| Description | High-Density Lipoprotein (HDL), as an anti-atherogenic lipoprotein, transports cholesterol from peripheral tissues to the liver for metabolism, where it is converted into bile acids or directly excreted from the intestine via bile. This process reduces cholesterol deposition on the arterial wall. High-Density Lipoprotein (HDL), as an anti-atherogenic lipoprotein, transports cholesterol from peripheral tissues to the liver for metabolism, where it is converted into bile acids or directly excreted from the intestine via bile. This process reduces cholesterol deposition on the arterial wall. HDL exerts its anti-atherosclerotic effects through various mechanisms, including promoting reverse cholesterol transport, anti-inflammatory and antioxidant activities, inhibiting thrombus formation, and improving endothelial cell function.Detection Principle: Cholesterol esterase (CHER) and cholesterol oxidase (CHOD) are chemically modified and used in conjunction with dextran sulfate and magnesium ions (or other compounds like sulfated cyclodextrin complexes) to reduce their enzymatic reactivity towards LDL, VLDL, and chylomicrons, making them selectively interact with HDL-cholesterol. Based on this principle, in the first reaction step, LDL, VLDL, and chylomicrons are complexed with reagents like dextran sulfate. In the second reaction step, using the chemically modified CHER and CHOD, HDL-cholesterol is directly measured without the need to separate other lipoproteins. Specifically, the chemically modified CHER catalyzes the hydrolysis of cholesterol esters to generate Free Cholesterol (FC). FC is then oxidized by CHOD to produce 4-cholestenone and hydrogen peroxide. Subsequently, hydrogen peroxide reacts with 4-aminoantipyrine and phenol under the catalysis of peroxidase (POD) to generate a red quinoneimine compound, which has a characteristic absorption peak at 546 nm. The HDL-C content is determined by measuring the absorbance at 546 nm.Component96TStorageReagent 118 mL2-8℃. Store in the dark.Reagent 26 mL2-8℃. Store in the dark.Reagent 31EA2-8℃. Store in the dark.Standard (Powder, 1 vial) Preparation:1. Before use, centrifuge at 8000 g, 4°C for 2 minutes to collect the powder at the bottom of the tube.2. Add 0.1 mL of distilled water to dissolve. Use within one week. The prepared concentration is as indicated on the label.User-Prepared Instruments and Reagents:Mortar (Homogenizer), balance, ice box (ice maker), benchtop centrifuge, adjustable micropipettes, water bath (oven, incubator, metal bath), 96-well plate, centrifuge tubes, microplate reader, distilled water (deionized water or ultrapure water are acceptable), ethanol.Experimental ProcedureIt is recommended to first perform a preliminary test using 1-3 samples with expected significant differences (e.g., different types or groups) to familiarize yourself with the procedure and to determine or adjust sample concentrations based on the preliminary results, preventing unnecessary waste of samples or reagents.1. Sample Extraction1.1 Tissue SamplesWeigh approximately 0.1 g of tissue sample and place it in a mortar. Add 1 mL of ethanol and homogenize in an ice bath. Centrifuge at 12,000 rpm, 4°C or room temperature for 10 minutes. Collect the supernatant for assay.Note: If increasing the sample amount, maintain a tissue mass (g) to ethanol volume (mL) ratio between 1:5 and 1:10.1.2 Liquid SamplesAssay clear liquid samples directly. If turbid, centrifuge and use the supernatant for assay.1.3 Serum SamplesFor routine, clear serum samples, add reagents directly according to the assay table and proceed with detection. If the serum sample has a high protein content, adding reagents as per the table may cause turbidity. In this case, first take 200 µL of serum + 200 µL of ethanol, mix well by inverting several times, centrifuge at 8,000 rpm, 4°C or room temperature for 5 minutes, and then collect the supernatant for assay.1.4 Bacterial/Cell SamplesCollect bacteria or cells into a centrifuge tube, centrifuge, and discard the supernatant. Add 1 mL of ethanol per approximately 5 million bacteria/cells. Disrupt the bacteria or cells by sonication in an ice bath (power 200W, pulse 3s on, 10s off, repeat 30 times). Centrifuge at 12,000 rpm, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.*Note: If increasing the sample amount, maintain a bacteria/cell count (10⁴) to ethanol volume (mL) ratio between 500:1 and 1000:1.*2. Assay Steps2.1 Preheat the microplate reader for 30 minutes (or wait for the instrument to complete its self-check). Set the wavelength to 546 nm.2.2 Thaw all reagents to room temperature (25°C). Add reagents sequentially to a 96-well plate as follows:Reagent (µL)Test TubeStandard Tube (once)Blank Tube (once)Sample2.5Standard2.5Distilled Water2.5Reagent 1180180180Mix well and incubate at 37°C for 5 minutes. Read the absorbance at 546 nm for each tube (A₁).Reagent 2606060Mix well and incubate at 37°C for 10 minutes. Read the absorbance at 546 nm for each tube (A₂). Calculate ΔA = A₂ - A₁ for each tube.Note:(1) If the A₂ value for the Test Tube is greater than 1, dilute the sample with ethanol. The dilution factor (D) must be substituted into the calculation formula.