| Description | Inquire | Description：Acetylcholinesterases (AChEs) are enzymes that hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline. AChE is located at the synaptic cleft and functions to terminate synaptic transmission by catalyzing the breakdown of ACh allowing cholinergic neurons to Description：Acetylcholinesterases (AChEs) are enzymes that hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline. AChE is located at the synaptic cleft and functions to terminate synaptic transmission by catalyzing the breakdown of ACh allowing cholinergic neurons to return to a resting state after activation. It is also found in membranes of red blood cells, motor and sensory fibers, muscles, nerves and central and peripheral tissues. Changes in AChE activity may result from exposure to certain insecticides, which act as cholinesterase inhibitors. Inhibitors of AChE are also used to treat certain conditions such as dementia.Acetylcholinesterase activity assay kit has been used to determine the activity of acetylcholinesterase in a rat organophosphate model and in brain tissue homogenates.Principle：Acetylcholinesterase can catalyze the hydrolysis of acetylcholine to choline, and the reaction of choline with disulfide p-nitrobenzoic acid to produce 5-merhydryl-nitrobenzoic acid (TNB). The product has a characteristic absorption peak at 412 nm, and the activity of acetylcholinesterase can be characterized by the change of light absorption valueThe Dilution Calculator EquationConcentration (start)xVolume (start)= Concentration (final)× Volume (final)This equation is commonly abbreviated as: C1V1 = C2V2... 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 | Annexin V ( annexin-V ) is a Ca2 + dependent phospholipid binding protein with a molecular weight of 35-36 KD, which can selectively bind to phosphatidylserine ( PS ). Phosphatidylserine ( PS ) is mainly distributed in the inner side of the cell membrane, that is, the side adjacent to the cytoplasm.Annexin V ( annexin-V ) is a Ca2 + dependent phospholipid binding protein with a molecular weight of 35-36 KD, which can selectively bind to phosphatidylserine ( PS ). Phosphatidylserine ( PS ) is mainly distributed in the inner side of the cell membrane, that is, the side adjacent to the cytoplasm. In the early stage of apoptosis, different types of cells will turn phosphatidylserine out to the cell surface and expose to the extracellular environment. At this time, using Annexin V labeled with fluorescent protein PE, that is, Annexin V-PE, combined with phosphatidylserine ( PS ), the eversion of phosphatidylserine, an important feature of apoptosis, can be directly detected by flow cytometry. Normal cells will not be stained by Annexin V-PE, apoptotic or necrotic cells will be stained by Annexin V-PE. Annexin V-PE can be used in combination with partially non-permeable nuclear dye ( 7-AAD / PI ) to distinguish cells at different stages of apoptosis. RedNucleus II provided in this kit is a far-red dye that belongs to an anthraquinone compound and cannot penetrate the intact cell membrane of living cells and early apoptotic cells. It is non-permeable, but can quickly stain the nucleus / dsDNA in dead and permeable cells. RedNucleus II is an ideal substitute for propidium iodide ( PI ) and 7-AAD.Combined with Annexin V-PE, it has better spectral characteristics without compensation regulation : it is not excited by ultraviolet light and does not overlap with PE / PE homologues, so it can be combined with FITC, PE and purple fluorescent dyes for multicolor analysis. When combined with Annexin V-PE, RedNucleus II was excluded from living cells and early apoptotic cells, while late apoptotic cells and dead cells were double-positive for Annexin V-PE and RedNucleus II. Annexin V-PE / RedNucleus II apoptosis detection kit can be detected by flow cytometry or other fluorescence detection equipment. Components: Components A598354(10T) A598354(50T) A598354(100T) A. 1×Annexin V Combining buffer solution 10 mL 50 mL 50 mL×2 B. Annexin V-PE 50 µL 250 µL 500 µL C. RedNucleus II 100 µL 500 µL 1 mLProduct parameters：Annexin v-pe:ex/em=488/578 nmrednucleus ii:ex/em=635/695 NMUsage method:1. Experimental design: Blank tube: Negative control group cells, without Annexin V-PE/RedNucleus II. Used to regulate voltage.Single staining tube: Positive control group cells were treated with Annexin V-PE alone/RedNucleus II alone. Used for adjusting compensation.Detection tube: Add Annexin V-PE/RedNucleus II to the processed cells. After adjusting the voltage compensation using blank tubes and single dye tubes, obtain the required flow data.2. Collect cells(1) For suspended cells:a. After inducing cell apoptosis, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, collect the cells, gently resuspend the cells in PBS, and count them.Note: PBS resuspension cannot be omitted. The process of PBS resuspension also serves to wash cells, ensuring the subsequent binding of Annexin V-PE.b. Take 5 × 104-1 × 105 resuspended cells, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, and add 100 µ L of 1 × Annexin V binding buffer to gently resuspend the cells. c. Add 5 µ L Annexin V-PE and mix gently.d. Add 5 µ L of RedNucleus II staining solution and mix gently.e. Incubate at room temperature (20-25 º C) in the dark for 15 minutes. Aluminum foil can be used to avoid light. During the incubation process, cells can be resuspended 2-3 times to improve staining efficiency.