| Description | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export | 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 miRNA extraction kit is specifically designed to isolate and purify miRNAs from various animal tissues, plant tissues, cells, serum, plasma and other samples. It can also extract small molecule RNAs such as siRNA and snRNA that are less than 200 nt, and can also be used for the extraction of The miRNA extraction kit is specifically designed to isolate and purify miRNAs from various animal tissues, plant tissues, cells, serum, plasma and other samples. It can also extract small molecule RNAs such as siRNA and snRNA that are less than 200 nt, and can also be used for the extraction of total RNA. This product combines phenol/guanidine lysis technology and silicon matrix membrane purification technology. The unique lysis solution can effectively inhibit RNases while removing most of DNA and proteins from cell or tissue samples through organic extraction. For some sensitive downstream experiments, if miRNA enrichment is required, this kit can be used to enrich miRNA separately. This product is suitable for a wide range of samples, with high purity of prepared RNA, and can be directly used for sensitive downstream applications, such as Northern Blot analysis, Real Time PCR, Microarray Analysis, etc. M665531Component50 TStorageM665531ATRIzon Reagent60 mL2-8℃. Protect from ligt.M665531BBuffer RWT (concentrate)15 mLRTM665531CBuffer RW2 (concentrate)11 mLRTM665531DRNase-Free Water10 mLRTM665531ESpin Columns RM with Collection Tubes50 setsRTM665531FSpin Columns RS with Collection Tubes50 setsRTM665531GRNase-Free Centrifuge Tubes (1.5 mL)50 EART Self prepared reagents: chloroform, anhydrous ethanol (newly opened or dedicated for RNA extraction).Preparation and important precautions before the experiment:To prevent RNase pollution, attention should be paid to the following aspects:1) Use RNase free plastic products and gun heads to avoid cross contamination.2) Glassware should be dry baked at a high temperature of 180 ℃ for 4 hours before use, while plastic containers can be soaked in 0.5 M NaOH for 10 minutes, thoroughly rinsed with water, and then sterilized under high pressure.3) Prepare the solution using water without RNase.4) Operators should wear disposable masks and gloves, and change gloves frequently during the experiment.2. The extracted samples should avoid repeated freeze-thaw cycles, otherwise it will affect the quantity and quality of miRNA extraction.Before the first use, anhydrous ethanol should be added to Buffer RWT and Buffer RW2 according to the instructions on the reagent bottle label.4. All centrifugation steps should be carried out at room temperature unless otherwise specified, and all operation steps should be carried out quickly.Operation steps:Protocol A: miRNA enrichment (can be directly used for sensitive downstream experiments)1. Sample processing1a Organization: Grind the organization in liquid nitrogen. Add 1 ml of TRIzon Reagent to every 30-50 mg of tissue, shake and mix well. The sample volume shall not exceed one tenth of the volume of TRIzon Reagent.1b Single layer culture of cells: Remove the culture medium, add TRIzon Reagent, and add 1 ml of TRIzon Reagent every 10 cm2 (the amount of lysis solution depends on the area of the culture bottle).1c Cell suspension: Centrifuge to obtain cell precipitate, discard supernatant. Add 1 ml of TRIzon Reagent to every 5 x 106-1 x 107 cells (cells do not require washing).1d Plasma or serum: Take 200 µ Add 5 times the volume of TRIzon Reagent to plasma or serum samples, shake and mix well for 30 seconds.2. After adding TRIzon Reagent to the sample, blow it repeatedly several times to fully crack it. Leave at room temperature for 5 minutes to completely separate the protein nucleic acid complex.3. Optional steps: Centrifuge at 4 ℃ 12000 rpm (~13400 × g) for 5 minutes, take the supernatant, and transfer it to a new centrifuge tube (provided by oneself) (if the sample contains more proteins, fats, polysaccharides, etc., this step can be performed).4. Add chloroform to the supernatant and add 200 to every 1 ml of TRIzon Reagent used µ Chloroform, cover the tube, vigorously shake for 15 seconds, and let it sit at room temperature for 5 minutes.Centrifuge at 5.4 ℃ and 12000 rpm for 15 minutes. The sample is divided into three layers: red organic phase, middle layer, and colorless aqueous phase. Transfer the upper colorless aqueous phase to a new centrifuge tube (self prepared).6. Add 1/3 volume of anhydrous ethanol to the solution obtained in step 5, mix well, and transfer the obtained solution and precipitate together into the adsorption column RM (Spin Columns RM) that has