| Description | Inquire | 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 | The content of this cell is too long for an XLSX file (more than 32767 characters). Please use the CSV format for this export | Inquire | Product introduction： The MA qPCR live bacteria detection kit provides an effective means for detecting bacterial activity. The kit provides a mixture of PMA dye and qPCR based on SYBR Green dye. The optimal amount of dye and the number of samples that can be treated may vary depending on theProduct introduction： The MA qPCR live bacteria detection kit provides an effective means for detecting bacterial activity. The kit provides a mixture of PMA dye and qPCR based on SYBR Green dye. The optimal amount of dye and the number of samples that can be treated may vary depending on the type of sample. PMA is a high-affinity DNA-binding dye, especially with double-stranded DNA. The dye itself has weak fluorescence, but it can emit brighter fluorescence after binding to nucleic acids. PMA is impermeable to cell membranes, so it can selectively modify the DNA of dead cells with damaged membranes. After the PMA-modified DNA is photolyzed by blue light ( ~ 464 nm ), the photoreactive azide group on the PMA is converted into a highly reactive nitrene radical, which reacts with any hydrocarbon near the DNA binding site to form a stable covalent nitrogen-carbon bond, resulting in permanent DNA modification. This modification process will make DNA insoluble and lost with cell debris during the later genomic DNA extraction process. The unbound PMA remaining in the solution reacts with water molecules under strong light irradiation to decompose into hydroxylamine compounds without cross-linking activity, so that it can no longer covalently bind to DNA. Based on this feature of PMA, PMA was combined with qPCR technology to form a new detection method, PMA-qPCR, for the screening of live bacteria. At present, the method has been verified in a variety of bacterial strains, yeast, fungi, viruses and parasites. The treatment of complex samples, such as manure or soil, may require optimization of sample dilution, dye concentration, and light treatment time. The treatment of diluted samples, such as water testing, may require filtration or concentration prior to dye treatment. Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. the components of the kit contain fluorescent dyes. Avoid light during use and storage. 3. for your safety and health, please wear experimental clothes and disposable gloves.Product parameters:Spectral characteristics :PMA: Ex = 464 nm; Ex/Em = 510/610 nm (following photolysis and reaction with DNA/RNA)Component： PMA：Ex = 464 nm; Ex/Em = 510/610 nm (following photolysis and reaction with DNA/RNA) Instruction： Precautions before use： 1.This live bacteria detection kit distinguishes dead bacteria and live bacteria according to cell membrane permeability. Many methods of killing bacteria cause damage to the cell membrane and are therefore compatible with this kit. But some methods, such as ultraviolet irradiation, may not immediately cause cell membrane rupture. Therefore, before selecting this kit, it is necessary to carry out literature search and pre-experiment to determine whether the kit is suitable for the bacterial type and killing method you choose. 2.After PMA treatment, the bacteria need to be photolyzed to covalently bind the dye to dead cell DNA. Photolysis operations can use blue or white light sources. Generally speaking, the brighter the lamp, the higher the efficiency of the photolysis step. Non-LED lamps ( such as halogen lamps ) may heat your sample and have a negative impact on the analysis. Ice is required to cool the sample during irradiation. 3.Sample can be cryopreservation after photolysis. Frozen samples before PMA treatment photolysis may damage the cell membrane and produce false negative results. If the sample needs to be frozen before detection, it is recommended to perform a pre-experiment first. 4.Part of the mechanism of PMA is to remove PMA covalently modified DNA from the sample by precipitation ; therefore, when extracting genomic DNA, it is necessary to use the same volume of genomic DNA eluent for volume normalization. The positive control can use the genomic DNA of living cells. 5.In order to verify the effectiveness of PMA in the test sample, the Ct ( dCt ) changes between- / + PMA can be compared. Experimental materials ( self-provided )：①Light source ( for the photolysis step after PMA modification of DNA ) ; ② Bacterial genomic DNA extraction kit ; ③ effective qPCR primers corresponding to the sample type Experimental procedure： 1.Suck 10 µL of E.coli bacterial solution in liquid LB medium, and culture E.coli in the bacterial incubator overnight or longer to the logarithmic growth phase ( OD600 ≈ 1.0 ) ; Note : The culture time is adjusted according to the experiment. 