| Description | DescriptionRefer to the product′s Certificate of Analysis for more information on a suitable instrument technique. Contact Technical Service for further support | 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 content N665859Component50 TStorageN665859ABuffer DS30 mLRTN665859BBuffer GTL15 mLRTN665859CBuffer GL15 mLRTN665859DBuffer GW1 (concentrate)13 mLRTN665859EBuffer GW2 (concentrate)15 mLRTN665859FBuffer TE10 mLRTN665859GProteinase K2×1.25 mLRTN665859HRNase A (100 mg/mL)0.4 Product content N665859Component50 TStorageN665859ABuffer DS30 mLRTN665859BBuffer GTL15 mLRTN665859CBuffer GL15 mLRTN665859DBuffer GW1 (concentrate)13 mLRTN665859EBuffer GW2 (concentrate)15 mLRTN665859FBuffer TE10 mLRTN665859GProteinase K2×1.25 mLRTN665859HRNase A (100 mg/mL)0.4 mLRTN665859ISpin Columns DF With Collection Tubes50 EA2-8℃N665859JCentrifuge Tubes (L-1.5 mL)50 EART Product IntroductionThis kit is suitable for the effective purification of genomic DNA from formalin-fixed, paraffin-embedded tissues.The product uses specially optimized dewaxing agent and lysis solution to release DNA from formalin-fixed or tissue sectioned samples, which does not involve the organic reagent xylene and does not need to be operated overnight; the digested samples are incubated at higher temperatures to remove formalin cross-linking of the free DNA, which can effectively improve the yield and purity of DNA; the optimized buffer system allows the inhibitors in the lysis solution to be specifically bound to the adsorbent membrane, which can be effectively removed by a two-step rinsing step. The optimized buffer system enables the DNA in the lysate to specifically bind to the adsorbent membrane, and the inhibitor is effectively removed by a two-step rinsing step, and finally eluted with low-salt buffer or water to obtain high-purity DNA.Meanwhile, configured with a high-efficiency microsorbent column, the elution volume can be as low as 20 µL.The purified DNA can be directly used for PCR, Real-time PCR, SNP Genotyping, STR genotyping, second-generation sequencing and pharmacogenomics research.The molecular weight of DNA isolated from formalin-fixed, paraffin-embedded samples is usually lower than that of DNA from fresh or frozen samples.The degree of DNA fragmentation depends on the type of sample, the duration of storage, and the conditions of fixation.Self-contained reagent: anhydrous ethanolPre-experiment Preparation and Important Notes1. After obtaining the sample, fix the sample in 4%-10% formalin as soon as possible, the fixation time should be 14-24 hours, too long a period of time will easily lead to genome breakage, affecting the downstream experiments. If the formaldehyde fixation time is too long or the sample has been stored for too long (> 1 year), it will easily lead to DNA integrity damage and unable to amplify long fragments.2. Ensure that the sample is thoroughly dehydrated before embedding; residual formalin will inhibit Proteinase K.3. Anhydrous ethanol should be added to Buffer GW1 and Buffer GW2 according to the instructions on the label of the reagent bottle before first use.4. Before use, please check Buffer GTL, Buffer GL and Buffer DS for any crystallization or precipitation. If there is any crystallization or precipitation, please re-dissolve Buffer GTL, Buffer GL and Buffer DS at 56℃ in a water bath.5. Preheat the water bath or thermostatic mixer to 56°C and keep the centrifuge at 25°C before starting the experiment.6. If downstream experiments are needed to reduce the low frequency of C>T:G>A transitions (artificial mutations) that occur to minimize the risk of false positives, 7 µL of UNG (1 U/uL) can be added after 1 hour of incubation at 90°C.Operation steps1. Sample processing:1a. Paraffin-embedded samples: Trim off excess paraffin from the tissue block with a scalpel to expose the tissue and then cut into 5-10µm slices. Take about 1×1cm2 slices (about 4-5 slices in total) and place them in a centrifuge tube (provided), add 160µL Buffer DS, vortex and shake for 10 seconds, then add 180µL Buffer GTL and 20µL Proteinase K, vortex and shake for 10 seconds. centrifuge the samples at 12,000rpm for 1 minute at 25℃.Note: 1) If the surface of the sample has been exposed to air, discard the 2-3 pieces that have been exposed to air and do not use them.2) DS will solidify below 18°C, and if it does it does not affect the following experiments.1b. Sample in formalin and other fixative: take about 20mg of sample, cut it into small pieces, place it in a centrifuge tube, add 