| Description | Lactate dehydrogenase (LDH or LD) is a stable protein present in the cytoplasm of normal cells and normally cannot pass through the cell membrane. When cells are damaged, membrane permeability increases, and LDH is released extracellularly. A decrease in intracellular LDH and an increase in LDH in Lactate dehydrogenase (LDH or LD) is a stable protein present in the cytoplasm of normal cells and normally cannot pass through the cell membrane. When cells are damaged, membrane permeability increases, and LDH is released extracellularly. A decrease in intracellular LDH and an increase in LDH in the culture medium occur. Measuring the LDH activity in the culture medium or the LDH leakage rate can reflect drug-induced cytotoxicity. LDH belongs to the oxidoreductase family and can reversibly catalyze the redox reaction between lactate (L) and pyruvate (P). The reaction formula is: Lactate + NAD⁺ → Pyruvate + NADH + H⁺, where L → P is the forward reaction and P → L is the reverse reaction. Detection Principle: Using NAD⁺ as a hydrogen acceptor, LDH catalyzes the dehydrogenation of lactate to generate pyruvate. Pyruvate then reacts with dinitrophenylhydrazine to form pyruvate dinitrophenylhydrazone, which appears brownish-red in an alkaline solution. The color intensity is proportional to the pyruvate concentration. The absorbance at 440 nm can be measured using a microplate reader. The released LDH activity during cytotoxicity or the LDH activity in other samples can be calculated using formulas. This kit can be used for routine LDH activity detection and is more commonly used for cytotoxicity assays using LDH release as an indicator.This kit is for scientific research use only and is not intended for clinical diagnosis or other purposes.L1501786Component100T500TStorageL1501786ALDH Assay Buffer3 mL15 mL2-8℃. Store in the dark.L1501786BNAD1EA2EA-20℃L1501786CPhenylhydrazine Color Solution3 mL15 mL2-8℃. Store in the dark.L1501786DAlkaline Color Solution10 mL50 mLRT.L1501786ELDH Releasing Agent (10X)2 mL10 mLRT.User-Prepared Instruments and Reagents1. 96-well plate cultured test and control group cell samples, sterile PBS, culture medium, distilled water.2. Microplate centrifuge, 96-well plate or centrifuge, centrifuge tubes, incubator or water bath, microplate reader.Experimental Procedure1. Sample Preparation1.1 LDH Release AssaySeed an appropriate number of cells into a 96-well culture plate based on cell size and growth rate, so that the cell density does not exceed 90% confluency at the time of detection.Aspirate the culture medium, wash once with PBS, add fresh culture medium.Set up corresponding control groups according to experimental needs:Background Blank Control Well A: Culture medium without cells.Sample Control Well B: Control cells without drug treatment.Maximum Enzyme Activity Control Well C: Lysed samples from untreated cells.Drug-treated Sample Well D: Cells treated with the drug.Continue cultivation.Before detection, take out the cell culture plate. Add LDH Releasing Agent (10X) to the "Maximum Enzyme Activity Control Well C" at a volume equal to 10% of the original culture medium volume. Mix thoroughly by pipetting up and down several times. Continue cultivation for about 1 hour.Centrifuge the cell culture plate at 400 g for 5 minutes using a microplate centrifuge.Aspirate 5 µL of supernatant from each well and transfer it to the corresponding wells of a new 96-well plate for subsequent LDH detection.1.2 Cytotoxicity and Cell Proliferation Assay for Intracellular Total LDHSeed an appropriate number of cells into a 96-well culture plate based on cell size and growth rate, so that the cell density does not exceed 90% confluency at the time of detection.Treat with different drugs and set up appropriate controls.Centrifuge the cell culture plate at 400 g for 5 minutes using a microplate centrifuge.Aspirate the culture medium.Add 150 µL of LDH Releasing Agent diluted 10-fold with PBS. Shake the plate to mix thoroughly. Continue cultivation for about 1 hour.Centrifuge the cell culture plate at 400 g for 5 minutes using a microplate centrifuge.Aspirate 5 µL of supernatant from each well and transfer it to the corresponding wells of a new 96-well plate for subsequent cytotoxicity detection.1.3 Protein Concentration DeterminationAfter sample preparation, the protein concentration can be determined using a BCA