| 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 | 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 | DescriptionMetathesis: Ruthenium-Based Metathesis CatalystsRuthenium metathesis catalysts kit I consists of 9 samples of Grubbs 1st and 2nd generation catalysts. These catalysts have applications in ring-closing and ring-opening metathesis, cross-metathesis, ring-opening metathesis polymerization (DescriptionMetathesis: Ruthenium-Based Metathesis CatalystsRuthenium metathesis catalysts kit I consists of 9 samples of Grubbs 1st and 2nd generation catalysts. These catalysts have applications in ring-closing and ring-opening metathesis, cross-metathesis, ring-opening metathesis polymerization (ROMP) and enyne metathesis.Metathesis: Ruthenium-Based Metathesis Catalysts... Read More | Product content: S665546Component50 TStorageS665546ABuffer QSL45 mLRTS665546BBuffer RIL11 mL2-8℃S665546CBuffer ML10 mLRTS665546DBuffer GW1 (concentrate)13 mLRTS665546EBuffer GW2 (concentrate)26 mLRTS665546FBuffer EBL13 mLRTS665546GRNase A240 µLRTS665546HLysis Tubes Ⅱ50 Product content: S665546Component50 TStorageS665546ABuffer QSL45 mLRTS665546BBuffer RIL11 mL2-8℃S665546CBuffer ML10 mLRTS665546DBuffer GW1 (concentrate)13 mLRTS665546EBuffer GW2 (concentrate)26 mLRTS665546FBuffer EBL13 mLRTS665546GRNase A240 µLRTS665546HLysis Tubes Ⅱ50 EARTS665546ISpin Columns DM With Collection Tubes50 EARTProduct IntroductionThis kit provides a method for extracting total DNA from soil or fecal samples, including the total DNA of cells, bacteria, parasites, and viruses in the samples. It is also suitable for extracting DNA from samples containing high concentrations of PCR reaction inhibitors. This reagent kit adopts a unique buffering system to efficiently bind DNA from the lysis solution to the adsorption column. Inhibitors of PCR and enzyme reactions, as well as residual impurities, can be effectively removed through washing steps. Finally, high-purity DNA can be obtained by washing with low salt buffer or water. The purified DNA can be directly used for downstream experiments such as second-generation sequencing (16S amplicons and metagenomes), library construction, PCR, qPCR, Southern Blot, enzyme digestion molecular markers, etc.Self prepared reagents1. Constant temperature mixer - Product number: CW25932. Anhydrous ethanol, isopropanol3. Vortex oscillator or tissue grinderPreparation and important precautions before the experiment1. 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 Buffer GW1 (concentrate) and Buffer GW2 (concentrate) according to the instructions on the reagent bottle label.3. Take out the buffer RIL before use and store it at 2-8 ℃ immediately after use.Operation steps1. Centrifuge the Lysis Tube briefly to allow the beads to settle at the bottom.2. a. Add 0.1-0.3 g of soil or fecal sample to Lysis Tube, and add 740-820 µ L Buffer QSL and 4 µ L RNase A, tighten the tube cover and briefly vortex to mix.b. If fecal samples are stored in non lytic fecal preservation solutions (such as CWY041S and CWY041M), add 200 to Lysis Tube µ L-600 µ L solid-liquid mixture, centrifuge at 13000 rpm for 1 minute, discard the storage solution (if the amount of solid after centrifugation is too small, it can be enriched again, but should not exceed 0.3g). Join 620 µ LBuffer QSL and 4 µ L RNase A, tighten the tube cover and briefly vortex to mix.3. Fix the Lysis Tube in an oscillating grinding device equipped with a 2 mL adapter and process it according to the optimized grinding conditions of your equipment (see appendix).4. Shake the Lysis Tube on a constant temperature mixer at 70 ℃ and 1200 rpm for 10 minutes. Subsequently, centrifuge at 13000 rpm for 2 minutes to precipitate solid particles. Transfer 540 µ Transfer the supernatant to a new 2 mL centrifuge tube.5. Add 180 µ L Buffer RIL, vortex for 5 seconds, centrifuge at 13000 rpm for 2 minutes.Attention: Remove the buffer RIL before use and store it at 2-8 ℃ immediately after use.6. Add 160 to the new centrifuge tube in sequence µ L Buffer ML, 480 µ Supernatant from step 5, 320 µ L isopropanol, vortex for 5 seconds.7. Transfer the solution from the previous step to 650 µ Centrifuge at 12000 rpm (~13400 × g) for 1 minute into the spin columns DM that have been loaded into the collection tube.8. Discard the waste liquid in the collection pipe and place the adsorption column back into the collection pipe. Repeat step 7 until all the solution has been transferred.9. 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.10. 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. 11. Repeat step 10.12.12000 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 can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).13. Place the adsorption column in a new centrifuge tube (self provided) and add 50-200 drops of suspended droplets to the middle of the adsorption column µ L Buffer EBL 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) Incubating at room temperature for 5 minutes before centrifugation can increase yield.2) Use an additional 50-100 µ Further elution with L buffer or sterilized water can increase yield.3) If you want to increase the final concentration of DNA, you can add the DNA eluent obtained in step 13 back onto the adsorption membrane and repeat step 13, but it may reduce the total yield.4) The elution buffer does not contain chelating agents, please store DNA at -20 ℃.5) The residual trace PCR inhibitors in the genomic DNA template may have adverse effects on the PCR reaction, which can usually be resolved by diluting the DNA by 2-10 times.Appendix: Grind the sample using one of the following methods1. Manually vortex oscillate at maximum speed on the vortex oscillator for 10 minutes.2. On a vortex oscillator equipped with a 1.5-2 mL horizontal centrifuge tube holder, oscillate at maximum speed for 10 minutes (keeping the Lysis Tube horizontal). If the sample size exceeds 12, extend by 5-10 minutes. For example, using Scientific Industries or Mobile's Vortex Genie2 vortex oscillator.3.When using Qiagen's TissueLyser II, grind at 25Hz for 10 minutes.4.When using Qiagen's PowerLyzer 24 Homogenizer, homogenize at 2000 rpm for 30 seconds, pause for 30 seconds, and then homogenize again at 2000 rpm for 30 seconds.5.When using FastPrep-24 from MP Biomedicals, the recommended speed is 6.0 and the time is 40 seconds... Read More |