500µL of 10mM PBS (PH7.4), vortex shaking, centrifuge at 12,000rpm for 1minute, discard the supernatant, and repeat 3 times. Add 180 µL Buffer GTL, 20 µL Proteinase K, vortex shaking to mix.2.56°C for 1 hour until the sample is completely dissolved. incubate at 90°C for 1 hour. centrifuge at 12,000 rpm, 25°C for 1 minute, and carefully pipette the lower aqueous phase (~180 µL) along the wall of the tube into a new centrifuge tube, trying to avoid aspirating the bottom precipitate and the upper layer of the wax solution.Note: 1) Samples can be left at room temperature after incubation at 56°C until the temperature of the water or dry bath reaches 90°C before placing the samples at 90°CIncubation.2) Optional step: add 7µL UNG (1U/µL), 50°C, 5min, no shaking. The purpose of this step is to minimize the risk of false positives by reducing the low-frequency occurrence of C>T:G>A transitions (artificial mutations) while effectively retaining the true occurrence of mutations.3. Optional step: If you need to remove RNA, you can lower the temperature of the sample to room temperature, then add 2µL of RNase A solution at a concentration of 100mg/mL, shake and mix well, and leave it at room temperature for 2 minutes.4. Add 20µL Proteinase K and incubate at 65℃, 450rpm for 15min.5. Add 200 µL of Buffer GL, mix well by vortexing and shaking, then add 200 µL of anhydrous ethanol and mix thoroughly by vortexing and shaking. Centrifuge briefly so that the solution on the wall of the tube collects at the bottom of the tube.Note: 1) Mix well immediately after adding Buffer GL and anhydrous ethanol.2) The addition of Buffer GL and anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.3) If more than one sample needs to be manipulated, the Buffer GL and anhydrous ethanol can be pre-mixed and spiked.6. Add all the solution obtained in step 5 to the adsorption columns (Spin Columns DF) that have been loaded into the collection tube, centrifuge at 25℃, 12000rpm for 2 minutes, pour out the waste liquid in the collection tube, and put the adsorption columns back into the collection tube.7. Add 500µL of Buffer GW1 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.8. Add 500µL of Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12000rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.Note: Step 8 can be repeated if further DNA purity is required.9.12 Centrifuge at 2000 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; ethanol residue can interfere with subsequent enzymatic reactions.10. Place the adsorption column in a new 1.5 mL collection tube, add 20-100 µL of Buffer TE or sterilized water to the middle of the adsorption column overhanging the column, let it stand at room temperature for 2-5 minutes, centrifuge it at 12,000 rpm for 1 minute, and collect the DNA solution.-20°C to preserve DNA.Note: 1) The pH value of the eluent has a great influence on the elution efficiency, if water is used as the eluent should ensure that its pH value is 7.0-8.5, the pH value is lower than 7.0 when the elution efficiency is not high.2) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 10 can be re-spiked onto the adsorbent membrane and left at room temperature for 2 minutes and centrifuged at 12,000 rpm for 1 minute... Read More | Products R669890Component50 TStorageR669890ADNase I1000 U-20℃. Avoid freeze/thaw cycle.R669890B10×Reaction Buffer1mL-20℃. Avoid freeze/thaw cycle.R669890CBuffer RL35 mLRTR669890DBuffer RW140 mLRTR669890EBuffer RW2 (concentrate)11 mLRTR669890FRNase-Free Water10 mLRTR669890GSpin Products R669890Component50 TStorageR669890ADNase I1000 U-20℃. Avoid freeze/thaw cycle.R669890B10×Reaction Buffer1mL-20℃. Avoid freeze/thaw cycle.R669890CBuffer RL35 mLRTR669890DBuffer RW140 mLRTR669890EBuffer RW2 (concentrate)11 mLRTR669890FRNase-Free Water10 mLRTR669890GSpin Columns FL with Collection Tubes50 setsRTR669890HSpin Columns RM with Collection Tubes50 setsRTR669890IRNase-Free Centrifuge Tubes (1.5 mL)100 EART ProductsThis kit adopts centrifugal adsorption columns with high efficiency and specificbinding of nucleic acids and unique buffer system, which can rapidly extract totalRNA from bacteria or cultured animal cells.The reaction can be completed in 30-40minutes, and the extracted total RNA is extremely pure and free of protein and othercontaminants, which is suitable for RT-PCR, Real-Time RT-PCR, microarray analysis,in vitro translation and other experiments. Self-contained reagents: Lysozyme, β-mercaptoethanol, anhydrous ethanol (freshlyopened or for RNA extraction). Pre-experiment Preparation and Important Notes 1. To prevent RNase contamination, attention should be paid to the following aspects:1) Use RNase-free plastics and tips to avoid cross-contamination. 