(2) For adherent cells:a. Suck out the cell culture medium into a suitable centrifuge tube, wash the adherent cells with PBS once, and add an appropriate amount of trypsin cell digestion solution (without EDTA) to digest the cells. Incubate at room temperature until gently blowing can remove the trypsin cell digestion solution when the adherent cells are blown down. Overdigestion of pancreatic enzymes should be avoided.Note: For adherent cells, the trypsin digestion step is crucial. If the trypsin digestion time is too short, cells need to be blown hard to detach, which can easily cause damage to the cell membrane and lead to false positives of cell necrosis; If the digestion time is too long, it can also cause cell membrane damage and false positives of cell necrosis, and even affect the binding of phosphatidylserine and Annexin V-PE on the cell membrane, thereby interfering with the detection of cell apoptosis.b. Add the cell culture medium collected in the previous step, gently blow down the cells, transfer them to a centrifuge tube, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, collect the cells, gently resuspend the cells in PBS and count them.Note: Adding the cell culture medium from the previous step is very important. On the one hand, it can collect cells that have already been suspended and undergone apoptosis or necrosis. On the other hand, the serum in the cell culture medium can effectively inhibit or neutralize residual trypsin. The residual trypsin will digest and degrade the subsequently added Annexin V-PE, leading to staining failure.c. Take 5 × 104-1 × 105 resuspended cells, centrifuge at 1000 rpm for 5 minutes, discard the supernatant, and add 100 µ L of 1 × Annexin V binding buffer to gently resuspend the cells. d. Add 5 µ L Annexin V-PE and mix gently.e. Add 5 µ L of RedNucleus II staining solution and mix gently.f. Incubate at room temperature (20-25 º C) in the dark for 15 minutes. Aluminum foil can be used to avoid light. During the incubation process, cells can be resuspended 2-3 times to improve staining efficiency.3. Result analysis:(1) Flow cytometry detection:a. After incubation, 400 µ L of 1 × Annexin V binding buffer can be directly added to resuspend the cells, and immediately detected on the machine. Annexin V-PE is excited by 488 nm/566 nm laser, and the fluorescence emission spectrum is detected at 578 nm (BL2 (FL2)/YL1 channel), while the RedNucleus II channel emission spectrum is approximately at 695 nm (RL1 (FL4) channel).b. On the scatter plot of the bivariate flow cytometer, live cells are shown in the lower left quadrant, which is (Annexin V-PE -/RedNucleus II -); The lower right quadrant represents early apoptotic cells, which are (Annexin V-PE+/RedNucleus II -); The upper right quadrant represents necrotic and late stage apoptotic cells, which are (Annexin V-PE+/RedNucleus II+); The upper left quadrant displays naked nuclear cells, which are (Annexin V-PE -/RedNucleus II+).(2) Fluorescence microscopy detection:a. Centrifuge at 1000 rpm for 5 minutes, collect cells, and gently resuspend them in 400 µ L of 1 × Annexin V binding buffer. Transfer the cells to a 96 well plate and settle for a moment or perform cell smear, then observe under a fluorescence microscope.b. Annexin V-PE is compatible with PE filters. RedNucleus II can use a far red long pass filter.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. to reduce the process of apoptosis, the incubation process can be operated on ice, but the incubation time should be extended to at least 30 min. 3. as apoptosis is a rapid process, it is recommended that samples be analyzed within 1 h after staining. 4. for adherent cells, digestion is a key step. If there are floating cells when adherent cells induce apoptosis, the floating cells and adherent cells should be collected and stained. Handle adherent cells with care to avoid artificial damage to cells. The trypsin digestion time is too short, and the cells need to be blown hard to fall off, which is easy to cause damage to the cell membrane and excessive intake of rednucleus II; If the digestion time is too long, the cell membrane is also prone to damage, and even affect the binding of phosphatidylserine and annexin v-pe on the cell membrane. When digesting, spread pancreatin on the bottom of the well plate, fully contact the pancreatin with the cells when shaking gently, then pour out most of the pancreatin, use the remaining small amount of pancreatin to digest for a period of time, and terminate when the gap between cells increases and the bottom of the bottle is spotted. Try not to use EDTA in the digestive juice, which will affect the binding of annexin V to PS. 5. after the adherent cells are digested with trypsin, it is recommended to stain after recovering in the optimal culture conditions and medium for about 30 min to avoid false positives. 6. in order to avoid losing cells when washing cells, you can use a large tip over a small tip to aspirate. 7. the optimal concentration of dye is determined by the specific experimental requirements. 8. fluorescent dyes have quenching problems. Please try to avoid light during storage and use to slow down fluorescence quenching. 9. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Early apoptosis detection, annexin V Kit... Read More | Inquire |