| 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 | Inquire | Inquire | Product contentN666081Component50 TStorageN666081ANc-Buffer A50 mL2-8℃N666081BNc-Buffer B3 mL2-8℃N666081CNc-Buffer C25 mL2-8℃N666081DProtease Inhibitor Cocktail750 µL-20℃. Avoid freeze/thaw cycle.ProductsThe Nc-Nucleus/Plasma Protein Extraction Kit is a simple and rapid Product contentN666081Component50 TStorageN666081ANc-Buffer A50 mL2-8℃N666081BNc-Buffer B3 mL2-8℃N666081CNc-Buffer C25 mL2-8℃N666081DProtease Inhibitor Cocktail750 µL-20℃. Avoid freeze/thaw cycle.ProductsThe Nc-Nucleus/Plasma Protein Extraction Kit is a simple and rapid method for extracting nucleus and plasma proteins from mammalian cells and tissues, and the extracted proteins remain biologically active. The kit first cleaves the cell membrane and releases plasma proteins using the plasma protein extraction reagent, and then centrifuges the nucleus to obtain a nucleus precipitate. Finally, the nuclear proteins are extracted by the nuclear protein extraction reagent. The extracted nuclear and plasma proteins are of high purity, effectively avoiding cross-contamination of nuclear and plasma proteins, and can be used for subsequent operations such as Western, Gel Shift, reporter gene detection and enzyme activity determination.Caveat1. If phosphorylated proteins are to be extracted, add a phosphatase inhibitor to the extraction reagent.2. All sample handling should be done on ice.3. The amount of reagents can be adjusted according to the specific experimental situation to ensure that the ratio of each reagent used is Nc-Buffer A:Nc-Buffer B:Nc-Buffer C = 100:5.5:50.4. Higher speeds can be used for centrifugation.ProcedureI Extraction of cytoplasmic and cytosolic proteins from cells1. Please remove the extraction reagents Nc-Buffer A and Nc-Buffer C for pre-cooling before protein extraction.2. Collect the cells and count them. Centrifuge to remove supernatant.3. 1×107 cells were added with 1 ml of Nc-Buffer A (added to Protease Inhibitor Cocktail at a ratio of 1:99 within 2-3 minutes prior to protein pumping), vortexed for 5 seconds to mix well, and incubated on ice for 20 minutes.Note: The characteristics of various cells are different, and the amount of Nc-Buffer A needs to be adjusted according to the characteristics of different cells. If the protein concentration is small, reduce the amount of Nc-Buffer A and subsequent Nc-Buffer B and Nc-Buffer C proportionally.4. Add 55 µl of Nc-Buffer B, vortex for 5 seconds to mix thoroughly, and incubate on ice for 1 minute.5. Centrifuge at 12,000 rpm (~13,400 x g) for 15 minutes at 4°C, collect the supernatant (as clean as possible) into a new centrifuge tube and store at -20°C (this extract is cytoplasmic protein).6. Add 500 µl of Nc-Buffer C (add Protease Inhibitor Cocktail at a ratio of 1:99 before use) to the precipitate obtained in the previous step, vortex for 5 seconds to mix thoroughly, resuspend the precipitate and incubate on ice for 40 minutes, vortexing and mixing at 10-minute intervals for about 15-30 seconds each time.7. Centrifuge at 12,000 rpm for 15 minutes at 4°C, collect the supernatant (as clean as possible) into a new centrifuge tube and store at -20°C (this extract is for cytosolic proteins).II Extraction of cytoplasmic and cytosolic proteins from tissues1. Sampling and preservation of tissues.2. Remove the extraction reagents Nc-Buffer A and Nc-Buffer C for pre-cooling before protein extraction.3. Weigh the tissue and add 1 ml of Nc-Buffer A per 100 mg of tissue (add Protease Inhibitor Cocktail 2-3 minutes before protein extraction at a ratio of 1:99), homogenize well on ice with a homogenizer, and incubate on ice for 20 minutes.Note: The characteristics of various tissues are different, and the amount of Nc-Buffer A needs to be adjusted according to different tissues. If the protein concentration is small, reduce the amount of Nc-Buffer A and subsequent Nc-Buffer B and Nc-Buffer C proportionally.4. Add 55 µl of Nc-Buffer B, vortex for 5 seconds to mix thoroughly, and place on ice for 1 minute of incubation.5. Centrifuge at 12,000 rpm for 15 minutes at 4°C, collect the supernatant (as clean as possible) into a new centrifuge tube and store at -20°C (this extract is cytoplasmic protein).6. Add 500 µl of Nc-Buffer C (add Protease Inhibitor Cocktail at a ratio of 1:99 before use) to the precipitate obtained in the previous step, vortex for 5 seconds to mix thoroughly, resuspend the precipitate and incubate on ice for 40 minutes, vortexing and mixing at 10-minute intervals at, each time for about 15-30 seconds.7. Centrifuge at 12,000 rpm for 15 minutes at 4°C, collect the supernatant (as clean as possible) into a new centrifuge tube and store at -20°C (this extract is cytosolic protein)... 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 |