2) RNase-free water should be used to prepare the solution. 3) Operators wear disposable masks and gloves, and change gloves diligently duringthe experiment. 2. Add β-mercaptoethanol to Buffer RL before use to reach a final concentrationof 1%, e.g., add 10 µl of β-mercaptoethanol to 1 ml of Buffer RL. Buffer RL withβ-mercaptoethanol can be stored at 4℃ for 1 month, if precipitation occurs, pleaseheat to dissolve and use.3. Anhydrous ethanol should be added to Buffer RW2 before first use according tothe instructions on the reagent bottle label. 4. All centrifugation steps are carried out at room temperature if not otherwisespecified, and all steps should be performed quickly. Procedure 1. Centrifuge at 12,000 rpm (~13,400 x g) at 4°C for 2 minutes to collect theorganisms (maximum volume of organisms should not exceed 1 x 109) and carefullyremove all supernatants. Note: Supernatants that leave residues can interfere with the subsequent digestionprocess. 2. Thoroughly resuspend the organisms with 100 µl of TE buffer containing Lysozymeand incubate at room temperature. The specific formulation and incubation time areas follows:/The final concentration of Lysozyme in TE bufferincubation timeG-germ400µg/ml3-5minG+germ3mg/ml5-10min 3. Add 350 µl of Buffer RL (check that β-mercaptoethanol has been added beforeuse), vortex and shake to mix (insoluble precipitate may appear in this step), addall of the solution and the precipitate to the filter columns (Spin Columns FL) thathave been loaded into the collection tubes, and centrifuge at 12,000 rpm for 2minutes. 4. Add 250 µl of anhydrous ethanol to the filtrate obtained in the previous stepand mix well (a precipitate may appear at this point). Transfer the resulting solution together with the precipitate to a Spin Columns RM packed in a collectiontube, centrifuge at 12,000 rpm for 1 min, discard the waste solution and put thecolumn back into the collection tube.5. Add 350 µl Buffer RW1 to the adsorbent column, centrifuge at 12,000 rpm for1min, discard the waste liquid and put the adsorbent column back into the collectiontube.6. Preparation of DNase I mixture: Take 52µl of RNase-Free Water, add 8µl of 10×Reaction Buffer and 20µl of DNase I (1U/µl) to it, mix well, and make a finalvolume of 80µl of reaction solution.7. Add 80µl of DNase I mixture directly to the adsorption column and incubate at20-30°C for 15 minutes.8. Add 350 µl Buffer RW1 to the adsorbent column, centrifuge at 12,000 rpm for1min, discard the waste liquid and put the adsorbent column back into the collectiontube.9. Add 500 µl of Buffer RW2 to the column (check that anhydrous ethanol is addedbefore use), centrifuge at 12,000 rpm for 1 min, and discard the waste solution.10. Repeat step 9.11. Place the adsorbent column back into the collection tube and centrifuge at 12,000rpm for 2 minutes. Note: The purpose of this step is to remove residual ethanol from the adsorptioncolumn; ethanol residue can interfere with subsequent enzymatic reactions (zymography, PCR, etc.).12. Load the adsorption column into a new RNase-Free collection tube, add 30-50 µl of RNase-Free Water to the middle of the adsorption membrane, leave it at roomtemperature for 1 minute, centrifuge at 12,000 rpm for 1 minute, collect the RNAsolution, and store the RNA at -70°C to prevent degradation. Note: 1) The volume of RNase-Free Water should not be less than 30 µl, too smallvolume affects the recovery rate. 2) If you want to increase the RNA yield, repeat step 12 with 30-50 µl of freshRNase-Free Water. If the RNA concentration is to be increased, the resulting solution can be reintroduced into the adsorption column and step 12 repeated... Read More | Component Description T665563Component50 TStorageApplicationT665563AVNTR3820 1 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563BVNTR41201 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563CVNTR32321 mL-20℃. Avoid freeze/thaw Component Description T665563Component50 TStorageApplicationT665563AVNTR3820 1 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563BVNTR41201 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563CVNTR32321 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563DMarkerⅠ300 µL-20℃. Avoid freeze/thaw cycle.DNA Molecular Weight Standard IT665563EMarkerⅡ250 µL-20℃. Avoid freeze/thaw cycle.DNA Molecular Weight Standard IIProduct