| Description | D-Lactate, typically present in the bloodstream at nanomolar concentrations, is produced by an intestinal source or via the methylglyoxal pathway. In mammals, D-Lactate metabolism requires D-Lactate hydrogenase and is metabolized slowly, thus an increase in blood concentration levels can lead to D-Lactate, typically present in the bloodstream at nanomolar concentrations, is produced by an intestinal source or via the methylglyoxal pathway. In mammals, D-Lactate metabolism requires D-Lactate hydrogenase and is metabolized slowly, thus an increase in blood concentration levels can lead to acidemia and acidosis. The severity of this D-lactic acidosis can be associated with neurotoxic symptoms. Significant D-Lactate accumulations in the body can also be related to impaired metabolism and excretion.D-Lactate Colorimetric Assay kit has been used to determine the stereospecificity of lactate produced.Suitability: Suitable for use with samples of serum, plasma, cells, culture and fermentation media.Principle: In this assay, D-Lactate is specifically oxidized by D-Lactate hydrogenase and generates a proportional colorimetric product measured at 450 nm. The useful concentration range in samples is 0.1-10 mM D-Lactate... 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 | Inquire | This product can rapidly, gently, and efficiently lyse mammalian cells, effectively extracting cytoplasmic and nuclear proteins. This reagent uses a mild formula to ensure that the extracted protein maintains biological activity and can be applied to various protein analysis experiments, such as This product can rapidly, gently, and efficiently lyse mammalian cells, effectively extracting cytoplasmic and nuclear proteins. This reagent uses a mild formula to ensure that the extracted protein maintains biological activity and can be applied to various protein analysis experiments, such as reporter gene and enzyme activity determination, immune detection, protein purification, etc. The extracted protein can be quantitatively analyzed using the BCA method. The reagent kit contains a mixture of protease inhibitors, which can effectively prevent protein degradation during the protein extraction process.M665813Component100 TStorageM665813AMammalian Protein Extraction Reagent100 mLRTM665813BProtease Inhibitor Cocktail (100×)1 mL-20℃. Avoid freeze/thaw cycle. precautions1. This product can effectively lyse adherent cells cultured on cell culture plates (without scraping) and suspended cells collected by centrifugation, with higher extraction efficiency than repeated freeze-thaw or ultrasound methods. But for the extraction of tissue proteins, it is recommended to use the tissue protein extraction kit (CW0891).The optimal dosage for protein extraction from adherent cells is listed in Table 1. Collecting cells first can reduce the amount of reagents used to obtain higher protein concentrations.3. The amount of extraction reagents used can also be estimated based on the number of cells. If 2 × 106 Hela cells weigh about 20 mg, 200 need to be added µ Extract reagents.4. The protein extracted from this product can be quantitatively analyzed using the BCA method.Operation steps● Protein extraction from adherent cells1. Please remove the required Mammalian Protein Extraction Agent for pre cooling before protein extraction.2. Carefully pour out the culture medium of adherent cells and rinse the cells with PBS.3. Add an appropriate amount of Mammalian Protein Extraction Reagent (add Protein Inhibitor Cocktail in a 1:99 ratio 2-3 minutes before protein extraction), blow adherent cells on ice with a gun tip, transfer the lysate to a centrifuge tube, incubate on ice for 20 minutes, and allow the cells to fully lyse (please refer to Appendix 1 for the amount of reagent used, and the time for placing on ice should be adjusted according to different cell types). 4. Centrifuge at 14000 × g for 5-10 minutes.5. Transfer the supernatant to a new tube for further analysis. ● Suspension cell protein extraction1. Please remove the required Mammalian Protein Extraction Agent for pre cooling before protein extraction.2. Suspend 2500 × g of cells, centrifuge for 10 minutes, and discard the supernatant. Rinse cells with PBS. 2500 × g, centrifuge for 10 minutes, discard the supernatant.3. Add an appropriate amount of Mammalian Protein Extraction Agent, and 2-3 minutes before protein extraction, add Protein Inhibitor Cocktail in a ratio of 1:99, which is 1 x working solution.4. Add at least 1 ml of 1x working solution to every 100 mg of cells. If the extracted sample size is large, a small amount of 1x working solution can be used to resuspend the cells first, and then the remaining working solution can be added.5. After blowing evenly, place it on ice for 20 minutes to allow the cells to fully lyse (the time for placing it on ice should be adjusted according to different cell types). 