Protein Assay Kit (Aladdin B665595 BCA Protein Quantification Kit or R1491648 Ready-to-Use BCA Protein Quantification Kit are recommended) to facilitate subsequent calculation of LDH content per unit protein weight in tissues or cells.2. Preparation of NAD SolutionTake one vial of NAD (powder) and dissolve it in 1.5 mL of deionized water.3. LDH Enzymatic ReactionAdd solutions sequentially according to the table below, taking care to avoid bubbles. If the enzyme activity in the sample is too high, reduce the sample volume or dilute appropriately before assay.Reagent (µL)Volume (µL)Test Sample (supernatant)5LDH Assay Buffer25NAD Solution5 Mix well, incubate at 37°C for 15 min. Phenylhydrazine Color Solution25 Mix well, incubate at 37°C for 15 min. Alkaline Color Solution100Distilled Water150 4. LDH Measurement Mix well and let stand at room temperature for 5 minutes. Measure the absorbance of each well at 440 nm using a microplate reader. 5. Result Calculation Cytotoxicity or Mortality Rate (%) = (A D - A B ) / (A C - A B ) × 100% If the absorbance value A γ of a known concentration *c* of an LDH enzyme standard and the absorbance value A γ0 of the standard blank control are measured simultaneously, the enzyme activity in the sample can be roughly calculated:LDH Activity in Test Sample (mU/mL) = (A B - A A ) / (A γ - A γ0 ) × *c* For accurate calculation of the absolute LDH enzyme activity in the sample, use a self-prepared LDH standard to plot a standard curve with the measured absorbance values. The enzyme activity of the sample can be calculated using the formula derived from the standard curve. Where: A A = Absorbance of Background Blank Control Well A A B = Absorbance of Sample Control Well B A C = Absorbance of Maximum Enzyme Activity Control Well C A D = Absorbance of Drug-treated Sample Well D 6. Results and Analysis The cytotoxicity of drugs or toxicants can be determined by directly comparing the LDH activity in each well. Higher LDH activity indicates higher cell membrane permeability and more severe cell damage.Precautions1. Use serum-free or low-serum concentration culture medium when culturing cells to exclude serum interference; otherwise, deviations may occur.2. EDTA inhibits LDH. Avoid using or thoroughly remove reagents containing EDTA during operation.3. Measure LDH as soon as possible after collection. If the collected cell culture medium is stored for too long, LDH activity may decrease.4. Use solutions prepared at the same time for the same batch of experiments. The volume of solutions used and the reaction time should be consistent.5. In the enzymatic reaction, the recommended supernatant sample volume is 2.5-10 µL. If the enzyme activity in the sample is too high, reduce the sample volume or dilute appropriately before assay.6. Measurement should be completed within 15 minutes after color development.7. The Alkaline Color Solution is somewhat corrosive; handle with care.8. Use reagents promptly after opening to avoid affecting subsequent experimental results.9. For your safety and health, please wear a lab coat and disposable gloves during operation... Read More | When apoptosis occurs, some DNA endonucleases will be activated. These endonucleases will cut off genomic DNA between nucleosomes and produce 180 bp-200 BP DNA fragments, which appear as a specific ladder pattern in agarose gel electrophoresis. When double strand or single strand breaks occurWhen apoptosis occurs, some DNA endonucleases will be activated. These endonucleases will cut off genomic DNA between nucleosomes and produce 180 bp-200 BP DNA fragments, which appear as a specific ladder pattern in agarose gel electrophoresis. When double strand or single strand breaks occur in genomic DNA, a large number of sticky 3'-oh ends will be generated, which can interact with YF under the catalysis of deoxyribonucleotide terminal transferase (TDT) ®/ CY dUTP binding can directly detect apoptotic cells by fluorescence microscopy or flow cytometry. This kind of method is called terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Because normal or proliferating cells have almost no DNA breaks, there is no 3'-oh formation and they can rarely be stained. TUNEL method can stain intact single apoptotic nuclei or apoptotic bodies in situ, can accurately reflect the typical biochemical and morphological characteristics of apoptosis, and can detect a very small number of apoptotic cells, so it is widely used in the study of apoptosis. This kit has a wide range of applications and can be used to detect apoptosis in frozen or paraffin sections, as well as cultured adherent cells or suspended cells. It can selectively detect apoptotic cells, but not necrotic cells or cells with DNA strand breaks caused by irradiation and drug treatment. This kit detects cell apoptosis with a short time-consuming, one-step staining reaction and can be detected after washing.Component： Instruction： Experimental materials (self provided)PBS buffer (1 x, pH~7.4). 