IntroductionThis kit is a genotyping product for human Mycobacterium tuberculosis based on the latest research progress in molecular epidemiology1) and optimized by process. It utilizes variable-number tandem repeats (VNTR) polymorphisms in the Mycobacterium tuberculosis genome for genotyping to differentiate clinical strains, and is a powerful tool for studying the molecular epidemiology of Mycobacterium tuberculosis and monitoring the status of tuberculosis transmission. Compared with other existing Mycobacterium tuberculosis VNTR typing systems based on the VNTR principle, this typing system has a stronger ability to discriminate strains prevalent in China1,2,3), and is therefore particularly suitable for the needs of Chinese users.By carefully optimizing the primer sequences of each PCR reaction and the composition of the premixed reaction solution, this product has a strong anti-interference power. Compared with the user's own reagents, this product significantly improves the signal intensity of specific bands and reduces the appearance of non-specific bands when using crude templates (boiling bacterial solution), which makes the experimental operation easier and quicker, and at the same time, improves the success rate of the test. The premixed reaction solution is chemically stable and can effectively withstand repeated freezing and thawing (10 times) and a longer period of time (one week) at room temperature, which is better adapted to the user's need for flexibility in the detection work.This kit is a companion product to the TB Genotyping Kit VNTR-9. For samples identified as clustered or identical strains by the VNTR-9 kit, this product can be used for finer further typing identification if necessary. The three high-resolution detection sites VNTR3820, VNTR4120 and VNTR3232 in this product can be used in combination with the nine detection sites in the VNTR-9 to increase the resolution index (Hunter-Gaston index (HGI) to 0.9931).References1) Luo T et al. Development of a hierarchical variable-number tandem repeat typing scheme for Mycobacterium tuberculosis in China. PLoS One. 2014 Feb 25. 9(2)2)Sun G et al. Discriminatory potential of a novel set of Variable Number of Tandem Repeats for genotyping Mycobacterium marinum. Vet Microbiol. 2011 Aug Vet Microbiol. 2011 Aug 26;152(1-2)3) Zhang L et al. Highly polymorphic variable-number tandem repeats loci for differentiating Beijing genotype strains of Mycobacterium tuberculosis in Shanghai, China. FEMS Microbiol Lett. 2008 May;282(1):22-31.matters needing attention1.This product is a companion to the TB genotyping kit VNTR-9. The strains to be tested should be tested by VNTR-9 typing test first, and then use this product for testing. And the results of this product should be integrated and analyzed with the results of VNTR-9.2.To avoid contamination, it is recommended that the preparation of the organisms be done within a different location than the preparation of the PCR Mix and that different pipettes be used.3.Care should be taken at all stages of sample DNA collection, extraction and amplification to ensure proper labeling and to prevent cross-contamination between different samples.4.Commonly used reagents and consumables need to be autoclaved before experimentation.5.Each tube of PCR Mix contains different primers and cannot be mixed. It can be dispensed into different amounts at once according to the experimental needs to avoid repeated freezing and thawing.6.To avoid splashing the reaction solution when opening the reaction tube, centrifuge briefly before opening the cap and collect the liquid at the bottom of the tube. In case of accidental splashing on gloves or table, change gloves immediately and wipe the table with 75% alcohol or dilute acid.7.Be careful not to cross-contaminate the PCR Mix when aspirating, and it is recommended that the pipette tip be wiped with 75% alcohol 2 times before taking Mix each time.8.Pre-experiment preparation: 1×TE buffer (PH=8.0), 0.5×TBE buffer, agarose, ethidium bromide (EB), normal PCR instrument, DNA electrophoresis equipment and gel imager, 0.2 ml PCR reaction tubes, octuplex or 96-well PCR tubes, pipettes of different sizes: 0.5-10 µl and 20-200 µl.Operation steps1. DNA template preparation:1.1. scrape a small amount (1-2 inoculation loops) of sample from solid medium, resuspend in 100ul TE and inactivate at 80°C for 30 minutes.1.2. The inactivated strain was taken out of the P3 laboratory as follows:Boil at 100°C for 10 minutes (be careful to avoid bursting the