been loaded into the collection tube. If you cannot add all the solution to the adsorption column at once, please transfer it multiple times. Centrifuge at 12000 rpm for 30 seconds, discard the adsorption column RM after centrifugation, and retain the effluent.7. Add 2/3 times the volume of anhydrous ethanol to the solution obtained in step 6 and mix well.8. Transfer the solution and precipitate obtained from the previous step into the adsorption column RS (Spin Columns RS) that has been loaded into the collection tube. If you cannot add all the solution to the adsorption column at once, please transfer it multiple times. Centrifuge at 12000 rpm for 30 seconds, discard the waste liquid in the collection tube, and place the adsorption column RS back into the collection tube.9. Add 700 to the adsorption column RS µ L Buffer RWT (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 30 seconds, discard the waste liquid in the collection tube, and place the adsorption column RS back into the collection tube.10. Add 500 to the adsorption column RS µ Buffer RW2 (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 30 seconds, discard the waste liquid in the collection tube, and place the adsorption column RS back into the collection tube.11. Repeat step 10.12. Centrifuge at 12000 rpm for 1 minute and discard the waste liquid from the collection tube. Place the adsorption column RS 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 RS, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).13. Place the adsorption column RS in a new RNase free centrifuge tube and add 30-50 to the middle of the adsorption column µ Place RNase Free Water at room temperature for 1 minute, centrifuge at 12000 rpm for 1 minute, collect RNA solution, and store the obtained RNA solution at -70 ℃ to prevent degradation.Attention:1) The volume of RNase Free Water should not be less than 30 µ l. Small volume affects the recovery rate.2) If you want to increase RNA production, you can use 30-50 µ Repeat step 13 for the new RNase Free Water.3) If you want to increase the RNA concentration, you can add the obtained solution back to the adsorption column RS and repeat step 13Protocol B: Extraction of total RNA (including miRNA and other small molecule RNAs<200 nt), steps 1-5 are the same as protocol A.6. Add 1.25 times the volume of anhydrous ethanol to the solution obtained in step 5 and mix well.7. Transfer the solution and precipitate obtained from the previous step into the spin columns RM that have been loaded into the collection tube. If you cannot add all the solution to the adsorption column RM at once, please transfer it multiple times. Centrifuge at 12000 rpm for 30 seconds, discard the waste liquid in the collection tube, and place the adsorption column RM back into the collection tube.8. Add 700 to the adsorption column RM µ L Buffer RWT (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 30 seconds, discard the waste liquid in the collection tube, and place the adsorption column RM back into the collection tube.9. Add 500 to the adsorption column RM µ Buffer RW2 (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 30 seconds, discard the waste liquid in the collection tube, and place the adsorption column RM back into the collection tube.10. Repeat step 9.11. Centrifuge at 12000 rpm for 1 minute and discard the waste liquid from the collection tube. Place the adsorption column RM at room temperature for a few minutes to thoroughly air dry. Attention: The purpose of this step is to remove residual ethanol from the adsorption column RM, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).12. Transfer the adsorption column RM into a new RNase free centrifuge tube and add 30-50 to the middle of the adsorption column µ Place RNase Free Water at room temperature for 1 minute, centrifuge at 12000 rpm for 1 minute, collect RNA solution, and store the obtained RNA solution at -70 ℃ to prevent degradation. Attention: 1) The volume of RNase Free Water should not be less than 30 µ l. Small volume affects the recovery rate.2) If you want to increase RNA production, you can use 30-50 µ Repeat step 12 for the new RNase Free Water.3) If you want to increase the RNA concentration, you can add the obtained solution back to the adsorption column RM and repeat step 12... 