(2) If ΔA for the Test Tube is lower than ΔA for the Blank Tube, consider increasing the sample volume V₁ (e.g., increase the sample volume in the Test Tube and the water volume in the Blank Tube to 5 µL or more, keeping Reagents 1 and 2 volumes unchanged; for the Standard Tube, keep at 2.5 µL and add 2.5 µL distilled water to make up volume) or increasing the sample weight W (e.g., to 0.2 g or more). The changed V₁ or W must then be substituted into the calculation formula.3. Calculation of Results3.1 Based on Sample MassDerived Formula:HDL-C (µmol/g weight) = (CStandard × V₂) × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) ÷ (W × V₁ ÷ V) × DSimplified Formula:HDL-C (µmol/g weight) = CStandard × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) ÷ W × D3.2 Based on Protein ContentDerived Formula:HDL-C (µmol/mg prot) = (CStandard × V₂) × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) ÷ (Cpr × V₁ ÷ V) × DSimplified Formula:HDL-C (µmol/mg prot) = CStandard × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) ÷ Cpr × D3.3 HDL-C Content in LiquidsDerived Formula:HDL-C (mmol/L) = (CStandard × V₂) × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) ÷ V₁ × DSimplified Formula:HDL-C (mmol/L) = CStandard × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) × D3.4 HDL-C Content in SerumDerived Formula:HDL-C (mmol/L) = (CStandard × V₂) × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) ÷ V₁ × 2 × DSimplified Formula:HDL-C (mmol/L) = 2 × CStandard × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) × D3.5 Based on Cell CountDerived Formula:HDL-C (nmol/10⁴ cells) = (CStandard × V₂) × 10³ × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) ÷ (500 × V₁ ÷ V) × DSimplified Formula:HDL-C (nmol/10⁴ cells) = 2 × CStandard × (ΔATest - ΔABlank) ÷ (ΔAStandard - ΔABlank) × DParameter Definitions:CStandard: Concentration as indicated on the label (mmol/L or µmol/mL)V₁: Volume of sample added (0.0025 mL)V: Volume of extraction buffer (ethanol) added (1 mL)V₂: Volume of standard added (0.0025 mL)D: Dilution factor (1 if not diluted)2: Dilution factor in serum pre-treatment500: Number of cells (in units of 10⁴)W: Sample weight (g)Cpr: Protein concentration of the supernatant (mg/mL); Aladdin's BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648) is recommended.Precautions1. It is recommended to first perform a preliminary test using 1-3 samples with expected significant differences (e.g., different types or groups) to familiarize yourself with the procedure. Based on the preliminary results, determine or adjust sample concentrations to prevent unnecessary waste of samples or reagents.2. This product is for research use only. Not for use in clinical diagnosis. For your safety and health, please wear a lab coat and disposable gloves during operation... Read More | Product introduction：Griess reagent can be used for spectrophotometric detection of nitrite. The reagent contains two chemicals, sulfonic acid and n- (1-naphthyl) ethylenediamine. Under acidic conditions, sulfamic acid is converted into diazonium salt by nitrite, which can form a highly Product introduction：Griess reagent can be used for spectrophotometric detection of nitrite. The reagent contains two chemicals, sulfonic acid and n- (1-naphthyl) ethylenediamine. Under acidic conditions, sulfamic acid is converted into diazonium salt by nitrite, which can form a highly colored azo dye with n- (1-naphthyl) ethylenediamine. This dye can be detected at 548 nm: because no is extremely unstable, it is oxidized to form nitrite and nitrate. Griess indirectly reflects the content of no by detecting the content of nitrite.Matters needing attention：1. before using Griess reagent, return it to room temperature and check the solution for precipitation. If Griess reagent I contains sediment when taken out, it can be placed in a 37 ℃ water bath until the sediment dissolves. 2. this product is potentially harmful. Avoid prolonged or repeated exposure. Avoid entering eyes, skin or clothing. Please wear lab clothes and disposable gloves for operation.Scope of application：No detectionComponent：Instruction：1.Griess Reagent I and II were taken out to restore the room temperature.2.Standard dilution : The standard NaNO2 ( 1-100 µM ) was diluted with the solution used for the sample to be tested. The standard was diluted to 1 µM, 10 µM, 20 µM, 40 µM, 80 µM and 100 µM, and 100 µL standard was added to each well. If the sample concentration is too low, the range of the standard curve can be appropriately reduced ( 1 µM, 2 µM, 3 µM, 4 µM, 6 µM, 8 µM, 10 µM ).3.Sample detection :( 1 ) According to the total volume of 200 µL / hole, 100 µL / hole sample was added to the 96-well plate ; if the sample is the supernatant of the culture medium, it can be sampled directly, and if there is sediment, the supernatant should be taken after centrifugation. If the sample is a cell or tissue, it can be quickly lysed by freeze-thaw, and then centrifuged to obtain the supernatant. The volume of less than 100 µL can be diluted with diH2O or 0.9 % NaCl ( corresponding standards also need to be diluted with diH2O or 0.9 % NaCl ).