0.2% Triton X -100 (PBS formulation). 0.1% Triton X -100 (PBS formulation, containing 5 mg/mLBSA)4% paraformaldehyde (prepared with PBS)Immunohistochemical penDewaxing solvent (paraffin section sample)Related reagents for paraffin section processingAnti fluorescence quenching and sealing agent. ddH2Oexperimental design. A. Positive control:Prepare positive control slides using DNaseI treatment. DNaseI can digest single or double stranded DNA and expose the 3 '- OH end, artificially causing cell apoptosis. One experiment per time is sufficient. (To verify if there are any issues with the experimental operation and reagent kit)B. Negative control:Use TUNEL Reaction Buffer without TdT Enzyme and replace TdT Enzyme with ddH2O. (Mainly to exclude non-specific staining caused by cell apoptosis, operational processes, and other reasons; and to adjust the exposure intensity of the shooting.)C. Experimental processing group.The experimental group operated normally according to the instructions.D. Experimental control group.The experimental group operated normally according to the instructions.Experimental steps1. Sample preparation:(1) For adherent cells or cell smearsa. Clean once with PBS.Note: If you are concerned that the cells on the cell smear may not adhere firmly, you can dry the sample to make the cells adhere more firmly.b. Fixation: Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and fix at 4 ℃ for 30 minutes. Clean twice with PBS.c. Translucency: Add an appropriate amount of 0.2% Triton X -100 (prepared with PBS) and let it penetrate at room temperature for 20 minutes. Clean twice with PBS.d. Step 2: TUNEL reaction.(2) For suspended cells or cell suspensionsa. Collect cells (3-5 x 106 cells), centrifuge at 1000 rpm for 5 minutes, and wash twice with PBS.b. Fixation: Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and resuspend the cells thoroughly. Fix at 4 ℃ for 30 minutes. Centrifuge at 2000 rpm for 5 minutes and clean twice with PBS.c. Translucency: Add an appropriate amount of 0.2% Triton X -100 (prepared with PBS) and let it penetrate at room temperature for 20 minutes. Centrifuge at 2000 rpm for 5 minutes and clean twice with PBS.d. Step 2: TUNEL reaction.(3) Paraffin tissue sectioninga. Dewaxing and hydration: Place the sliced samples sequentially in xylene I (10 min) → xylene II (10 min) → 100% ethanol I (5 min) → 100% ethanol II (5 min) → 95% ethanol (5 min) → 90% ethanol (5 min) → 80% ethanol (5 min) → 70% ethanol (5 min) → ddH2O rinse for 5 min, rinse twice.Note: Xylene is toxic and volatile. Please perform this operation in a fume hood.b. Use filter paper to dry the liquid around the sliced sample, and circle the sample contour with an immunohistochemical pen for downstream transparency and labeling.Note: If it is found that the contour circle of immunohistochemistry strokes is damaged in subsequent experimental operations, it needs to be redrawn in a timely manner.c. Transparency: Dilute 2 mg/mL of ProteinaseK solution with PBS in a ratio of 1:100 to a final concentration of 20 µ g/mL. Add 100 µ L dropwise to each sample to cover all sample areas. Incubate at 20-37 ℃ for 20 minutes.Note: Protein K can penetrate the cell membrane and nuclear membrane, allowing subsequent staining reagents to fully enter the nucleus for reaction and improve labeling efficiency. An excessively long incubation time increases the risk of tissue slices falling off the carrier film during subsequent washing steps, while a too short incubation time may result in insufficient permeability treatment and affect labeling efficiency. To obtain better results, the concentration, incubation time, and temperature of Protein K need to be optimized according to different types of tissue samples.d. Wash the slices twice with PBS, each time for 5 minutes. Use filter paper to remove excess liquid, and place the processed sample in a wet box to keep it moist.Note: Protein K must be washed thoroughly in this step, otherwise it will seriously interfere with subsequent labeling reactions.e. Step 2: TUNEL reaction.