| 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 aladdin 488 Caspase-3 live cell assay kit contains the aladdin 488 Caspase-3 substrate and the Ac-DEVD-CHO Caspase-3 inhibitor. aladdin 488 Caspase-3 Substrate provides an effective tool for detecting apoptosis based on Caspase-3 activity, suitable for fluorescence microscopy and flow cytometry.The aladdin 488 Caspase-3 live cell assay kit contains the aladdin 488 Caspase-3 substrate and the Ac-DEVD-CHO Caspase-3 inhibitor. aladdin 488 Caspase-3 Substrate provides an effective tool for detecting apoptosis based on Caspase-3 activity, suitable for fluorescence microscopy and flow cytometry. Compared with other fluorescent substrates or fluorescent inhibitors of Caspase based on ( FLICA ) analysis, aladdin 488 Caspase-3 Substrate does not inhibit the apoptosis process of intact cells while detecting Caspase-3 activity. Substrate is composed of fluorescent DNA dyes coupled with Caspase-3 DEVD recognition sequence. Substrate initially had no fluorescence and entered the cytoplasm through the cell membrane. In apoptotic cells, Caspase-3 cleaves the Substrate and releases high-affinity DNA staining, which migrates to the nucleus to label DNA and emits bright green fluorescence.Therefore, aladdin 488 Caspase-3 Substrate is bifunctional, which can not only detect Caspase-3 activity, but also visualize the morphological changes of the nucleus during apoptosis. Aladdin 488 staining can be fixed in formaldehyde and compatible with subsequent immunostaining experiments.Parameters:aladdin 488：Ex/Em = 500/530 nm (with DNA)Component：Points for attention：1.Please instantaneously centrifuge the product to the bottom of the tube before use, and then carry out subsequent experiments. 2.Cells can be co-stained with a final concentration of 1µM Hoechst 33342 dye to produce blue fluorescence staining of the nucleus ( Ex / Em = 346 / 460 nm ). 3.Aladdin 488 staining can be fixed by formaldehyde, but it is not compatible with methanol fixation. 4.Formaldehyde-fixed aladdin 488-stained cells can be treated with 0.1 % TritonX-100 for subsequent staining, but the brightness of the treated staining may be weakened. 5.Fluorescent dyes all have quenching problems, please try to avoid light to slow down the fluorescence quenching. 6.For your safety and health, please wear experimental clothes and wear disposable gloves.Scope of application：Caspase 3 kit and apoptosis detectionUsage:1. Experimental optimization: The experimental steps provided below are based on the endpoint detection system. Aladdin 488 Substrate can also be used for long-term cell incubation course research. Cell density, substrate concentration, and inhibitor concentration may need to be optimized. The optimal substrate concentration may be between 1-10 µ Between M. Cells can be incubated with substrates in culture medium, PBS, or other buffer of your choice. For adherent cells, we recommend replacing them with fresh culture media containing substrates to prevent background heterogeneity. The operation of changing the medium or washing the cells after substrate incubation is freely selectable.2. We suggest that you set the following controls:A. Negative control: cells that do not induce apoptosis;B. Positive control: cells that induce apoptosis;C. Inhibitor control: Induce cell apoptosis while incubating Caspase-3/7 inhibitors (or 10-30 minutes in advance), and finally add Aladdin 488 Caspase-3 substrate.3. The Caspase-3/7 inhibitor Ac-DEVD-CHO in the Ac-DEVD-CHO Caspase-3 inhibitor control kit can be used to confirm that Caspase-3/7 depends on the fluorescence signal of aladdin 488. For inhibitor control, the final concentration of the inhibitor should be at least twice the substrate concentration (e.g. when using 5 µ At substrate M aladdin 488, the concentration of Ac-DEVD-CHO is 10 µ M). Before adding the substrate, incubate Ac-DEVD-CHO at room temperature for 15-30 minutes. After adding the substrate, continue to retain the inhibitor in the incubation solution. Ac-DEVD-CHO is a reversible competitive inhibitor. In certain cell types, effective Caspase-3/7 inhibitors require the use of irreversible inhibitors, such as Z-DEVD-FMK, or the addition of inhibitors before or during apoptosis induction.4. Flow cytometry(1) Choose appropriate methods to induce cell apoptosis, with untreated cell samples as controls.