| Description | The carbon nutritional status in plants and the quality characteristics of agricultural products are often evaluated using sugar content as an important indicator. Monosaccharides and some oligosaccharides (such as maltose) contain free aldehyde or ketone groups, possess reducibility, and are The carbon nutritional status in plants and the quality characteristics of agricultural products are often evaluated using sugar content as an important indicator. Monosaccharides and some oligosaccharides (such as maltose) contain free aldehyde or ketone groups, possess reducibility, and are classified as reducing sugars. Polysaccharides and sucrose are non-reducing sugars. The total sugar content can be determined by measuring the monosaccharide content after hydrolysis, utilizing the property that non-reducing sugars can be hydrolyzed to monosaccharides by acid.Detection Principle: Reducing sugars are oxidized to sugar acids under alkaline heating conditions, while 3,5-dinitrosalicylic acid (DNS) is reduced to a brownish-red amino compound. Within a certain range, the amount of reducing sugar is proportional to the color intensity of the brownish-red product. The absorbance of this brownish-red substance is measured at 540 nm using a microplate reader. This absorbance value has a linear relationship with the reducing sugar content. The reducing sugar and total sugar content in the sample are calculated using a standard curve.This kit is for scientific research use only and is not intended for clinical diagnosis or other purposes.P1501777Component100T300TStorageP1501777AGlu Standard (1 mg/mL)1 mL1 mL2-8℃P1501777BDNS Detection Solution10 mL30 mLRT. Store in the dark.P1501777CColor Solution (for Total Sugar)5 mL10 mLRT. Store in the dark.User-Prepared Instruments and Reagents1. Distilled water, Hydrochloric acid solution, Sodium hydroxide solution2. 50 mL centrifuge tubes, 1 mL centrifuge tubes, Centrifuge, Water bath or incubator, Microplate reader, 96-well plate, Water bathExperimental Procedure1. Extraction of Reducing Sugars1.1 Weigh 0.5-3 g of plant sample, cut into pieces, add about 3 mL of distilled water and homogenize. Transfer to a beaker or conical flask. Rinse the grinder 2-3 times with 12 mL of distilled water and transfer the rinsate to the same container.1.2 Incubate in a 50°C water bath for 30 min, stirring occasionally to ensure thorough extraction of reducing sugars.1.3 Transfer the precipitate and extract to a 50 mL centrifuge tube. Centrifuge at 4000 g for 5 min.1.4 Collect the supernatant. Add 20 mL of distilled water to the precipitate, mix well, and centrifuge again at 4000 g for 5 min.1.5 Collect the supernatant. Combine the supernatants from the two steps. Dilute to 100 mL with distilled water (this is the extract). Mix well. This serves as the test solution for reducing sugars.2. Hydrolysis and Extraction of Total Sugars2.1 Weigh 0.5-3 g of plant sample, cut into pieces, add about 3 mL of distilled water and homogenize. Transfer to a beaker or conical flask. Rinse the grinder 2-3 times with 12 mL of distilled water and transfer the rinsate to the same container.2.2 Add 10 mL of 6 M hydrochloric acid solution to the container, mix well, then heat in a boiling water bath for 30 min for hydrolysis, stirring occasionally.2.3 Take 2 drops and place on a glass slide, add 1 drop of Color Solution (about 50 µL) to check if hydrolysis is complete. If hydrolysis is complete, no blue color should develop.2.4 After hydrolysis, cool to room temperature. Add 6 M sodium hydroxide solution to adjust the pH to 7.4. Dilute to 100 mL with distilled water, mix well. Centrifuge at 4000 g for 5 min or filter.2.5 Take 10 mL of the supernatant or filtrate and dilute to 100 mL with distilled water, creating a 10-fold diluted total sugar hydrolysate (extract). Take 50 µL of this total sugar hydrolysate to measure its reducing sugar content.3. Glucose Standard PreparationTake clean centrifuge tubes or test tubes and prepare a series of Glu standards according to the table below.Standard Working SolutionGlu Standard (1 mg/mL) (mL)Distilled Water (mL)Concentration (mg/mL)10.010.040.220.020.030.430.030.020.640.040.010.850.0501.04. Assay SetupTake 1 mL centrifuge tubes. Set up Blank, Standard, and Test wells according to the table below. Add solutions sequentially, avoiding bubbles. Mix carefully. If the sugar concentration in the sample is too high, reduce the sample