| Description | Glucokinase (GK, EC 2.7.1.2) is a member of the hexokinase family, primarily found in mature hepatocytes and pancreatic islet cells. Under normal physiological conditions, the main role of GK is to monitor blood glucose levels. Glucokinase (GK) phosphorylates glucose to produce glucose-6-phosphate. Glucokinase (GK, EC 2.7.1.2) is a member of the hexokinase family, primarily found in mature hepatocytes and pancreatic islet cells. Under normal physiological conditions, the main role of GK is to monitor blood glucose levels. Glucokinase (GK) phosphorylates glucose to produce glucose-6-phosphate. This product is further coupled with glucose-6-phosphate dehydrogenase and NADP+, and the increase in NADPH absorbance is measured at 340 nm, thereby calculating the enzyme activity.Component50TStorageExtraction Buffer60 mL2-8℃Reagent 140 mL2-8℃Reagent 21EA-20℃Reagent 31EA2-8℃Reagent PreparationReagent 2 (Powder, 1 vial):Before opening, ensure the powder is at the bottom of the vial (tap manually if needed).Add 2.2 mL of distilled water to dissolve.The storage period is the same as the kit's expiry date.Reagent 3 (Powder, 1 vial):Before opening, ensure the powder is at the bottom of the vial (tap manually if needed).Add 36 mL of Reagent 1 to dissolve.The storage period is the same as the kit's expiry date.User-Prepared Instruments & MaterialsMortar (homogenizer), ice bucket (ice maker), benchtop centrifuge, adjustable pipettes, water bath (oven, incubator, metal bath), 1 ml quartz cuvette, centrifuge tubes, UV spectrophotometer, distilled water (deionized water or ultrapure water is acceptable).Sample Extraction1. Tissue Samples: Weigh approximately 0.1 g of tissue, add 1 mL of Extraction Buffer, and homogenize on ice. Centrifuge at 12000 rpm, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.Note: If increasing the sample amount, use a ratio of 1:5 to 1:10 (tissue weight (g) : Extraction Buffer volume (mL)) for extraction.2. Bacterial/Cell Samples: Collect bacteria or cells into a centrifuge tube by centrifugation and discard the supernatant. Take 5 million bacteria or cells, add 1 mL of Extraction Buffer, and disrupt using ultrasound on ice (power 20% or 200 W, ultrasonicate for 3 s, interval 10 s, repeat 30 times). Centrifuge at 12000 rpm, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.Note: If increasing the sample amount, use a ratio of 500-1000 (x10⁴ cells) : 1 (mL Extraction Buffer) for extraction.3. Liquid Samples: Detect directly. If the sample is turbid, centrifuge and use the supernatant for detection.Assay Procedure1. Preheat the UV spectrophotometer for at least 30 minutes. Set the wavelength to 340 nm. Zero the instrument with distilled water.2. Pre-warm the prepared Reagent 2 and Reagent 3 at 25°C for 5 minutes to reach room temperature.3. In a 1 mL quartz cuvette (1 cm light path), add sequentially:Reagent (µL)Test CuvetteSample80Reagent 240Reagent 36804. Mix well. Read the absorbance at 340 nm at 1 minute (A1) and then again at 21 minutes (i.e., after 20 minutes) (A2). Calculate ΔA = A2 - A1.Notes:1. If ΔA is close to zero, the reaction time can be appropriately extended to 30 minutes or longer before reading A2. The modified reaction time (T) must be substituted into the calculation formula. Alternatively, increase the sample volume appropriately. The modified sample volume (V1) must be substituted into the calculation formula.2. If the increasing trend is unstable, read the absorbance every 10 seconds and select a linear increasing period for calculation. The corresponding ΔA value should be substituted into the calculation formula.GK Activity Calculation1. Based on Sample Protein Concentration:Unit Definition: One unit of enzyme activity is defined as the generation of 1 nmol NADPH per minute per mg of protein.Formula:GK (nmol/min/mg prot) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (V1 × Cpr) ÷ T = 80.4 × ΔA ÷ Cpr2. Based on Sample Fresh Weight:Unit Definition: One unit of enzyme activity is defined as the generation of 1 nmol NADPH per minute per gram of fresh tissue.Formula:GK (nmol/min/g fresh weight) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (W × V1 ÷ V) ÷ T = 80.4 × ΔA ÷ W3. Based on Bacterial/Cell Density:Unit Definition: One unit of enzyme activity is defined as the generation of 1 nmol NADPH per minute per 10⁴ bacteria/cells.Formula:GK (nmol/min/10⁴ cell) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (500 × V1 ÷ V) ÷ T = 0.16 × ΔA4. Based on Liquid Volume:Unit Definition: One unit of enzyme activity is defined as the generation of 1 nmol NADPH per minute per mL of liquid.Formula:GK (nmol/min/mL) = [ΔA × V2 ÷ (ε × d) × 10⁹] ÷ V1 ÷ T = 80.4 × ΔAParameter Description:ε: NADPH molar extinction coefficient, 6.22 × 10³ L/mol/cmd: Light path of the 1 mL quartz cuvette, 1 cmV: Volume of Extraction Buffer added, 1 mLV1: Volume of sample supernatant added, 0.08 mLV2: Total reaction volume, 0.8 mL = 8 × 10⁻⁴ LT: Reaction time, 20 minW: Sample mass, g500: Bacteria or cell number, in units of 10⁴Cpr: Protein concentration of the supernatant, mg/mL; Aladdin BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648) are recommended.PrecautionsIt is recommended to first select 1-3 samples with significant differences (e.g., different types or groups) for preliminary