| 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 | Bacterial protein extraction reagents use mild non-ionic detergents and are suitable for extracting recombinant proteins expressed in Escherichia coli and insect cells. During the extraction process, there is no need for ultrasonic fragmentation, effectively avoiding contamination of exogenous Bacterial protein extraction reagents use mild non-ionic detergents and are suitable for extracting recombinant proteins expressed in Escherichia coli and insect cells. During the extraction process, there is no need for ultrasonic fragmentation, effectively avoiding contamination of exogenous proteins. This product can be applied to extract soluble proteins from bacterial lysates. The bacterial protein extraction kit adds a mixture of lysozyme, DNase I, and protease inhibitors to the extraction reagent, which can improve the efficiency of protein extraction and reduce the viscosity caused by DNA, effectively avoiding protein degradation. The extracted protein maintains biological activity and can be subjected to downstream operations such as IP, Western blot, and protein purification. Component B665764 100 preps Bacterial Protein Extraction Reagent 100 ml Protease Inhibitor Cocktail (100x) 1 ml Lysozyme （50 mg/ml） 200µl DNaseⅠ（1,000 U/ml） 100µl Notes:1. This product is suitable for extracting proteins from fresh or frozen bacterial and insect cells.2. This product uses Tris buffer system. Please use the same buffer system for protein purification after extraction.3. The protein lysis solution obtained from this product can be used for protein quantification using BCA or Bradford method.4. For special strains, if the extraction effect is not ideal, the sample can be frozen before protein extraction.5. Depending on the specific situation, protease inhibitors, salts, chelating agents, reducing agents, etc. can be added to this product.Operation steps: ● Insect cell protein extraction1. Collect cells by low-speed centrifugation. Add 10 to every 1 ml of Bacterial Protein Extraction Agent µ The Protein Inhibitor Cocktail is 1 x working fluid.2. Weigh the wet weight of the cells and add 1 x working solution at a rate of 10 ml/g.3. After resuspension, incubate on ice for 20 minutes (the ice storage time should be adjusted according to different cell types).Centrifuge at 4.15000 × g for 15 minutes to isolate soluble proteins. ● Extraction of soluble bacterial proteins 1. Centrifuge for 10 minutes at a rate of 5000 × g and collect the bacterial cells.2. Optional steps: Add 1 ml of Bacterial Protein Extraction Reagent every 1 ml µ DNase I (1000 U/ml), 2 µ Lysozyme (50 mg/ml) and 10 µ Protein Inhibitor Cocktail, vortex oscillation and mixing. 3. Add 20 ml of Bacterial Protein Extraction Reagent to each gram of bacterial precipitate, and add the extraction solution to the bacterial precipitate. Vortex thoroughly or use a pipette to blow up and down until the bacterial precipitate is completely resuspended.4. After resuspension, incubate at room temperature for 10-15 minutes (the storage time should be adjusted according to different cell types). 5. Centrifuge at 15000 × g for 5 minutes.6. Transfer the supernatant to a new centrifuge tube (the supernatant is soluble protein) for protein quantification and downstream experiments.Note: If the target protein exists in the form of inclusion bodies, inclusion body protein solution can be used for dissolution or expression conditions can be optimized to increase the expression of soluble proteins.Frequently asked questions: Problem Possible reasons Resolvent The target protein is insoluble The target protein is expressed as an inclusion body Optimize expression conditions or add Lysozyme and DNase I to protein extraction reagents using inclusion body protein solution After adding Lysozyme, the target protein has not been extracted yet Temperature too low Restore the reagent to room temperature After adding Lysozyme, the target protein has not been extracted yet Lysozyme Decreased or inactivated activity Add more Lysozymes or replace with new enzymes Extract has high viscosity DNase I Decreased or inactivated activity Add more DNase I or replace with a new DNase I to increase the final concentration of magnesium ions to 2 mM After protein extraction, most of the proteins still exist in the precipitate Excessive protein content Add Lysozyme and DNase I The protein extraction reagent has sediment precipitation Temperature too low Restore the protein extraction reagent to room temperature... Read More | Calcein AM /PI Double Staining Kitis utilized for simultaneous fluorescence staining of viable and dead cells. This kit contains Calcein-AM and Propidium Iodide (PI) solutions, which stains viable and dead