| Description | Inquire | 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 | The perfect KitAlysis Labware starter kit that combines the KitAlysis Inertion Box (Z742064) with the KitAlysis 24-Well Reaction Block and Screwdriver Set (Z742107).Provides an inert environment to run oxygen sensitive cross-coupling reactions in a laboratory fume hood.Designed to be used with The perfect KitAlysis Labware starter kit that combines the KitAlysis Inertion Box (Z742064) with the KitAlysis 24-Well Reaction Block and Screwdriver Set (Z742107).Provides an inert environment to run oxygen sensitive cross-coupling reactions in a laboratory fume hood.Designed to be used with KitAlysis High-Throughput Screening Kits.Components:Ιnertion Box24-Well Reaction BlockTorque Screwdriver set with bitReaction Block Replacement Screws (10ea)... Read More | Product content: M665559Component50 TStorageM665559ABuffer GTT15 mLRTM665559BBuffer GL15 mLRTM665559CBuffer GW1（concentrate）13 mLRTM665559DBuffer GW2（concentrate）15 mLRTM665559EBuffer GE15 mLRTM665559FProteinase K1.25 mLRTM665559GSpin CoLumns DM with CoLLection Tubes50 Product content: M665559Component50 TStorageM665559ABuffer GTT15 mLRTM665559BBuffer GL15 mLRTM665559CBuffer GW1（concentrate）13 mLRTM665559DBuffer GW2（concentrate）15 mLRTM665559EBuffer GE15 mLRTM665559FProteinase K1.25 mLRTM665559GSpin CoLumns DM with CoLLection Tubes50 EART Product Introduction:This reagent kit is suitable for extracting high-purity total DNA from fresh or frozen mouse or rat tails. The method provided by this reagent kit is simple and feasible, and the purification process does not require phenol or chloroform extraction. It can obtain DNA fragments up to 50 kb, and can also effectively recover fragments of 100 bp. This reagent kit uses a unique lysis solution to effectively lyse mouse tail samples. The optimized buffer system efficiently binds the DNA generated after the lysis of mouse tail to the silica matrix adsorption column, while other pollutants can flow through the membrane; Inhibitors of PCR and other enzymatic reactions can be effectively removed through a two-step washing process, followed by washing with low salt buffer or water to obtain high-purity DNA. The purified DNA can be directly used for downstream experiments such as enzyme digestion, PCR, ReaL Time PCR, library construction, Southern BLot, and molecular labeling.Self prepared reagent: anhydrous ethanol.Preparation and important precautions before the experiment:1. Samples should avoid repeated freeze-thaw cycles, otherwise it may result in smaller extracted DNA fragments and a decrease in extraction volume.2.Before the first use, anhydrous ethanol should be added to BufferGW1 and BufferGW2 according to the instructions on the reagent bottle label.3. Before use, please check if there is any crystallization or precipitation in the Buffer GL. If there is any crystallization or precipitation, please dissolve the Buffer GL again in a 56 ℃ water bath.Operation steps:1. Take a tail of a rat or two mice with a length of 0.4-0.6 cm, grind it into fine powder in liquid nitrogen or cut it into pieces and place it in a centrifuge tube (provided by oneself). Join 180 µ L Buffer GTT, shake and mix well. Note: Ensure that the starting quantity of the organization does not exceed the recommended range.2. Add 20 µ L Protein K, vortex oscillation, thoroughly mix.3. Place in a 56 ℃ water bath until the tissue solution is completely clear. Generally, digestion is required for 6-8 hours. During the incubation process, vortex oscillation is required to evenly disperse the sample. Note: 1) If there is still gel like substance after incubation and vortex oscillation, digest overnight or add 20 more if necessary µ L Protein K digestion will not affect subsequent operations. 2) To remove RNA, add 4 after completing the above steps µ L 100 mg/mL RNase A solution, shake well and let stand at room temperature for 5-10 minutes.4.12000 rpm (~13400 × g) for 1 minute to remove undigested tissues similar to mouse hair. Transfer the supernatant to a new centrifuge tube (provided by oneself).5. Add 200 µ L Buffer GL, vortex oscillation, thoroughly mixed. Join 200 µ L anhydrous ethanol, vortex and shake, thoroughly mix. Short centrifugation allows the solution on the tube wall to be collected to the bottom of the tube.Attention: 1) After adding Buffer GL and anhydrous ethanol, immediately vortex and shake to mix well.2) If multiple samples are operated together, Buffer GL and anhydrous ethanol can be mixed in equal proportions and added to the samples together.3) The addition of Buffer GL and anhydrous ethanol may produce white precipitates, which will not affect