(4) Frozen tissue sectionsa. Fixation: Take out frozen sections and warm them back to room temperature. Add an appropriate amount of 4% paraformaldehyde (prepared with PBS) and fix at room temperature for 30 minutes. Wash twice with PBS for 10 minutes each time.Note: If you are concerned that formaldehyde cleaning may not be clean enough, it may affect the final dyeing effect. After formaldehyde fixation is completed, an appropriate amount of 2 mg/mL glycine can be added and washed for 10 minutes to neutralize the residual fixing solution, and then PBS cleaning can be carried out.b. Use filter paper to dry the liquid around the sliced sample, and circle the sample contour with an immunohistochemical pen for downstream transparency and labeling.Note: If it is found that the contour circle of immunohistochemistry strokes is damaged in subsequent experimental operations, it needs to be redrawn in a timely manner.c. Transparency: Dilute 2 mg/mL of ProteinaseK solution with PBS in a ratio of 1:100 to a final concentration of 20 µ g/mL. Add 100 µ L dropwise to each sample to cover all sample areas. Incubate at 20-37 ℃ for 20 minutes.Note: Protein K can penetrate the cell membrane and nuclear membrane, allowing subsequent staining reagents to fully enter the nucleus for reaction and improve labeling efficiency. An excessively long incubation time increases the risk of tissue slices falling off the carrier film during subsequent washing steps, while a too short incubation time may result in insufficient permeability treatment and affect labeling efficiency. To obtain better results, the concentration, incubation time, and temperature of Protein K need to be optimized according to different types of tissue samples.d. Wash the slices twice with PBS, each time for 5 minutes. Use filter paper to remove excess liquid, and place the processed sample in a wet box to keep it moist.Note: Protein K must be washed thoroughly in this step, otherwise it will seriously interfere with subsequent labeling reactions.e. Step 2: TUNEL reaction.(5) Positive treatment (only the positive control is subjected to this step, and other samples are directly subjected to the TUNEL reaction step)a. Dilute 10 x DNase I Buffer with ddH2O in a ratio of 1:10 to 1 x DNase I Buffer for later use.b. Drip 100 µ L of 1xDNase I Buffer onto the processed sample, covering all sample areas, and equilibrate at room temperature for 5 minutes.c. Dilute DNase I (2 U) with 1 x DNase I Buffer at a ratio of 1:100/ µ L) A working solution with a final concentration of 20 U/mL.d. Discard the buffer and add 100 µ Incubate DNase I working solution with a concentration of 20 U/mL at room temperature for 10 minutes.e. Discard DNase I working solution and clean twice with PBS.f. Step 2: TUNEL reaction.2. TUNEL reaction(1) Prepare TUNEL reaction solution (ready to use):/1 sample5sample10 sampleTdT enzyme1 µL5 µL10 µLYF®488/555/594/640 TUNEL Reaction Buffer49 µL245 µL490 µLTUNEL Total volume of reaction solution50 µL250 µL500 µL(2) For adherent cells, cell smears, or tissue sectionsa. Add 50 to each sample µ L TUNEL reaction solution, evenly cover the sample with the reaction solution. The appropriate time for dark incubation at 37 ℃ (recommended staining time for cells is 30 minutes to 1 hour, and tissue staining time is 2 hours).Note: 50 µ L TUNEL reaction solution is suitable for smear, slicing, or 96 well plates (other different well plates can adjust the volume of TUNEL reaction solution appropriately to cover cells). If the sample to be tested is a smear, slice, or in a 24 well plate, 12 well plate, or 6 well plate, anti evaporation film can be used, or self sealing bags or other appropriate materials can be used to cut circular plastic sheets slightly smaller than the holes. After adding TUNEL reaction solution dropwise, cover the sample to prevent the evaporation of TUNEL reaction solution and make the TUNEL reaction solution evenly cover the sample.b. Discard the TUNEL reaction solution, wash twice with PBS, and then wash three times with 0.1% Triton X -100 (PBS preparation, containing 5 mg/mL BSA) for 5 minutes each