| Description | Pyruvate phosphate dikinase (PPDK, EC 2.7.9.1) is a rate-limiting enzyme in the C4 pathway and Crassulacean acid metabolism (CAM) pathway. It catalyzes the three-step conversion of ATP, pyruvate, and Pi to phosphoenolpyruvate. This enzyme is primarily located in the chloroplast stroma of C4 plants Pyruvate phosphate dikinase (PPDK, EC 2.7.9.1) is a rate-limiting enzyme in the C4 pathway and Crassulacean acid metabolism (CAM) pathway. It catalyzes the three-step conversion of ATP, pyruvate, and Pi to phosphoenolpyruvate. This enzyme is primarily located in the chloroplast stroma of C4 plants and plays a crucial regulatory role in photosynthetic function. The assay measures PPDK activity based on its reverse reaction, which converts phosphoenolpyruvate, AMP, and PPi into pyruvate, ATP, and Pi. The generated pyruvate is then further catalyzed by lactate dehydrogenase (LDH) in the presence of NADH to produce lactate and NAD+. The rate of decrease in NADH absorbance at 340 nm is measured and used to calculate PPDK activity.Component100TStorageExtraction Buffer100 mL2-8℃Reagent 125 mL2-8℃Reagent 22 EA-20℃Reagent 3 40 µL2-8℃Note for Reagent 3: The volume is small. Briefly centrifuge the tube before use if the liquid is adhered to the wall.User-Prepared Instruments & Materials UV spectrophotometer or microplate reader, benchtop centrifuge, adjustable pipettes, micro quartz cuvette or 96-well plate, mortar, ice, and distilled water.Sample Preparation Homogenize the tissue sample on ice using a mortar and pestle in Extraction Buffer with a recommended ratio of 1:5 to 1:10 (tissue weight (g) : Extraction Buffer volume (mL)). (For example, weigh about 0.1 g of tissue and add 1 mL of Extraction Buffer). Centrifuge the homogenate at 8000 g, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.Assay Procedure1. Instrument Setup: Preheat the spectrophotometer or microplate reader for at least 30 minutes. Set the wavelength to 340 nm. Zero the instrument with distilled water.2. Sample Measurement:2.1 Working Solution Preparation: Just before use, add one vial of Reagent 2 to 10 mL of Reagent 1 and add 5 µL of Reagent 3. Mix thoroughly and incubate at 37°C for 5 minutes. Any unused solution should be aliquoted and stored at -20°C. Avoid repeated freeze-thaw cycles.2.2 Reaction Setup: Add 10 µL of the sample supernatant and 190 µL of the Working Solution into a micro quartz cuvette or a well of a 96-well plate. Mix immediately and record the initial absorbance value at 340 nm (A1). After incubating at 37°C for exactly 5 minutes, record the absorbance value again (A2). Calculate ΔA = A1 - A2. PPDK Activity Calculation 1. Calculation for Micro Quartz Cuvette Assay: 1.1 Based on Sample Protein Concentration: Unit Definition: One unit of enzyme activity is defined as the amount that consumes 1 nmol of NADH per minute per mg of protein. Formula: PPDK Activity (nmol/min/mg prot) = [ΔA × V total_reaction ÷ (ε × d) × 10⁹] ÷ (V sample × Cpr) ÷ T = 643 × ΔA ÷ Cpr 1.2 Based on Sample Fresh Weight: Unit Definition: One unit of enzyme activity is defined as the amount that consumes 1 nmol of NADH per minute per gram of fresh tissue. Formula: PPDK Activity (nmol/min/g fresh weight) = [ΔA × V total_reaction ÷ (ε × d) × 10⁹] ÷ (W × V sample ÷ V total_extract ) ÷ T = 643 × ΔA ÷ W 2. Calculation for 96-Well Plate Assay: 2.1 Based on Sample Protein Concentration: Unit Definition: One unit of enzyme activity is defined as the amount that consumes 1 nmol of NADH per minute per mg of protein. Formula: PPDK Activity (nmol/min/mg prot) = [ΔA × V total_reaction ÷ (ε × d) × 10⁹] ÷ (V sample × Cpr) ÷ T = 1286 × ΔA ÷ Cpr 2.2 Based on Sample Fresh Weight: Unit Definition: One unit of enzyme activity is defined as the amount that consumes 1 nmol of NADH per minute per gram of fresh tissue. Formula: PPDK Activity (nmol/min/g fresh weight) = [ΔA × V total reaction ÷ (ε × d) × 10⁹] ÷ (W × V sample ÷ V total extract ) ÷ T = 