| Description | IntroductionHexokinase (HK, EC 2.7.1.1) is widely present in animals, plants, microorganisms, and cultured cells. It is the first key enzyme in the glucose degradation pathway, catalyzing the conversion of glucose to glucose-6-phosphate, which serves as the intersection point of glycolysis and the IntroductionHexokinase (HK, EC 2.7.1.1) is widely present in animals, plants, microorganisms, and cultured cells. It is the first key enzyme in the glucose degradation pathway, catalyzing the conversion of glucose to glucose-6-phosphate, which serves as the intersection point of glycolysis and the pentose phosphate pathway.Assay PrincipleHK catalyzes the synthesis of Glucose-6-Phosphate (G6P) from Glucose. Glucose-6-Phosphate Dehydrogenase (G6PDH) then further catalyzes the dehydrogenation of G6P, generating NADPH. NADPH has a characteristic absorption peak at 340 nm.Component48T96TStorageExtraction Buffer60 mL60 mL×22-8℃Reagent Ⅰ14 mL28 mL2-8℃Reagent Ⅱ1EA1EA-20℃. Store in the dark.Reagent Ⅲ1EA1EA-20℃. Store in the dark.Note: Please check the quantity of all components before starting the experiment. An additional 10% of each component is provided for standard curve preparation or pilot experiments.Required Materials and Equipment (Not Provided)TypeNameNotesInstrumentMicroplate ReaderMust be capable of measuring absorbance at 340 nmConsumables96-well UV PlateUV-transparent plateReagentsPhysiological SalineFor sample washingOtherHomogenizer (for tissue samples), Incubator, Ice box, Refrigerated centrifuge, Adjustable pipettes and tipsUsing a multichannel pipette is recommended for high-throughput experiments to improve efficiencyInstructions for Use1. Reagent Preparation试剂名称 Reagent NamePreparationNotesExtraction BufferReady-to-use; equilibrate to room temperature (RT) before use.Store at 4°CReagent ⅠReady-to-use; equilibrate to room temperature (RT) before use.Store at 4°CWorking Reagent ⅡPrepare immediately before use:• For 48T: Dissolve contents of Reagent Ⅱ in 10.8 mL Reagent Ⅰ• For 96T: Dissolve contents of Reagent Ⅱ in 21.6 mL Reagent ⅠKeep protected from light on ice during the experiment. Aliquot and store unused portions at -20°C protected from light for up to one month. Avoid repeated freeze-thaw cycles.Working Reagent ⅢPrepare immediately before use:1. Dissolve Reagent Ⅲ: • For 48T: in 0.5 mL Reagent Ⅰ • For 96T: in 1 mL Reagent Ⅰ2. Dilute the dissolved Reagent Ⅲ 10-fold with Reagent Ⅰ to make the Working Reagent Ⅲ.Keep protected from light on ice during the experiment. Aliquot and store unused portions at -20°C protected from light for up to one month. Avoid repeated freeze-thaw cycles.2. Sample PreparationNote: The use of fresh samples is highly recommended. HK activity decreases significantly upon sample freezing.2.1 Animal/Plant TissuesWeigh approximately 0.1 g of tissue. Add 1 mL of Extraction Buffer and homogenize on ice. Centrifuge the homogenate at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.2.2 Cells, Bacteria, or FungiCollect 5×10⁶ cells/bacteria/fungi. Wash with pre-cooled physiological saline and centrifuge at 800 g for 2 min. Discard the supernatant. Add 1 mL of Extraction Buffer and disrupt the cells by sonication on ice (5 min total, 20% power or 200 W, pulse 3s on/7s off, repeat 30 times). Centrifuge the lysate at 8000 g, 4°C for 10 min. Collect the supernatant and keep it on ice for assay.2.3 Serum (or Plasma)Assay directly.3. Assay Procedure3.1 Microplate Reader Preparation: Preheat for at least 30 min. Set the wavelength to 340 nm.3.2 Working Solution Preparation: Prepare immediately before use. Each well requires 190 µL of Working Solution. It is recommended to prepare enough for 2 extra wells to account for pipetting loss.For a single well: Mix 180 µL of Working Reagent Ⅱ with 10 µL of Working Reagent Ⅲ.The Working Solution must be prepared fresh. Incubate it at 37°C for 10 min before the assay.3.3 Assay Setup: Pipette into wells of the 96-well UV plate as follows:ReagentTest