volume or dilute appropriately before assay. It is best to set up 2-3 replicate wells for samples and take the average.Reagent (µL)Blank WellStandard WellTest WellDistilled Water50//Glu Standard (1-5)/50/Extract//50DNS Detection Solution100100100Heat accurately in a boiling water bath for 5 min. Remove, cool to room temperature with tap water. Add 250 µL distilled water.5. Reducing Sugar MeasurementMix well. Transfer 300 µL sequentially to the corresponding wells of a 96-well plate. Measure the absorbance of Standard and Test wells at 540 nm, using the Blank well to zero the instrument.6. Result Calculation6.1 Standard Curve PlottingUsing the Glu standards (1-5), i.e., the standard glucose concentrations (mg/mL) as the x-axis and the corresponding absorbance values as the y-axis, plot the standard curve. Find the corresponding glucose concentration on the standard curve based on the absorbance of the extract.6.2 Content CalculationPercentage Content of Reducing Sugars:Reducing sugar content per 100 g sample (g) = (c × V T ) / (m × 1000) × 100 = (c × V T ) / (m × 10)Percentage Content of Total Sugars:Total sugar content per 100 g sample (g) = (c × N × V T ) / (m × 1000) × 100 × 0.9 = (c × N × V T ) / (m × 10) × 0.9Parameter Descriptionc: Sugar amount found from the standard curve (mg/mL)V T : Total volume of the extract, 100 mLm: Mass of the plant sample, gN: Dilution factor of the total sugar hydrolysate, 10Precautions1. Avoid repeated freeze-thaw cycles for the aforementioned low-temperature reagents to prevent inactivation or decreased efficiency.2. If test samples cannot be assayed immediately, store at 2-8°C; stable for 3 days.3. If the sample reducing sugar concentration is too high, dilute with distilled water and re-assay, multiplying the result by the dilution factor.4. The total sugar calculation formula is used when there are few interfering impurities and the reducing sugar content is relatively small compared to the total sugar content. Multiplying by 0.9 accounts for the water consumed during the hydrolysis of total sugars to monosaccharides.5. 6 M Hydrochloric Acid Preparation: Generally, commercially available concentrated hydrochloric acid is 11.6-12 M. Mix concentrated hydrochloric acid with distilled or deionized water 1:1 (v/v) to prepare 6 M HCl. Caution: Hydrochloric acid dissolution in water releases heat; handle carefully to avoid injury.6. 6 M Sodium Hydroxide Preparation: Dissolve 24 g of sodium hydroxide in distilled or deionized water, make up to 100 mL. Caution: Sodium hydroxide dissolution in water releases heat; handle carefully to avoid injury.7. Use reagents promptly after opening to avoid affecting subsequent experimental results... Read More | Product Content D669986Component50 TStorageD669986ABuffer SA15 mLRTD669986B2×PCR MasterMix1 mL-20℃. Avoid freeze/thaw cycle.D669986CProteinase K12.5 mgRTD669986DProteinase K Storage Buffer1.25 mLRTProductsThis kit adopts a unique buffer system containing all the reagents for rapid Product Content D669986Component50 TStorageD669986ABuffer SA15 mLRTD669986B2×PCR MasterMix1 mL-20℃. Avoid freeze/thaw cycle.D669986CProteinase K12.5 mgRTD669986DProteinase K Storage Buffer1.25 mLRTProductsThis kit adopts a unique buffer system containing all the reagents for rapid preparation of genomic DNA and PCR amplification, and is suitable for one-step extraction of genomic DNA from various plant and animal tissues and bacteria and for PCR amplification. The whole extraction process does not require liquid nitrogen grinding, organic solvent extraction, anhydrous ethanol precipitation, and the quality of extracted DNA is stable. The 2×PCR MasterMix provided in this kit is a highly compatible PCR reagent that can amplify DNA samples efficiently and specifically, which includes DNA polymerase, dNTPs, MgCl2, reaction buffer, PCR reaction enhancer and so on. It is characterized by fast and easy, high sensitivity, high specificity, good stability, etc. It is especially suitable for high throughput screening.Pre-experiment Preparation and Important Notes1. Add the specified amount of Proteinase K Storage Buffer to Proteinase K to dissolve it and store it at -20℃. Do not leave the prepared Proteinase K at room temperature for a long time, and avoid repeated freezing and thawing to avoid affecting its activity.2. Repeated freezing and thawing of the samples should be avoided, as this will result in smaller DNA fragments