| Description | NAD Kinase (NADK, EC 2.7.1.23) is widely present in animals, plants, microorganisms, and cultured cells. It is the only known enzyme that catalyzes the phosphorylation of NAD⁺ to NADP⁺ in vivo. It can utilize ATP or inorganic polyphosphate [poly(P)] as a phosphoryl donor to catalyze the NAD Kinase (NADK, EC 2.7.1.23) is widely present in animals, plants, microorganisms, and cultured cells. It is the only known enzyme that catalyzes the phosphorylation of NAD⁺ to NADP⁺ in vivo. It can utilize ATP or inorganic polyphosphate [poly(P)] as a phosphoryl donor to catalyze the phosphorylation of NAD(H), generating NADP(H). Therefore, NADK plays a crucial role in synthesizing NADP(H) and regulating the balance between NAD(H) and NADP(H).Assay PrincipleNADK catalyzes the phosphorylation of NAD⁺ to generate NADP⁺. The generated NADP⁺ is then reduced to NADPH by Glucose-6-Phosphate Dehydrogenase (G6PDH). The rate of increase in NADPH, measured by the rise in absorbance at 340 nm, reflects the activity of NADK.Component50TStorageExtraction Buffer50 mL2-8℃Reagent 125 mL2-8℃Reagent 250 mL2-8℃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 Preparation1.Bacteria, Cells, or Tissues:Bacteria or Cultured Cells: Collect cells by centrifugation and discard the supernatant. Add 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.Tissues: Homogenize tissue on ice in Extraction Buffer at a ratio of 1:5-10 (w/v) (e.g., 0.1 g tissue in 1 ml buffer). Centrifuge the homogenate at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice.2.Serum (or Plasma) Samples: Assay directly.Assay Procedure:1.Preheat the spectrophotometer for at least 30 min. Set wavelength to 340 nm. Zero with distilled water.2.Pre-warm Reagent 1 and Reagent 2 at 37°C (for mammalian samples) or 25°C (for other species) for at least 15 min.3.Working Solution I Preparation: Add 12 mL of Reagent 1 to the contents of Reagent 3. Mix thoroughly. Aliquot and store unused portions at -20°C. Avoid repeated freeze-thaw cycles.Working Solution II Preparation: Add 45 mL of Reagent 2 to the contents of Reagent 4. Mix thoroughly. Aliquot and store unused portions at -20°C. Avoid repeated freeze-thaw cycles.4.Assay Setup:ReagentTest Tube (µL)Control Tube (µL)Sample100100Working Solution I400Reagent 1400Mix thoroughly. Incubate at 37°C (mammalian) or 25°C (other species) for 15 min.Immediately boil for 2 min (tighten caps to prevent evaporation).Cool on ice.Centrifuge at 10,000 g, 25°C for 10 min. Collect the supernatant.5.Detection:ReagentVolume (µL)Supernatant (from step 4)200Working Solution II800Add reagents to a new tube or cuvette. Mix thoroughly after addition.Let the reaction stand at room temperature for 15 min.Measure the absorbance at 340 nm.Calculate ΔA = ATest - AControl.NADK Activity Calculation:General Parameters:VTotal (Total reaction volume for detection step) = 5 × 10⁻⁴ L (0.5 mL = 500 µL)ε (NADPH molar extinction coefficient) = 6.22 × 10³ L/mol/cmd (Cuvette light path) = 1 cmVSample (Sample volume in initial reaction) = 0.1 mL (100 µL)VSample Total (Total extraction volume) = 1 mLT (Reaction time for NADK enzyme step) = 15 minCpr (Sample protein concentration, mg/mL)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 generates 1 nmol of NADP⁺ per minute per ml of serum.Calculation:NADK Activity (nmol/min/ml) = [ΔA × VTotal ÷ (ε × d) × 10⁹] ÷ VSample ÷ TSimplified Formula: NADK (nmol/min/ml) = 53.59 × ΔA2. For Tissues, Bacteria, or Cells:a. Based on Sample Protein Concentration:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADP⁺ per minute per mg of protein.Calculation:NADK Activity (nmol/min/mg prot) = [ΔA × VTotal ÷ (ε × d) × 10⁹] ÷ (VSample × Cpr) ÷ TSimplified Formula: NADK (nmol/min/mg prot) = 53.59 × ΔA ÷ Cprb. Based on Sample Fresh Weight:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADP⁺ per minute per gram of fresh tissue.Calculation:NADK Activity (nmol/min/g fresh weight) = [ΔA × VTotal ÷ (ε × d) × 10⁹] ÷ (W × VSample / VSample Total) ÷ TSimplified Formula: NADK (nmol/min/g fresh weight) = 53.59 × ΔA ÷ Wc. Based on Bacterial or Cell Density:Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADP⁺ per minute per 10⁴ cells.Calculation (example for 5 million cells in 1 ml extract):NADK Activity (nmol/min/10⁴ cell) = [ΔA × VTotal ÷ (ε × d) × 10⁹] ÷ (500 × VSample / VSample Total) ÷ TSimplified Formula: NADK (nmol/min/10⁴ cell) = 0.107 × ΔAPrecautionsBefore formal assay, it is essential to perform a pilot test with 2-3 samples expected to have significant differences in activity... 