| Description | Free Fatty Acids (FFA), also known as Non-Esterified Fatty Acids (NEFA), are primarily produced by the hydrolysis of neutral fats. They are intermediate products in fat metabolism, involved in cell proliferation, inflammatory responses, and hormone regulation. FFA can also act as signaling moleculesFree Fatty Acids (FFA), also known as Non-Esterified Fatty Acids (NEFA), are primarily produced by the hydrolysis of neutral fats. They are intermediate products in fat metabolism, involved in cell proliferation, inflammatory responses, and hormone regulation. FFA can also act as signaling molecules with various physiological functions. Free fatty acids are closely related to lipid metabolism, glucose metabolism, and endocrine function. Their concentration is an important physiological and biochemical indicator, serving as an auxiliary parameter for disease evaluation and diagnosis, and also reflecting quality changes during food storage.Detection Principle: FFAs combine with copper ions to form copper soaps, which are soluble in chloroform. The copper ions can then react with a chromogenic solution to form a purplish-red complex. This product has a characteristic absorption peak at 550 nm. The FFA content can be quantified by measuring the change in absorbance.Detection Range: 0.0313 - 2 mMSensitivity: 0.0156 mMApplicable Samples: Serum (plasma), animal/plant tissues, cells, bacteria.A1492746Component48T96TStorageA1492746ACu Reagent6 mL12 mL2-8℃. Store in the dark.A1492746BChromogen15 mL30 mL2-8℃. Store in the dark.A1492746CStandard (16.41 mg Palmitic Acid)1 EA1 EA2-8℃. Store in the dark.User-Prepared Instruments and ReagentsMicroplate reader or visible spectrophotometer (capable of measuring absorbance at 550 nm)Incubator, Ice maker, Low-temperature centrifuge96-well plate or micro glass cuvettes, Adjustable pipettes and tipsHomogenizer (for tissue samples)Glass bottle (for preparing extraction buffer)n-Heptane, Anhydrous methanol, ChloroformExperimental Procedure1. Reagent PreparationReagent NameReagent PreparationPrecautionsExtraction Buffer (Self-prepared)In a glass bottle, mix Chloroform : n-Heptane : Anhydrous Methanol = 28 : 21 : 1. Cap tightly and mix well.Store at 4°C protected from light.Cu ReagentReady-to-use; equilibrate to room temperature before use; mix well before use.Store at 4°C protected from light.ChromogenReady-to-use; equilibrate to room temperature before use.Store at 4°C protected from light.StandardBefore use, dissolve contents in 1 mL of Extraction Buffer to obtain a 64 mM Standard solution. Mix well.Unused dissolved Standard can be stored in a tightly sealed glass bottle at 4°C protected from light for 1 month.2. Standard Curve SetupDilute the 64 mM Standard further with Extraction Buffer as shown in the table below.Standard No.Standard (µL)Extraction Buffer Volume (µL)Standard Concentration (mM)Std.120µL of 64mM stock6202Std.2100µL of Std.11001Std.3100µL of Std.21000.5Std.4100µL of Std.31000.25Std.5100µL of Std.41000.125Std.6100µL of Std.51000.0625Std.7100µL of Std.61000.0313Note: Prepare freshly diluted standards for each experiment.3. Sample PreparationNote: Fresh samples are recommended. If not used immediately, samples can be stored at -80°C for up to 6 months.3.1 Animal Tissues: Weigh approximately 0.1 g of tissue, add 1 mL of Extraction Buffer, and homogenize on ice. Centrifuge at 8,000 rpm, 4°C for 10 min. Collect the supernatant and keep on ice for detection.3.2 Plant Tissues: Weigh approximately 0.1 g of tissue, add 1 mL of Extraction Buffer, and grind. Disrupt by ultrasonic homogenization on ice (power 20% or 200 W, ultrasonicate for 3 s, interval 7 s, repeat 30 times). Centrifuge at 8,000 rpm, 4°C for 10 min. Collect the supernatant and keep on ice for detection.3.3 Cells or Bacteria: Collect 5 million cells or bacteria into a centrifuge tube. Wash with cold PBS, centrifuge, and discard the supernatant. Add 1 mL of Extraction Buffer. Disrupt by ultrasonic homogenization on ice (power 20% or 200 W, ultrasonicate for 3 s, interval 7 s, repeat 30 times). Centrifuge at 8,000 rpm, 4°C for 10 min. Collect the supernatant and keep on ice for detection.3.4 Serum (Plasma) and other liquids: Detect directly.4. Assay Steps4.1 Instrument Preparation: Preheat the microplate reader or visible spectrophotometer for at least 30 minutes. Set the wavelength to 550 nm. For spectrophotometers, zero the instrument with deionized water.4.2 Sample Assay (Add reagents sequentially to EP tubes):ReagentBlank Tube (µL)Standard Tube (µL)Test Tube (µL)Extraction Buffer240200200Various Std.0400Sample0040Cap the tubes tightly and vortex at medium speed for 30 seconds.Cu Reagent808080Cap the tubes tightly and vortex at medium speed for 30 seconds. Incubate at room temperature (25°C) for 20 minutes. Centrifuge at 2,000 g, room temperature (25°C) for 5 minutes.Upper Phase505050Chromogen2002002004.3 Incubate at room temperature (25°C) for 5 minutes. Transfer 200 µL from each tube to the corresponding wells of a 96-well plate or micro glass cuvettes. Measure the absorbance at 550 nm.Calculate ΔAtest=Atest-Ablank and