Well (µL)Sample10Working Solution1903.4 Absorbance Measurement: Immediately after adding the Working Solution, mix thoroughly and measure the absorbance at 340 nm at 10 seconds (A₁) and again after exactly 10 minutes of incubation at 37°C (at 10 min 10 sec, A₂).4. Result CalculationThe following derived and simplified calculation formulas are provided and are equivalent.4.1 Data ProcessingCalculate ΔA = A₂ - A₁.4.2 Sample HK Activity Calculation① Based on Sample Mass (U/g)Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADPH per minute per gram of sample.Calculation:HK (U/g) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ × W) ÷ T × nSimplified Formula: HK (U/g) = 643.09 × ΔA ÷ W × n② Based on Cell/Bacteria/Fungi Count (U/10⁴)Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADPH per minute per 10⁴ cells/bacteria/fungi.Calculation:HK (U/10⁴) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ × 500) ÷ T × nSimplified Formula: HK (U/10⁴) = 643.09 × ΔA ÷ 500 × n③ Based on Liquid Volume (U/mL)Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADPH per minute per milliliter of liquid.Calculation:HK (U/mL) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (Vₛₐₘₚₗₑ / Vₛₐₘₚₗₑₜₒₜₐₗ) ÷ T × nSimplified Formula: HK (U/mL) = 643.09 × ΔA × n④ Based on Protein Concentration (U/mg prot)Definition: One unit of activity is defined as the amount of enzyme that generates 1 nmol of NADPH per minute per milligram of protein.Calculation:HK (U/mg prot) = [ΔA × Vₜₒₜₐₗ ÷ (ε × d) × 10⁹] ÷ (Vₛₐₘₚₗₑ × Cpr) ÷ T × nSimplified Formula: HK (U/mg prot) = 643.09 × ΔA ÷ Cpr × nParameter Description:ε: NADPH molar extinction coefficient = 6.22 × 10³ L/mol/cmd: Light path of the 96-well UV plate = 0.5 cm10⁹: Conversion factor (1 mol = 1 × 10⁹ nmol)Vₜₒₜₐₗ: Total reaction volume = 200 µL = 2 × 10⁻⁴ LVₛₐₘₚₗₑ: Volume of supernatant added to the reaction = 10 µL = 1 × 10⁻⁵ LVₛₐₘₚₗₑₜₒₜₐₗ: Volume of Extraction Buffer added = 1 mLCpr: Sample protein concentration (mg/mL)W: Sample mass (g)T: Reaction time = 10 min500: Cell/Bacteria/Fungi count = 5 × 10⁶, expressed in units of 10⁴n: Sample dilution factorPrecautionsBefore formal testing, it is recommended to perform a pilot experiment using 2-3 samples expected to have significant activity differences.For tissue and cell samples, protein concentration measurement can be used to normalize results between samples.This kit is compatible with spectrophotometer detection. Adjust the preparation volumes of detection reagents proportionally according to the spectrophotometer's requirements.Biochemical reagents are generally irritating and biologically toxic. For your safety and health, please implement appropriate biosafety precautions throughout the experiment. Wear a lab coat, mask, gloves, head cover, and other protective equipment. Perform experiments in a fume hood or biosafety cabinet.This product is for scientific research use only. It is not intended for clinical diagnosis.Frequently Asked Questions (FAQ)1. What should I do if the measured ΔA is too high or too low?If ΔA > 0.5, the sample HK activity is too high. Dilute the supernatant appropriately with Extraction Buffer (include the dilution factor *n* in the calculation) or shorten the reaction time to 5 min.If ΔA < 0.005, the sample HK activity is too low. Increase the sample volume (keep the Working Solution volume constant and adjust the variable in the formula accordingly) or extend the reaction time (e.g., to 15 or 30 min).2. Can multiple samples be assayed simultaneously for high-throughput detection?The initial reaction rate is fast. It is not recommended to run a large number of samples simultaneously. If a multichannel pipette is unavailable, it is best for two individuals to perform the experiment together—one person timing and the other measuring the absorbance—to ensure the accuracy of the results... Read More | Inquire | Inquire | 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 | 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 |