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 | Inquire | D-Lactate, typically present in the bloodstream at nanomolar concentrations, is produced by an intestinal source or via the methylglyoxal pathway. In mammals, D-Lactate metabolism requires D-Lactate hydrogenase and is metabolized slowly, thus an increase in blood concentration levels can lead to D-Lactate, typically present in the bloodstream at nanomolar concentrations, is produced by an intestinal source or via the methylglyoxal pathway. In mammals, D-Lactate metabolism requires D-Lactate hydrogenase and is metabolized slowly, thus an increase in blood concentration levels can lead to acidemia and acidosis. The severity of this D-lactic acidosis can be associated with neurotoxic symptoms. Significant D-Lactate accumulations in the body can also be related to impaired metabolism and excretion.D-Lactate Colorimetric Assay kit has been used to determine the stereospecificity of lactate produced.Suitability: Suitable for use with samples of serum, plasma, cells, culture and fermentation media.Principle: In this assay, D-Lactate is specifically oxidized by D-Lactate hydrogenase and generates a proportional colorimetric product measured at 450 nm. The useful concentration range in samples is 0.1-10 mM D-Lactate... Read More | R669988 Component 50T Storage R669988A DNase I 1000 U -20℃. Avoid freeze/thaw cycle. R669988B 10×Reaction Buffer 1000 µL -20℃. Avoid freeze/thaw cycle. R669988C Buffer RL 35 mL RT R669988D Buffer RLC 35 mL RT R669988E Buffer RW1 40 mL RT R669988F Buffer RW2 (concentrate) 11 mL R669988 Component 50T Storage R669988A DNase I 1000 U -20℃. Avoid freeze/thaw cycle. R669988B 10×Reaction Buffer 1000 µL -20℃. Avoid freeze/thaw cycle. R669988C Buffer RL 35 mL RT R669988D Buffer RLC 35 mL RT R669988E Buffer RW1 40 mL RT R669988F Buffer RW2 (concentrate) 11 mL RT R669988G RNase-Free Water 10 mL RT R669988H Spin Columns FL with Collection Tubes 50 sets RT R669988I Spin Columns RM with Collection Tubes 50 sets RT R669988J RNase-Free Centrifuge Tubes (1.5 mL) 50 EA RTProductsThis kit is used for the extraction and purification of high-quality total RNA from a variety of plants, and is also suitable for the extraction of fungal mycelial RNA. The unique separation column is used for homogenization and filtration of high viscosity plant or fungal lysates, while the silicon matrix membrane is used to adsorb the RNA for purification, so that various contaminants, such as polysaccharides, are effectively removed by washing, and the eluted RNA can be directly used in various downstream experiments. The molecular weight of RNA extracted by this kit is more than 200 bases, with high purity and almost no DNA residue. For RNA experiments that are very sensitive to trace DNA, the residual DNA can be removed by digestion on a column using RNase-free DNase. The extracted RNA can be used in Northern Blot, Dot Blot, RT-PCR and in vitro translation experiments.Self-contained reagents: β-mercaptoethanol, anhydrous ethanol (freshly opened or for RNA extraction).Pre-experiment Preparation and Important Notes1. To prevent RNase contamination, attention should be paid to the following aspects:1) Use RNase-free plastics and tips to avoid cross-contamination.2) RNase-free water should be used to prepare the solution.(3) Operators wear disposable masks and gloves, and change gloves diligently during the experiment.2. To prevent RNase contamination, attention should be paid to the following aspects:1) Use RNase-free plastics and tips to avoid cross-contamination.(2) Glassware should be dry-roasted at 180°C for 4 hours before use, and plasticware can be soaked in 0.5M NaOH for 10 minutes, rinsed thoroughly with water and autoclaved.3) RNase-free water should be used to prepare the solution.