsorption column overhanging the column, let it stand at room temperature for 2-5 minutes, centrifuge it at 12,000 rpm for 1 minute, and collect the DNA solution.-20°C to preserve DNA.Note: 1) The pH value of the eluent has a great influence on the elution efficiency, if water is used as the eluent should ensure that its pH value is 7.0-8.5, the pH value is lower than 7.0 when the elution efficiency is not high.2) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 10 can be re-spiked onto the adsorbent membrane and left at room temperature for 2 minutes and centrifuged at 12,000 rpm for 1 minute... Read More | Product Content R669990Component50 TStorageR669990ADNase I1000 U-20℃. Avoid freeze/thaw cycle.R669990B10×Reaction Buffer1 mL-20℃. Avoid freeze/thaw cycle.R669990CBuffer RL35 mLRTR669990DBuffer RW135 mLRTR669990EBuffer RW2 (concentrate)11 mLRTR669990FRNase-Free Water10 Product Content R669990Component50 TStorageR669990ADNase I1000 U-20℃. Avoid freeze/thaw cycle.R669990B10×Reaction Buffer1 mL-20℃. Avoid freeze/thaw cycle.R669990CBuffer RL35 mLRTR669990DBuffer RW135 mLRTR669990EBuffer RW2 (concentrate)11 mLRTR669990FRNase-Free Water10 mLRTR669990GSpin Columns RM with Collection Tubes50 setsRTR669990HRNase-Free Centrifuge Tubes (1.5 mL)50 EART ProductsThis kit combines highly efficient guanidine isothiocyanate cleavage technology with silica matrix membrane purification for the efficient extraction of total RNA from animal cells and tissues, typically up to 30 mg of tissue or 1x107 cells as a starting sample. The kit also allows recovery of incompletely purified RNA, in vitro transcription and RNA from enzymatic reactions. high quality RNA with molecular weights greater than 200 bases can be extracted and purified using the kit with virtually no DNA residue. If RNA experiments that are very sensitive to trace DNA are to be performed, residual DNA can be removed by on-column digestion using RNase-free DNase. The extracted RNA can be used in downstream experiments such as RT-PCR, Nothern Blot and Dot Blot. 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. Avoid repeated freezing and thawing of the extracted samples, otherwise it will affect the amount and quality of RNA extraction.3. Please add β-mercaptoethanol to Buffer RL before use, add 10µl of β-mercaptoethanol to 1ml of Buffer RL. Buffer RL with β-mercaptoethanol can be stored for 1 month at room temperature.4. Anhydrous ethanol should be added to Buffer RW2 before first use according to the instructions on the reagent bottle label.5. Buffer RL may be heated at 56°C to dissolve if precipitation occurs and then left at room temperature.All centrifugation steps are performed at room temperature and all maneuvers are performed quickly.Procedure1. Sample handling1a Tissue: Grind tissue in liquid nitrogen. Add 600 µl Buffer RL for every 20-30 mg of tissue (check for addition of β-mercaptoethanol before use), and 350 µl Buffer RL for tissue samples of less than 20 mg. Sample volume is not to exceed one-tenth of the Buffer RL volume.1b Cells in monolayer culture: Lysed or processed into cell suspension directly in culture flask, centrifuged to obtain cell precipitate, discarded the supernatant, added 600µl Buffer RL for every 6-10 cm2 of culture area, 350µl Buffer RL for less than 6cm2, and blown several times repeatedly to make the cells lysed sufficiently.1c Cell suspension: centrifuge at 12,000 rpm (~13,400 × g) for 1 min and discard the supernatant to obtain the cell precipitate. Add 600 µl Buffer RL for every 5×106-1×107 cells, and 350 µl Buffer RL for less than 5×106 cells, and blow several times repeatedly to fully lysate.Note: 1) Try to get rid of the cell culture medium, which may inhibit cell lysis affecting RNA yield.2) Try to keep the cells well suspended and well lysed, otherwise RNA yield is affected.2. After the sample is fully lysed, leave it at room temperature for 5 minutes to allow complete separation of the protein-nucleic acid complex.3. Centrifuge at 12,000 rpm for 2-5 min and remove the supernatant for the following operations.4. Add 1x volume (600µl or 350µl) of 70% ethanol (prepared without RNase water) to the solution obtained in step 3 and mix well.Note: The addition of ethanol may produce a precipitate that will not affect subsequent experiments.5. Add all of the solution obtained in the previous step to the Spin Columns RM in the collection tube. If you cannot add all of the solution to the column at once, transfer it in two passes, centrifuge at 12,000 rpm for 1 minute, and discard the waste solution. Place the column back into the collection tube.Note: The maximum loading capacity of the adsorption column is 100µg, do not overload as this will affect the yield and purity of the RNA.6. 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.7. Preparation of DNase I mixture: Take 52 µl of RNase-Free Water, add 8 µl of 10×Reaction Buffer and 20 µl of DNase I (1 U/µl) to it, mix well, and prepare a final volume of 80 µl of reaction solution.8. Add 80µl of DNase I mixture directly to the adsorption column and incubate at 20-30°C for 15 minutes.9. Add 200 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.10. Add 500µl Buffer RW2 to the column (check that anhydrous ethanol is added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the column back into the collection tube.11. Repeat step 10.12. 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 a few minutes to thoroughly dry the anhydrous ethanol in the adsorption column.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).13. Transfer the adsorbent 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 min, centrifuge at 12,000 rpm for 1 min, collect the RNA solution, and store the RNA at -70°C to prevent degradation.Note: 1) The volume of RNase-Free Wate 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 13 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 13 repeated... Read More |