time. This way, free unreacted markers can be removed cleanly.c. (Optional) Add an appropriate concentration of 5 to each sample µ DAPI staining solution with a concentration of g/mL, incubated at room temperature in dark for 5 minutes. After staining, discard DAPI staining solution and wash twice with PBS for 5 minutes each time.d. (Optional) Slice sealing: Add 50 drops to each sample µ L anti fluorescence quenching sealing agent (anti fluorescence quenching sealing agent may not be suitable for certain dyes, it is recommended to conduct pre experimental testing for compatibility before the experiment), cover the cover glass, gently tap the cover glass with the blunt end of tweezers to remove bubbles and ensure complete sealing.e. Use filter paper to remove excess liquid and add 100 to the sample area µ Keep the sample moist with PBS and immediately observe under a fluorescence microscope.(3) For suspended cells or cell suspensionsa. Add 50 to each sample tube µ Gently resuspend cells in LTUNEL reaction solution and incubate at 37 ℃ in the dark for 30-1 hour. Gently resuspend cells with a micropipette every 15 minutes.b. Centrifuge at 2000 rpm for 5 minutes, discard TUNEL reaction solution, and wash twice with 0.1% Triton X -100 (PBS preparation, containing 5 mg/mLBSA) for 5 minutes each time. This way, free unreacted markers can be removed cleanly.c. Add 100 to each sample tube µ L concentration is 5 µ DAPI staining solution with a concentration of g/mL, incubated at room temperature in dark for 5 minutes.d. Join 400 µ L PBS resuspended cells and immediately detected with a flow cytometer or observed under a fluorescence microscope after smearing.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. when the staining background is heavy or non-specific staining is obvious, the staining time can be appropriately reduced. 3. it is recommended to add negative control and positive control groups during the experiment. 4. please wear mask and gloves when using component A. if it contacts the skin, please wash it with plenty of water immediately. 5. fluorescent dyes have quenching problems. Please try to avoid light to slow down fluorescence quenching. 6. for your safety and health, please wear experimental clothes and disposable gloves.Product parameters：490/515 nm；Scope of application：Late apoptosis detection, TUNEL Kit... Read More | Product introduction：Product introduction：Cell Cycle Assay Kit Plus ( Cell Cycle Assay Kit Plus ) has certain applicability for live cells and fixed cell cycle detection. For different types of cells, whether it is applicable or not needs to be determined after testing. Cell Cycle Product introduction：Product introduction：Cell Cycle Assay Kit Plus ( Cell Cycle Assay Kit Plus ) has certain applicability for live cells and fixed cell cycle detection. For different types of cells, whether it is applicable or not needs to be determined after testing. Cell Cycle Assay Kit Plus ( Cell Cycle Assay Kit Plus ) uses RedNucleus I staining to detect cell cycle. RedNucleus I is a far-infrared nucleic acid dye with cell membrane permeability, which can quickly enter living cells, specifically bind to DNA, and perform cell cycle detection on living cells without RNase digestion. Compared with the traditional PI staining method, the cells do not need to be broken or fixed, and the operation is simpler. RedNucleus I is a fluorescent dye of double-stranded DNA, and the fluorescence intensity after binding to double-stranded DNA is proportional to the content of double-stranded DNA. The intracellular DNA content can be measured by flow cytometry, and then the cell cycle analysis can be carried out according to the distribution of DNA content. After RedNucleus I staining, assuming that the fluorescence intensity of G0 / G1 phase cells is 1, the theoretical value of the fluorescence intensity of G2 / M phase cells containing two copies of genomic DNA is 2, and the fluorescence intensity of S phase cells undergoing DNA replication is between 1-2. In addition, RedNucleus I is compatible with dyes such as Horizon BV / BUV, FITC and R-PE, and can be periodically detected after sample staining.The kit is usually used to detect the cell cycle of cultured adherent or suspended cells. If it is used for cell cycle detection of tissues, the tissues must be digested into a single cell state.