| Description | Phosphoenolpyruvate Carboxykinase (PEPCK, EC 4.1.1.32) is widely present in animals, plants, microorganisms, and cells. It catalyzes the conversion of oxaloacetate to phosphoenolpyruvate and is a key regulatory enzyme in the gluconeogenesis pathway.Assay PrinciplePEPCK catalyzes the conversion of Phosphoenolpyruvate Carboxykinase (PEPCK, EC 4.1.1.32) is widely present in animals, plants, microorganisms, and cells. It catalyzes the conversion of oxaloacetate to phosphoenolpyruvate and is a key regulatory enzyme in the gluconeogenesis pathway.Assay PrinciplePEPCK catalyzes the conversion of Oxaloacetate to Phosphoenolpyruvate and CO₂. Pyruvate Kinase and Lactate Dehydrogenase subsequently catalyze the sequential oxidation of NADH to NAD⁺. The rate of decrease in NADH absorbance at 340 nm is measured, which reflects PEPCK activity.Component50TStorageAcidic Extraction Buffer60 mL2-8℃Reagent 145 mL2-8℃Reagent 241 µL2-8℃Reagent 31EA-20℃Reagent 41EA-20℃Required Materials and Equipment (Not Provided)UV spectrophotometer, benchtop centrifuge, adjustable pipettes, 1 ml quartz cuvette, mortar and pestle, ice, and distilled water.Sample Preparation:*Note: The provided sample-to-buffer ratios (1:1, w/v or based on cell count) using microliters (µl) are highly unusual and likely a typo in the original text. Standard protocols use milliliters (ml). The calculations also imply ml. The following protocol assumes the intended volumes are in milliliters (ml).*Bacteria or Cultured Cells:Collect cells by centrifugation and discard the supernatant.Add Acidic Extraction Buffer at a ratio of 1 ml per 5-10 million cells (e.g., 1 ml for 5 million cells).Sonicate on ice (20% power or 200W, pulse 3s on/10s off, repeat 30 times).Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.Tissues:Homogenize tissue on ice in Acidic Extraction Buffer at a ratio of 1:5-10 (w/v) (e.g., 0.1 g tissue in 1 ml buffer).Centrifuge at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.Serum (or Plasma) Samples:Assay directly.Assay Procedure:Preheat the spectrophotometer for at least 30 minutes. Set the wavelength to 340 nm. Zero the instrument with distilled water.Preparation of Working Solution: Just before use, transfer and dissolve Reagent 2 and Reagent 3 into Reagent 1. Mix well. Aliquot and store any unused portions at -20°C. Avoid repeated freeze-thaw cycles.Preparation of Reagent 4: Just before use, dissolve the contents of the vial in 2.5 mL of distilled water. Mix well. Aliquot and store any unused portions at -20°C. Avoid repeated freeze-thaw cycles.Pre-warm the Working Solution and dissolved Reagent 4 at 37°C (for mammalian samples) or 25°C (for other species) for 5 minutes.In a 1 ml quartz cuvette, add:50 µl sample50 µl dissolved Reagent 4900 µl pre-warmed Working SolutionMix immediately and record the initial absorbance (A₁) at 340 nm. Record the absorbance again (A₂) after exactly 1 minute. Calculate ΔA = A₁ - A₂.Note: For this kit, if ΔA is greater than 0.1, dilute the sample with Acidic Extraction Buffer by an appropriate factor (account for this dilution factor 'n' in the calculations) so that ΔA is less than 0.1 to improve detection sensitivity.PEPCK Activity Calculation:General Parameters for 1 ml Cuvette (d = 1.0 cm):Vₜₒₜₐₗ (Total reaction volume) = 0.001 L (1000 µL)ε (NADH molar extinction coefficient) = 6220 L/mol/cmd (Cuvette light path) = 1.0 cmVₛₐₘₚₗₑ (Sample volume in reaction) = 0.05 mL (50 µL) [Note: Corrected from 0.05µL, which is implausible]T (Reaction time) = 1 minVₛₐₘₚₗₑₜₒₜₐₗ (Total extract volume) = 1 mL (for tissues/cells) [Note: Corrected from 1µL]Cpr (Sample protein concentration, mg/mL) [Note: Corrected from mg/µL]W (Sample mass, g)500 (Cell/Bacteria count in millions for example calculation: 5 million)1. For Serum (Plasma):Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per ml of serum.Calculation:PEPCK Activity (nmol/min/ml) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ Vₛₐₘₚₗₑ ÷ TSimplified Formula: PEPCK (nmol/min/ml) = 3215 × ΔA2. For Tissues, Bacteria, or Cells:Based on Sample Protein Concentration:Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per mg of protein.Calculation:PEPCK Activity (nmol/min/mg prot) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (Vₛₐₘₚₗₑ × Cpr) ÷ TSimplified Formula: PEPCK (nmol/min/mg prot) = 3215 × ΔA ÷ CprBased on Sample Fresh Weight:Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per gram of fresh tissue.Calculation:PEPCK Activity (nmol/min/g fresh weight) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (W × Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ) ÷ TSimplified Formula: PEPCK (nmol/min/g fresh weight) = 3215 × ΔA ÷ WBased on Bacterial or Cell Density:Definition: One unit of activity is defined as the amount of enzyme that consumes 1 nmol of NADH per minute per 10⁴ cells.Calculation (example for 5 million cells in 1 ml extract):PEPCK Activity (nmol/min/10⁴ cell) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (500 × Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ) ÷ TSimplified Formula: PEPCK (nmol/min/10⁴ cell) = 6.43 × ΔAPrecautionsBefore formal assay, it is essential to perform a pilot test with 2-3 samples expected to have significant differences in activity... Read More | Inquire | DescriptionPhoto KitAlysis Starter Kit enables screening of 24 micro-scale simultaneous photocatalytic reactions with consistent and reproducible photon intensity. User guide is provided in the below hyperlink.Photo KitAlysis Operating InstructionsComponents:Photo KitAlysis LED ControllerBlue LED DescriptionPhoto KitAlysis Starter Kit enables screening of 24 micro-scale simultaneous photocatalytic reactions with consistent and reproducible photon intensity. User guide is provided in the below hyperlink.Photo KitAlysis Operating InstructionsComponents:Photo KitAlysis LED ControllerBlue LED Array (470 nm)Photo KitAlysis Reaction BlockTorque screwdriverSmall screwdriver to easily remove torqued screws after reaction is completeFeatures:Designed and tested by synthetic chemists.Controller provides repeatable milliamp selection for photon intensity0-30 mA variable LED output3 different LED options: blue (470 nm, included), green (527 nm, sold separately), and white (sold separately)Non-magnetic LED baseChemically resistant LED coverPTFE coated cablingDesigned to be used withPhoto KitAlysis High-Throughput Reaction Screening Kit(sold separately).Best when used withKitAlysis Benchtop Inertion Box(sold separately)... 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 | Products contentProducts IntroductionThis kit is suitable for simple, rapid and efficient isolation and purification of DNA/RNA from whole blood, tissue homogenates, swabs, serum, plasma and other cell-free body fluids, etc. The unique buffer system enables the viral nucleic acids in the lysate to Products contentProducts IntroductionThis kit is suitable for simple, rapid and efficient isolation and purification of DNA/RNA from whole blood, tissue homogenates, swabs, serum, plasma and other cell-free body fluids, etc. The unique buffer system enables the viral nucleic acids in the lysate to bind to the silica gel centrifugal adsorbent columns in a highly efficient manner, and the viral nucleic acids obtained are of high purity and stable quality, free of protein, nuclease and other impurities, and can be used in a variety of routine operations, including PCR, fluorescence quantitative PCR and other experiments. It can be used for a variety of routine operations, including PCR, fluorescence quantitative PCR and other experiments.Bring your own instrumentsThermostatic mixer.Pre-experiment Preparation and Important Notes1. Read these instructions carefully before experimenting.2. If Proteinase K is to be stored for a long period of time, please keep it at -20℃.3. Check Buffer RLC for crystallization or precipitation prior to use, and if crystallization or precipitation occurs, redissolve Buffer RLC in a 56°C water bath.4. Pre-treatment of tissue samples: Take 20 mg of tissue samples into 1.5 mL centrifuge tubes (self-provided), add 500 µL of Buffer RLC, and after the tissue homogenizer breaks up, centrifuge the samples for 1 minute at 12,000 rpm (~13,400×g), and take 200 µL of supernatant as samples. procedure1. Take a 1.5 mL centrifuge tube (provided), add 500 µL of Buffer RLC, 200 µL of sample, 20 µL of Proteinase K, vortex for 5 s, and then place it in a thermostatic mixer at 1200 rpm for 10 min at room temperature. Note: For wet swab samples, 200 µL of sample was taken after sufficiently shaking and mixing. Note: For wet swabs, 200 µL was taken from the sample after it was soaked in 400 µL of saline, shaken and mixed thoroughly for 5 minutes, and then centrifuged at 12,000 rpm for 1 minute, and 200 µL was taken for extraction.2. Instantly remove the centrifuge tube and add the solution from step 1 to the Spin Columns DM in the collection tube. centrifuge at 12,000 rpm (~13,400 x g) for 1 minute, pour off the waste liquid from the collection tube, and return the column to the collection tube.3. Add 500 µL of Buffer PGWT to the adsorbent column, centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid from the collection tube, and return the column to the collection tube.4. Add 500 µL of Buffer GWT2 to the adsorbent column, centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid from the collection tube, and return the column to the collection tube.5. Centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Place the adsorption column at room temperature for 2 minutes and allow to dry.6. Place the column in a new collection tube (RNase-Free Centrifuge Tube), add 40-100 µL of RNase-Free Water to the center of the column membrane, let it stand at room temperature for 2 minutes, and then centrifuge at 12,000 rpm for 1 minute to collect the nucleic acid solution. Store at -80℃ for a long time... Read More |