| Description | Low-Density Lipoprotein (LDL) in plasma is the main carrier of endogenous cholesterol. It is degraded and metabolized by binding to the LDL receptor (LDL-R) on cell membranes and serves as the primary vehicle for transporting cholesterol to peripheral tissues. However, when LDL, especially oxidized Low-Density Lipoprotein (LDL) in plasma is the main carrier of endogenous cholesterol. It is degraded and metabolized by binding to the LDL receptor (LDL-R) on cell membranes and serves as the primary vehicle for transporting cholesterol to peripheral tissues. However, when LDL, especially oxidized LDL (OX-LDL), is present in excess, the cholesterol it carries accumulates in the arterial walls, increasing the risk of atherosclerosis. Atherosclerosis is the pathological basis and risk factor for the majority of cardiovascular and cerebrovascular diseases.Detection Principle: In a cholesterol assay system containing cholesterol esterase (CHER) and cholesterol oxidase (CHOD), specific surfactants are added to selectively solubilize LDL-C for the determination of LDL-cholesterol. Other lipoproteins (HDL, VLDL, chylomicrons) do not react due to inhibition by the surfactants and sugar compounds, remaining in the form of lipoproteins in the reaction mixture. Based on this principle, LDL-cholesterol can be measured directly. Subsequently, esterase catalyzes the hydrolysis of cholesterol esters to generate Free Cholesterol (FC). FC is oxidized by cholesterol oxidase to produce 4-cholestenone and hydrogen peroxide. Hydrogen peroxide then reacts with 4-aminoantipyrine and other components to produce a red quinoneimine compound, which has a characteristic absorption peak at 546 nm. The LDL-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.Standard1EA2-8℃. 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 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:LDL-C (µmol/g weight) = (CStandard × V2 ) × (ΔATest - ΔABlank ) ÷ (ΔAStandard - ΔABlank ) ÷ (W × V1 ÷ V) × DSimplified Formula:LDL-C (µmol/g weight) = CStandard × (ΔATest - ΔABlank ) ÷ (ΔAStandard - ΔABlank ) ÷ W × D3.2 Based on Protein ContentDerived Formula:LDL-C (µmol/mg prot) = (CStandard × V2 ) × (ΔATest - ΔABlank ) ÷ (ΔAStandard - ΔABlank ) ÷ (Cpr × V1 ÷ V) × DSimplified Formula:LDL-C (µmol/mg prot) = CStandard × (ΔATest - ΔABlank ) ÷ (ΔAStandard - ΔABlank ) ÷ Cpr × D3.3 LDL-C Content in LiquidsDerived Formula:LDL-C (mmol/L) = (CStandard × V2 ) × (ΔATest - ΔABlank ) ÷ (ΔAStandard - ΔABlank ) ÷ V1 × DSimplified Formula:LDL-C (mmol/L) = CStandard × (ΔATest - ΔABlank ) ÷ (ΔAStandard - ΔABlank ) × D3.4 Based on Cell CountDerived Formula:LDL-C (nmol/10⁴ cells) = (CStandard × V2 ) × 10³ × (ΔATest - ΔABlank ) ÷ (ΔAStandard - ΔABlank ) ÷ (500 × V1 ÷ V) × DSimplified Formula:LDL-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)500: 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 | DescriptionThe plasma protein lecithin:cholesterol acyltransferase (LCAT) catalyzes the transfer of an acyl group from the sn2 position of phosphatidylcholine to the 3-hydroxyl group of cholesterol forming cholesteryl ester. This activity occurs on the surface of high density lipoprotein (HDL) and DescriptionThe plasma protein lecithin:cholesterol acyltransferase (LCAT) catalyzes the transfer of an acyl group from the sn2 position of phosphatidylcholine to the 3-hydroxyl group of cholesterol forming cholesteryl ester. This activity occurs on the surface of high density lipoprotein (HDL) and the cholesteryl esters formed by LCAT are incorporated into the core of HDL.Preparation instructionsSuitable for high-throughput screening, mechanism of action studies and structureactivity relationship (SAR) work of LCAT in plasma and serumPrincipleThe LCFC-LCAT Acyltransferase Activity Assay is a fluorometric assay useful for measuring the acyltransferase activity of LCAT in serum or plasma. The method detects changes in LCAT free cholesterol (LCFC) levels in the sample without the use of c... Read More | Product contentcomponent50T200TBuffer LP125mL100mLBuffer LP210mL40mLBuffer LP3 (concentrate)21ml84mlBuffer GW2 (concentrate)15mL75mlBuffer GE15mL60mLRNase A（10 mg/ml）300µl1.25mLSpin Columns DM with Collection Tubes50200ProductsThis kit uses centrifugal adsorption columns with highProduct contentcomponent50T200TBuffer LP125mL100mLBuffer LP210mL40mLBuffer LP3 (concentrate)21ml84mlBuffer GW2 (concentrate)15mL75mlBuffer GE15mL60mLRNase A（10 mg/ml）300µl1.25mLSpin Columns DM with Collection Tubes50200ProductsThis kit uses centrifugal adsorption columns with high efficiency and specific binding of nucleic acids and a unique buffer system, which is suitable for extracting genomic DNA from a wide variety of different fresh or frozen plant tissues with maximum removal of impurities from the plant tissues. The kit eliminates the need for phenol/chloroform extraction and is safe to handle. The extracted genomic DNA fragments are large, high purity, stable and