| 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 content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export | 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 | Products contentProducts IntroductionThe Single Cell Whole Genome Amplification Kit can be used as a template for whole genome amplification of single cells or micro samples. The total time for single-cell amplification is about 3 hours, and 2-5 µg of genomic DNA, with a size of 200-1500 bp, Products contentProducts IntroductionThe Single Cell Whole Genome Amplification Kit can be used as a template for whole genome amplification of single cells or micro samples. The total time for single-cell amplification is about 3 hours, and 2-5 µg of genomic DNA, with a size of 200-1500 bp, can be obtained after lysis, pre-amplification and amplification. The amplified product can be widely used in second-generation sequencing, large fragment copy number variation analysis, SNP typing, qPCR analysis and gene chip analysis.Bring your own instruments and reagentsPCR instrument Reaction tubes: low adsorption tubes recommended Gun Heads: High quality filtered gun heads are recommended Microcentrifuge, vortex mixercaveat The sensitivity of this product is very high, the experimental operation should be completed in a positive pressure ultra-clean bench or clean environment, the concentration of the amplification reaction products is high, should be well isolated to avoid aerosol contamination caused by amplification products.Operation flow diagramprocedurePre-experiment preparationSingle cells were obtained by flow cytometry sorting, buffer dilution, micromanipulation and laser microdissection. It is recommended that the cells be washed prior to the experiments with a 1× PBS solution free of Mg2+ and Ca2+, taking care to ensure that the volume of PBS solution in subsequent experiments does not exceed 2 µl. take note of Since the whole experiment is carried out in the same PCR tube and the reaction volume is small, the pipette tip should not touch the liquid in the tube when adding liquid, so as to avoid taking single cells or DNA out of the reaction system; when pipetting, please add the liquid along the wall of the tube carefully and do not blow the liquid in the PCR tube; before the reaction, please centrifuge briefly to make sure that the liquid in the reaction system is mixed evenly. Thaw the cell lysate, pre-amplifier and amplifier on ice before use.cell lysis 1）Mix Cell Lysis Buffer and Cell Lysis Enzyme according to the number of reactions N, shake to mix, centrifuge briefly and set aside.2）Mix single cells with the cell lysis mix in a PCR tube and run the following program.2. Pre-amplification reaction1）Mix Cell Lysis Buffer and Cell Lysis Enzyme according to the number of reactions N, shake to mix, centrifuge briefly and set aside.2）Add 5 µl of pre-amplification mix to 10 µl of lysis reaction product from the previous step and run the following program. 3. Amplification reaction1）Mix Amplification Buffer and Amp Enzyme Mix according to the number of reactions N, mix with shaking, centrifuge briefly and set aside.2）Add 60 µl of amplification mix to 15 µl of pre-amplification reaction product from the previous step and run the following program.Note: The number of cycles can be adjusted as needed, 14 cycles are recommended for single cells obtained by flow sorting, etc.Amplification product detection 1. Agarose gel electrophoresis 5 µl of the amplified product was subjected to agarose gel electrophoresis (1% agarose gel, 110 V, 25-35 min), and the amplified product was 200-1500 bp in size. 2. Quantitative Amplification products were subjected to magnetic bead or column purification, and purified products were quantified using Qubit with a final yield of 2-5 µg... Read More |