| Description | Acetate Kinase (ACK) is primarily found in microorganisms. It catalyzes the conversion of acetate and ATP to acetyl phosphate and ADP, serving as a key enzyme in bacterial carbon and energy metabolism, and plays a central role particularly in the methanogenesis metabolism of archaea.Assay Acetate Kinase (ACK) is primarily found in microorganisms. It catalyzes the conversion of acetate and ATP to acetyl phosphate and ADP, serving as a key enzyme in bacterial carbon and energy metabolism, and plays a central role particularly in the methanogenesis metabolism of archaea.Assay PrincipleACK catalyzes the synthesis of Acetyl Phosphate and ADP from Sodium Acetate and ATP. Pyruvate Kinase then catalyzes the conversion of ADP and Phosphoenolpyruvate (PEP) to ATP and Pyruvate. Subsequently, Lactate Dehydrogenase catalyzes the reduction of Pyruvate by NADH to produce Lactate and NAD⁺. The rate of oxidation of NADH to NAD⁺, measured by the decrease in absorbance at 340 nm, reflects ACK activity.Component48T96TStorageExtraction Buffer60 mL60 mL×22-8℃ReagentⅠ15 mL30 mL2-8℃ReagentⅡ1EA2EA-20℃. Store in the dark.Reagent III25 µL50 µLNote: It is recommended to perform a pilot experiment with 2-3 samples expected to have significant differences before formal testing.Required Materials and Equipment (Not Provided)Microplate reader or UV spectrophotometer (capable of measuring absorbance at 340 nm)96-well UV plate or micro quartz cuvetteAdjustable pipettes and tipsConstant temperature water bathIce makerCentrifugeDeionized waterHomogenizer (for tissue samples)Reagent PreparationExtraction Buffer: Ready-to-use. Equilibrate to room temperature (RT) before use. Store at 4°C.Caution: Extraction Buffer is toxic and has a pungent odor. It is recommended to handle it within a fume hood.Reagent Ⅰ: Ready-to-use. Equilibrate to RT before use. Store at 4°C.Working Reagent Ⅱ: Prepare immediately before use. For one vial of Reagent Ⅱ, add 11 mL of Reagent Ⅰ and 19.8 µL of Reagent III. Mix thoroughly to dissolve. Prepare fresh for each use. Can be stored protected from light at -20°C for one month.Reagent Ⅲ: Ready-to-use. Equilibrate to RT before use. Store at 4°C protected from light.Sample Preparation*Note: The use of fresh samples is recommended. If not used immediately, samples can be stored at -80°C for up to one month. Control the temperature and time during thawing. If thawed at room temperature, complete the process within 4 hours.*1.Tissues: Weigh approximately 0.1 g of sample. Add 1 mL of Extraction Buffer and homogenize on ice. Centrifuge the homogenate at 15,000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.2.Cells or Bacteria: Collect 5 million cells or bacteria by centrifugation. Wash the pellet with cold PBS, centrifuge, and discard the supernatant. Add 1 mL of Extraction Buffer. Disrupt the cells/bacteria by sonication on ice (200W power, pulse 3s on/10s off, repeat 30 times). Centrifuge the lysate at 15,000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.3.Serum (Plasma) or other liquid samples: Assay directly. If the solution is turbid, centrifuge first and use the supernatant for assay.Note: To determine protein concentration, Aladdin's BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648) is recommended.Assay Procedure1.Preheat the microplate reader or spectrophotometer for 30 min. Set the wavelength to 340 nm. Zero the spectrophotometer with deionized water.2.Pre-warm a sufficient volume of the prepared Working Reagent Ⅱ at 37°C (for mammalian samples) or 25°C (for other species) for 5 minutes. Use immediately.3.Assay Setup (perform in a 96-well UV plate or micro quartz cuvette):ReagentTest Well (µL)Sample20Working Reagent Ⅱ180Mix thoroughly immediately after addition. Measure the absorbance at 340 nm at 10 seconds (A₁) and again at 190 seconds (A₂). Calculate ΔA = A₁ - A₂.Note: It is advised to run a pilot test with 2-3 samples showing expected significant variation beforehand. If ΔA is less than 0.05, consider increasing the sample volume or extending the reaction time to 10 or 20 minutes before measurement. If ΔA is greater than 1.0, dilute the sample further with Extraction Buffer (multiply the result by the dilution factor) or reduce the amount of sample used for extraction.Result CalculationNote: Both the derived and simplified calculation formulas are provided and are equivalent. The simplified formulas (in bold) are recommended for final calculation.1. Calculation for 96-Well UV PlateGeneral Parameters for 96-Well Plate:ε (NADH molar extinction coefficient) = 6.22 × 10³ L/mol/cmd (Light path of 96-well plate) = 0.5 cmVₜₒₜₐₗ (Total reaction volume) = 0.0002 L (200 µL)Vₛₐₘₚₗₑ (Sample volume in reaction) = 0.02 mL (20 µL)T (Reaction time) = 3 minVₛₐₘₚₗₑₜₒₜₐₗ (Total extraction volume) = 1 mLCpr (Sample protein concentration, mg/mL)W (Sample mass, g)500 (Cell/Bacteria count in millions: 5 × 10⁶)1.1 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:ACK Activity (U/mg prot) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (Vₛₐₘₚₗₑ × Cpr) ÷ TSimplified Formula: ACK (U/mg prot) = 1072 × ΔA ÷ Cpr1.2 Based on Sample Mass:Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per gram of fresh sample.Calculation:ACK Activity (U/g fresh weight) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (W × Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ) ÷ TSimplified Formula: ACK (U/g fresh weight) = 1072 × ΔA ÷ W1.3 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/bacteria in the reaction system.Calculation (for 5 million cells in 1 ml extract):ACK Activity (U/10⁴) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (500 × Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ) ÷ TSimplified Formula: ACK (U/10⁴) = 2.144 × ΔA1.4 Based on Liquid Volume:Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per milliliter of sample.Calculation:ACK Activity (U/mL) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ Vₛₐₘₚₗₑ ÷ TSimplified Formula: ACK (U/mL) = 1072 × ΔA2. Calculation for Micro Quartz CuvetteUse the formulas above but adjust the light path *d* from 0.5 cm to 1.0 cm.Precautions1. Keep samples and all reagents on ice during the assay procedure to prevent denaturation and loss of activity.2. The temperature of the reaction mixture must be maintained at 37°C or 25°C. When using a cuvette, a small beaker filled with deionized water pre-warmed to 37°C or 25°C (placed in a water bath) can be used to hold the cuvette and maintain temperature during the reaction.3. This product is for scientific research use only. It is not intended for clinical diagnosis. 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 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... 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