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. this product is applicable to the detection of living cells and fixed cell cycle with certain limitations. Whether it is applicable to different types of cells needs to be determined after testing. If fixation is needed, it is recommended to use ice bath pre cooling 75-80% ethanol -20 ℃ to fix cells overnight. 3. fluorescent dyes have quenching problems. Please try to avoid light during storage and use to slow down fluorescence quenching. 4. for your safety and health, please wear experimental clothes and disposable gloves.Instruction： Experimental materials ( self-provided )：①cell lines or other cell samples ( self-prepared ) ；②This kit ; ③ trypsin ( self-prepared ) ;④ Cell culture medium containing FBS ( self-prepared ) ; Experimental procedure： 1.Preparation of cell samples : ( 1 ) ( This step is for adherent cells, if suspended cells, can be carried out directly step ( 2 ) ) Digest cells with trypsin, add cell culture medium, gently blow away cells, collected into the centrifuge tube. Note : The number of cells on the machine needs to reach 50,000 and above, so the initial number of cells collected needs to be sufficient. ( 2 ) Centrifuged about 1000 g for 3-5 min to precipitate cells. Carefully remove the supernatant, add about 1 mL of ice bath pre-cooled 1 × staining buffer ( 10 × staining buffer diluted with diH2O at 1 : 10 ), re-suspend the cells. Repeat once. ( 3 ) Centrifuged about 1000 g for 3-5 min to precipitate cells. After the supernatant was discarded, 1 mL of culture medium was added to re-suspend the cells ( for fixed cells, 1 × PBS can also be used to re-suspend ). Gently flick the bottom of the centrifuge tube to properly disperse the cells to avoid cell aggregation. 2.Staining : 4 µL of RedNucleus I staining solution was added to each tube of cell samples, slowly and fully mixed, and incubated at room temperature in dark for 20 min ( or incubated at 37 ° C in dark for 5-10 min ). The optimal incubation time of different cells is different, and the staining time can be adjusted and optimized according to the actual staining effect to obtain a more ideal staining effect. 3.Flow cytometry detection and analysis : Excited at 638 nm by flow cytometry, it is recommended to detect in RL3 or FL4 channels, or use RL1 and RL2 channels. Cell DNA content analysis and light scattering analysis were performed using appropriate analysis software.Scope of application：Cell cycle detection... Read More | DescriptionTakasago (R)-Ru Cymene Kit I comprises of ruthenium-based biphenyl phosphine cymene catalysts containing either BINAP and SEGPHOS®ligands. These highly reactive and selective catalysts are useful in a variety of asymmetric reactions, mainly asymmetric hydrogenation | Product contentY666144Component50 TStorageY666144ABuffer P115 mLRTY666144BBuffer P215 mLRTY666144CBuffer N320 mLRTY666144DBuffer PS15 mLRTY666144EBuffer PB10 mLRTY666144FBuffer PW (concentrate)10 mLRTY666144GBuffer EB10 mLRTY666144HGlass Beads2 gRTY666144IRNase A (10mg/mL)150 µLRTY666144JSpin Product contentY666144Component50 TStorageY666144ABuffer P115 mLRTY666144BBuffer P215 mLRTY666144CBuffer N320 mLRTY666144DBuffer PS15 mLRTY666144EBuffer PB10 mLRTY666144FBuffer PW (concentrate)10 mLRTY666144GBuffer EB10 mLRTY666144HGlass Beads2 gRTY666144IRNase A (10mg/mL)150 µLRTY666144JSpin Columns DM with Collection Tubes50 setsRTProductsThis kit is improved on the basis of common alkaline lysis method, the glass beads can effectively break the yeast cell wall, the new silica matrix membrane and buffer system can efficiently and specifically bind the plasmid DNA, and at the same time can maximize the removal of proteins and other impurities, the whole process is convenient and fast, no need to use toxic and harmful reagents, and can be processed at the same time for multiple samples. In addition to yeast cells, it can also be used in E. coli. Plasmid DNA extracted with this kit can be used in various molecular biology experiments, such as ligation, transformation, sequencing and library screening.Self-contained reagents: β-mercaptoethanol, anhydrous ethanol.Pre-experiment Preparation and Important Notes1. All components can be stably stored in dry, room temperature (15-30℃) environment for 1 year, the adsorption column can be stored at 2-8℃ for a longer period of time, and Buffer P1 with RNase A can be stably stored at 2-8℃ for 6 months.2. Before