| Description | Inquire | Inquire | 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 | Calcium, the most abundant mineral in the human body, is a crucial intracellular element that is responsible for regulating many physiological and pathological processes. Calcium is found in either the free ion form or in bound complexes, for example the calcium phosphate and calcium carbonate Calcium, the most abundant mineral in the human body, is a crucial intracellular element that is responsible for regulating many physiological and pathological processes. Calcium is found in either the free ion form or in bound complexes, for example the calcium phosphate and calcium carbonate complexes that make up bone tissue. Numerous physiological processes, including muscle contraction, cell adhesion, hormones/ neurotransmitters release, glycogen metabolism, cell proliferation/differentiation, blood clotting, nerve or synapthetic impulse transmission, and structural support of the skeleton are regulated by calcium signaling. Defects in the integrity of cell-specific calcium signaling systems may be associated with certain human diseases.Calcium Colorimetric Assay kit has been used to measure calcium concentration in hippocampal samples and MC3T3-E1 mouse osteoblast cell line, which were cultured in osteogenic induction medium... Read More | Apoptosis refers to the cell autonomous and orderly death controlled by genes to maintain the stability of the internal environment. Apoptosis is different from cell necrosis. Apoptosis generally refers to a programmed cell death process that occurs during the development of body cells or under the Apoptosis refers to the cell autonomous and orderly death controlled by genes to maintain the stability of the internal environment. Apoptosis is different from cell necrosis. Apoptosis generally refers to a programmed cell death process that occurs during the development of body cells or under the action of some factors through the regulation of intracellular genes and their products. Cell necrosis is a cell death process that is caused by strong physical and chemical or biological factors to cause disordered changes in cells. The difference between apoptosis and necrosis lies in the characteristic morphological and biochemical changes, including the changes of cell membrane permeability and nuclear chromatin, the contraction of cytoplasm and the loss of membrane asymmetry. The oxazole yellow/pi membrane permeability apoptosis detection kit produced by our company is a dual fluorescence detection kit based on oxazole yellow and PI dyes. This kit is suitable for fluorescence microscopy, flow cytometry, fluorescence microplate reader and other fluorescence detection systems. Oxazole yellow is a non cell membrane penetrating cyanine monomer green fluorescent dye with high affinity for DNA. It basically has no fluorescence when it is not bound to DNA, but can emit bright green fluorescence after binding to DNA. When apoptosis occurs, the permeability of cell membrane changes. At this time, oxazole yellow can enter the cell and bind to DNA, emitting bright green fluorescence. Therefore, it is often used for the detection of apoptosis. It should be noted that oxazole yellow can also stain dead cells, so it needs to be double stained with PI that specifically fluorescently stains dead cells to effectively determine apoptosis. PI (propidium iodide) is a red fluorescent dye that can stain DNA. It is an analog of pyridine bromide that releases red fluorescence after embedding double stranded DNA. Although PI cannot pass through the membrane of living cells, it can cross the damaged cell membrane of dead cells to stain nuclei. Therefore, oxazole yellow combined with PI can be directly used for the detection of apoptosis. Apoptotic cells show green fluorescence, dead cells show both red and green fluorescence positive, and living cells have little or no fluorescence.Components: Components O598364-50T A. Oxazole yellow dye 50 µL B. Propidium Iodide (PI) 50 µLUsage (using flow cytometry as an example):1. Cell preparation(1) For adherent cells, after trypsin digestion, resuspend in culture medium and wash once with pre cooled PBS; The digestion time of trypsin should not be too long to prevent false positives. Note: Digest with trypsin and allow the cells to recover in the optimal cell culture conditions and medium for about 30 minutes, then stain.(2) For suspended cells, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, and wash once with pre cooled PBS.2. Cell stainingSuspend cells in pre cooled PBS, with a recommended cell count of 106 cells/mL per sample. Add 1 µ L Oxazole Yellow and 1 µ L to 1 mL of the samplePI， Gently blow and mix well. Incubate on ice in the dark for 30 minutes. Note: We suggest adding the following two experimental controls:Blank tube: negative control group cells, without dye, used to regulate voltage.Single staining tube: Positive control group cells were treated with only two tubes, Oxazole yellow and PI, for regulating compensation.3. Flow detectionAfter incubation, the sample can be directly detected by flow cytometry, or centrifuged at 1000 rpm for 5 minutes, the supernatant can be aspirated, and the sample can be resuspended in 1 mL of pre cooled PBS for flow cytometry detection. Oxazole yellow can be excited by a 488 nm laser, and the detected fluorescence emission spectrum is around 530 ± 30 nm (FITC channel), while the PI channel emission spectrum is around 617 nm (PI or PE channel).Product parameters：Oxazole yellow dye:ex/em = 491 / 509 nm (bound DNA); Propidium iodine:ex/em = 535 / 617 nm (combined with DMatters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. fluorescent dyes have quenching problems. Please try to avoid light to slow down fluorescence quenching. 3. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Membrane permeability apoptosis assay... Read More |