| 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 | 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 introduction：Griess reagent can be used for spectrophotometric detection of nitrite. The reagent contains two chemicals, sulfonic acid and n- (1-naphthyl) ethylenediamine. Under acidic conditions, sulfamic acid is converted into diazonium salt by nitrite, which can form a highly Product introduction：Griess reagent can be used for spectrophotometric detection of nitrite. The reagent contains two chemicals, sulfonic acid and n- (1-naphthyl) ethylenediamine. Under acidic conditions, sulfamic acid is converted into diazonium salt by nitrite, which can form a highly colored azo dye with n- (1-naphthyl) ethylenediamine. This dye can be detected at 548 nm: because no is extremely unstable, it is oxidized to form nitrite and nitrate. Griess indirectly reflects the content of no by detecting the content of nitrite.Matters needing attention：1. before using Griess reagent, return it to room temperature and check the solution for precipitation. If Griess reagent I contains sediment when taken out, it can be placed in a 37 ℃ water bath until the sediment dissolves. 2. this product is potentially harmful. Avoid prolonged or repeated exposure. Avoid entering eyes, skin or clothing. Please wear lab clothes and disposable gloves for operation.Scope of application：No detectionComponent：Instruction：1.Griess Reagent I and II were taken out to restore the room temperature.2.Standard dilution : The standard NaNO2 ( 1-100 µM ) was diluted with the solution used for the sample to be tested. The standard was diluted to 1 µM, 10 µM, 20 µM, 40 µM, 80 µM and 100 µM, and 100 µL standard was added to each well. If the sample concentration is too low, the range of the standard curve can be appropriately reduced ( 1 µM, 2 µM, 3 µM, 4 µM, 6 µM, 8 µM, 10 µM ).3.Sample detection :( 1 ) According to the total volume of 200 µL / hole, 100 µL / hole sample was added to the 96-well plate ; if the sample is the supernatant of the culture medium, it can be sampled directly, and if there is sediment, the supernatant should be taken after centrifugation. If the sample is a cell or tissue, it can be quickly lysed by freeze-thaw, and then centrifuged to obtain the supernatant. The volume of less than 100 µL can be diluted with diH2O or 0.9 % NaCl ( corresponding standards also need to be diluted with diH2O or 0.9 % NaCl ).( 2 ) According to 50 µL / hole, Griess Reagent I was added to each hole.( 3 ) According to 50 µL / hole, Griess Reagent II was added to each hole.( 4 ) The absorbance was measured at 540 nm. If there is no 540 nm filter, 520-560 nm filter can also be. If there is no microplate reader or a suitable filter, the concentration of nitric oxide in the sample can also be determined by visual colorimetry. A more precise concentration gradient is required for the standard when visual colorimetric... Read More | Product contentP666142Component200 TStorageP666142ABuffer P160 mLRTP666142BBuffer P260 mLRTP666142CBuffer N380 mLRTP666142DBuffer PB35 mLRTP666142EBuffer PW (concentrate)25 mLRTP666142FBuffer EB30 mLRTP666142GRNase A (10 mg/mL)600 µLRTP666142HSpin Columns DM with Collection Tubes200 EART Product contentP666142Component200 TStorageP666142ABuffer P160 mLRTP666142BBuffer P260 mLRTP666142CBuffer N380 mLRTP666142DBuffer PB35 mLRTP666142EBuffer PW (concentrate)25 mLRTP666142FBuffer EB30 mLRTP666142GRNase A (10 mg/mL)600 µLRTP666142HSpin Columns DM with Collection Tubes200 EART Product IntroductionThis kit is suitable for extracting 1-5 ml of bacterial solution. Based on the lysis of cells by alkaline lysis method, it adopts a unique silica matrix membrane adsorption technology and reagent formulation, and efficiently and exclusively binds plasmid DNA in solution by centrifugal adsorption columns in a high-salt state, and each adsorption column can adsorb a maximum of 30 µg of plasmid DNA, and removes proteins, genomes, RNAs, and other impurities to the greatest extent possible. The plasmid DNA obtained can be directly used for cell transfection, PCR, digestion, sequencing, ligation and other biological experiments.Self-contained reagent: anhydrous ethanol.Pre-experiment Preparation and Important Notes1. All components can be stably stored in dry, room temperature (15-30℃) environment for 1 year, the adsorption column can be stored at 2-8℃ for a longer period of time, and Buffer P1 with RNase A can be stably stored at 2-8℃ for 6 months.2. Before the first use, add all the RNase A solution into Buffer P1, mix well, and store it at 2-8°C. Before use, leave it at room temperature for a period of time, and then use it after recovering to room temperature.3. Anhydrous ethanol should be added to Buffer PW according to the instructions on the label of the reagent bottle before first use.4. If precipitation is found in Buffer P2, Buffer N3, or Buffer PB before use, the clarification can be restored by water bath at 37℃ for a few minutes (please do not shake Buffer P2 violently).5. Be careful not to touch Buffer P2, Buffer N3 and Buffer PB directly, and tighten the lid immediately after use.6. The amount and purity of extracted plasmid is related to the concentration of bacterial culture, strain type, plasmid size, plasmid copy number and other