| Description | Inquire | Description：Acetylcholinesterases (AChEs) are enzymes that hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline. AChE is located at the synaptic cleft and functions to terminate synaptic transmission by catalyzing the breakdown of ACh allowing cholinergic neurons to Description：Acetylcholinesterases (AChEs) are enzymes that hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline. AChE is located at the synaptic cleft and functions to terminate synaptic transmission by catalyzing the breakdown of ACh allowing cholinergic neurons to return to a resting state after activation. It is also found in membranes of red blood cells, motor and sensory fibers, muscles, nerves and central and peripheral tissues. Changes in AChE activity may result from exposure to certain insecticides, which act as cholinesterase inhibitors. Inhibitors of AChE are also used to treat certain conditions such as dementia.Acetylcholinesterase activity assay kit has been used to determine the activity of acetylcholinesterase in a rat organophosphate model and in brain tissue homogenates.Principle：Acetylcholinesterase can catalyze the hydrolysis of acetylcholine to choline, and the reaction of choline with disulfide p-nitrobenzoic acid to produce 5-merhydryl-nitrobenzoic acid (TNB). The product has a characteristic absorption peak at 412 nm, and the activity of acetylcholinesterase can be characterized by the change of light absorption valueThe Dilution Calculator EquationConcentration (start)xVolume (start)= Concentration (final)× Volume (final)This equation is commonly abbreviated as: C1V1 = C2V2... Read More | Product IntroductionAlamar Blue detection reagent provides a simple, rapid, reliable and safe method for cell proliferation and cytotoxicity detection, which is suitable for high-throughput detection experiments. The main component of the detection reagent is a redox indicator. In the oxidized stateProduct IntroductionAlamar Blue detection reagent provides a simple, rapid, reliable and safe method for cell proliferation and cytotoxicity detection, which is suitable for high-throughput detection experiments. The main component of the detection reagent is a redox indicator. In the oxidized state, it appears purple-blue and non-fluorescent, while in the reduced state, it turns into a reduction product with pink or red fluorescence, with an absorption peak of 530-560nm and an emission peak of 590nm.In the process of cell proliferation, the ratios of NADPH/NADP, FADH/FAD, FMNH/FMN and NADH/NAD in the cell increase and are in a reducing environment. The dye taken into the cell is reduced by these metabolic intermediates and cytochromes and then released outside the cell and dissolved in the culture medium, changing the culture medium from non-fluorescent indigo blue to fluorescent pink. Finally, use an ordinary spectrophotometer or fluorophotometer for detection, and the absorbance and fluorescence intensity are proportional to the number of active cells.Instructions1. Add 10µl of detection reagent to 100µl of cell suspension, and incubate in a cell incubator for 2-6 hours. The color of the medium changes from indigo blue to pink and you can proceed to the next step.2. It is recommended to use a fluorescence microplate reader for detection, the excitation light wavelength is between 530-560 nm, the emission light wavelength is 590 nm, and the relative fluorescence unit (RFU) is recorded.3. Draw a standard curve or cell growth curve: the ordinate (Y axis) is the relative fluorescence unit (RFU); the abscissa (X axis) is the cell number or time point or drug concentration.Precautions1. The appropriate density of cells can increase the detection sensitivity. For 96-well plates, we recommend seeding 100 microliters of cells per well. The cell concentration range is: 100-10,000/well for adherent cells, 2,000-50,000/well for suspension cells, and medium as a blank control. For 384-well plates, the cell concentration and seeding volume are both halved.2. The whole process should be aseptic operation, because microbial contaminants can also reduce the detection reagents and affect the experimental results.3. Pay attention to the concentration of inoculated cells and the incubation time after adding detection reagents. If the cell concentration is too high or the incubation time is too long, it will cause a secondary reduction reaction, resulting in colorlessness and disappearance of fluorescence.4. When incubating, avoid light.5. This product can use fluorescence or spectrophotometric detection, but the sensitivity of fluorescence is high, and the experimental error is small. Fluorescence detection is recommended... Read More | 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 | This product is a cDNA first strand synthesis kit specially prepared for the first step experiment of two-step RT-PCR. The reverse transcriptase used in this kit is a novel and efficient reverse transcriptase that utilizes E. coli engineered bacteria for recombination and expression. It removes This product is a cDNA first strand synthesis kit specially prepared for the first step experiment of two-step RT-PCR. The reverse transcriptase used in this kit is a novel and efficient reverse transcriptase that utilizes E. coli engineered bacteria for recombination and expression. It removes RNase H activity and enhances its thermal stability. It can synthesize cDNA first strands using extremely low amounts of total RNA or mRNA, with an initial sample size as low as pg level. SuperRT reverse transcriptase has