1286 × ΔA ÷ W Parameters Explanation: V total_reaction : Total reaction volume, 2×10⁻⁴ L ε: Molar extinction coefficient of NADH, 6.22×10³ L/mol/cm d: Light path (1 cm for micro cuvette; 0.5 cm for 96-well plate) V sample : Volume of sample supernatant added, 0.01 mL V total extract : Total volume of extraction buffer added, 1 mL T: Reaction time, 5 min Cpr: Sample protein concentration, mg/mL W: Sample mass, g Notes It is essential to perform a preliminary assay using 2-3 samples expected to have significant activity differences before formal testing... Read More | The bacterial viability / toxicity detection kit contains two fluorescent dyes. Nucgreen is a green nucleic acid dye that can stain live and dead bacteria; Ethd III is a red nucleic acid dye that only stains dead bacteria with damaged cell membranes. When nucgreen and ethd III are properly mixed, The bacterial viability / toxicity detection kit contains two fluorescent dyes. Nucgreen is a green nucleic acid dye that can stain live and dead bacteria; Ethd III is a red nucleic acid dye that only stains dead bacteria with damaged cell membranes. When nucgreen and ethd III are properly mixed, the bacteria with intact cell membrane appear green, while the bacteria with damaged cell membrane can appear green and red under different channels, respectively. A common criterion for bacterial viability is the ability to propagate in a suitable nutrient medium, known as a growth assay. This kit is generally in good agreement with the growth assay results in liquid or solid medium. However, under certain conditions, membrane damaged bacteria may recover and propagate in nutrient medium, and such bacteria will be identified as dead bacteria in this assay. On the contrary, some bacteria with intact membranes may not be able to propagate in nutrient medium, but will be recognized as viable bacteria in this assay. Therefore, if there is a large difference between the test results of this kit and the bacterial growth assay, the above possibilities should be considered. Component： Product parameters： NucGreen: Ex/Em = 503/530 nm (结合 DNA)；EthD-III: Ex/Em = 530/620 nm (结合 DNA)。Usage:1 Preparation of control samples for live and dead bacteria (optional)1. Cultivate 4 mL of bacteria in liquid medium until late logarithmic phase.2. Prepare two 1 mL bacterial solutions in an EP tube and centrifuge for 10-15 minutes under 5000-10000 g conditions.3. Remove the supernatant and add 0.3 mL of 0.85% NaCl resuspended bacteria to one of the EP tubes, and 1 mL of 0.85% NaCl resuspended bacteria to the other tube.4. Add 0.7 mL of isopropanol to a tube containing 0.3 mL of 0.85% NaCl, and mix thoroughly (with a final concentration of 70% isopropanol) to prepare a dead bacterial sample.5. Incubate the two samples at room temperature for 1 hour and mix every 15 minutes.6. Centrifuge the two samples at 5000-10000 g for 10-15 minutes.7. Remove the supernatant, add 1 mL of 0.85% NaCl to resuspend the bacteria in both samples, and centrifuge again as in step 6.8. Use a spectrophotometer to measure the absorbance values (OD670) of two bacterial suspensions at 670 nm.9. Adjust the density of the two bacterial suspensions (live and dead) to 108 bacteria/mL (OD670 ≈ 0.3), and then dilute with 0.85% NaCl at 1:100 to achieve a final density of 106 bacteria/mL.10. Mix two bacterial suspensions as shown in the table below to obtain the required live cell ratio: dead cell ratio.Table 1 Mix live and dead bacterial suspensions by a certain volume to achieve the required ratio of live and dead cellsLive cells: Dead cellsVolume of viable bacterial suspension（mL）Volume of dead bacterial suspension（mL）0:10001.010:900.10.920:800.20.830:700.30.750:500.50.5100:01.00II Staining methods for fluorescence microscopy observation1. Mix 1 volume of component A, NucGreen, and 2 volumes of component B, EthD-III, in a microcentrifuge tube. After thorough mixing, add 8 volumes of 0.85% NaCl solution