the first use, add all the RNase A solution to Buffer P1, mix well, and store at 2-8℃.3. Anhydrous ethanol should be added to Buffer PW before first use according to the instructions on the reagent bottle label.4. Before use, please check whether Buffer P2 and Buffer N3 are crystallized or precipitated. If there is any crystallization or precipitation phenomenon, it can be clarified by taking a water bath at 37℃ for a few minutes to restore the clarity.5. Be careful not to touch Buffer P2 and Buffer N3 directly, and tighten the lid immediately after use.6. The amount of plasmid extracted is related to the yeast strain, plasmid copy number, culture conditions, etc. Usually, yeast plasmid copy number is very low, which is difficult to be detected by electrophoresis or spectrophotometer method.Procedure1. Take 1-5 ml of yeast culture (maximum 5×107 yeast cells, generally for Saccharomyces cerevisiae OD = 1.0, equivalent to 1-2×107 cells/ml) and add it to a centrifuge tube (self-provided), centrifuge for 30 seconds at 12,000 rpm (~13,400×g), collect the bacterial precipitate, and aspirate as much as possible to discard the supernatant.2. Add 250µl Buffer P1 to the bacterium (please check if RNase A has been added first) and resuspend the precipitate.3. Add 40mg of Glass Beads to the above mixture and vortex and shake for 10 minutes.4. Add 250 µl of Buffer P2 to the centrifuge tube, mix gently by turning up and down 6-8 times, and let stand at room temperature for 5-10 minutes, at which time the bacterial solution should become clear and viscous.Note: Mix gently, do not shake violently, so as not to interrupt the genomic DNA, resulting in genomic DNA fragments mixed in the extracted plasmid. If the solution does not become clear, it suggests that the amount of bacteria may be too large and the lysis is not complete, and the amount of bacteria should be reduced.5. Add 350 µl of Buffer N3 to the centrifuge tube and immediately mix gently up and down 6-8 times, at which point a white flocculent precipitate appears, and centrifuge at 12,000 rpm for 20 minutes.Note: Buffer N3 should be mixed immediately after addition to avoid localized precipitation.6. Column Equilibration: Add 200 µl of Buffer PS to the Spin Columns DM in the collection tube, 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.7. Add the supernatant from step 5 to the adsorbent column that has been loaded into the collection tube, taking care not to aspirate the precipitate.Note: The maximum volume of the adsorption column is 750 µl, and the solution is passed through the column in 2 times.8. Centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube and place the adsorption column back into the collection tube.9. Add 150 µl Buffer PB 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.10. Add 750 µl Buffer PW to the adsorption column (please check that anhydrous ethanol has been added first), centrifuge at 12,000 rpm for 1 minute, and pour off the waste liquid in the collection tube.11. Place the column back into the recovery collection tube and centrifuge at 12,000 rpm for 2 minutes, pouring off the waste liquid. Leave the 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 (digestion, PCR, etc.).12. Place the adsorbent column in a new centrifuge tube, add 50-100 µl of Buffer EB to the center of the adsorbent membrane dropwise, let it stand at room temperature for a few minutes, centrifuge at 13,000 rpm for 1 minute, and collect the plasmid solution into the centrifuge tube. Store the plasmid at -20°C.Attention:1) To increase the recovery efficiency of the plasmid, the resulting solution can be reintroduced into the adsorbent column, left at room temperature for a few minutes, centrifuged at 13,000 rpm for 1 minute, and the plasmid solution collected into a centrifuge tube.2) When the plasmid copy number is low or >10 kb, Buffer EB is preheated at 65-70°C in a water bath, which can increase the extraction efficiency.3) Usually yeast plasmids have very low copy number and are difficult to detect by electrophoresis or spectrophotometry. If the extracted plasmid is to be used in the next step of the experiment, it is usually recommended to use 1-5µl of the plasmid as PCR template, and 5-10µl of the plasmid for transformation of E. coli.4) Commercial high transformation efficiency receptor cells should be used for transformation of E. coli... Read More |