ΔAstd=Astd-Ablank (The blank tube only needs to be set up once).Note: The measurement must be completed within 30 minutes after color development. It is recommended to perform preliminary experiments with 2-3 samples expected to have significant differences before formal testing. If Atest exceeds the detection range of the instrument, dilute the sample further with Extraction Buffer and multiply the result by the dilution factor.5. Result CalculationWe provide both derived and simplified calculation formulas, which are equivalent. The simplified formulas in bold are recommended as the final calculation formulas.5.1 Standard Curve PlottingPlot the standard curve with standard concentration as the y-axis and ΔAstd as the x-axis (using concentration as the y-axis facilitates calculation). Substitute ΔAtest into the standard curve equation to obtain y (mM).5.2 Sample FFA Content Calculation(1) Based on sample mass:FFA Content (µmol/g fresh weight) = y × Vextract ÷ W × n = y ÷ W × n(2) Based on bacterial or cell count:FFA Content (µmol/10⁴ cells) = y ÷ (Cell or Bacterial Count ÷ Vextract ) × n = y ÷ 500 × n = 0.002 × y × n(3) Based on liquid volume:FFA Content (µmol/L) = 1000 × y × nParameter Description:Vextract : Volume of Extraction Buffer added, 1 mLW: Sample mass, gn: Sample dilution factor (if further diluted)500: Cell or bacterial count, in units of 10⁴1000: Unit conversion factor, 1 L = 1000 mL6. Result PresentationTypical Standard Curve: y = 0.679x - 0.0109, R² = 0.9988(Free Fatty Acid (FFA) standard curve analyzed using a 96-well plate. Data and curve are for reference only; users must establish their own standard curve based on their experiment.)Precautions1. Biochemical reagents are generally irritating and biologically toxic. For your safety and health, please implement appropriate biosafety precautions throughout the experiment. Wear personal protective equipment such as lab coats, masks, gloves, and hair caps. Perform experiments in a fume hood or biosafety cabinet.2. This product is for scientific research use only. Not intended for clinical diagnosis... 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 | Inquire | The fluorescent dye PKH67 is suitable for conventional cell membrane labeling. It is a green fluorescent dye that can track cells in vitro and in vivo. It labels cells by binding to the lipid components of the membrane structure. PKH67 has low cytotoxicity, low fluorescence background, high fat The fluorescent dye PKH67 is suitable for conventional cell membrane labeling. It is a green fluorescent dye that can track cells in vitro and in vivo. It labels cells by binding to the lipid components of the membrane structure. PKH67 has low cytotoxicity, low fluorescence background, high fat solubility, can easily penetrate cell membranes, and has strong and stable green fluorescence. PKH67-labeled cells can be used for in vitro and in vivo proliferation studies, and have the function of not staining neighboring cells. In the process of cell division and proliferation, the fluorescence intensity of PKH67 will gradually decrease as the cells divide. The labeled fluorescence can be evenly distributed to the two sub-generation cells, so its fluorescence intensity is half that of the parent cell. According to this feature, It can be used to detect cell proliferation, cell cycle estimation and cell division, etc. The fluorescence of PKH67-labeled cells is very uniform, and the fluorescence distribution of sub-generation cells after division is also more uniform. In the process of cell division and proliferation, PKH67-labeled fluorescence can be evenly distributed between the two sub-generation cells, and the fluorescence intensity becomes half of that of the parent cell. According to the difference in fluorescence intensity, the undivided cells can be detected by flow cytometry. One time (1/2 the fluorescence intensity), the second time (1/4 the fluorescence intensity), three times (1/8 the fluorescence intensity), and more divisions of cells. PKH67 can detect splits up to six times or even more. In addition to the detection of cell proliferation, PKH67 can also be used for in vitro tracking of cells. After labeling, the fluorescence expression is stable in the cell, and the positive labeling rate is over 98%. The labeled cells have good morphology, which can effectively observe the cells in vitro. Induce differentiation; or inject labeled cells into the body, it can effectively show the migration and differentiation of transplanted cells in living tissues. PKH67-labeled cells can be used for in vivo observation for as long as several weeks. It is often used for in vivo cell detection experiments and experiments to observe long-term cell activity using fluorescence electron microscope. PKH67 is less toxic and does not affect cell proliferation. This method is simple to operate, does not use radioactive isotopes, and poses no safety hazards. You can get the desired experimental data faster, more accurately and more safely.Due to the longer length of the charcoal tail, internal studies have shown that PKH67 is less transferred