| Description | 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 Content D669986Component50 TStorageD669986ABuffer SA15 mLRTD669986B2×PCR MasterMix1 mL-20℃. Avoid freeze/thaw cycle.D669986CProteinase K12.5 mgRTD669986DProteinase K Storage Buffer1.25 mLRTProductsThis kit adopts a unique buffer system containing all the reagents for rapid Product Content D669986Component50 TStorageD669986ABuffer SA15 mLRTD669986B2×PCR MasterMix1 mL-20℃. Avoid freeze/thaw cycle.D669986CProteinase K12.5 mgRTD669986DProteinase K Storage Buffer1.25 mLRTProductsThis kit adopts a unique buffer system containing all the reagents for rapid preparation of genomic DNA and PCR amplification, and is suitable for one-step extraction of genomic DNA from various plant and animal tissues and bacteria and for PCR amplification. The whole extraction process does not require liquid nitrogen grinding, organic solvent extraction, anhydrous ethanol precipitation, and the quality of extracted DNA is stable. The 2×PCR MasterMix provided in this kit is a highly compatible PCR reagent that can amplify DNA samples efficiently and specifically, which includes DNA polymerase, dNTPs, MgCl2, reaction buffer, PCR reaction enhancer and so on. It is characterized by fast and easy, high sensitivity, high specificity, good stability, etc. It is especially suitable for high throughput screening.Pre-experiment Preparation and Important Notes1. Add the specified amount of Proteinase K Storage Buffer to Proteinase K to dissolve it and store it at -20℃. Do not leave the prepared Proteinase K at room temperature for a long time, and avoid repeated freezing and thawing to avoid affecting its activity.2. Repeated freezing and thawing of the samples should be avoided, as this will result in smaller DNA fragments and a decrease in the amount of extracted DNA.3. Before use, please check Buffer SA for crystallization or precipitation. If crystallization or precipitation occurs, please re-dissolve Buffer SA in a 56℃ water bath.4. The PCR MasterMix provided with this product is 2×, when using it, you need to add template and primer, and add RNase-Free Water to make up the volume, so that its concentration is 1× to carry out the reaction.Procedure1. Fetch:Plant material: take about 10 mg of sample in a centrifuge tube (provided); Animal material: take about 10 mg of sample in a centrifuge tube (provided);Bacteria: Take 200-800 µL of bacteria in good growth condition in a centrifuge tube (self-provided) and collect the bacteria.2. Add 200 µL of Buffer SA and vortex to mix.Note: In the case of plant leaves and animal tissues, they should be ground with a pestle and mortar as much as possible: in the case of plant seeds, they should be crushed and finely ground beforehand; bacterial and 1-3 mm rat-tail samples can be directly vortex lysed.3. Add 10µL of Proteinase K, mix well, incubate at 56℃ for 10 minutes, and treat at 95℃ for 5 minutes.Note: 1) In the case of animal tissue samples, the incubation time at 56°C may be extended to 30 minutes as appropriate; if there is any incompletely digested tissue, it should be removed as thoroughly as possible after centrifugation in the next step.2) Be careful not to exceed 5 minutes when treating at 95°C.4. 13,000 rpm (~17,900 x g), centrifugation for 5 minutes.5. Transfer the supernatant to a new centrifuge tube (self-prepared) and use it directly for PCR amplification, or store the solution at 4℃ or -20℃.6. PCR amplification:1) PCR reaction system:The following examples are conventional PCR reaction systems and reaction conditions, which should be improved and optimized according to the template, primer structure and target fragment size in actual operation.reagents20 µL systemfinal concentration2×PCR MasterMix10 µL1×Forward Primer, 10 µM1 µL0.4 µMReverse Primer, 10 µM1 µL0.4 µMTemplate DNA1-2 µL RNase-free Waterup to 20 µLNote: Please use the final concentration of 0.2-0.6µM as a reference for setting the range of primer concentration. If the amplification efficiency is not high, the concentration of primer can be increased; if a non-specific reaction occurs, the concentration of primer can be decreased, thus optimizing the reaction system.2）PCR reaction conditions:movetemptimingpremutability94°C2mindenaturation94°C30sannealing (metallurgy)55-65°C30s30-40 cyclesreach72°C60sultimate extension72°C5minNote: 1) In general, the annealing temperature is 5℃ lower than the melting temperature of the amplification primer Tm, and the annealing time is generally 30-60 seconds. When the desired amplification efficiency cannot be obtained, the annealing temperature should be lowered appropriately; when a non-specific reaction occurs, the annealing temperature should be raised, thus optimizing the reaction conditions.