to obtain a 100 x dye solution.2. Every 100 µ L bacterial suspension, add 1 µ 100 x dye solution of L.3. Mix thoroughly and incubate at room temperature in the dark for 15 minutes.4. Take 5 µ The bacterial suspension after L staining was dropped onto a glass slide with an 18 mm square cover glass.5. Observe under a fluorescence microscope. The fluorescence of live and dead bacteria can be observed simultaneously under any standard FITC long-acting filter. Alternatively, live (green fluorescent) and dead (red fluorescent) bacteria can be observed using FITC and Cy3 (or Texas Red) channels, respectively.Attention: (1) Before staining bacteria, attention must be paid to removing residues of growth media. Nucleic acid and other media components can bind to NucGreen and EthD-III dyes in some way, resulting in unacceptable staining changes. A simple washing step is usually sufficient to remove interfering media components from bacterial suspension. It is not recommended to use phosphate buffer solutions as they can reduce staining efficiency. (2) Before starting the formal experiment, the dye concentration should be adjusted to distinguish between NucGreen labeling live bacteria and EthD-III labeling dead bacteria. The optimal concentration may vary depending on the bacterial strain. It is generally best to use the lowest dye concentration that can provide sufficient signal. The above conditions have been optimized for staining live/dead cells of Escherichia coli.III Before starting the staining method experiment of flow cytometry, please read the precautions under the fluorescence microscope staining steps.According to Table 1, add 11 different proportions of live and dead bacteria to the EP tube. Each of the 11 samples has a volume of 1 mL.2. Add 12 µ The A component of L, NucGreen, and 24 µ The B component EthD-III of L was mixed in a microcentrifuge tube. Add 3 to each of the 11 samples µ Mix the mixed dyes of L thoroughly by blowing them up and down several times. (Note: Additional control bacterial samples need to be prepared for separate NucGreen and EthD-III staining)3. Incubate at room temperature in the dark for 15 minutes.4. Analyze each sample using a flow cytometer, detect NucGreen positive cells using FITC channels, and detect EthD-III positive cells using PI or PE channels.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. if the orifice plate is used for detection, a small amount of bacterial liquid can be left for imaging after standing for 10 min, which can effectively reduce the background. 3. in order to be closer to the real results, it is recommended to keep the brightness of red fluorescence consistent with that of green fluorescence in merge pictures. 4. fluorescent dyes have quenching problems. Please try to avoid light during experimental operation to slow down fluorescence quenching. 5. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Staining of dead and live bacteria... Read More | Products content Box 1: Circularization reagentC666001Component16 TStorageC666001ASplint Oligo20 µL-20℃.Avoid freeze/thaw cycle. C666001B5×Splint Buffer T4250 µL-20℃.Avoid freeze/thaw cycle. C666001CDNA Ligase50 µL-20℃.Avoid freeze/thaw cycle. C666001DDigestion Products content Box 1: Circularization reagentC666001Component16 TStorageC666001ASplint Oligo20 µL-20℃.Avoid freeze/thaw cycle. C666001B5×Splint Buffer T4250 µL-20℃.Avoid freeze/thaw cycle. C666001CDNA Ligase50 µL-20℃.Avoid freeze/thaw cycle. C666001DDigestion Buffer20 µL-20℃.Avoid freeze/thaw cycle. C666001EDigestion Enzyme I70 µL-20℃.Avoid freeze/thaw cycle. C666001FDigestion Enzyme III25 µL-20℃.Avoid freeze/thaw cycle. Box 2: Magnetic Beads for DNA Purification and RecoveryC666001Component16 TStorageC666001GCMPure4×1.5 mL2-8℃Products IntroductionThe Cyclization Kit is a modular kit tailored for the MGI high-throughput sequencing platform. With this kit, PCR products after junction ligation can be prepared into