Description
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