| Description | Pyruvate Kinase (PK) is widely present in animals, plants, microorganisms, and cultured cells. It catalyzes the final step of glycolysis, serving as one of the key rate-limiting enzymes in this process and a crucial enzyme for ATP production. Therefore, determining PK activity is of significant Pyruvate Kinase (PK) is widely present in animals, plants, microorganisms, and cultured cells. It catalyzes the final step of glycolysis, serving as one of the key rate-limiting enzymes in this process and a crucial enzyme for ATP production. Therefore, determining PK activity is of significant importance.Assay PrinciplePK catalyzes the conversion of Phosphoenolpyruvate (PEP) and ADP to ATP and Pyruvate. Lactate Dehydrogenase (LDH) further catalyzes the reaction between NADH and Pyruvate to produce Lactate and NAD⁺. The rate of decrease in NADH absorbance at 340 nm is measured, which reflects PK activity.Component50TStorageExtraction Buffer60 mL2-8℃Reagent A50 mL2-8℃Reagent B 2EA-20℃Reagent C25 µL×22-8℃Required Materials and Equipment (Not Provided)UV spectrophotometer, benchtop centrifuge, water bath, adjustable pipettes, 1 ml quartz cuvette, mortar and pestle, ice, and distilled water.Sample Preparation1.Bacteria or Cultured Cells:Collect bacteria or cells into a centrifuge tube, centrifuge, and discard the supernatant.Add Extraction Buffer at a ratio of 1 ml per 5-10 million cells (e.g., 1 ml for 5 million cells/bacteria).Sonicate on ice (20% power or 200W, pulse 3s on/10s off, repeat 30 times).Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.2.Tissues:Homogenize tissue on ice in Extraction Buffer at a ratio of 1:5-10 (w/v) (e.g., 0.1 g tissue in 1 ml buffer).Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.3.Serum (or Plasma) Samples:Assay directly.Assay Procedure1.Preheat the spectrophotometer for at least 30 minutes. Set the wavelength to 340 nm. Zero the instrument with distilled water.2.Sample Assay:(1) Preparation of Working Reagent II (WR II): Just before use, dissolve the contents of one vial of Reagent B in 22.5 ml of Reagent A and 2.65 ml distilled water. Mix thoroughly. Incubate WR II at 37°C (for mammalian samples) or 25°C (for other species) in a water bath for 5 minutes. Prepare fresh for each use.(2) Preparation of Working Reagent III (WR III): Just before use, dissolve the contents of one tube of Reagent C in 1.5 ml distilled water. Mix thoroughly. Prepare fresh for each use.(3) Reaction Setup: In a 1 ml quartz cuvette, add:50 µl sample50 µl WR III900 µl WR IIMix thoroughly and immediately record the absorbance (A₁) at 340 nm at 20 seconds. Record the absorbance again (A₂) after 2 minutes and 20 seconds (140 seconds total). Calculate ΔA = A₁ - A₂.PK Activity CalculationGeneral Formula:PK Activity = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (Vₛₐₘₚₗₑ ÷ Vₛₐₘₚₗₑₜₒₜₐₗ) ÷ TWhere:Vₜₒₜₐₗ = Total reaction volume = 0.000975 L (975 µl)ε = NADH molar extinction coefficient = 6220 L/mol/cmd = Light path length = 1 cm10⁹ = Conversion factor from moles to nanomoles (nmol)T = Reaction time = 2 minVₛₐₘₚₗₑ = Sample volume added to reaction = 0.050 mlVₛₐₘₚₗₑₜₒₜₐₗ = Total volume of extract used = 1 ml (for tissues/cells)Cpr = Sample protein concentration (mg/ml)W = Sample mass (g)500 = Cell/Bacteria count (in millions, for the example calculation: 5 million = 500 × 10⁴)1. For Serum (Plasma):Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per ml of serum.Calculation:PK Activity (nmol/min/ml) = [ΔA × 0.000975 ÷ (6220 × 1) × 10⁹] ÷ 0.050 ÷ 2Simplified Formula: PK (nmol/min/ml) = 2613 × ΔA2. For Tissues, Bacteria, or Cells:a. Based on Sample Protein Concentration:* Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per mg of protein.* Calculation:PK Activity (nmol/min/mg prot) = [ΔA × 0.000975 ÷ (6220 × 1) × 10⁹] ÷ (0.050 × Cpr) ÷ 2Simplified Formula: PK (nmol/min/mg prot) = 2613 × ΔA ÷ Cprb. Based on Sample Fresh Weight:* Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per gram of tissue.* Calculation:PK Activity (nmol/min/g fresh weight) = [ΔA × 0.000975 ÷ (6220 × 1) × 10⁹] ÷ (W × 0.050 / 1) ÷ 2Simplified Formula: PK (nmol/min/g fresh weight) = 2613 × ΔA ÷ Wc. Based on Bacterial or Cell Density:* Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per 10⁴ cells.* Calculation (using the example of 5 million cells extracted in 1 ml):PK Activity (nmol/min/10⁴ cell) = [ΔA × 0.000975 ÷ (6220 × 1) × 10⁹] ÷ (5 × 0.050 / 1) ÷ 2Simplified Formula: PK (nmol/min/10⁴ cell) = 5.226 × ΔA... 