single-stranded circular DNA libraries suitable for MGI sequencers. All reagents provided in the kit have been subjected to stringent quality control and functional validation to maximize the stability and reproducibility of library construction. Provide your own instruments, reagents and consumables1. Magnetic frame: DynaMagTM-2 (Cat. No. 12321D) is recommended.2. "Qubit" 3.0 Fluorescence Quantimeter (ThermoFisher, Cat. No. Q33216)3. Qubit" ssDNA Assay Kit (Invitrogen, Cat. No. Q10212)4. Anhydrous ethanol, EB (10 mM Tris-HCl, pH 8.0), NF Water (pH between 7.0 and 8.0).5. reaction tubes: low adsorption PCR tubes with 1.5 mIEP tubes are recommended: 5.Tip: It is recommended to use a high quality filter tip to prevent contamination of kits and libraries. Pre-experiment Preparation and Important Notes 1. Sample preparation.PCR product: 2330 ng total (total amount when multiple PCR products are mixed) in a volume of 49 pL (if the volume of PCR product is insufficient, add NF Water to bring the total volume to 49 pl). -PCR product: Fragment size: The fragment peak is between 200-500 bp. -PCR product fragment size: Fragment peaks between 200-500 bp. -PCR product modification: Fixed sequences (with Index) for MGISEQ-2000, MGISEQ-200 and BGISEQ-500 sequencing platforms were added.2. Reagent preparation-Remove the corresponding reagents from the kit, centrifuge briefly, and place the enzyme mixture on ice until ready to use: buffers need to be dissolved at room temperature before use, then centrifuged with shaking and placed on ice until ready to use, and NF Water and EB are placed at room temperature until ready to use: "Please make up the mixture on ice:Precipitation may appear after the buffer in the kit is dissolved, the precipitation does not affect the function of the reagent, please shake and mix well until the precipitation disappears and then use. Schematic diagram of the cyclization process procedurecyclize 1. 1 wl of Splint Oligo was added to the 49JI PCR product. The product was denatured and incubated on a PCR instrument at 95°C for 3 min, then immediately transferred to an ice bath and allowed to stand for 2 min. 2. The reaction mixture was prepared on ice according to the following system. 3. Add 15ul of the above reaction mixture to 50µl of denatured DNA.4. Place the above PCR tubes on the PCR instrument under the following conditions Reaction. digest 1. Prepare the digestion reaction solution on ice according to the following system. 2. After the cyclization reaction, add 8l of digestion reaction solution directly to the cyclization system, mix well, centrifuge briefly and then place the PCR tube on the PCR instrument and react under the following conditions. 3. Purification was carried out immediately after the reaction.Purification of digestive products1. Remove CMPure at room temperature 30 minutes prior to use and mix well with shaking.2. Transfer the digested product to a 1.5 mIEP tube, pipette 340 pICMPure into the digested product, mix well by gently blowing 10 times with a pipette and incubate for 10 minutes at room temperature.3. Instantaneous centrifugation, place the EP tube on a magnetic rack and let stand for 5 minutes until the liquid is clear, pipette and discard the supernatant.4. Keep the EP tube fixed on a magnetic rack, add 250ul of freshly prepared 80% ethanol, let it stand at room temperature for 1 minute, then carefully discard the supernatant.5. Repeat step 4 once, try to suck up the liquid at the bottom of the tube: Note: Do not suck up the magnetic beads, so as not to affect the yield.6. Keep the EP tube fixed on the magnetic rack, open the cap and dry it at room temperature for 5-10 minutes.7. Remove the EP tube from the magnetic rack, add 35ul of EB or NF Water for DNA elution, pipette blow to mix and dissolve at room temperature for 10 min.8. Centrifuge instantaneously, place the EP tube on a magnetic rack and let stand for 2 minutes until the liquid is