| Description | Acridine Orange (AO) is a metachromatic fluorescent dye whose emission color varies depending on the target it binds to:When binding to double-stranded DNA: It intercalates between base pairs and emits green fluorescence upon excitation (Ex 488 nm, Em 530 nm).When binding to single-stranded RNA or Acridine Orange (AO) is a metachromatic fluorescent dye whose emission color varies depending on the target it binds to:When binding to double-stranded DNA: It intercalates between base pairs and emits green fluorescence upon excitation (Ex 488 nm, Em 530 nm).When binding to single-stranded RNA or lysosomes: It attaches via electrostatic interactions and emits orange-red fluorescence (Em 640 nm).Under a fluorescence microscope, Acridine Orange permeates the membranes of normal cells, staining the nucleus with uniform green or yellow-green fluorescence. In apoptotic cells, due to chromatin condensation and fragmentation into apoptotic bodies, AO stains them with intense, condensed yellow-green fluorescence or fragmented yellow-green particles. In necrotic cells, the yellow-green fluorescence is reduced or absent.Acridine Orange is often used in combination with Propidium Iodide (PI) for dual staining. Since PI stains only dead cells, producing orange-red fluorescence, this method allows differentiation among normal, apoptotic, and necrotic cells.ComponentsA1456513Component50 Test100 TestStorage ConditionQuantity Per TestA1456513ADilution Buffer10 mL50 mL2-8℃0.1 mL per 0.5-1.0 × 10⁶ cellsA1456513BAO Staining Solution100 µL500 µL2-8℃, Protect from light. Do not freeze1 µL per 0.5-1.0 × 10⁶ cellsNote: The recommended number of cells to stain per test is 0.5-1.0 × 10⁶ cells.Procedure1. Preparation of Acridine Orange Staining Solution b. Mix the AO Staining Solution with the Dilution Buffer at a ratio of 1:1000 to prepare the working solution. For example, add 10 µL of AO Staining Solution to 10 mL of Dilution Buffer to obtain 10 mL of Acridine Orange staining solution. 2. Staining with Acridine Orangea. For adherent cells: (a) Gently aspirate the culture medium from the plate. Rinse with PBS for about 10 seconds, then remove PBS. (b) Add Acridine Orange staining solution and incubate at room temperature for 5 minutes. Remove the staining solution and rinse with PBS for about 10 seconds. Repeat the rinse once. Note: For adherent cells cultured in a 6-well plate with a confluence exceeding 80%, it is recommended to add the staining working solution at a volume of 1 mL per well. This volume can be optimized based on the specific experimental system.(c) Incubate at room temperature for 5 minutes. (c) Add an appropriate amount of cell culture medium, staining buffer, or other suitable solution to cover the well bottom. Observe under a microscope. Depending on the detection requirements, green fluorescence can be observed at Ex/Em = 488/530 nm, and red fluorescence can be observed at Ex/Em = 540/640 nm. Alternatively, measure fluorescence intensity using a fluorescence microplate reader with bottom-reading capability.b. For suspension cells: (a) Take 1 mL of cell suspension. Centrifuge at 500g for 5 minutes at room temperature. Gently aspirate the medium, resuspend in PBS, and centrifuge again at 500g for 5 minutes. Remove PBS. (b) Add an appropriate amount of Acridine Orange staining solution to achieve a cell density of approximately 10⁶ cells/mL.(c) Incubate at room temperature for 5 minutes. (d) A drop of the sample was directly applied onto a glass slide, covered with a coverslip, and examined under a microscope. Depending on the detection requirements, green fluorescence can be observed at Ex/Em = 488/530 nm, and red fluorescence can be observed at Ex/Em = 540/640 nm. Alternatively, after staining, analyze directly by flow cytometry or measure fluorescence with a microplate reader.Note: Centrifugation to remove staining solution can reduce background fluorescence. For suspension cells or adherent cells in suspension, consider reducing the AO staining solution concentration by 2–5 times and shortening the staining time to 2 minutes.Precautions1. AO Staining Solution is toxic. Handle with care. 2. For your safety and health, wear a lab coat and disposable gloves. 3. Fluorescent dyes are susceptible to quenching. It is recommended to complete detection on the same day after staining... 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.Composition: Composition 20T 50T A. aladdin®640 TUNEL Reaction Buffer 1 mL 2 ×1.25 mL B. TdT Enzyme 20 µL 50 µL C. Proteinase K (2 mg/mL) 40 µL 100 µL D. DNase I (2 U/µL) 5 µL 13 µL E. 10 ×DNase I Buffer 100 µL 260 µL Product parameters：642/662 nm； 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.Scope of application：Late apoptosis detection, TUNEL Kit... Read More | Product IntroductionBCIP (5-Bromo-4-chloro-3-indolyl phosphate) 5-bromo-4-chloro-3-indolyl-phosphate + NBT (tetrazolium nitro blue) is the best substrate for alkaline phosphatase (AP) One of the combination. Under the catalysis of alkaline phosphatase, BCIP will be hydrolyzed to produce a highly Product IntroductionBCIP (5-Bromo-4-chloro-3-indolyl phosphate) 5-bromo-4-chloro-3-indolyl-phosphate + NBT (tetrazolium nitro blue) is the best substrate for alkaline phosphatase (AP) One of the combination. Under the catalysis of alkaline phosphatase, BCIP will be hydrolyzed to produce a highly reactive product, which reacts with NBT to form an insoluble dark blue to blue-violet compound. This kit can be used for the enzymatic color development of IHC and Western Blot experiments of the AP system. Under AP catalysis, a dark blue precipitate is produced where AP conjugates are combined on tissue sections or blotting membranes. The location and expression of the target protein can be determined based on the color reaction.Product Components40×BCIP: 1 ml40×NBT: 1 mlBCIP/NBT Buffer: 40 mlPrecautions1. The working fluid should be prepared for immediate use, and the prepared working fluid will be effective within 1 hour.2. The amount of working fluid must be sufficient to ensure complete coverage of the tissue sheet or blotting membrane. To3. In order to obtain the best experimental results, be sure to optimize the experimental conditions.4. NBT is poisonous, please take necessary protective measures when using it.5. This product is only used for scientific research, not for human experiments or human treatment.Instructions1. BCIP/NBT color developing working solution preparation:According to the required amount, mix 40×BCIP, 40×NBT and BCIP/NBT Buffer in a volume ratio of 1:1:38 to form the BCIP/NBT color developing working solution.2. Color rendering:1) Blotting membrane color development: Drop the prepared working solution on the blotting membrane (or pour the blotting membrane into the BCIP/NBT color developing working solution), and incubate for 3-10 minutes at room temperature and dark. After the color development is completed, the film is immersed in water to terminate the reaction.2) Color development of tissue sections or cell slides: Drop an appropriate amount of BCIP/NBT color developing working solution on the tissue sections or cell slides that need color development, and incubate at room temperature for 3-10 minutes in the dark. Observe under the microscope to control the color development time. When the best color development effect is reached, rinse with tap water to stop the color development. After color development, the slices are counter-stained, dehydrated and transparent, and can be stored for a long time after mounting... Read More | Inquire | Inquire |