| 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 | Description：Acetylcholinesterases (AChEs) are enzymes that hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline. AChE is located at the synaptic cleft and functions to terminate synaptic transmission by catalyzing the breakdown of ACh allowing cholinergic neurons to Description：Acetylcholinesterases (AChEs) are enzymes that hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline. AChE is located at the synaptic cleft and functions to terminate synaptic transmission by catalyzing the breakdown of ACh allowing cholinergic neurons to return to a resting state after activation. It is also found in membranes of red blood cells, motor and sensory fibers, muscles, nerves and central and peripheral tissues. Changes in AChE activity may result from exposure to certain insecticides, which act as cholinesterase inhibitors. Inhibitors of AChE are also used to treat certain conditions such as dementia.Acetylcholinesterase activity assay kit has been used to determine the activity of acetylcholinesterase in a rat organophosphate model and in brain tissue homogenates.Principle：Acetylcholinesterase can catalyze the hydrolysis of acetylcholine to choline, and the reaction of choline with disulfide p-nitrobenzoic acid to produce 5-merhydryl-nitrobenzoic acid (TNB). The product has a characteristic absorption peak at 412 nm, and the activity of acetylcholinesterase can be characterized by the change of light absorption valueThe Dilution Calculator EquationConcentration (start)xVolume (start)= Concentration (final)× Volume (final)This equation is commonly abbreviated as: C1V1 = C2V2... Read More | Products contentN665993Component240 TStorageN665993AIndex N501 Primers for Illumina240 µL-20℃. Avoid freeze/ Thaw cycle.N665993BIndex N925-N948 Primers for Illumina24×10 µL-20℃. Avoid freeze/ Thaw cycle. Products Introduction This kit is a companion kit to the transposase-Products contentN665993Component240 TStorageN665993AIndex N501 Primers for Illumina240 µL-20℃. Avoid freeze/ Thaw cycle.N665993BIndex N925-N948 Primers for Illumina24×10 µL-20℃. Avoid freeze/ Thaw cycle. Products Introduction This kit is a companion kit to the transposase-based Rapid DNA Library Construction Kit for Illumina platform library construction. Each kit contains one N5 primer and 24 N7 primers, which can be used to prepare 24 different single-ended Index libraries. All reagents provided in the kits have been subjected to stringent quality control and functional validation to maximize the stability and reproducibility of library construction. The libraries can be used for sequencing on Illumina platforms such as HiSeq X-10/4000/2500/2000 and MiSeq. Provide your own instruments, reagents and consumables1. Magnetic frame: DynaMagTM-2 is recommended.2. DNA purification and recovery kit: It is recommended to use Kangwei DNA purification and recovery kit by magnetic bead method.3. DNA building kit: It is recommended to use the Kangwei Century transposase method second-generation sequencing rapid DNA building kit.4. Anhydrous ethanol.5. Reaction tubes: It is recommended to use low adsorption PCR tubes with 1.5 ml centrifuge tubes;Tip: It is recommended to use a high quality filter tip to prevent contamination of kits and library samples. Pre-experiment Preparation and Important NotesPlease centrifuge briefly before opening the cap so that the liquid collects at the bottom of the tube to avoid cross-contamination between different primers. ProcedureFor the use of the CombiVision Second Generation Sequencing Multisample Primer Kit, please follow the CombiVision Second Generation Sequencing Rapid DNA Library Kit protocol.Index N501 Primer for IlluminaIndex N901-N996 Primer for Illumina... Read More | This kit combines efficient guanidine isothiocyanate lysis technology with silicon matrix membrane purification technology to efficiently extract total RNA from animal cells and tissues. The starting sample usually has a maximum of 30 mg of tissue or 1 x 107 cells. This reagent kit can also recover This kit combines efficient guanidine isothiocyanate lysis technology with silicon matrix membrane purification technology to efficiently extract total RNA from animal cells and tissues. The starting sample usually has a maximum of 30 mg of tissue or 1 x 107 cells. This reagent kit can also recover partially purified RNA, RNA obtained from in vitro transcription and enzymatic reactions. This reagent kit can extract and purify high-quality RNA with a molecular weight greater than 200 bases, with almost no DNA residue. If RNA experiments are to be conducted that are highly sensitive to trace amounts of DNA, residual DNA can be digested and removed on a column using DNase I without RNase. The extracted RNA can be used for downstream experiments such as RT-PCR, Northern Blot, Dot Blot, etc. R666020Component50 TStorageR666020ABuffer RL35 mLRTR666020BBuffer RW140 mLRTR666020CBuffer RW2 (concentrate)11 mLRTR666020DRNase-Free Water10 mLRTR666020ESpin Columns RM with Collection Tubes50 setsRTR666020FRNase-Free Centrifuge Tubes (1.5 mL)50 EART Self prepared reagents: β- Mercaptoethanol, anhydrous ethanol (newly opened or dedicated for RNA extraction).Preparation and important precautions before the experimentTo prevent RNase pollution, attention should be paid to the following aspects:1) Use RNase free plastic products and gun heads to avoid cross contamination.2) Glassware should be dry baked at a high temperature of 