| Description | 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:D665967Component200 TStorageD665967ABuffer PB120 mLRTD665967BBuffer PS60 mLRTD665967CBuffer PW (concentrate)25 mLRTD665967DBuffer EB30 mLRTD665967ESpin Columns DM with Collection Tubes200 EART Product Introduction: This reagent kit adopts a new silicon-based membrane technology and Product content:D665967Component200 TStorageD665967ABuffer PB120 mLRTD665967BBuffer PS60 mLRTD665967CBuffer PW (concentrate)25 mLRTD665967DBuffer EB30 mLRTD665967ESpin Columns DM with Collection Tubes200 EART Product Introduction: This reagent kit adopts a new silicon-based membrane technology and reagent formula. Through a rapid and simple three-step process of binding, washing, and elution, 100 bp-10 kb DNA fragments can be purified and recovered from PCR products or enzyme reaction solutions (enzyme cutting, linking, probe labeling, etc.). Each adsorption column can adsorb up to 10 kb of DNA fragments µ G DNA, while minimizing impurities such as primers, oligonucleotides, enzymes, etc. The purified and recovered DNA has high purity and concentration, good integrity, and high recovery rate, and can be directly used for molecular biology experiments such as sequencing, linking and transformation, labeling, and in vitro transcription.Self prepared reagent: anhydrous ethanol.Preparation and important precautions before the experiment:1. All components can be stably stored in a dry, room temperature (15-30 ℃) environment for 1 year, and can be stored at 2-8 ℃ for longer periods of time. When the solution is stored at low temperature, it should be left at room temperature for a period of time before use, and then restored to room temperature before use.2. This reagent kit can selectively recover all DNA fragments from the solution. If you need to selectively recover specific fragments while removing other fragments of different sizes, please choose our company's gel recovery reagent kit.3.Before the first use, anhydrous ethanol should be added to the Buffer PW according to the instructions on the reagent bottle label.4. Before use, please check if there is any crystallization or precipitation in the Buffer PB. If there is any crystallization or precipitation, you can take a water bath at 37 ℃ for a few minutes to restore clarity.5. The recovery efficiency 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. All centrifugation steps can be performed at room temperature.Operation steps:1. Estimate the volume of DNA reaction solution, add 5 times the volume of Buffer PB, and mix thoroughly (without removing paraffin or mineral oil).Note: 1) If the DNA reaction system is 50 µ l (excluding paraffin oil volume), add 250 µ l Buffer PB.2) After adding Buffer PB, check the pH value of the solution. If the pH value is greater than 7.5, add 10-30 to it µ 3 M sodium acetate (pH 5.0) was used to adjust the pH value to 5-7.2. 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.3. Add the solution obtained in step 1 to the adsorption column that has been loaded into the collection tube, let it stand at room temperature for 1 minute, centrifuge at 13000 rpm for 30-60 seconds, 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, it can be added in batches.4. Add 500 µ l of Buffer PW to the adsorption column (please check if anhydrous ethanol has been added before use), centrifuge at 13000 rpm for 30-60 seconds, discard the waste liquid in the collection tube, and place the adsorption column in the recovery tube.Note: If purified DNA is used for salt sensitivity experiments (such as flat end ligation experiments or direct sequencing), it is recommended to add Buffer PW and let it stand for 2-5 minutes before centrifugation.5.13000 rpm for 1 minute 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.). To ensure that downstream experiments are not affected by residual ethanol, it is recommended to open the cover of the adsorption column and place it at room temperature for a few minutes to thoroughly dry the residual ethanol in the adsorbent material at the bottom.6. Place the adsorption column into a new centrifuge tube (provided by oneself), add 30-50 µ l Buffer EB to the middle position of the adsorption membrane by hanging droplets, and let it stand at room temperature for 1 minute. Centrifuge at 13000 rpm for 1 minute and collect DNA solution- Store DNA at 20 ℃.Attention:1) 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 (the pH value of water can be adjusted to this range using NaOH).2) To improve the recovery of DNA, the solution obtained by centrifugation can be added back to the adsorption column, left at room temperature for 2 minutes, and centrifuged at 13000 rpm for 1 minute.3) The elution volume should not be less than 30 µ l. A small volume will affect the recovery efficiency... Read More | DescriptionWhite LED Array for Photo KitAlysis high-throughput screening platform. For use with Photo KitAlysis Starter Kit (Z742612). User guide is provided in the below hyperlink.Photo KitAlysis Operating InstructionsFeatures:Designed and tested by synthetic chemists.Controller provides repeatableDescriptionWhite LED Array for Photo KitAlysis high-throughput screening platform. For use with Photo KitAlysis Starter Kit (Z742612). User guide is provided in the below hyperlink.Photo KitAlysis Operating InstructionsFeatures:Designed and tested by synthetic chemists.Controller provides repeatable milliamp selection for photon intensity (sold seperately)0-30 mA variable LED outputNon-magnetic LED baseChemically resistant LED coverPTFE coated cablingPhoto Kitalysis Starter Kitrequired for operation (sold separately). Best when used withKitAlysis Benchtop Inertion Box(sold separately)... Read More | Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 500ug of high-purity plasmid DNA from 120-300ml bacterial Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 500ug of high-purity plasmid DNA from 120-300ml bacterial culture for sequencing, in vitro transcription and translation, restriction enzyme digestion, bacterial transformation and other molecular biology experiments.Scope of application：Nucleic acid extraction and purification... Read More | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export |