2.Two portions of live E.coli, 400 µL each, were placed in a clean centrifuge tube ; 3. ( Recommended ) Preparation of dead E.coli. If the dead E.coli is needed as a control, the dead E.coli can be obtained by heating the living E.coli in a water bath at 95 °C for 5 min, or at 58 °C for 3 h. the subsequent operation of the dead E. coli is the same as that of the living E. coli ; 4.Two copies of live E.coli, one without PMA treatment, and one with 25 µM PMA treatment ( the optimal PMA concentration for treating different types or different sources of bacteria needs to be consulted in the relevant literature ) ; 5.The PMA-treated samples were placed on a shaker at room temperature and incubated in the dark for 10 min to fully mix the dye with the sample ; 6.Exposure of the sample, you can use blue or white light source, irradiation time to explore their own. For example, a 60 W blue light can be used for 15 min. Note : 1 If a halogen lamp is used, we recommend that the PMA-treated sample tube be placed on an ice block 20 cm away from the light source. Ice should be placed in a transparent tray. Adjust the light source to point directly to the sample, photolysis for 5-15 min ; if the bacteria obtained from the environment are directly used for experiments, due to the complexity or turbidity of the environmental samples, the photolysis time needs to be prolonged appropriately. 7.Treated and untreated live E.coli 5000 × g, centrifuged for 10 min, remove the supernatant ; 8.Select the appropriate genomic DNA extraction kit according to the sample type, and use the same elution volume for each group of samples when elution DNA. Note : DNA extraction steps refer to the instructions of the kit used. Part of the mechanism of action of PMA is to remove PMA-bound DNA from the sample by precipitation ; therefore, when extracting genomic DNA, each group should use the same volume of genomic DNA eluent for volume normalization ( the amount of genomic DNA extracted from dead bacteria and live bacteria is inconsistent, so the concentration of the two is significantly different ). 9.Preparation of reaction mixture according to the following system : Note : 1 For the DNA extracted by commercial DNA extraction kit, the qPCR template was optimized with 2 µL as the initial volume ; 2 The template volume should not exceed 10 % of the final reaction volume ; 3 Template concentration : gDNA as template, usually 1-10 ng ; the final concentration of PCR primers is usually 0.4µM, which can get better results. When the reaction performance is poor, the primer concentration can be adjusted in the range of 0.2-1µM. 10.Slightly vortex the reaction mixture, transfer the fixed volume to the PCR tube. 11. Test procedure Note : 1 The extension time is adjusted according to the instrument ; the Taq enzyme in mix can be activated within 2 min, but the genomic DNA may require longer denaturation time, which can be increased at this time, and the specific denaturation time can be adjusted according to the sample type.12. ( Optional ) Data analysis Using live bacteria and dead bacteria as controls, the number of live cells in the sample was analyzed and calculated. It is recommended to verify the suitability of primers and PCR procedures before starting PMA qPCR detection of live bacteria. Calculation of dead and living bacteria control dCt ( 1 ) After the end of qPCR, the Ct value of each sample was calculated by instrument software ; ( 2 ) By calculating the dCt of each control bacteria, it was judged whether PMA successfully inhibited the amplification of dead bacterial DNA. The calculation is as follows : dCt live = Ct ( live, PMA treated ) -Ct ( live, PMA untreated ) dCt die = Ct ( die, PMA treated ) -Ct ( die, PMA untreated ) ( 3 ) The dCt expectation of living bacteria is close to 0 ± 1, which indicates that PMA does not affect the amplification of living cell DNA ;( 4 ) The expected value of dCt of dead bacteria is greater than 4 ( dCt is 4 means that it is reduced by about 16 times, that is, 94 % of dead bacterial DNA is removed ; a dCt of 8 indicated a decrease of about 250 times, that is, 99.6 % of the dead bacterial DNA was removed ).( 5 ) The dCt of dead bacteria depends on many factors, including : strain / cell type ; the way bacteria are killed ; the concentration of PMA used ; amplified sequence length. 13. Calculation of the proportion of viable ( optional ) bacteria If the control results of dead and live bacteria are normal, the proportion of live bacteria in the sample can be calculated.( 1 ) Calculate the dCt value of the sample : dCt sample = Ct ( sample, PMA treated ) -Ct ( sample, PMA untreated ) ( 2 ) Conversion of dCt value to live bacteria ratio : PMA inhibition multiple = 2 ( sample dCt ) Viable bacteria % = 100 / PMA inhibition multiple 14. ( Optional ) Calculate the absolute number of live bacteria If you want to calculate the absolute number of viable bacteria in the sample, you need to use a known number of target bacteria genomic DNA to make a standard curve. It is recommended that the diluted concentrations of several groups of genomes are within the range of the qPCR analysis system.( 1 ) qPCR was performed with the appropriate genome, and the Ct value was used as the ordinate, and the number of cells was used as the abscissa. The R2 value is calculated to determine the linearity, and the slope and y-axis intercept are displayed. ( 2 ) Calculate the copy number of the experimental samples : Ct = slope * cell number + y axis intercept ( y = mx + b ) Bacterial count sample = ( Ct-y axis intercept ) / slope Note : The live bacterial DNA was not lost during the purification process. Examples : Scope of application：Live bacteria detection... Read More |