180 ℃ for 4 hours before use, while plastic containers can be soaked in 0.5 M NaOH for 10 minutes, thoroughly rinsed with water, and then sterilized under high pressure.3) Prepare the solution using water without RNase.4) Operators should wear disposable masks and gloves, and change gloves frequently during the experiment.2. The extracted samples should avoid repeated freeze-thaw cycles, otherwise it will affect the quantity and quality of RNA extraction.3. Before use, please check if there is any crystallization or precipitation in the Buffer RL. It can be heated at 56 ℃ and re solved. Please add Buffer RL before use β- Mercaptoethanol, with a final concentration of 1%. Add 10 to 1ml Buffer RL µ L β- Mercaptoethanol. join β- The buffer RL room temperature of mercaptoethanol can be stored for one month.4. Before the first use, anhydrous ethanol should be added to Buffer RW2 according to the instructions on the reagent bottle label.5. All centrifugation steps should be carried out at room temperature unless otherwise specified, and all operation steps should be carried out quickly.6. If downstream experiments are highly sensitive to DNA, it is recommended to treat RNA with DNase I that does not contain RNase.Operation steps1. Sample processing1a organization: Grind the organization in liquid nitrogen. Add 600 to every 20-30 mg of tissue µ L Buffer RL (check if it is added before use) β- Mercaptoethanol), tissue sample less than 20 mg plus 350 µ Buffer RL. The sample volume shall not exceed one tenth of the buffer RL volume.1b Single layer culture of cells: The cells are directly lysed or processed into cell suspensions in a culture bottle, centrifuged to obtain cell precipitates, and the supernatant is discarded. 600 is added every 6-10 cm2 of culture area µ Buffer RL, less than 6 cm2, add 350 µ Blow buffer RL several times to fully crack it.1c cell suspension: Centrifuge at 12000 rpm (~13400 × g) for 1 minute to discard the supernatant and obtain cell precipitate. Add 600 cells every 5 × 106-1 × 107 cells µ Buffer RL, less than 5 × 106 cells added to 350 µ Blow buffer RL several times to fully crack it.Attention:1) Try to eliminate the cell culture medium as much as possible, as it may inhibit cell lysis and affect RNA production.2) Try to fully suspend and lyse the cells, otherwise it will affect RNA production.2. After the sample is fully lysed, it should be left at room temperature for 5 minutes to completely separate the protein nucleic acid complex.3. Centrifuge at 2000rpm for 2-5 minutes, take the supernatant and proceed to the next step.4. Add 1 volume (600) µ L or 350 µ l) Mix 70% ethanol (prepared without RNase water) well.Attention: Adding ethanol may cause precipitation and will not affect subsequent experiments.5. Add all the solution obtained in step 4 to the Spin Columns RM that has been loaded into the collection tube. If it is not possible to add all the solution to the adsorption column at once, please transfer it in two batches, centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column in the collection tube. Attention: The maximum loading capacity of the adsorption column is 100 µ g, do not overload, otherwise it will affect the yield and purity of RNA.6. Add 700 to the adsorption column µ Centrifuge at 12000 rpm for 1 minute, discard the waste liquid from the collection tube, and place the adsorption column in the collection tube.Optional steps: If conducting RNA experiments that are highly sensitive to trace amounts of DNA, replace step 6 with the following steps.1) Add 350 to the adsorption column µ L Buffer RW1, centrifuge at 12000 rpm for 15 seconds, discard the waste liquid, and place the adsorption column back into the recovery manifold.2) Preparation of DNase I mixture: Take 52 µ Add 8 RNase Free Water to it µ 10 x Reaction Buffer and 20 µ DNase I (1 U/ µ l) Mix well and prepare to a final volume of 80 µ The reaction solution of L.Attention: The above system is configured according to our company's DNase I reaction system. Please refer to the corresponding manual for other company products.3) Add 80 µ l of the prepared DNase I reaction solution directly to the adsorption column and incubate at 20-30 ℃ for 15 minutes.4) Add 350 to the adsorption column µ L Buffer RW1, centrifuge at 12000 rpm for 15 seconds, discard the waste liquid, and place the adsorption column back into the recovery manifold.7. Add 500 to the adsorption column µ Buffer RW2 (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column in the collection tube.8. Repeat step 7. 9. Centrifuge at 12000 rpm for 2 minutes and discard the waste liquid from the collection tube. Place the adsorption column at room temperature for a few minutes to thoroughly air dry.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).10. Place the adsorption column in a new RNase free centrifuge tube, and add 30-50 to the middle of the adsorption column in the air µ Place RNase Free Water at room temperature for 1 minute, centrifuge at 12000 rpm for 1 minute, collect RNA solution, and store RNA at -70 ℃ to prevent degradation.Attention:1) The volume of RNase Free Water should not be less than 30 µ l. Small volume affects the recovery rate.2) If you want to increase RNA production, you can use 30-50 µ Repeat step 10 for the new RNase Free Water.3) If you want to increase the RNA concentration, you can add the obtained solution back to the adsorption column and repeat step 10... 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 |