strong affinity for RNA and can read RNA templates with high GC content and complex secondary structures, obtaining high yields of cDNA. This product contains all the reagents required for reverse transcription from RNA templates to cDNA first strand, including Super RT efficient reverse transcriptase, reaction buffer, primers, dNTP, etc. It is simple and convenient to use. This system has high compatibility with subsequent PCR and quantitative PCR experiments, and is suitable for various DNA polymerase reactions. S665657 Component 100 T Storage S665657A SuperRT, 200 U/µL 100 µL -20℃. Avoid freeze/thaw cycle. S665657B 5×SuperRT Buffer 500 µL -20℃. Avoid freeze/thaw cycle. S665657C Primer Mix 240 µL -20℃. Avoid freeze/thaw cycle. S665657D dNTP Mix, 2.5 mM Each 500 µL -20℃. Avoid freeze/thaw cycle. S665657E RNase-Free Water 1 mL -20℃. Avoid freeze/thaw cycle.Product features:·Efficient reverse transcription: It has a high affinity for RNA templates, with a reverse transcription efficiency of up to 90%, and can recognize pg level templates.·Free response to complex templates: Even templates with high GC content and complex secondary structures can achieve good results without high-temperature denaturation.Notes:1. During the operation process, RNase contamination should be avoided to prevent RNA degradation or cross contamination during experiments. It is recommended to perform RNA operations in specialized areas, use specialized instruments and consumables, and have operators wear masks and disposable gloves, and frequently change gloves.2. Disposable plastic containers should be used as much as possible for experiments. If glass containers are used, they should be treated with a 0.1% DEPC (diethyl pyrocarbonate) aqueous solution at 37 ℃ for 12 hours, and sterilized under high pressure at 120 ℃ for 30 minutes before use. Alternatively, glass containers should be sterilized under dry heat at 180 ℃ for 60 minutes before use. The sterile water used in the experiment should be treated with 0.1% DEPC and then subjected to high-pressure sterilization.3. All reagents in this reagent kit should be gently mixed upside down before use, avoiding foaming as much as possible, and used after brief centrifugation. The enzymes involved should be returned to -20 ℃ as soon as possible after use to avoid repeated freeze-thaw cycles.If the initial amount of RNA is less than 50 ng, it is recommended to add RNA enzyme inhibitors (RNAsin). This kit is not provided.Usage:Note: 1 ng -5 µ g of total RNA can establish a 20 µ l reaction system. If the total RNA amount is greater than 5 µ g, please expand the reaction system proportionally.Steps for reverse transcription:1. Dissolve the RNA template, Primer Mix, dNTP Mix, SuperRT Buffer, SuperRT, and RNase Free Water and place them on ice for later use.2. Prepare a reaction system according to the following table, with a total volume of 20 µ L. Reagent 20 µlReaction system Final concentration dNTP Mix，2.5 mM Each 4 µl 500 µM Each Primer Mix 2 µl / RNA Template X µl 50 pg-5 µg SuperRT，200 U/µl 1 µl / RNase-Free Water up to 20 µl / Attention:1) If the initial amount of RNA is less than 50 ng, it is recommended to add RNA enzyme inhibitors (RNAsin). This kit is not provided.2) Primer Mix is formulated from Oligo (dT) and Random Primer. Oligo dT Primer or Gene Specific Primer can be used according to experimental needs, with a recommendation of 20 µ The reaction system Oligo dT Primer is 50 pmol, or Gene Specific Primer is 2 pmol.3. Vortex shake and mix well, briefly centrifuge to collect the solution on the pipe wall to the bottom of the pipe.Incubate at 4.42 ℃ for 30-50 minutes and 85 ℃ for 5 minutes. After the reaction is complete, centrifuge briefly and cool on ice.5. Reverse transcripts can be directly used for PCR reactions and fluorescence quantitative PCR reactions, or stored at -20 ℃ for a long time. Reagent 20 µ Final concentration of reaction system dNTP Mix, 2.5 mM Each 4 µ L 500 µ M Each Primer Mix 2 µ RNA Template X µ L 50 pg-5 µ g 5 x SuperRT Buffer 4 µ 1 x SuperRT, 200 U/ µ L 1 µ RNase Free Water up to 20 µ Lii If the reverse transcription efficiency is low, or the RNA template secondary structure is complex and the GC content is high, the following steps are recommended:1. Dissolve the RNA template, Primer Mix, dNTP Mix, SuperRT Buffer, SuperRT, and RNase Free Water and place them on ice for later use.2. Configure the reaction system according to the following table, with a total volume of 15 µ L. Reagent 20 µlReaction system Final concentration dNTP Mix，2.5 mM Each 4 µl 500 µM Each Primer Mix 2 µl / RNA Template X µl 50 pg-5 µg RNase-Free Water up to 15 µl / Note: Primer Mix is formulated from Oligo (dT) and Random Primer. Oligo dT Primer or Gene Specific Primer can be used according to experimental needs. 3. Incubate at 70 ℃ for 10 minutes and quickly ice bath for 2 minutes.4. Centrifuge briefly to collect the solution on the tube wall to the bottom of the tube.5. Continue to add the following reagents to the above reaction solution: Reagent 20 µlReaction system Final concentration 5×SuperRT Buffer 4 µl 1× SuperRT，200 U/µl 1 µl / Note: If the initial amount of RNA is less than 50 ng, it is recommended to add RNA enzyme inhibitors (RNasins). This kit is not provided. 6. Incubate at 42 ℃ for 30-50 minutes and 85 ℃ for 5 minutes.7. After the reaction is complete, centrifuge briefly and cool on ice.8. Reverse transcripts can be directly used for PCR reactions and fluorescence quantitative PCR reactions, or stored at -20 ℃ for a long time... Read More |