experiments to familiarize yourself with the procedure. Determine or adjust the sample concentration based on the preliminary results to prevent unnecessary waste of samples or reagents... Read More | Inquire | Product content: G665990Component200 TStorageG665990ABuffer PG100 mLRTG665990BBuffer PS60 mLRTG665990CBuffer PW (concentrate)50 mLRTG665990DBuffer EB30 mLRTG665990ESpin Columns DM with Collection Tubes200 EART Product Introduction:This kit uses a new silicon-based plasma membrane technology and Product content: G665990Component200 TStorageG665990ABuffer PG100 mLRTG665990BBuffer PS60 mLRTG665990CBuffer PW (concentrate)50 mLRTG665990DBuffer EB30 mLRTG665990ESpin Columns DM with Collection Tubes200 EART Product Introduction:This kit uses a new silicon-based plasma membrane technology and reagent formulation. Through the unique centrifugal adsorption column and the DNA washing elution step, 100 bp-10 kb DNA fragments can be recovered and purified from ordinary or low melting point agarose gel. The sol speed is fast and the recovery rate is high. The sol solution contains a pH indicator, which can be used to determine whether the sol recovery has reached the optimal state based on its color. Each adsorption column can adsorb up to 10 µ G DNA, while effectively removing impurities such as primers, enzymes, mineral oil, and agarose. The purified and recovered DNA has high purity and concentration, good integrity, and can be directly used for molecular biology experiments such as sequencing, linking and transformation, labeling, and in vitro transcription.Self prepared reagents: anhydrous ethanol, isopropanol.Preparation and important precautions before the experiment:1.Before the first use, anhydrous ethanol should be added to the Buffer PW according to the instructions on the reagent bottle label.2. Before use, please check the Buffer PG. If crystallization or precipitation occurs, it can be left in a 37 ℃ water bath for 3-5 minutes to restore clarity.3. It is best to use a new electrophoresis buffer during electrophoresis to avoid affecting the electrophoresis and recovery efficiency; The following experiment requires high requirements, please use TAE electrophoresis buffer as much as possible.4.When cutting glue, the UV irradiation time should be as short as possible to avoid damage to DNA.5. The recovery rate is related to the initial amount of DNA and the elution volume. The smaller the initial amount, the smaller the elution volume, and the lower the recovery rate.6. Preheat the water bath to 50 ℃.7. Buffer PG contains a pH indicator. When the pH is ≤ 7.5, the color of the solution is yellow, and DNA can effectively bind to the membrane. When the pH is too high, the color of the solution turns orange red and purple, which needs to be adjusted.8. All centrifugation steps can be performed at room temperature.Operation steps:1. Cut the single purpose DNA strip from the agarose gel (try to cut the excess), put it into a clean centrifuge tube (self prepared), and weigh and calculate the weight of the gel (record the weight of the centrifuge tube in advance).Attention: If the volume of the adhesive block is too large, it can be cut into small pieces.2. Add one time of the volume of Buffer PG (if the gel weighs 100 mg, its volume can be regarded as 100 µ l. And so on.3.50 ℃ water bath and gently invert the centrifuge tube every 2-3 minutes until the sol turns yellow to ensure full dissolution of the gel block. If there are still unsolved glue blocks, you can add some more sol solution or continue to let it stand for a few minutes until the glue blocks are completely dissolved.Note: 1) After the gel is completely dissolved, the gel solution is yellow, and subsequent operations can be carried out; If the glue solution is orange red or purple, 10-30 can be added to the glue solution µ 3 M sodium acetate (pH 5.0), adjust the color of the solution to yellow before proceeding with subsequent operations.2) After the gel block is completely dissolved, it is best to lower the temperature of the gel solution to room temperature before loading the column. The adsorption column has a weaker ability to bind DNA at higher temperatures.4. (Optional step) When the recovered fragment is less than 300 bp, add 1/2 of the gel volume of isopropanol, and mix it upside down (if the gel weighs 100 mg, add 50 µ Isopropanol of L.5. Column balance: Add 200 to the spin columns DM that have been loaded into the collection tube µ Centrifuge at 13000 rpm (~16200 × g) for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.6. Add the solution obtained from steps 3 or 4 to the adsorption column that has been loaded into the collection tube, let it stand at room temperature for 2 minutes, centrifuge at 13000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column in the collection tube.Attention: The volume of the adsorption column is 750 µ l. If the sample volume is greater than 750 µ L can be added in batches.7. Add 450 to the adsorption column µ LBuffer PW (please check if anhydrous ethanol has been added before use), centrifuge at 13000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column in the collection tube.Note: If purified DNA is used for salt sensitive experiments (such as flat end ligation or direct sequencing), it is recommended to add Buffer PW and let it stand for 2-5 minutes before centrifugation.8. Repeat step 7.9.13000 rpm for 1 minute and discard the waste liquid from the collection tube.