cells, respectively(Fig. 1). Calcein-AM, an acetoxymethyl ester of calcein, is highly Calcein AM /PI Double Staining Kitis utilized for simultaneous fluorescence staining of viable and dead cells. This kit contains Calcein-AM and Propidium Iodide (PI) solutions, which stains viable and dead cells, respectively(Fig. 1). Calcein-AM, an acetoxymethyl ester of calcein, is highly lipophilic and cell membrane permeable. Though Calcein-AM itself is not a fluorescent molecule, the calcein generated from Calcein-AM by esterase in a viable cell emits a strong green fluorescence (excitationat 490 nm, emission at515 nm). Therefore, Calcein-AM only stains viable cells. On the other hand, PI, a nuclei staining dye, cannot pass through a viable cell membrane. It reaches the nucleus by passing through disordered areas of dead cell membrane, and intercalates with the DNA double helix of the cell to emit red fluorescence (excitation: 535 nm,emmision: 617 nm). Since both calcein and PI-DNA can be excited with 490 nm, simultaneous monitoring of viable and dead cells is possible with a fluorescence microscope. With 545 nm excitation, only dead cells can be observed (Fig. 1). Since optimal staining conditions differ from cell line to cell line, we recommend that a suitable concentration of PI and Calcein-AM be individually determined. Please note that PI is suspected to be highly carcinogenic;careful handling is required.Required Equipment and Materials:Microscope with 490 nm excitation filter and 530 nm emission filter；CO2incubator；10 µl and 200 µl adjustable pipettes, PBSSolution A (Calcein-AM)；Solution B (PI) Storage Condition: -20oC ；Shipping Condition: blue ice.Application:Assay Procedure1)Add 2.5 µl Solution A and 12.5 µl Solution B to 5 ml PBS to prepare assay solution.*2)Wash the cell with PBS several times to remove residual esterase activity.3)Add 100uLof assay solution to200uL105~106CELLSsolution and incubate the mixture at 37oC for 15 min.4)Detect fluorescence using a fluorescence mircoscope with 490 nm excitationfor simultaneous monitoring of viable and dead cells.With 545 nm excitation, only dead cells can be observed.*The following steps may be necessary tooptimizethe suitable concentration of each reagent:1)Prepare dead cells by 10 min incubation in 0.1% saponin or 0.1-0.5% digitonin or by 30 min incubation in 70% ethanol.2)Stain dead cells with 0.1-10 µM PI solution to find a PI concentration that stains the nucleus only, not the cytosol.3)Stain dead cells with 0.1-10 µM Calcein-AM solution to find a Calcein-AM concentration that does not stain the cytosol. Then stainviable cells with that Calcein-AM solution to check whether the viable cell can be stained... Read More | Product contentU665751Component100 TStorageU665751A2×UltraSYBR One Step Buffer1.4 mL-20℃. Avoid freeze/ Thaw cycle. Protect from light.U665751BUltraSYBR One Step EnzymeMix50 µL-20℃. Avoid freeze/ Thaw cycle. Protect from light.U665751C50×High ROX50 µL-20℃. AvoidProduct contentU665751Component100 TStorageU665751A2×UltraSYBR One Step Buffer1.4 mL-20℃. Avoid freeze/ Thaw cycle. Protect from light.U665751BUltraSYBR One Step EnzymeMix50 µL-20℃. Avoid freeze/ Thaw cycle. Protect from light.U665751C50×High ROX50 µL-20℃. Avoid freeze/ Thaw cycle. Protect from light.U665751DRNase-Free Water1.5 mL-20℃. Avoid freeze/ Thaw cycle. Product Introduction This product is a specialized kit for one-step Real-Time RT-qPCR. The SYBR Green I fluorescent dye contained can bind to all double-stranded DNA, allowing this product to be used for the detection of many different target sequences without the need to synthesize specific labeling probes. Real Time RT-qPCR reaction using this product, reverse transcription and quantitative PCR are carried out in the same reaction system, there is no need to add reagents during the reaction, no need to open the cap of the tube, avoiding contamination while improving the efficiency of the experiment. The new high-efficiency reverse transcriptase RNase H is activity-deficient, which reduces the degradation of RNA in the reverse transcription reaction. The enzyme has high reverse transcription efficiency and can perform a good reverse transcription reaction on a small amount of RNA template. It has high affinity to RNA and can read through RNA templates with high GC content and complex secondary structure. New efficient hot start enzyme, the enzyme activity is closed at room temperature, thus effectively avoiding non-specific amplification caused by non-specific binding of primers and templates or primer dimerization at room temperature, which greatly improves the accuracy of fluorescence quantitative PCR reaction. The included buffer system maximizes the efficacy of both enzymes at the same time and improves efficiency. This