(2) Adhering cells should be digested with trypsin or other methods before performing the aladdin 488 Caspase-3 experiment.(3) Resuspend cells with culture medium or buffer to achieve a cell density of 106 cells/mL(4) Suck 0.2 mL of cell suspension into a flow cytometry test tube.(5) Inhibitor control samples were treated with Ac-DEVD-CHO on cells (see 3 above) Ac-DEVD-CHO Caspase-3 inhibitor control.(6) 200 µ Add 5 to L cell suspension µ Substrate of 0.2 mM and immediately mix to achieve a substrate concentration of 5 µ M. The optimal substrate concentration for different cells may vary and requires analysis and optimization.(7) Incubate cells at room temperature in dark for 15-30 minutes.(8) Join 300 µ L-medium or PBS, analyzed by flow cytometry. Detect the channel for green fluorescence (Ex/Em=485/515 nm).5. Fluorescence microscope(1) Choose appropriate methods to induce cell apoptosis, with untreated cell samples as controls.(2) Inhibitor control samples were treated with Ac-DEVD-CHO on cells (see 3 above) Ac-DEVD-CHO Caspase-3 inhibitor control.(3) Using a solution containing 5 µ M Substrate's fresh culture medium or PBS is used to replace the cell culture medium (see 1 above) Experimental optimization). For the inhibitor control group, the inhibitor was incubated together with the substrate.(4) Incubate cells at room temperature for 30 minutes or longer.(5) Cells can be directly observed in culture media containing Substrate. For the endpoint analysis method, PBS was used to clean the cells, fluorescence microscopy was used to observe the cells, and a filter (Ex/Em=485/515 nm) was used to observe green fluorescence.6. Fluorescence enzyme-linked immunosorbent assay (ELISA) reader(1) Adherent cells grow in black 96 well plates; Suspend cells, adjust the density to 106 cells/mL, and divide 0.2 mL of cell suspension into one well.(2) Choose appropriate methods to induce cell apoptosis, with untreated cell samples as controls. Note: Cells may be processed in tubes or bottles and then transferred to a 96 well detection plate.(3) Inhibitor control samples were treated with Ac-DEVD-CHO on cells (see 3 above) Ac-DEVD-CHO Caspase-3 inhibitor control.(4) For suspended cells, directly add Substrate and mix well. For adherent cells, use a solution containing 5 µ M Substrate's fresh culture medium or PBS is used to replace the cell culture medium (see 1 above) Experimental optimization). For the inhibitor control group, the inhibitor was incubated together with the substrate.(5) Cells can be directly observed in culture media containing Substrate.(6) For suspended cells, gently shake to resuspend the cells. The fluorescence enzyme-linked immunosorbent assay instrument is set with an excitation wavelength of 488 nm and an emission wavelength of 520 nm. Suggest using bottom collection method for adherent cells. Changes in the density of adherent cells may lead to inaccurate readings... Read More | Alanine Aminotransferase (ALT), also known as serum glutamic-pyruvic transaminase (SGPT), is a pyridoxal-phosphate-dependent enzyme that catalyzes the reversible transfer of an amino group from alanine to α-ketoglutarate, generating pyruvate and glutamate. ALT is found primarily in liver and Alanine Aminotransferase (ALT), also known as serum glutamic-pyruvic transaminase (SGPT), is a pyridoxal-phosphate-dependent enzyme that catalyzes the reversible transfer of an amino group from alanine to α-ketoglutarate, generating pyruvate and glutamate. ALT is found primarily in liver and serum, but occurs in other tissues as well. Hepatocellular injury often results in an increase of serum ALT levels and serum ALT levels can be used as a marker for liver injury.ALT Activity Assay kit has been used to determine the activity of alanine aminotransferase (ALT) in serum samples... Read More | DescriptionProvides 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 and KitAlysis 24-Well Reaction Block | Inquire |