| Description | Fructokinase (FK, EC 2.7.1.4) regulates the interconversion between sucrose and starch and is involved in the regulation of plant metabolism and growth development. Fructokinase (FK) phosphorylates fructose to generate fructose-6-phosphate. This product is subsequently acted upon by a series of Fructokinase (FK, EC 2.7.1.4) regulates the interconversion between sucrose and starch and is involved in the regulation of plant metabolism and growth development. Fructokinase (FK) phosphorylates fructose to generate fructose-6-phosphate. This product is subsequently acted upon by a series of composite enzymes, reducing NADP+ to NADPH. The enzyme activity of fructokinase is determined by measuring the rate of increase in NADPH absorbance at 340 nm.Component100TStorageExtraction Buffer120 mL2-8℃Reagent 120 mL2-8℃Reagent 21EA-20℃Reagent 31EA-20℃Reagent 41EA2-8℃Reagent 51EA2-8℃Reagent PreparationReagent 2 (Powder, 1 vial):Before use, centrifuge at 8000 g, 4°C for 2 min to collect the powder at the bottom (tap manually if needed).Add 1.1 mL of distilled water to dissolve.The storage period is the same as the kit's expiry date.Reagent 3 (Liquid, 1 vial):Before use, centrifuge at 8000 g, 4°C for 2 min to collect the liquid at the bottom (tap manually if needed).Add 1.05 mL of distilled water to dissolve.The storage period is the same as the kit's expiry date.Reagent 4 (Powder, 1 vial):Before opening, ensure the powder is at the bottom of the vial (tap manually if needed).Add 17 mL of Reagent 1 to dissolve.The storage period is the same as the kit's expiry date.Reagent 5 (Liquid, 1 vial):Before use, centrifuge at 8000 g, 4°C for 2 min to collect the liquid at the bottom (tap manually if needed).Add 1.1 mL of distilled water 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), 96-well plate, centrifuge tubes, microplate reader, 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 1:1000~5000 (bacteria/cell count (x10⁴) : Extraction Buffer volume (mL)) for extraction.*3. Liquid Samples: Detect directly. If the sample is turbid, centrifuge and use the supernatant for detection.Assay Procedure1. Preheat the microplate reader for at least 30 minutes. Set the wavelength to 340 nm.2. Thaw all reagents to room temperature (25°C).3. In a well of the 96-well plate, add sequentially:Reagent (µL)Test WellSample20Reagent 210Reagent 310Reagent 4150Mix well and incubate at 37°C for 5 minutes. 4. Add:Reagent (µL)Test WellReagent 5105. Mix well. Immediately read the absorbance at 340 nm (A1) and then read again after incubating at 37°C for 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; or the sample volume V1 can be increased appropriately (with a corresponding decrease in Reagent 4 volume). The modified reaction time (T) and sample volume (V1) must be substituted into the calculation formula.2. If the initial absorbance A1 is too high (e.g., >2, as in deeply pigmented plant leaves), appropriately reduce the sample volume V1. The modified V1 must be substituted into the calculation formula. Alternatively, add a small amount of activated carbon to the sample, mix, let stand for 5 min, then centrifuge at 12000 rpm, 4°C for 10 min, and use the supernatant for detection.3. 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.FK 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:FK (nmol/min/mg prot) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (Cpr × V1) ÷ T = 160.77 × 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:FK (nmol/min/g fresh weight) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (W × V1 ÷ V) ÷ T = 160.77 × 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:FK (nmol/min/10⁴ cell) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (500 × V1 ÷ V) ÷ T = 0.322 × 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:FK (nmol/min/mL) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ V1 ÷ T = 160.77 × ΔAParameter Description:ε: NADPH molar extinction coefficient, 6.22 × 10³ L/mol/cmd: Light path of the 96-well plate, 0.5 cmV: Volume of Extraction Buffer added, 1 mLV1: Volume of sample supernatant added, 0.02 mLV2: Total reaction volume, 0.2 mL = 2.0 × 10⁻⁴ LT: Reaction time, 20 minW: Sample mass, g500: 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.Precautions It 