product has high sensitivity, high specificity, wide linear range, and more accurate quantification of target genes.ROX dye is used to correct the fluorescence signal error generated between wells of a quantitative PCR instrument, and is generally used with Real Time PCR amplifiers from ABI, Stratagene, and other companies. The excitation optics vary from instrument to instrument, so the concentration of ROX dye must be matched to the corresponding fluorescence quantitative PCR instrument. Instruments that do not require ROX calibration (U665567) Roche LightCycler 480, Roche LightCyler 96, Bio-rad iCyler iQ, iQ5, CFX96 and others. Instruments that require High ROX calibration (U665751) ABI Prism 7000/7300/7700/7900, Eppendorf, ABI Step One/Step One Plus, and others.matters needing attention1. Before using the reagents in this kit, please mix them gently by turning them up and down to avoid foaming as much as possible, and use them after brief centrifugation.2. This product uses RNA as the template for one-step RT-PCR experiment, RNase contamination should be avoided during operation, it is recommended to operate RNA in a special area, use special instruments and consumables, the operator with a mask and disposable gloves and often change the gloves, the experiment-related consumables should be processed with 0.1% DEPC (diethyl ether of pyrocarbonate) aqueous solution at 37℃ for 12 hours and autoclaved for 30 minutes before use. Sterilize for 30 minutes before use.3. UltraSYBR One Step RT-qPCR Buffer contains SYBR Green I fluorescent dye. Avoid bright light when storing this product or preparing PCR reaction solutions.4. Repeated freezing and thawing of each reagent in this kit should be avoided; repeated freezing and thawing may degrade the product performance. This product can be stored for a long time at -20℃, protected from light. If frequent use is required in the short term, it can be stored at 2-8℃.5. This kit must use specific primers, the choice of primers can be selected according to specific experiments, the good or bad primer design directly affects the results of RT-PCR reaction, the design of primers need to consider the GC content, primer length, primer position, the secondary structure of the PCR product and other factors, it is recommended to use a professional primer design software for design.6. This product cannot be used for fluorescent quantitative PCR by the probe method.Usage1. Dissolve RNA template, primers, 2× UltraSYBR One Step Buffer, UltraSYBR One Step EnzymeMix and RNase-Free Water and set aside on ice.2. PCR reaction system:Reagents25 µl Reaction systemFinal concentration2×UltraSYBR One Step Buffer12.5 µl1×Forward Primer，10 µM0.5 µl0.2 µM¹⁾Reverse Primer，10 µM0.5 µl0.2 µM¹⁾UltraSYBR One Step EnzymeMix0.5 µl RNA TemplateX µl10 pg – 100 ng50×Low ROX or High ROX（optional）2）0.5 µl1×RNase-Free Waterup to 25 µlNote: 1) Usually, the primer concentration of 0.2µM can get better results, and the final concentration of 0.1-0.5µM can be used as a reference for setting the range. If the amplification efficiency is not high, the concentration of primer can be increased; when non-specific reaction occurs, the concentration of primer can be decreased, thus optimizing the reaction system.(2) The excitation optical system varies from instrument to instrument, choose to add 50×Low ROX or 50×High ROX according to the instrument using fluorescence quantification.3. Vortex and shake to mix, centrifuge briefly, and collect the solution at the bottom of the tube.4. RT-qPCR reaction conditions (fluorescence quantitative PCR is a two-step method), this program is based on the ABI 7500 fluorescence quantitative PCR instrument as an exampleNote: 1) It is recommended to use two-step PCR reaction program, if you improve the reaction specificity, you can increase the annealing temperature to 60-64 ℃ as a reference for the setting range; if you do not get good experimental results due to the use of primers with lower Tm values, etc., you can try to carry out three-step PCR amplification.(2) For melting curve analysis, please set up the program recommended by the fluorescence quantitative PCR instrument used, and this program is set up with the ABI 7500 fluorescence quantitative PCR instrument as a reference.RT-qPCR reaction conditions (fluorescence quantitative PCR was a three-step method):Note: 1) For three-step PCR amplification, please use the range of 56℃-64℃ as the setting reference for the annealing temperature.(2) For melting curve analysis, please set up the program recommended by the fluorescence quantitative PCR instrument you are using, this program is ABI750 fluorescent quantitative PCR instrument as a reference setting... 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