(2) The extension time is set according to the size of the fragment to be amplified, and the amplification efficiency of Taq DNA Polymerase included in this product is 1kb/30s. 3) The number of cycles can be set according to the downstream application of the amplification product. If the number of cycles is too low, the amplification is insufficient; if the number of cycles is high, the chance of mismatch will increase and the non-specific background will be serious. Therefore, the number of cycles should be minimized under the premise of ensuring the product yield.(3) Result detection: 5 µL of reaction product was taken at the end of the reaction and directly detected by agarose gel electrophoresis... Read More | Inquire | Products contentN665978Component384 TStorageN665978AIndex N502-N522 Primers for Illumina 16×24 µL-20℃. Avoid freeze/thaw cycle.N665978BIndex N701-N729 Primers for Illumina24×16 µL-20℃. Avoid freeze/thaw cycle. Products IntroductionThis kit is a companion to the Products contentN665978Component384 TStorageN665978AIndex N502-N522 Primers for Illumina 16×24 µL-20℃. Avoid freeze/thaw cycle.N665978BIndex N701-N729 Primers for Illumina24×16 µL-20℃. Avoid freeze/thaw cycle. Products IntroductionThis kit is a companion to the transposase-based rapid DNA library construction kit, designed for Illumina platform library construction. It contains 16 N5 primers and 24 N7 primers, which can be used to prepare 384 different bipartite Index libraries. All reagents provided in the kit have been subjected to stringent quality control and functional validation to maximize the stability and reproducibility of library construction. The libraries can be used for sequencing on Illumina platforms such as HiSeq X-10/4000/2500/2000 and MiSeq.Provide your own instruments, reagents and consumables1. Magnetic frame: DynaMagTM-2 is recommended.2. DNA purification and recovery kit: It is recommended to use Kangwei DNA purification and recovery kit by magnetic bead method.3. DNA building kit: It is recommended to use the Kangwei Century transposase method second-generation sequencing rapid DNA building kit.4. Anhydrous ethanol.5. Reaction tubes: It is recommended to use low adsorption PCR tubes with 1.5 ml centrifuge tubes; Tip: It is recommended to use a high quality filter tip to prevent contamination of kits and library samples. Pre-experiment Preparation and Important NotesPlease centrifuge briefly before opening the cap so that the liquid collects at the bottom of the tube to avoid cross-contamination between different primers.procedure For the use of the CombiVision Second Generation Sequencing Multisample Primer Kit, please follow the CombiVision Second Generation Sequencing Rapid DNA Library Kit protocol. Index N502-N522 Primers for Illumina Index N701-N729 Primers for Illumina... Read More | This kit is suitable for extracting total RNA from fresh whole blood (blood samples treated with anticoagulants such as citrate, EDTA, or heparin). It can process up to 1.5 ml of whole blood and elute to obtain high-purity RNA with a molecular weight greater than 200 bp. Multiple samples can be This kit is suitable for extracting total RNA from fresh whole blood (blood samples treated with anticoagulants such as citrate, EDTA, or heparin). It can process up to 1.5 ml of whole blood and elute to obtain high-purity RNA with a molecular weight greater than 200 bp. Multiple samples can be completed simultaneously within 1 hour. This product does not require the ultra centrifugation step of CsCl purification and LiCl or ethanol precipitation. It does not contain toxic solvents such as phenol or chloroform. The purified RNA effectively removes enzyme inhibitors and pollutants such as heme and heparin. It can be directly used in various molecular biology routine experiments, such as RT-PCR, Northern Blot, Dot Blot, in vitro translation, and so on.Self prepared reagents: β- Mercaptoethanol, 70% ethanol (prepared with water without RNase), anhydrous ethanol. R666034 Component 50 T Storage R666034A Buffer RBL (10×) 60 mL RT R666034B Buffer RL 35 mL RT R666034C Buffer RW1 40 mL RT R666034D Buffer RW2 (concentrate) 11 mL RT R666034E RNase-Free Water 10 mL RT R666034F Spin Columns FL with Collection Tubes 50 sets RT R666034G Spin Columns RM with Collection Tubes 50 sets RT R666034H RNase-Free Centrifuge Tubes (1.5 mL) 50 EA RT Preparation and important precautions before the experimentTo 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 0.5M 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 sample should avoid repeated freezing and thawing, otherwise it will affect the yield and quality of RNA extraction. The sample can be stored in Buffer RL at -70 ℃ for one month.3. Before use, please check if there is any crystallization or precipitation in the Buffer RL. It can be dissolved again in a 56 ℃ water bath. Please add Buffer RL before use β- Mercaptoethanol, with a final concentration of 1%. Add 10 to 1 ml Buffer RL µ L β- Mercaptoethanol. join β- The buffer RL