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 occur in 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 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 sample 5 sample 10 sample TdT enzyme 1 µL 5 µL 10 µL YF®488/555/594/640 TUNEL Reaction Buffer 49 µL 245 µL 490 µL TUNEL Total volume of reaction solution 50 µL 250 µL 500 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：590/617nm； Scope of application：Late apoptosis detection, TUNEL Kit... Read More | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export | Product contentcomponent50T200TBuffer LP125mL100mLBuffer LP210mL40mLBuffer LP3 (concentrate)21ml84mlBuffer GW2 (concentrate)15mL75mlBuffer GE15mL60mLRNase A（10 mg/ml）300µl1.25mLSpin Columns DM with Collection Tubes50200ProductsThis kit uses centrifugal adsorption columns with highProduct contentcomponent50T200TBuffer LP125mL100mLBuffer LP210mL40mLBuffer LP3 (concentrate)21ml84mlBuffer GW2 (concentrate)15mL75mlBuffer GE15mL60mLRNase A（10 mg/ml）300µl1.25mLSpin Columns DM with Collection Tubes50200ProductsThis kit uses centrifugal adsorption columns with high efficiency and specific binding of nucleic acids and a unique buffer system, which is suitable for extracting genomic DNA from a wide variety of different fresh or frozen plant tissues with maximum removal of impurities from the plant tissues. The kit eliminates the need for phenol/chloroform extraction and is safe to handle. The extracted genomic DNA fragments are large, high purity, stable and reliable quality, suitable for PCR, fluorescence quantitative PCR, molecular labeling, library construction and other experiments.Self-contained reagent: anhydrous ethanolPre-experiment Preparation and Important Notes1. Repeated freezing and thawing of the sample should be avoided, as this may result in smaller fragments of extracted DNA and a decrease in the amount extracted.2. Anhydrous ethanol should be added to Buffer LP3 and Buffer GW2 according to the instructions on the label of the reagent bottle before first use. Check Buffer LP1 and Buffer LP2 for crystallization or precipitation before use. If crystallization or precipitation occurs, re-dissolve Buffer LP1 and Buffer LP2 in a 56°C water bath. Procedure1. Take about 100mg of fresh plant tissue or about 20mg of dry weight tissue and add liquid nitrogen to grind it fully.2. Collect the ground powder into a centrifuge tube (self-provided), add 400 µl Buffer LP1 and 6 µl RNase A (10 mg/ml), vortex and oscillate for 1 minute, and leave it at room temperature for 10 minutes to allow for full cleavage.Note: 1) Use vortex shaking or pipette blowing to fully lyses the tissue, incomplete tissue lysis will affect the final DNA yield. 2) Do not mix Buffer LP1 with RNase A prior to use.3. Add 130 µl Buffer LP2, mix well and vortex for 1 minute.4. Centrifuge at 12,000 rpm (~13,400 x g) for 5 minutes and transfer the supernatant to a new centrifuge tube (supplied).5. Add 1.5 times the volume of Buffer LP3 (check that anhydrous ethanol has been added before use) and mix thoroughly (e.g., 500 µl filtrate to 750 µl Buffer LP3).Note: Buffer LP3 should be mixed immediately after addition; precipitation may occur but will not affect subsequent experiments.6. Add all of the solution and precipitate obtained in the previous step to the adsorption columns (Spin Columns DM) that have been loaded into the collection tubes, if the solution cannot be added all at once, it can be transferred in several times. centrifuge the columns at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tubes, and put the columns back into the collection tubes.7. Add 500 µl of Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.Note: If the adsorbent membrane appears green, add 500 µl of anhydrous ethanol to the adsorbent column, centrifuge the column at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorbent column back into the collection tube.8. Repeat step 7.9. 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 several minutes to dry thoroughly.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.).10. Place the adsorption column in a new centrifuge tube (supplied), add 50-100 µl of Buffer GE or sterilized water dropwise to the middle of the adsorbent membrane, leave it at room temperature for 2-5 minutes, and centrifuge it at 12,000 rpm for 1 minute to collect the DNA solution. -The DNA solution was collected by centrifugation at 12,000 rpm for 1 min.Note: 1) If the downstream experiment is sensitive to pH or EDTA, you can use sterilized water for elution. The pH value of the eluent has a great influence on the elution efficiency, if you use water as the eluent, you should ensure that the pH value is 7.0-8.5 (you can use NaOH to adjust the pH value of the water to this range), and when the pH value is lower than 7.0, the elution efficiency is not high.2) Incubation at room temperature for 5 minutes prior to centrifugation increases yield.(3) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 10 can be re-added to the adsorbent membrane and repeat step 10; if the elution volume is less than 100µl, the final concentration of DNA can be increased, but it may reduce the total DNA yield. If the amount of DNA obtained is less than 1µg, 50µl Buffer GE is recommended for elution.4) Because DNA stored in water is subject to acidic hydrolysis, for long-term storage, elution with Buffer GE and storage at -20°C are recommended... Read More | 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 |