6. Centrifuge at 14000 × g for 15 minutes.7. Transfer the supernatant to a new tube for further analysis.Table 1. Recommended usage of extraction reagents Cell culture plate type or dish type Extraction reagent usage 100 mm 500-1,000 µl 60 mm 250-500 µl 6-well culture plate 200-400 µl /well 24-well culture plate 100-200 µl /well 96-well culture plate 50-100 µl /well Table 2. Common Problems and Solutions Problem Possible reasons Resolvent Low extraction rate Low protein expression level Optimize transfection system Low extraction rate Insufficient reagent usage Increase the usage of extraction reagents Low extraction rate Reagent unable to dissolve cell membrane Increase cracking time or increase shaking amplitude Unable to obtain membrane protein This product is more suitable for extracting nuclear plasma protein Using eukaryotic cell membrane protein extraction kit... Read More | Q665720 Component 200T Storage Q665720A Buffer L2 25 mL RT Q665720B Buffer N3 80 mL RT Q665720C Buffer PB 35 mL RT Q665720D Buffer PW (concentrate) 25 mL RT Q665720E Buffer EB 30 mL RT Q665720F RNase A (10 mg/mL) 800 渭L RT Q665720G Spin Columns DM with Collection Tubes 200 EA RTProduct Q665720 Component 200T Storage Q665720A Buffer L2 25 mL RT Q665720B Buffer N3 80 mL RT Q665720C Buffer PB 35 mL RT Q665720D Buffer PW (concentrate) 25 mL RT Q665720E Buffer EB 30 mL RT Q665720F RNase A (10 mg/mL) 800 渭L RT Q665720G Spin Columns DM with Collection Tubes 200 EA RTProduct IntroductionThe biggest feature of this kit: simple and fast, high extraction volume. The whole extraction process does not take more than 10 minutes, without centrifugation to collect bacteria and resuspend the bacterium, directly add the unique super lysate Buffer L2 to the cultured bacterial solution, followed by neutralization, centrifugation and passing through the column, and the extracted plasmid can be as high as 30 µg, and maximize the removal of proteins, genomes and other impurities. The extracted plasmid DNA can be directly used for bacterial transformation, digestion, PCR, in vitro transcription, sequencing and other downstream experiments.Self-contained reagent: anhydrous ethanol.Pre-experiment Preparation and Important Notes1. The kit can be stored in a dry, room temperature (15-30°C) environment for 1 year. For longer storage, the centrifuge columns can be placed at 2-8°C.2. Before the first use, add all of the RNase A solution to Buffer N3, mix well, and store at 2-8°C.3. Anhydrous ethanol should be added to Buffer PW before the first use according to the instructions on the reagent bottle label.4. If there is any precipitation in Buffer L2 before use, please put it in a 37℃ water bath and keep mixing until the solution becomes clear before use.Operation steps1. Take 600 µl of bacterial culture into a 1.5 ml centrifuge tube (supplied).2. Add 100 µl of Buffer L2 to the above centrifuge tube and gently turn the solution up and down 8 times; the solution should change from turbid to a clear purple color, indicating complete lysis. The cleavage time should not exceed 2 minutes.3. Add 350 µl of Buffer N3 to the above centrifuge tube (please check that RNaseA has been added first) and immediately mix well by turning up and down about 8-10 times, at which point the solution should turn completely yellow and a yellow precipitate should form. centrifuge at 13,000 rpm for 2-3 minutes.4. Slowly pour the supernatant obtained in step 3 into the prepared adsorption columns (Spin Columns DM with Collection Tubes) to avoid sedimentation into the columns.5. Centrifuge at 13,000 rpm for 15 seconds, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.6. Add 150 µl Buffer PB to the adsorption column and centrifuge at 13,000 rpm for 15 seconds.7. Add 400 µl Buffer PW to the adsorption column (please check that anhydrous ethanol has been added first) and centrifuge at 13,000 rpm for 1 minute.8. Place the adsorbent column in a new centrifuge tube (self-provided), add 30-100 µl Buffer EB to the middle part of the adsorbent membrane, centrifuge at 13,000 rpm for 1 min, collect the plasmid DNA, and store at -20°C for long term storage.When the amount of extracted bacterial liquid is >600µl, the following procedure can be used:1. This kit can extract up to 3ml of bacterial solution, if the amount of extracted bacterial solution is more than 600µl, it is necessary to centrifuge the bacterial solution exceeding 600µl at 13,000rpm for 30 seconds (to collect the bacterial body), discard the supernatant and then add 600µl of bacterial solution, and then resuspend the bacterial body at the bottom of the tube thoroughly and then proceed to the following operation.2. Add 100µl Buffer L2 to the above centrifuge tube, gently invert the solution up and down 10 times, if the solution is not clarified, need to continue to invert the mixing until the solution becomes a clear purple color, the lysis time should not be more than 2 minutes. (If the solution is still turbid, the amount of bacteria is too large, and the amount of bacteria should be reduced appropriately.)3. Add 350 µl of Buffer N3 to the above centrifuge tube (please check that RNaseA has been added first) and immediately mix well by turning up and down until the purple solution turns completely yellow and a yellow precipitate is formed before proceeding to the next step. centrifuge at 13,000 rpm for 5 minutes.4. Transfer the supernatant to a new centrifuge tube, add 200 µl of isopropanol, mix up and down several times, mix well and transfer to the adsorbent column (Spin Columns DM with Collection Tubes), due to the amount of solution is too large, this time, it is necessary to centrifuge the column in two separate times, centrifugation at 13,000 rpm for 15 seconds, pour off the waste liquid in the collection tube, and put the adsorbent column back to the The adsorbent column should be placed back into the collection tube.5. Add 150 µl Buffer PB to the adsorption column and centrifuge at 13,000 rpm for 15 seconds.6. Add 400 µl Buffer PW to the adsorption column (please check that anhydrous ethanol has been added first) and centrifuge at 13,000 rpm for 1 minute.7. Place the adsorbent column in a new centrifuge tube (self-provided), add 50-200 µl Buffer EB to the middle part of the adsorbent membrane, leave it at room temperature for 2 min, centrifuge at 13,000 rpm for 1 min, collect the plasmid DNA, and store it at -20°C for a long time... Read More |