and a decrease in the amount of extracted DNA.3. Before use, please check Buffer SA for crystallization or precipitation. If crystallization or precipitation occurs, please re-dissolve Buffer SA in a 56℃ water bath.4. The PCR MasterMix provided with this product is 2×, when using it, you need to add template and primer, and add RNase-Free Water to make up the volume, so that its concentration is 1× to carry out the reaction.Procedure1. Fetch:Plant material: take about 10 mg of sample in a centrifuge tube (provided); Animal material: take about 10 mg of sample in a centrifuge tube (provided);Bacteria: Take 200-800 µL of bacteria in good growth condition in a centrifuge tube (self-provided) and collect the bacteria.2. Add 200 µL of Buffer SA and vortex to mix.Note: In the case of plant leaves and animal tissues, they should be ground with a pestle and mortar as much as possible: in the case of plant seeds, they should be crushed and finely ground beforehand; bacterial and 1-3 mm rat-tail samples can be directly vortex lysed.3. Add 10µL of Proteinase K, mix well, incubate at 56℃ for 10 minutes, and treat at 95℃ for 5 minutes.Note: 1) In the case of animal tissue samples, the incubation time at 56°C may be extended to 30 minutes as appropriate; if there is any incompletely digested tissue, it should be removed as thoroughly as possible after centrifugation in the next step.2) Be careful not to exceed 5 minutes when treating at 95°C.4. 13,000 rpm (~17,900 x g), centrifugation for 5 minutes.5. Transfer the supernatant to a new centrifuge tube (self-prepared) and use it directly for PCR amplification, or store the solution at 4℃ or -20℃.6. PCR amplification:1) PCR reaction system:The following examples are conventional PCR reaction systems and reaction conditions, which should be improved and optimized according to the template, primer structure and target fragment size in actual operation.reagents20 µL systemfinal concentration2×PCR MasterMix10 µL1×Forward Primer, 10 µM1 µL0.4 µMReverse Primer, 10 µM1 µL0.4 µMTemplate DNA1-2 µL RNase-free Waterup to 20 µLNote: Please use the final concentration of 0.2-0.6µM as a reference for setting the range of primer concentration. If the amplification efficiency is not high, the concentration of primer can be increased; if a non-specific reaction occurs, the concentration of primer can be decreased, thus optimizing the reaction system.2）PCR reaction conditions:movetemptimingpremutability94°C2mindenaturation94°C30sannealing (metallurgy)55-65°C30s30-40 cyclesreach72°C60sultimate extension72°C5minNote: 1) In general, the annealing temperature is 5℃ lower than the melting temperature of the amplification primer Tm, and the annealing time is generally 30-60 seconds. When the desired amplification efficiency cannot be obtained, the annealing temperature should be lowered appropriately; when a non-specific reaction occurs, the annealing temperature should be raised, thus optimizing the reaction conditions.(2) The extension time is set according to the size of the fragment to be amplified, and the amplification efficiency of Taq DNA Polymerase included in this product is 1kb/30s. 3) The number of cycles can be set according to the downstream application of the amplification product. If the number of cycles is too low, the amplification is insufficient; if the number of cycles is high, the chance of mismatch will increase and the non-specific background will be serious. Therefore, the number of cycles should be minimized under the premise of ensuring the product yield.(3) Result detection: 5 µL of reaction product was taken at the end of the reaction and directly detected by agarose gel electrophoresis... Read More | DescriptionMetathesis: Ruthenium-Based Metathesis CatalystsRuthenium metathesis catalysts kit I consists of 9 samples of Grubbs 1st and 2nd generation catalysts. These catalysts have applications in ring-closing and ring-opening metathesis, cross-metathesis, ring-opening metathesis polymerization (DescriptionMetathesis: Ruthenium-Based Metathesis CatalystsRuthenium metathesis catalysts kit I consists of 9 samples of Grubbs 1st and 2nd generation catalysts. These catalysts have applications in ring-closing and ring-opening metathesis, cross-metathesis, ring-opening metathesis polymerization (ROMP) and enyne metathesis.Metathesis: Ruthenium-Based Metathesis Catalysts... 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 | Inquire |