(4) Operators wear disposable masks and gloves, and change gloves diligently during the experiment.3. Avoid repeated freezing and thawing of the extracted samples, otherwise it will affect the amount and quality of RNA extraction.4. Please add β-mercaptoethanol to Buffer RL before use, add 10µl of β-mercaptoethanol to 1ml of Buffer RL, it can be stored for 1 month at room temperature. Buffer RL with β-mercaptoethanol can be stored at room temperature for 1 month. β-mercaptoethanol is not required for use of Buffer RLC.5. Anhydrous ethanol should be added to Buffer RW2 before first use according to the instructions on the reagent bottle label.6. If precipitation occurs in Buffer RL and Buffer RLC, heat to dissolve and leave at room temperature.7. All centrifugation steps are carried out at room temperature and all steps are performed quickly. Procedure1. 50-100 mg of plant tissue is quickly ground to a powder in liquid nitrogen and added to 600 µl of Buffer RL (check for addition of β-mercaptoethanol before use) or Buffer RLC. vortexing and oscillating to allow for adequate lysis.Note: 1) The main component of Buffer RL is guanidine isothiocyanate, which is suitable for lysis of most plant tissues. However, in some plant tissues (e.g. endosperm of corn), due to the special secondary metabolites, guanidine isothiocyanate causes precipitation of the sample, resulting in poor RNA extraction, in this case, Buffer RLC can be added instead of Buffer RL.2) Incubation at 56°C for 1-3 minutes helps tissue lysis, but do not incubate at high temperatures for plants with high starch content.2. Transfer all the liquid obtained in step 1 to an adsorption column (Spin Columns FL) that has been loaded into a collection tube, centrifuge at 12,000 rpm (~13,400 x g) for 2 minutes, and transfer the supernatant from the collection tube to a new centrifuge tube (supplied).Note: 1) The tip of the tip of the gun can be cut off when aspirating liquids to facilitate sampling.2) Spin Columns FL removes most of the debris, but a small portion will still flow out and a precipitate will form in the collection tube after centrifugation, so be careful to avoid aspirating the precipitate when proceeding to the next step.3. Add 0.5 times the volume of anhydrous ethanol to the clean lysate obtained in step 2 and mix rapidly.Note: Precipitation may occur upon addition of ethanol, but does not affect subsequent tests.4. Transfer the solution obtained in the previous step to the Spin Columns RM in the collection tube. If it is not possible to add all of the solution to the column at one time, centrifuge the column at 12,000 rpm for 15 seconds in two batches, discard the waste solution and put the column back into the collection tube.5. Add 350 µl Buffer RW1 to the adsorbent column, centrifuge at 12,000 rpm for 1 min, discard the waste liquid and put the adsorbent column back into the collection tube.6. Preparation of DNase I mixture: Take 52µl of RNase-Free Water, add 8µl of 10×Reaction Buffer and 20µl of DNase I (1U/µl) to it, mix well, and make a final volume of 80µl of reaction solution.7. Add 80µl of DNase I mixture directly to the adsorption column and incubate at 20-30°C for 15 minutes.8. Add 350 µl of Buffer RW1 to the adsorption column, centrifuge at 12,000 rpm for 1 minute, discard the waste liquid and put the column back into the collection tube.9. Add 500 µl of Buffer RW2 to the column (check that anhydrous ethanol is added before use), centrifuge at 12,000 rpm for 15 seconds, and discard the waste solution.10. Repeat step 9.11. Place the adsorbent column back into the collection tube, centrifuge at 12,000 rpm for 1 minute, and allow the column to come to room temperature for a few minutes to thoroughly dry out the anhydrous ethanol in the adsorbent column.Note: The purpose of this step is to remove residual ethanol from the adsorption column; ethanol residue can interfere with subsequent enzymatic reactions (zymography, PCR, etc.).12. Load the adsorption column into a new centrifuge tube, add 30-50 µl of RNase-Free Water to the middle of the adsorbent membrane, leave it at room temperature for 1 minute, centrifuge at 12,000 rpm for 1 minute, and store the resulting RNA solution at -70°C to prevent degradation.Note: 1) The volume of RNase-Free Water should not be less than 30 µl, too small volume affects the recovery rate.2) If you want to increase the RNA yield, repeat step 12 with 30-50 µl of fresh RNase-Free Water.3) If the RNA concentration is to be increased, the resulting solution can be reintroduced into the adsorption column and step 12 repeated... Read More |