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 contentS665868Component50 TStorageS665868ABuffer GL25 mLRTS665868BBuffer GW1 (concentrate)13 mLRTS665868CBuffer GW2 (concentrate)15 mLRTS665868DBuffer GE15 mLRTS665868EProteinase K2×1.25 mLRTS665868FSpin Columns DM with Collection Tubes50 setsRTProduct IntroductionThis kit is suitable Product contentS665868Component50 TStorageS665868ABuffer GL25 mLRTS665868BBuffer GW1 (concentrate)13 mLRTS665868CBuffer GW2 (concentrate)15 mLRTS665868DBuffer GE15 mLRTS665868EProteinase K2×1.25 mLRTS665868FSpin Columns DM with Collection Tubes50 setsRTProduct IntroductionThis kit is suitable for the extraction of genomic DNA from fresh saliva or saliva/preservation solution mixture.The purification process of this product does not require the use of toxic solvents such as phenol or chloroform, and ethanol precipitation is not necessary. The optimized buffer system enables DNA to bind heterogeneously to the silica matrix centrifugal adsorption column, and the inhibitors of PCR and other enzymatic reactions can be effectively removed by a two-step washing step, and finally eluted with a low-salt buffer or water to obtain high-purity DNA.The purified obtained can be directly used for enzyme digestion, PCR, Real-Time PCR, library construction, Southern Blot, molecular labeling and other downstream experiments.Self-contained reagent: anhydrous ethanolPre-experiment Preparation and Important Notes1. Repeated freezing and thawing of the sample should be avoided, as this may result in smaller fragments of extracted DNA and a decrease in the amount extracted.2. Anhydrous ethanol should be added to Buffer GW1 and Buffer GW2 according to the instructions on the label of the reagent bottle before first use.3. Before use, please check whether Buffer GL appears to be crystallized or precipitated.Redissolve in a 56°C water bath.4. If the downstream experiments are sensitive to RNA contamination, 4 µL DNase-Free RNase A can be added in step 3(100 mg/mL).5. For prolonged storage of salivary DNA at room temperature, our Salivary DNA Preservation Tubes are recommended.Operation steps1. Add 400 µL of saliva sample or saliva/preservation solution mixture.Note: 1) Saliva mixtures added to the preservation solution require a 50°C water bath for 1 hour or an empty 50°C temperature chamber for 2 hours prior to extraction.2) If an increase in sample volume is required, multiply the volumes of Proteinase K, Buffer GL, and anhydrous ethanol in Steps 2-4, and the liquid can be transferred in multiple times in Step 5.2. Add 40 µL of Proteinase K.3. Add 400µL Buffer GL, vortex and shake to mix thoroughly, and water bath at 56℃ for 15-30 minutes.Note: If RNA removal is required, add 4 µL of RNase A solution at a concentration of 100 mg/mL after the above steps are completed, vortex for 15 seconds, and leave at room temperature for 2 minutes.4. Centrifuge briefly to remove water droplets from the inside of the tube cap. Add 400 µL of anhydrous ethanol and mix well by vortexing and shaking. Centrifuge briefly.Note: 1) Vortex and shake to mix immediately after adding Buffer GL and anhydrous ethanol.The addition of Buffer GL and anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.2) A sol-gel product may be formed after GL and anhydrous ethanol, in which case vigorous shaking or vortexing is recommended.3) The solution obtained in the previous step is added to the adsorption column in the Collection Tube.5. (Spin Column DM) in the collection tube, and if the solution cannot be added all at once, it can be transferred in several times. centrifuge at 12,000 rpm (∼13,400 × g) for 1 min, pour off the waste solution in the collection tube, and put the adsorption column back into the collection tube.6. Add 500 µL of Buffer GW1 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.7. Add 500 µL of Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.Note: Step 7 can be repeated if further DNA purity is required.8. Centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Leave the adsorption column at room temperature for several minutes to dry thoroughly.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).9. Place the adsorption column in a new centrifuge tube (supplied), add 50-200 µL of Buffer GE or sterilized water to the middle of the adsorption column overhanging the column, let it stand at room temperature for 2-5 minutes, and centrifuge at 12,000 rpm for 1 minute to collect the DNA solution.-20°C to preserve DNA.Note: 1) If the downstream experiment is sensitive to pH or EDTA, you can use sterilized water for elution. The pH of the eluent has a great influence on the elution efficiency, if water is used as the eluent should ensure that its pH is 7.0-8.5 (you can use NaOH to adjust the pH of the water to this range), and the elution efficiency is not high when the pH is lower than 7.0.2) Buffer GE preheated in a 65-70°C water bath and incubated at room temperature for 5 min before centrifugation can increase the yield.3) Because DNA preserved in water is subject to acidic hydrolysis, for long-term storage, elution with Buffer GE and storage at -20°C is recommended... Read More |