between cells than PKH2. In in vivo studies using PKH1 and PKH2, the fluorescence intensity will slowly lose. Since this is a behavioral characteristic of green cell linker dye rather than red cell linker dye, PKH67 will have similar properties. The correlation between the in vitro cell membrane retention of non-dividing cells and the in vivo fluorescence half-life reveals that the in vivo fluorescence half-life of PKH67 is 10-12 days. Other green cell linker dyes with similar half-lives have been used to monitor the transport of lymphocytes and macrophages in the body within one to two months. The results indicate that PKH67 can also be used for medium-term in vivo tracking studies.The dye can stably bind to the lipid region of the cell membrane and emit fluorescence, and is mainly used for cell labeling in vitro, cell proliferation research in vitro, and cell tracing research in vivo and in vitro. The fluorescence half-life of PKH67 in vivo is 10-12 days. Compared with PKH-67, PKH-26 has a longer half-life, and the half-life of PKH26 labeled on rabbit red blood cells is more than 100 days. Especially suitable for in vitro proliferation research and long-term in vivo cell tracking research. After PKH67 labels the cells, flow cytometry is usually used for cell proliferation detection.Kit components0.1ml kits: P266290A-0.1ml P266290B-10ml1ml kits: P266290A-1ml P266290B-60mlDyes with A suffix and diluents with B suffix are used togetherPKH67 labeled cells show green fluorescence, the fluorescence wavelength: λex=490 nm, λem=502 nm.Storage conditions: -20℃ protected from light, valid for 1 yearPrecautions●Staining concentration varies according to the type of cell and the number of cells in each well.● The prepared PKH67 mother liquor is very easy to dissolve. It is recommended to store in aliquots and freeze-dry at ≦-20℃.● PKH67 working solution should be prepared for immediate use, and cannot be prepared in advance, because PKH67 will decompose due to the absorption of water and affect the dyeing effect.● PKH67 is easily decomposed and will deteriorate quickly in the water solution. Please avoid contact with water during use of mother liquor. The working fluid is in contact with the water during the process of labeling the cells within the permitted time range.● PKH67 fluorescent dye is a DMSO solution. It will solidify and stick to the bottom, wall or cap of the tube at a lower temperature such as 4℃ and ice bath. After being taken out of the refrigerator, it will return to room temperature and become After the liquid is in the state, remove the cap from the bottom of the tube. It can be used after it has completely melted in a 37°C water bath.● The number of generations or time that can be traced after different cell types are marked is quite different. Please make a test based on the actual situation or reference documents.Instructions1. Staining solution preparation:(1) Take out the PKH67 reagent from the refrigerator, let it stand for a few minutes to room temperature, or after a 37°C water bath, leave the tube containing PKH67, and be sure to leave the tube for a few minutes before opening the lid to allow the reagent to fully fall into the tube The lid can only be opened after the bottom.(2) According to the number of cell samples to be tested, dilute the probe 10 times with the diluent, and then use a suitable solution (such as non-clear medium, HBSS or PBS) to dilute the PKH67 mother liquor 25 times to prepare a stain Work fluid. The best working solution concentration should be adjusted according to different cells and your own experimental system. Generally, the cells can be diluted 250 times according to the final concentration of the mother liquor in the kit. Some cells may need to increase the concentration appropriately.2. Cell staining(1) Resuspend the prepared cells to be tested in 100µl of staining solution to a cell concentration of about 107/ml. You can also perform in-situ staining, as long as the staining solution is enough to cover the cells.(2) Culture the cells at 2～8℃ for 15～30 minutes. The best culture time is different for different cells.It is recommended to incubate the labeled cells in the staining solution at 37°C for 5 minutes, and then at 4°C for 15 minutes.Low-temperature incubation can reduce the endocytosis of the dye by the cells, help the dye to label the plasma membrane, and reduce the possibility of the dye localizing to cytoplasmic vesicles.(3) After separation, remove the supernatant, collect the cells, wash the cells 1-2 times with PBS or non-clear medium, and finally add PBS or non-clear medium to resuspend the cells.(4) Take 500µl of cell suspension and test with flow cytometer. Ex/Em=490/502nm.(5) Subsequently, the cells can be cultured according to the normal culture method.(6) The labeling effect can be directly observed under a fluorescence microscope, or the cell proliferation can be detected by a flow cytometer after an appropriate period of culture, or used for cell fluorescence traces for other specific experimental purposes... 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 |