cap of the EP tube during boiling to avoid letting water into the tube), place immediately on ice for 2 minutes, centrifuge at 12,000 rpm (~13,400 × g) for 10 minutes, take the supernatant and place in another sterile EP tube, label it, and store at -20°C.2. Testing procedures:2.1. Remove the TB Genotyping Kit HV-3, allow the liquid to equilibrate to room temperature, mix by shaking slightly 3-4 times, and then centrifuge at 12,000 rpm (~13,400 x g) for 5 seconds to allow the capped liquid to fall back into the tube.2.2.Three-locus VNTR typing: strains with identical results at 12 loci need to be further VNTR typed, i.e., the following four loci are added for comparison.1）PCR amplification: the reaction system was 20 µl. 19 µl of PCR Mix of VNTR3820, VNTR4120, and VNTR3232 were added to each PCR tube, 1 µl of DNA template was added, and mixed well.2）Amplification conditions:3) Gel preparation and electrophoresis:a: Notes:Important! Positive (H37Rv strain DNA) and negative controls (deionized water) need to be set up for each experiment.Key! This experiment is based on agarose gel electrophoresis to interpret the genotype of VNTR locus, therefore, in order to make the results accurate, it is necessary to follow the unified standard operation in this step of electrophoresis, and the following points should be noted:a-1: The comb used for glue making is 18 holes.a-2: The two wells on the left and right sides of the gel were discarded due to the tendency to distort the bands during electrophoresis, affecting the interpretation of the results, or a negative control was spotted in one of the wells. The remaining 16 wells were divided into 12 samples, 3 DNA Markers and 1 positive control. The order of spotting was "1, 2, M, 3, 4, 5, 6, M, 7, 8, 9, 10, M, 11, 12, H37Rv", the numbers represent samples, and M represents DNA Marker.a-3: When PCR amplification products are subjected to the first electrophoresis and Marker I is used, the gel concentration is 1%, the voltage is 150 V, and the time is 100-120 min.a-4: If the amplification product fragment is too large (>1000bp) and needs to be electrophoresed again and Marker II is used, the gel concentration is 0.8%, the voltage is 150V and the time is 150 minutes.b: Gluing as well as the electrophoresis process:PCR amplification products were electrophoresed using a 1% agarose gel.To prepare 1% agarose gel, 12×12 cm gel tray was used to make the gel, each gel was 80 ml.b-1: Weigh 0.8g of agarose, add 80ml of 0.5×TBE, weigh it on the balance and put it into the microwave oven, heat it on high for 2-3 minutes to make the agarose dissolve completely, shake it well, and observe it as a homogeneous and transparent solution without particles, then weigh it again on the balance and make up the appropriate amount of double-distilled water to keep the concentration of the gum unaffected.b-2: When the melted gel was cooled to about 55°C add 4 µl of ethidium bromide (10ug/ml) and gently swirl to mix well. The gel was made with an 18-tooth comb and the warm gel was poured into a 12 × 12 cm gel tray.b-3: Allow the gel to completely set (40 minutes at room temperature), carefully pull out the comb, remove the tray, and place it in the electrophoresis tank. Add 0.5× TBE buffer to the electrophoresis tank, not exceeding the gel surface by 1-2mm.b-4: Sample electrophoresis: add 12 samples to each gel (the topmost wells are not sampled), add 3-5µl PCR products to each well, and at the same time add three 5µl DNA MarkerⅠ to each gel. The voltage is 150V and the electrophoresis time is 100-120 minutes. This step is the key to the accuracy of the final readings of each point, and needs to be operated uniformly according to this standard.b-5: Some loci have amplification products greater than 1000bp in clinical strains, and these amplification products were then electrophoresed using 0.8% agarose gel, with DNA Marker II added as a control for the band size, voltage 150V, electrophoresis time 150 minutes.4) Results display:5) Analysis of results:a. If the genotypes of the three highly variable loci are also the same in different strains, they can be identified as clustered strains;b. If the high variant readings are highly similar, i.e., only 1-2 high variant sites are different, they need to be combined with epidemiologic data to identify if they are clustered strains;c. If all 3 high variant loci are genotypically discordant, identify as a single strain.Appendix 1: Rules for reading VNTR lociAppendix 2: VNTR locus repeat unit readout table... Read More |