clarified, transfer the supernatant to a new EP tube. -Store at 20C and leave to prepare DNB... Read More | Products Content:F666101Component500 U5000 UStorageF666101AFastStar Probe Buffer (for bisDNA)2×1.2 mL2×12 mL-20℃. Avoid freeze/thaw cycle. Protect from light.F666101BSuperFastStar DNA Polymerase (5U/µL)100 µL1 mL-20℃. Avoid freeze/thaw cycle. Protect from light.Products Content:F666101Component500 U5000 UStorageF666101AFastStar Probe Buffer (for bisDNA)2×1.2 mL2×12 mL-20℃. Avoid freeze/thaw cycle. Protect from light.F666101BSuperFastStar DNA Polymerase (5U/µL)100 µL1 mL-20℃. Avoid freeze/thaw cycle. Protect from light.Products IntroductionThis product is mainly used for PCR using bisulfite-treated DNA as template, in which SuperFastStar DNA Polymerase is a new high-efficiency hot-start enzyme modified by bis-monoclonal antibody, which is completely blocked at room temperature, thus effectively avoiding non-specific amplification caused by the non-specific binding of the primer to the template or the primer dimerization under the condition of room temperature. The optimized FastStar Probe Buffer (for bisDNA) contains PCR Buffer, dNTPs and Mg2+, etc., which is easy to use as customers only need to add templates, primers and probes.caveat1 Before use, please mix the product gently by turning it up and down after it has been completely melted and centrifuged briefly.2. Avoid repeated freezing and thawing of the product, which may degrade its performance. This product can be stored at -20℃ for a long period of time, protected from light. If frequent use is required within a short period of time, it can be stored at 2-8℃.Usage The following examples are conventional PCR reaction systems and conditions, which should be improved and optimized according to the template, primer structure and target fragment size.1.PCR reaction system Note: 1) Usually, better results can be obtained with a primer concentration of 0.2 µM, and 0.1-1.0 µM can be used as a reference for setting the range.2）The concentration of the probe used is related to the fluorescence quantitative PCR instrument used, the type of probe, and the type of fluorescent labeling substance, so please refer to the instrument manual or the specific requirements for the use of each fluorescent probe to adjust the concentration.3）Usually the amount of DNA template is 10-100 ng of genomic DNA or 1-10 ng of cDNA as a reference. Since the templates of different species contain different copy numbers of the target gene, the templates can be diluted in gradients to determine the optimal amount of template to use.2.PCR reaction conditionsNote: 1) The initial denaturation of this product at 95°C for 30s is sufficient for enzyme activation; complex templates can be extended to 3min denaturation.(2) It is recommended to use two-step PCR reaction program, if you can't get good experimental results due to the use of primers with lower Tm value, etc., you can try three-step PCR amplification, and the annealing temperature should be set in the range of 56℃-64℃ as a reference... Read More | Ketone bodies, 3-hydroxybutyric acid (BOH) and acetoacetic acid (AcAc), are produced in the liver primarily from oxidation of fatty acids, and are normally present at low concentrations in urine and blood. Increased ketone concentrations in the blood may lead to metabolic acidosis, which has been Ketone bodies, 3-hydroxybutyric acid (BOH) and acetoacetic acid (AcAc), are produced in the liver primarily from oxidation of fatty acids, and are normally present at low concentrations in urine and blood. Increased ketone concentrations in the blood may lead to metabolic acidosis, which has been associated with diabetes, childhood hypoglycemia, growth hormone deficiency, alcohol or salicylate intoxication, and inborn errors of metabolism.Ketone Body Assay has been used to measure the release of ketone bodies in the human liver cancer cell line HepG2 culture medium... Read More |