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).10. Place the adsorption column into a new 1.5 ml centrifuge tube (provided by oneself), and add 50 drops to the middle position of the adsorption membrane in the air µ L Buffer EB, leave at room temperature for 2 minutes. Centrifuge at 13000 rpm for 1 minute and collect DNA solution- Store DNA at 20 ℃.Attention:1) To improve the recovery of DNA, the solution obtained by centrifugation can be re dropped onto the adsorption column, left at room temperature for 2 minutes, and centrifuged at 13000 rpm for 1 minute.2) The elution volume should not be less than 30 µ l. A small volume will affect the recovery efficiency.3) When recovering DNA fragments larger than 10 kb, Buffer EB should be preheated in a 50 ℃ water bath to increase recovery efficiency.Note: This reagent kit is also suitable for the purification and recovery of PCR products. Add an equal volume of Buffer PG to the PCR reaction solution and mix thoroughly (for small fragments with a recovery of less than 150bp, the solution volume can be increased to three times to improve the recovery rate). Follow step 5 above for further operations... Read More | This reagent kit uses highly sensitive silver dye, which can be applied to protein staining of denatured and non denatured gels. It has the advantages of clear target bands, low background, and flexible control of operation time. In addition, this reagent kit has added a short-term sensitization This reagent kit uses highly sensitive silver dye, which can be applied to protein staining of denatured and non denatured gels. It has the advantages of clear target bands, low background, and flexible control of operation time. In addition, this reagent kit has added a short-term sensitization step, which can significantly reduce the background and enhance the brightness of the target band. P665901Component20 TStorageP665901ASilver Stain Sensitizer (500×)2×1 mLRTP665901BSilver Stain Enhancer3 mLRTP665901CSilver Stain2×250 mLRTP665901DSilver Stain Developer4×125 mLRT Matters needing attention1. Please prepare 50 ml of fixed solution (ultrapure water: ethanol: acetic acid=6:3:1), 50 ml of eluent (10% ethanol), and 50 ml of termination solution (5% acetic acid) in advance.2. Please use deionized water and clean glass or plastic containers during operation, and wear disposable gloves for operation.The entire silver dyeing process needs to be carried out on a shaker, with a rotation speed of about 60 rpm.4. Self prepared ethanol and glacial acetic acid are required.Instructions for useThe dosage of each solution in the following operation steps takes the gel with a size of 8.5 × 5.5 cm and a thickness of 1.0 mm as an example. The gel is immersed in the solution completely, and is operated on a shaker, with a general dosage of 25 ml. For large gel, the dosage of each solution should be scaled up according to the gel volume. Please prepare 50 ml of fixed solution (ultrapure water: ethanol: glacial acetic acid=6:3:1), 50 ml of eluent (10% ethanol), and 50 ml of termination solution (5% glacial acetic acid) in advance.1. Water washing: After electrophoresis is completed, wash the gel twice with ultrapure water for 5 minutes each time.2. Fixation: Fix the gel twice with 25 ml of fixative solution for 15 minutes each time.3. Elution: Wash the adhesive twice with eluent, each time for 5 minutes.4. Water washing: Wash the glue twice with ultrapure water, each time for 5 minutes.5. Sensitization: put the gel washed in the previous step into the silver dye sensitization working solution, incubate it accurately for 1 minute at room temperature, and then wash it with ultrapure water for three times, each time for 20 seconds. Preparation of silver staining sensitization working solution: Take 50 µ l Silver Stain Sensitivity (500 x) and add it to 25 ml of ultrapure water, mix well.6. Silver staining: discard ultrapure water and incubate gel in silver staining working solution for 30 minutes. Preparation of silver staining working solution: Take 25ml Silver Stain and add 50 µ l Silver Stain Enhanced to mix well.7. Water washing: Quickly wash the glue twice with ultrapure water, with each washing accurately controlled for 20 seconds.8. Development: Immerse the washed gel in the developer immediately and incubate it at room temperature for 2-3 minutes until the protein strip is clear. Preparation of developer: Take 25ml Silver Stain Developer and add 30 µ l Silver Stain Enhanced to mix well. Attention: Within 30 seconds of development, protein bands begin to appear and continue to develop for 2-3 minutes. If the protein band appears lighter, the development time can be appropriately extended to 5 minutes or more.9. Termination: After washing the developer on the gel with the termination solution, soak the gel in a new termination solution to react for 10 minutes.Experimental imagesSilver staining results of BSA protein samples after 10% SDS-PAGE gel electrophoresisThe molecular weight of BSA protein is about 66 kD, and the loading amounts from left to right are 50 ng, 10 ng, and 5 ng, respectively... Read More | Inquire |