| Description | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export | 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：Used to isolate lymphocytes from human organsMatters needing attention：1. samples, reagents and experimental environment in the whole process shall be carried out at 20 ± 2 ℃. In order to obtain the best experimental results, it is best to carry out the Product introduction：Used to isolate lymphocytes from human organsMatters needing attention：1. samples, reagents and experimental environment in the whole process shall be carried out at 20 ± 2 ℃. In order to obtain the best experimental results, it is best to carry out the experiment within 2 h of sampling. The longer the sample is stored, the worse the cell separation effect is. The separation effect is even worse after the sample is placed for more than 6 h, or even cannot achieve the purpose of separation. 2. in this experiment, it is better not to use plastic products with high polymerization materials (such as polystyrene), but use non-static, low static ionization heart tubes and glass products without alkali treatment, because the electrostatic effect will lead to cell adhesion, and the surface of alkali treated glass will become rough, which will affect the effect of cell separation. 3. aspirating too many lymphocyte layers and separation liquid layers will cause the granulocytes at the junction of separation liquid to be aspirated, thus increasing the number of mixed granulocytes. 4. when the amount of separating solution is greater than that of tissue single cell suspension sample, the separation effect is better.Scope of application：Lymphocyte isolation... Read More | This reagent kit is for research purposes only. Purpose of use: This reagent kit is used to determine the content of lactose in serum, plasma, and related liquid samples.Experimental principle:This kit applies enzyme-linked immunosorbent assay to determine the level of lactose in the sample. This reagent kit is for research purposes only. Purpose of use: This reagent kit is used to determine the content of lactose in serum, plasma, and related liquid samples.Experimental principle:This kit applies enzyme-linked immunosorbent assay to determine the level of lactose in the sample. Purified lactose antibodies were coated on a microplate to produce solid-phase antibodies. Lactose was added to the microplate of the coated monoclonal antibody, along with HRP labeled lactose antigens, to compete for binding. After thorough washing, the substrate TMB was added for colorimetry. The depth of sample color is negatively correlated with the content of lactose in the sample. Measure the absorbance (OD value) at a wavelength of 450nm using an enzyme-linked immunosorbent assay (ELISA) reader, and calculate the content of lactose in the sample through a standard curve.Kit composition:130times concentrated washing solution20ml×1 bottle8.1Standard S1（80µg/L）0.5ml×1bottle2Enzyme-linked immunosorbent assay6ml×1 bottle8.2Standard S2（40µg/L）0.5ml×1bottle3Enzyme labeling coated plate96 holes x 1 pieces8.3Standard S3（20µg/L）0.5ml×1bottle4Color reagent A solution6ml×1 bottle8.4Standard S4（10µg/L）0.5ml×1bottle5Color developer B solution6ml×1 bottle8.5Standard S5（5µg/L）0.5ml×1bottle6Stop solution6ml×1 bottle9Instructions1 copy7Sample Diluent6ml×1 bottle10Microplate Sealers2 sheetsSpecimen requirements:1. Specimen processing:(1) After collecting the water sample, it is repeatedly freeze-thawed three times at -20 ℃, and then filtered through glass fiber for future reference(2) The tissue samples should be extracted using butanol: methanol: water (5:25:70 V: V: V), or extracted according to relevant literature. The experiment should be conducted as soon as possible after extraction. If the experiment cannot be conducted immediately, the specimen can be stored at -20 ℃ for future reference2. Samples containing NaN3 cannot be detected as NaN3 inhibits the activity of horseradish peroxidase (HRP).Operation steps:1. Sample addition: Set up standard wells, blank wells (blank control wells do not include samples and enzyme-linked immunosorbent assay reagents, the other steps are the same), and sample wells to be tested. Add 50 microliters to the standard well on the enzyme-linked immunosorbent assay (ELISA) plate, and first add 40 diluents to the sample well to be tested µ l. Then add 10 more samples to be tested µ L (The final dilution of the sample is 5 times). Add the sample to the bottom of the enzyme-linked immunosorbent assay (ELISA) plate well, avoiding touching the well wall as much as possible. Gently shake and mix well.2. Enzyme addition: Add 50 enzyme labeled reagents to each well µ l. Excluding blank holes.3. Warm incubation: Seal the plate with a sealing film and incubate at 37 ℃ for 60 minutes.4. Solution preparation: Dilute 30 times the concentrated washing solution with distilled water and set aside for later use5. Washing: Carefully remove the sealing film, discard the liquid, shake dry, fill each well with washing solution, let it stand for 30 seconds, then discard. Repeat this process 5 times and pat dry.6. Color development: Add color development agent A50 to each well first µ l. Add color developer B50 again µ l. Gently shake and mix well, and develop color at 37 ℃ in the dark for 15 minutes7. Termination: Add 50% termination fluid to each hole µ l. Terminate the reaction (at this point, the blue color immediately turns yellow).8. Measurement: Zero the blank hole and sequentially measure the absorbance (OD value) of each hole at a wavelength of 450nm. The measurement should be conducted within 15 minutes after adding the termination solution.Calculation:Draw a standard curve on a coordinate paper with the concentration of the standard substance as the x-axis and the OD value as the y-axis. Based on the OD value of the sample, determine the corresponding concentration from the standard curve; Multiply it by the dilution factor; Alternatively, a linear regression equation can be used to calculate the standard curve using the concentration and OD value of the standard substance. The OD value of the sample can be substituted into the equation to calculate the sample concentration, which is then multiplied by the dilution factor to obtain the actual concentration of the sample.Notes:1. The kit should be balanced at room temperature for 15-30 minutes before use when taken out from the cold storage environment. If the enzyme coated plate is not used up after opening, the Flat noodles should be stored in a sealed bag.2. Concentrated detergent may precipitate crystals. When diluted, it can be heated in a water bath to aid in dissolution. Washing does not affect the results.3. A sampler should be used for each step of sample addition, and its accuracy should be regularly calibrated to avoid experimental errors. It is best to control the sample addition time within 5 minutes. If there are a large number of specimens, it is recommended to use a firing gun for sample addition.4. Please make a standard curve at the same time as each measurement, preferably with a re hole. If the content of the substance to be tested in the sample is too high (the OD value of the sample is greater than the OD value of the first well of the standard well), please dilute the sample diluent by a certain multiple (n times) before measurement. When calculating, please multiply the total dilution multiple (x n x 5).5. The sealing film is only for one-time use to avoid cross contamination.6. Please store the substrate in dark.7. Strictly follow the instructions and determine the test results based on the reading of the enzyme-linked immunosorbent assay (ELISA) reader8. All samples, washing liquids, and various waste should be treated as infectious substances.9. The components of this reagent with different batch numbers shall not be mixed.Detection range:two µ G/L-90 µ G/L... Read More | Inquire |