( 2 ) According to 50 µL / hole, Griess Reagent I was added to each hole.( 3 ) According to 50 µL / hole, Griess Reagent II was added to each hole.( 4 ) The absorbance was measured at 540 nm. If there is no 540 nm filter, 520-560 nm filter can also be. If there is no microplate reader or a suitable filter, the concentration of nitric oxide in the sample can also be determined by visual colorimetry. A more precise concentration gradient is required for the standard when visual colorimetric... 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 | DescriptionPhoto KitAlysis Starter Kit enables screening of 24 micro-scale simultaneous photocatalytic reactions with consistent and reproducible photon intensity. User guide is provided in the below hyperlink.Photo KitAlysis Operating InstructionsComponents:Photo KitAlysis LED ControllerBlue LED DescriptionPhoto KitAlysis Starter Kit enables screening of 24 micro-scale simultaneous photocatalytic reactions with consistent and reproducible photon intensity. User guide is provided in the below hyperlink.Photo KitAlysis Operating InstructionsComponents:Photo KitAlysis LED ControllerBlue LED Array (470 nm)Photo KitAlysis Reaction BlockTorque screwdriverSmall screwdriver to easily remove torqued screws after reaction is completeFeatures:Designed and tested by synthetic chemists.Controller provides repeatable milliamp selection for photon intensity0-30 mA variable LED output3 different LED options: blue (470 nm, included), green (527 nm, sold separately), and white (sold separately)Non-magnetic LED baseChemically resistant LED coverPTFE coated cablingDesigned to be used withPhoto KitAlysis High-Throughput Reaction Screening Kit(sold separately).Best when used withKitAlysis Benchtop Inertion Box(sold separately)... Read More | Product DescriptionAcetyl esterase (sialate-O-acetylesterase) is a recombinant protein from Tannerella forsythia, ATCC 43037 strain, expressed in Escherichia coli. The enzyme removes acetyl groups attached via an O- group, mainly 9-, 8- and 7-. It can be used for monitoring of diacetylation of Product DescriptionAcetyl esterase (sialate-O-acetylesterase) is a recombinant protein from Tannerella forsythia, ATCC 43037 strain, expressed in Escherichia coli. The enzyme removes acetyl groups attached via an O- group, mainly 9-, 8- and 7-. It can be used for monitoring of diacetylation of sialic acids on products such as erythropoietin (EPO).The Zyme Acetyl Esterase Kit removes 9-, 8- and 7-O-acetyl groups from released sialic acids, released glycans or glycoproteins. It is commonly used for the characterization of highly-sialylated biotherapeutics such as EPO, FSH and blood clotting factors.Molecular Weight76.3 kDContentsAcetyl esterase – PBS pH7.5 buffer containing 10 mM Tris-HClReaction Buffer – 500 mM sodium acetate pH5.5Number of SamplesSufficient for up to 50 samples.Amount of SampleUp to 10 µg glycoprotein, up to 2.5 µg released glycans and up to 1 µg free sialic acid per digestion.Suitable SamplesAcetyl esterase (sialate-O-acetylesterase) can act upon complex glycoprotein samples, such as erythropoietin (EPO), bovine submaxillary mucin and oral epithelial cell-bound glycans, and on N- and O-glycans released from a glycoprotein. Either fluorescently labelled or unlabelled glycans are suitable. It can also be used on released sialic acids.Unit DefinitionOne unit (U) of acetyl esterase is defined as the amount of enzyme required to produce 300 µmole of 4-nitrophenol and acetate in 1 minute at 30°C in a buffer containing 50 mM Tris-HCl, 140 mM NaCl, pH 8.5, from 4-nitrophenyl acetate, a chromogenic esterase substrateStorageProtect from sources of heat and light. When stored correctly, the enzyme should be stable for 24 months from date of purchase. Exposure to ambient temperatures (20 – 26°C) over 3 days does not result in a reduction of enzymatic activity.ShippingThe product should be shipped at 4°C.HandlingEnsure that any glass, plastic ware or solvents used with this item are free of environmental carbohydrates. Use powder-free gloves for all sample handling procedures and avoid contamination with environmental carbohydrate.SafetyPlease read the Safety Data Sheets (SDSs) for all chemicals used. All processes involving labelling reagents should be performed using appropriate personal safety protection – safety glasses, chemically resistant gloves (e.g. nitrile), lab coat, and when appropriate, in a laboratory fume cupboard.For research use only. Not for human or drug use ApplicationAcetyl esterase (sialate-O-acetylesterase) can be used to remove 9-, 8- and 7-O-acetyl groups from released sialic acids, released glycans or glycoproteins... Read More |