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 | 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 | Inquire | Inquire | Product content R669871Component50 TStorageR669871ADNase I1000 U-20℃. Avoid freeze/thaw cycle.R669871B10×Reaction Buffer1mL-20℃. Avoid freeze/thaw cycle. R669871CBuffer DS30 mLRTR669871DBuffer GTL15 mLRTR669871EBuffer GL25 mLRTR669871FProteinase K12.5 mgRTR669871GProteinase K Product content R669871Component50 TStorageR669871ADNase I1000 U-20℃. Avoid freeze/thaw cycle.R669871B10×Reaction Buffer1mL-20℃. Avoid freeze/thaw cycle. R669871CBuffer DS30 mLRTR669871DBuffer GTL15 mLRTR669871EBuffer GL25 mLRTR669871FProteinase K12.5 mgRTR669871GProteinase K Storage Buffer1.25 mLRTR669871HBuffer RW140 mLRTR669871IBuffer RW2 (concentrate)11 mLRTR669871JRNase-Free Water10 mLRTR669871KSpin Columns RS with Collection Tubes50 setsRTR669871LRNase-Free Centrifuge Tubes (1.5 mL)50 EART Product IntroductionThis kit is suitable for effectively purifying total RNA from formalin fixed and paraffin embedded tissues. Suitable for extracting total RNA with improved purity from paraffin embedded tissues or sections less than 30mg. This kit does not require the use of phenol/chloroform extraction or isopropanol precipitation, and can complete the extraction of multiple samples within one hour. This product uses specially optimized lysis solution and protease K to release RNA from formalin fixed or tissue slice samples without overnight operation; After digestion, the sample is incubated at a higher temperature to remove the inhibitory effect caused by formalin cross-linking, effectively releasing RNA from tissue slices and avoiding endangering RNA integrity; The optimized buffer system allows RNA in the lysis solution to specifically bind to the silica gel adsorption membrane, while other pollutants can flow through the membrane; It can be effectively removed through rinsing steps, and the washed RNA can be directly used for experiments such as RT-PCR, Real Time PCR, and Western blot analysis.Self prepared reagents: anhydrous ethanol (newly opened or dedicated for RNA extraction), 10mM PBS (pH 7.4).Preparation and important precautions before the experiment1. Add 0.625ml Protein K Storage Buffer to Protein K to dissolve it and store at -20 ℃. The prepared Protein K should not be left at room temperature for a long time to avoid repeated freeze-thaw cycles, which may affect its activity.2. To prevent RNase pollution, attention should be paid to the following aspects:1) Use RNase free plastic products and gun heads to avoid cross contamination.2) Glassware should be dry baked at a high temperature of 180 ℃ for 4 hours before use, while plastic containers can be soaked in 0.5M NaOH for 10 minutes, thoroughly rinsed with water, and then sterilized under high pressure.3) Prepare the solution using water without RNase.4) Operators should wear disposable masks and gloves, and change gloves frequently during the experiment.3. After obtaining the sample, it should be fixed in 4% -10% formalin as soon as possible, with a suitable fixation time of 14-24 hours. Excessive time can lead to RNA breakage and affect downstream experiments.4. Ensure that the sample before embedding is thoroughly dehydrated, as residual formalin will inhibit the action of Protein K.5. Before the first use, anhydrous ethanol should be added to Buffer RW2 according to the instructions on the reagent bottle label.Before use, please check if there is any crystallization or precipitation in Buffer GTL, Buffer GL, and Buffer DS. If there is any crystallization or precipitation, please dissolve Buffer GTL, Buffer GL, and Buffer DS again in a 56 ℃ water bath.Operation steps1. Sample processing1a. Paraffin embedded sample: Use a surgical knife to trim off excess paraffin from the tissue block, expose the tissue, and cut into 5-10 µ m thin slices.Attention: If the surface of the sample has already been exposed to air, please discard 2-3 pieces that come into contact with the air and do not use them.1b. Samples in fixed solutions such as formalin: Take approximately 20mg of the sample, cut it into small pieces, place it in a centrifuge tube, and add 500 µ 10mM PBS (PH7.4), vortex oscillation, centrifugation at 12000 rpm (~13400 × g) for 1 minute, discard the supernatant, repeat 