subsequent experiments.6. Add all the solutions obtained in step 5 to the adsorption column (Spin CoLumins DM) that has 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.7. Add 500 to the adsorption column µ L Buffer GW1 (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.8. Add 500 to the adsorption column µ L Buffer GW2 (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.Note: To further improve DNA purity, repeat step 8.9.12000 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.).10. Place the adsorption column in a new centrifuge tube (provided by oneself) and add 50-200 to the middle of the adsorption column in the air µ L Buffer GE or sterilized water, leave at room temperature for 2-5 minutes, centrifuge at 12000 rpm for 1 minute, collect DNA solution, and store DNA at -20 ℃.Note: 1) If downstream experiments are sensitive to pH or EDTA, they can be washed off with sterilized water. The pH value of the eluent has a significant impact on the elution efficiency. If water is used as the eluent, its pH value should be ensured to be between 7.0-8.5 (NaOH can be used to adjust the pH value of the water to this range). When the pH value is below 7.0, the elution efficiency is not high.2) Incubating at room temperature for 5 minutes before centrifugation can increase yield.3) Use an additional 50-200 µ Re washing with L Buffer GE or sterilized water can increase yield.4) If you want to increase the final concentration of DNA, you can add the DNA eluent obtained in step 10 back onto the adsorption membrane and repeat step 10; If the elution volume is less than 200 µ L. It is possible to increase the final concentration of DNA, but it may reduce the total yield. If the amount of DNA is less than 1 µ g. Recommended 50 µ L Buffer GE or off... Read More | Product DescriptionAcetyl esterase (sialate-O-acetylesterase) is a recombinant protein from Tannerella forsythia, ATCC 43037 strain, expressed in Escherichia coli. The enzyme removes acetyl groups attached via an O- group, mainly 9-, 8- and 7-. It can be used for monitoring of diacetylation of Product DescriptionAcetyl esterase (sialate-O-acetylesterase) is a recombinant protein from Tannerella forsythia, ATCC 43037 strain, expressed in Escherichia coli. The enzyme removes acetyl groups attached via an O- group, mainly 9-, 8- and 7-. It can be used for monitoring of diacetylation of sialic acids on products such as erythropoietin (EPO).The Zyme Acetyl Esterase Kit removes 9-, 8- and 7-O-acetyl groups from released sialic acids, released glycans or glycoproteins. It is commonly used for the characterization of highly-sialylated biotherapeutics such as EPO, FSH and blood clotting factors.Molecular Weight76.3 kDContentsAcetyl esterase – PBS pH7.5 buffer containing 10 mM Tris-HClReaction Buffer – 500 mM sodium acetate pH5.5Number of SamplesSufficient for up to 50 samples.Amount of SampleUp to 10 µg glycoprotein, up to 2.5 µg released glycans and up to 1 µg free sialic acid per digestion.Suitable SamplesAcetyl esterase (sialate-O-acetylesterase) can act upon complex glycoprotein samples, such as erythropoietin (EPO), bovine submaxillary mucin and oral epithelial cell-bound glycans, and on N- and O-glycans released from a glycoprotein. Either fluorescently labelled or unlabelled glycans are suitable. It can also be used on released sialic acids.Unit DefinitionOne unit (U) of acetyl esterase is defined as the amount of enzyme required to produce 300 µmole of 4-nitrophenol and acetate in 1 minute at 30°C in a buffer containing 50 mM Tris-HCl, 140 mM NaCl, pH 8.5, from 4-nitrophenyl acetate, a chromogenic esterase substrateStorageProtect from sources of heat and light. When stored correctly, the enzyme should be stable for 24 months from date of purchase. Exposure to ambient temperatures (20 – 26°C) over 3 days does not result in a reduction of enzymatic activity.ShippingThe product should be shipped at 4°C.HandlingEnsure that any glass, plastic ware or solvents used with this item are free of environmental carbohydrates. Use powder-free gloves for all sample handling procedures and avoid contamination with environmental carbohydrate.SafetyPlease read the Safety Data Sheets (SDSs) for all chemicals used. All processes involving labelling reagents should be performed using appropriate personal safety protection – safety glasses, chemically resistant gloves (e.g. nitrile), lab coat, and when appropriate, in a laboratory fume cupboard.For research use only. Not for human or drug use ApplicationAcetyl esterase (sialate-O-acetylesterase) can be used to remove 9-, 8- and 7-O-acetyl groups from released sialic acids, released glycans or glycoproteins... Read More |