room temperature of mercaptoethanol can be stored for one month.4. Before the first use, anhydrous ethanol should be added to Buffer RW2 according to the instructions on the reagent bottle label.5. This reagent kit cannot be used for RNA extraction from frozen blood samples with anticoagulants added.6.10 × Buffer RBL needs to be diluted 10 times with water without RNase before use, and then stored at 2-8 ℃ after dilution.7. If downstream experiments are highly sensitive to DNA, it is recommended to treat RNA with DNase I that does not contain RNase.8. All centrifugation steps should be carried out at room temperature unless otherwise specified, and all operation steps should be carried out quickly.Operation steps1. Add 5 times the volume of 1 x Buffer RBL to fresh anticoagulant whole blood samples of 0.5-1.5 ml (please dilute 10 x Buffer RBL with RNase free water before use), gently vortex or invert and mix well. Incubate on ice for 10-15 minutes, mix twice during the incubation process.Attention: During the incubation process, the cloudy suspension will become transparent, indicating that red blood cells have been lysed. If necessary, the incubation time can be extended to 20 minutes. 2. Centrifuge at 4 ℃, 2100 rpm (~400 × g) for 10 minutes, and carefully discard the supernatant.3. Add 2 times the volume of the blood sample to the above precipitate with 1 x Buffer RBL (please dilute 10 x Buffer RBL with RNase free water before use), gently vortex, and resuspend the precipitate thoroughly. 4. Centrifuge at 4 ℃ and 2100 rpm for 10 minutes, carefully and thoroughly remove the supernatant.Note: This step must completely remove the supernatant, otherwise it will affect the lysis and lead to a decrease in RNA production.5. Add Buffer RL to the precipitate (check if it has been added before use β- Mercaptoethanol, 0.5-1.5 ml of blood sample added to 600 µ L Buffer RL, or less than 0.5 ml of blood sample added to 350 µ L Buffer RL, mix well.6. Transfer the obtained liquid to the spin columns FL that have been loaded into the collection tube, centrifuge at 12000 rpm (~13400 × g) for 2 minutes, collect the filtrate, and discard the filter column.7. Add 1 volume (600) to the obtained filtrate µ L or 350 µ l) Mix 70% ethanol (prepared without RNase water) well.Attention: Adding ethanol may cause precipitation and will not affect subsequent experiments.8. Add all the solution obtained in the previous step to the spin columns RM that have been loaded into the collection tube. If the solution cannot be added at once, it can be transferred in multiple batches. Centrifuge at 12000 rpm for 15 seconds, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.9. Add 700 to the adsorption column µ Centrifuge at 12000 rpm for 15 seconds, discard the waste liquid from the collection tube, and place the adsorption column back into the collection tube.Optional steps: If conducting RNA experiments that are highly sensitive to trace amounts of DNA, replace step 9 with the following steps.1) Add 350 to the adsorption column µ Centrifuge at 12000 rpm for 15 seconds, discard the waste liquid from the collection tube, and place the adsorption column back into the collection tube.2) Preparation of DNase I mixture: Take 70 µ Reaction Buffer and 10 µ L DNase I storage solution, gently mix and prepare to a final volume of 80 µ The reaction solution of L.Attention: The above system is configured according to our company's DNase I (D665537) reaction system. Please refer to the corresponding manual for other company products.1) Add 350 to the adsorption column µ Centrifuge at 12000 rpm for 15 seconds, discard the waste liquid from the collection tube, and place the adsorption column back into the collection tube.2) Preparation of DNase I mixture: Take 70 µ Reaction Buffer and 10 µ L DNase I storage solution, gently mix and prepare to a final volume of 80 µ The reaction solution of L.Attention: The above system is configured according to our company's DNase I (D665537) reaction system. Please refer to the corresponding manual for other company products.3) Add 80 µ l of the prepared DNase I reaction solution directly to the adsorption column and incubate at 20-30 ℃ for 15 minutes.4) Add 350 to the adsorption column µ Centrifuge at 12000 rpm for 15 seconds, discard the waste liquid from the collection tube, and place the adsorption column back into the collection tube.10. Add 500 to the adsorption column µ Buffer RW2 (check if anhydrous ethanol has been added before use), centrifuge at 12000 rpm for 15 seconds, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.11. Repeat step 10. 12. Centrifuge at 12000 rpm for 2 minutes 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.).13. Place the adsorption column 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 RNA 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 and repeat step 13... Read More |