3 times, and proceed directly to step 3.2. Choose option A or option B to remove paraffinOption AA1. Take approximately 1 × 1cm2 of slices (4-5 slices in total) and place them in a centrifuge tube (prepared by oneself), then add 500 slices µ L Buffer DS, vortex oscillation for 10 seconds. Incubate at 56 ° C for 3 minutes.Centrifuge at A2.12000 rpm for 2 minutes, be careful to discard the supernatant and avoid attracting sediment.Option BB1. Take approximately 4-5 slices of approximately 1 × 1 cm2 and place them in a centrifuge tube (self prepared). Add 1ml of xylene, cover the tube tightly, and vortex for 10 seconds.B2.Centrifuge at 12000 rpm for 2 minutes, be careful to remove the supernatant and avoid removing sediment.B3. Add 1ml of anhydrous ethanol, vortex and shake well. Centrifuge at 12000 rpm for 2 minutes, discard the supernatant, and be careful not to absorb or discard the sediment.B4. Open the tube cover and incubate at room temperature or up to 37 ° C for 10 minutes until there is no ethanol residue.3. Add 150µ L Buffer GTL, resuspended precipitation; Join 10µl Protein K, vortex oscillation mixing.4.Incubate at 56 ℃ for 15 minutes until the sample is completely dissolved. Incubate at 80 ℃ for 15 minutes. Short centrifugation allows the solution on the tube wall to be collected to the bottom of the tube.Note: 1) The purpose of this step is to repair nucleic acids denatured by formaldehyde. Incubating at a high temperature or for too long may cause RNA breakage, resulting in RNA fragments.2) The sample incubated at 56 ℃ can be placed at room temperature until the temperature of the water or dry bath reaches 80 ℃, and then the sample can be incubated at 80 ℃.5. Place on ice for 3 minutes, centrifuge at 12000 rpm for 15 minutes, transfer the supernatant to a new centrifuge tube, be careful not to suck sediment.6. Add 320 to the supernatant µ L Buffer GL, vortex oscillation thoroughly mixed.7. Join 720 µ Mix anhydrous ethanol thoroughly with vortex oscillation.Attention: After adding anhydrous ethanol, there may be a small amount of precipitate precipitation, but it does not affect subsequent operations.8. Add all the solutions obtained in step 7 to the spin columns RS that have been loaded into the collection tube. If the solution cannot be added at once, it can be transferred multiple times. Centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.Optional steps: If genomic DNA needs to be removed, the following steps can be followeda. Add 350 to the adsorption column µ L Buffer RW1, centrifuge at 12000 rpm for 1 minute, discard the waste liquid, and place the adsorption column back into the recovery manifold.b. Preparation of DNase I mixture: Take 52 µ Add 8 RNase Free Water to it µ 10 x Reaction Buffer and 20 µ DNase I (1U/ µ l) Mix well and prepare to a final volume of 80 µ The reaction solution of L.c. Add 80 µ l of DNase I mixture directly to the adsorption column and incubate at 20-30 ℃ for 15 minutes.d. Add 350 to the adsorption column µ L Buffer RW1, centrifuge at 12000 rpm for 1 minute, discard the waste liquid, and place the adsorption column back into the recovery manifold.9. Add 500 to the adsorption column µ Buffer RW2 (check if anhydrous ethanol has been added before use), centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.10. Repeat step 9.Centrifuge at 11.12000 rpm for 2 minutes and discard the waste liquid from the collection tube. Place the adsorption column at room temperature for a few minutes to thoroughly air dry.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which will affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).12. Place the adsorption column in a new RNase free centrifuge tube, and add 20-50µl to the middle of the adsorption column in the air Place RNase Free Water at room temperature for 2-5 minutes, centrifuge at 12000 rpm for 1 minute, collect RNA solution, and store RNA at -20 ℃.Note: 1) The volume of RNase Free Water should not be less than 20 µ l. Small volume affects the recovery rate. 2) If you want to increase RNA production, you can use 20-50 µ Repeat step 12 for the new RNase Free Water.3) If you want to increase the RNA concentration, you can add the obtained solution back to the adsorption column and repeat step 12... Read More |