factors.Procedure1. Take 1-5 ml of the overnight culture and add it to a centrifuge tube (self-prepared), centrifuge for 30 seconds at 13,000 rpm (~16,200×g) to collect the bacterial precipitate, and discard the supernatant as much as possible.2. Add 250 µl of Buffer P1 to the centrifuge tube with the bacterial precipitate (please check that RNase A has been added first), mix well using a pipette or vortex shaker, and suspend the bacterial precipitate.Note: If the bacterial mass is not thoroughly mixed, it will affect the lysis effect, resulting in low extraction and purity.3. Add 250µl of Buffer P2 to the centrifuge tube and mix gently up and down 4-6 times, mixing well to lyse the organisms, at which point the solution should become clear and viscous.Note: Mix gently, do not shake vigorously to avoid interrupting the genomic DNA and causing the extracted plasmid to be mixed with genomic DNA fragments. This step should take no more than 5 minutes to avoid damage to the plasmid.4. Add 350 µl of Buffer N3 to the centrifuge tube and immediately mix gently up and down for 8-10 times, mixing well so that a white flocculent precipitate should appear. centrifuge at 13,000 rpm for 5 minutes.Note: Buffer N3 should be mixed immediately after addition to avoid localized precipitation.5. Transfer the supernatant obtained in step 4 to the Spin Columns DM that have been loaded into the collection tube, centrifuge at 13,000 rpm for 30 seconds, pour off the waste liquid from the collection tube, and place the column back into the collection tube.6. Add 150 µl Buffer PB to the adsorption column and centrifuge at 13,000 rpm for 30 seconds.7. Add 400 µl Buffer PW to the adsorption column (please check that anhydrous ethanol has been added first), centrifuge at 13,000 rpm for 1 minute, and pour off the waste liquid in the collection tube.8. Place the adsorbent column in a new centrifuge tube (supplied), add 50-100 µl Buffer EB to the middle of the adsorbent membrane, leave it at room temperature for 2 minutes, centrifuge at 13,000 rpm for 1 minute, and collect the plasmid solution into the centrifuge tube. -The plasmid solution was collected into the centrifuge tube.Note: 1) To increase the recovery efficiency of the plasmid, the resulting solution can be reintroduced into the adsorbent column, left at room temperature for 2 minutes, centrifuged at 13,000 rpm for 1 minute, and the plasmid solution collected into a centrifuge tube.2) For low plasmid copy number or >10 kb, Buffer EB is preheated at 65-70°C in a water bath to increase extraction efficiency... Read More | Products contentProducts IntroductionThis product uses the principle that the difference between the concentration of salt ions inside and outside the cell can cause the cell membrane to burst to lyses the cell and releases the genomic DNA, without the need of extracting and purifying the genomic Products contentProducts IntroductionThis product uses the principle that the difference between the concentration of salt ions inside and outside the cell can cause the cell membrane to burst to lyses the cell and releases the genomic DNA, without the need of extracting and purifying the genomic DNA.This product is suitable for a variety of sources of samples, and can be used as a template for PCR and qPCR experiments after sample processing, and can achieve the effect of the purified DNA used as a template for PCR and qPCR experiments. Usage1. Depending on the type of sample, prepare the appropriate sample size according to the table below.2. Add the sample to a 1.5-mi centrifuge tube and add the recommended volume of Solution A as shown in the table below. Vortex for 20 s and allow to stand at room temperature for 3-5 min or incubate in a metal bath at 95°C for 3-5 min as recommended in the table below.3. After the sample has been sufficiently lysed (samples incubated in a metal bath at 95°C should be brought to room temperature), add the recommended volume of Solution B as shown in the table below and vortex for 30s.4. Store processed samples at 4°C if the next test is to be performed within 2 hours, or at -20°C if the next test cannot be performed immediately.take note of1) Depending on the requirements of the experimental conditions, the amount of samples can be expanded or reduced, and the amount of Solution A and Solution B can be increased in equal proportions.2) For blood and cell samples, the temperature of room temperature lysis is required to be around 25C. If the ambient temperature does not reach 25°, the lysis time can be extended appropriately, or the vortex shaking time can be extended to ensure that the samples are fully lysed. If there is no relevant professional instrument, the centrifuge tube can be shaken vigorously to ensure adequate lysis.3) After the tissue sample is made into tissue homogenate by adding 10 times the volume of saline, it can be processed in the same way as blood samples.4) Strictly prohibit the use of expired products, please do not mix different reagents.5) laboratory supplies should be regularly cleaned and 10% of the 84 disinfectant solution or ultraviolet lamp for anti-pollution treatment, special areas dedicated to prohibit cross use, so as to avoid contamination, the end of the test, the bench should be cleaned immediately... Read More |