reliable quality, suitable for PCR, fluorescence quantitative PCR, molecular labeling, library construction and other experiments.Self-contained reagent: anhydrous ethanolPre-experiment Preparation and Important Notes1. Repeated freezing and thawing of the sample should be avoided, as this may result in smaller fragments of extracted DNA and a decrease in the amount extracted.2. Anhydrous ethanol should be added to Buffer LP3 and Buffer GW2 according to the instructions on the label of the reagent bottle before first use. Check Buffer LP1 and Buffer LP2 for crystallization or precipitation before use. If crystallization or precipitation occurs, re-dissolve Buffer LP1 and Buffer LP2 in a 56°C water bath. Procedure1. Take about 100mg of fresh plant tissue or about 20mg of dry weight tissue and add liquid nitrogen to grind it fully.2. Collect the ground powder into a centrifuge tube (self-provided), add 400 µl Buffer LP1 and 6 µl RNase A (10 mg/ml), vortex and oscillate for 1 minute, and leave it at room temperature for 10 minutes to allow for full cleavage.Note: 1) Use vortex shaking or pipette blowing to fully lyses the tissue, incomplete tissue lysis will affect the final DNA yield. 2) Do not mix Buffer LP1 with RNase A prior to use.3. Add 130 µl Buffer LP2, mix well and vortex for 1 minute.4. Centrifuge at 12,000 rpm (~13,400 x g) for 5 minutes and transfer the supernatant to a new centrifuge tube (supplied).5. Add 1.5 times the volume of Buffer LP3 (check that anhydrous ethanol has been added before use) and mix thoroughly (e.g., 500 µl filtrate to 750 µl Buffer LP3).Note: Buffer LP3 should be mixed immediately after addition; precipitation may occur but will not affect subsequent experiments.6. Add all of the solution and precipitate obtained in the previous step to the adsorption columns (Spin Columns DM) that have been loaded into the collection tubes, if the solution cannot be added all at once, it can be transferred in several times. centrifuge the columns at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tubes, and put the columns back into the collection tubes.7. Add 500 µl of Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorption column back into the collection tube.Note: If the adsorbent membrane appears green, add 500 µl of anhydrous ethanol to the adsorbent column, centrifuge the column at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the adsorbent column back into the collection tube.8. Repeat step 7.9. Centrifuge at 12,000 rpm for 2 minutes and pour off the waste liquid in the collection tube. Leave the adsorption column at room temperature for several minutes to dry thoroughly.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).10. Place the adsorption column in a new centrifuge tube (supplied), add 50-100 µl of Buffer GE or sterilized water dropwise to the middle of the adsorbent membrane, leave it at room temperature for 2-5 minutes, and centrifuge it at 12,000 rpm for 1 minute to collect the DNA solution. -The DNA solution was collected by centrifugation at 12,000 rpm for 1 min.Note: 1) If the downstream experiment is sensitive to pH or EDTA, you can use sterilized water for elution. The pH value of the eluent has a great influence on the elution efficiency, if you use water as the eluent, you should ensure that the pH value is 7.0-8.5 (you can use NaOH to adjust the pH value of the water to this range), and when the pH value is lower than 7.0, the elution efficiency is not high.2) Incubation at room temperature for 5 minutes prior to centrifugation increases yield.(3) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 10 can be re-added to the adsorbent membrane and repeat step 10; if the elution volume is less than 100µl, the final concentration of DNA can be increased, but it may reduce the total DNA yield. If the amount of DNA obtained is less than 1µg, 50µl Buffer GE is recommended for elution.4) Because DNA stored in water is subject to acidic hydrolysis, for long-term storage, elution with Buffer GE and storage at -20°C are recommended... Read More | Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 500ug of high-purity plasmid DNA from 120-300ml bacterial Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 500ug of high-purity plasmid DNA from 120-300ml bacterial culture for sequencing, in vitro transcription and translation, restriction enzyme digestion, bacterial transformation and other molecular biology experiments.Scope of application：Nucleic acid extraction and purification... Read More | Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 100u of high-purity plasmid DNA from 30-100 ml of Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 100u of high-purity plasmid DNA from 30-100 ml of bacterial culture for sequencing, in vitro transcription and translation, restriction enzyme digestion, bacterial transformation and other molecular biology experiments.Scope of application：Nucleic acid extraction and purification... Read More |