| 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 | DescriptionCholesteryl ester transfer protein (CETP) is present in normal human plasma and transfers neutral lipids from high density lipoproteins (HDL) to very low density lipoprotein (VLDL) and low density lipoprotein (LDL). CETP plays an important role in lipoprotein metabolism and influences theDescriptionCholesteryl ester transfer protein (CETP) is present in normal human plasma and transfers neutral lipids from high density lipoproteins (HDL) to very low density lipoprotein (VLDL) and low density lipoprotein (LDL). CETP plays an important role in lipoprotein metabolism and influences the reverse cholesterol transport pathway.Preparation instructionsSuitable for high-throughput screening (HTS), mechanism of action (MOA) studies, and structure-activity relationship (SAR) work in CETP sources.PrincipleThe CETP RP Activity Assay uses a proprietary substrate that enables the detection of CETP-mediated neutral lipid mass transfer. The method is useful for measuring CETP activity in recombinant protein (RP) or purified CETP samples and has a high D... Read More | Glycogen and starch generate glucose-1-phosphate (1PG/G1P) during the process of phosphohydrolysis. This reagent kit provides a simple, sensitive, and rapid determination method: Glucose-1-phosphate (1PG/G1P) is reduced from NADP+to NADPH by the sequential action of phosphoglucose mutase and Glycogen and starch generate glucose-1-phosphate (1PG/G1P) during the process of phosphohydrolysis. This reagent kit provides a simple, sensitive, and rapid determination method: Glucose-1-phosphate (1PG/G1P) is reduced from NADP+to NADPH by the sequential action of phosphoglucose mutase and phosphoglucose dehydrogenase. The content of glucose-1-phosphate (1PG/G1P) in the sample can be calculated by detecting the increase in NADPH at 340nm.Composition and preparation of reagent kit: Reagent name Specifications Save requirements Remarks Extraction solution Liquid 100mL x 1 bottle 4 ℃ storage / Reagent 1 Powder mg x 1 tube 4 ℃ storage Shake or centrifuge the reagent a few times before use to make it fall to the bottom, then dissolve it in 1.2mL of distilled water for later use. Reagent 2 Powder mg x 1 tube Store at -20 ℃ Shake or centrifuge the reagent a few times before use to make it fall to the bottom, then dissolve it in 1.2mL of distilled water for later use. Reagent 3 Liquid 16mL x 1 bottle 4 ℃ storage / Reagent 4 Powder mg x 1 tube Store at -20 ℃ Shake or centrifuge the reagent a few times before use to make it fall to the bottom, then add 1 Dissolve 1mL of distilled water for later use. TRC 1 powder 4 ℃ storage Only used to identify whether the reagents in the kit are normal (not involved in result calculation). Usage: Use a pre standard tube (GIP) to shake the powder a few times until it falls to the bottom, then add 0.5mL of distilled water and mix well to dissolveDilute GIP with a concentration of 4mg/mL and then dilute it four times to 1mg/mL for later use: follow the instructions in the sample addition table for the measuring tube operationRequired instruments and supplies:ELISA reader, 96 well plate, desktop centrifuge, adjustable pipette, mortar, ice and distilled water.Determination of glucose-1-phosphate (1PG/G1P) content:1. Sample preparation① Organizational sample:Suggest weighing around 0 1g of tissue, add 1mL of extraction solution, and homogenize in an ice bath. Centrifuge at 12000rpm, 4 ℃ for 10 minutes, take the supernatant, and place it on ice for testing.[Note]: If the sample size is increased, it can be extracted in a ratio of tissue mass (g) to extraction solution volume (mL) of 1:5-10.② Bacterial/cellular samples:Collect bacteria or cells into a centrifuge tube first, centrifuge and discard the supernatant; Take about 5 million bacteria or cells and add them to 1mLExtract solution, sonicate bacteria or cells (ice bath, power 200W, sonication for 3s, interval 10s, repeated 30 times); Centrifuge at 12000rpm at 4 ℃ for 10 minutes, take the supernatant, and place it on ice for testing.[Note]: If the sample size is increased, extraction can be carried out in a ratio of 500-1000:1 of bacteria/cell quantity (104) to extraction solution (mL).③ Liquid sample: direct detection.2. Machine testing:① Preheat the enzyme-linked immunosorbent assay (ELISA) reader for at least 30 minutes and adjust the wavelength to 340nm.② Thaw the reagent to room temperature (25 ℃);③ Add reagents to the 96 well plate in the following order according to the table:② Thaw the reagent to room temperature (25 ℃);③ Add reagents to the 96 well plate in the following order according to the table: Reagent name (µL） Measurement tube Blank tube (only done once) Reagent 1 10 10 Reagent 2 10 10 Reagent 3 150 170 Sample 20 / Mix well, incubate at room temperature (25 ℃) for 20 minutes, and then read A1 at 340nm (if the A value continues to increase, the incubation time needs to be extended until the absorbance value remains unchanged within 2 minutes). Reagent 4 10 10 Mix well, incubate at room temperature (25 ℃) for 20 minutes, and then read A2 at 340nm (if the A value continues to increase, the incubation time needs to be extended until the absorbance value remains unchanged within 2 minutes). Δ A=(A2-A1) measurement - (A2-A1) blank.[Note] 1 If the difference in Δ A is hovering around zero, the sample size V1 can be increased (such as increasing to 50 µ L, the three phases of the reagent should be reduced while keeping the total volume unchanged), or the sample sampling mass W can be increased. The changed V1 and W need to be substituted into the formula for recalculation.If the A2 value exceeds 1.2, the amount of sample added V1 can be reduced (such as to 10 µ L, the three-phase reagent should be increased while keeping the total volume unchanged), or the sample can be diluted with distilled water (keeping the sample addition system unchanged), and the changed V1 and D need to be substituted into the formula for recalculation.Result calculation:1. Calculated by sample weight:1PG/G1P content (µ g/g fresh weight)=[(Δ A ÷ (ε× d) × V2 × 106 × MR] ÷ (W × V1 ÷ V) × D=836 × Δ A ÷ W × D2. Calculated by the number of cells:1PG/G1P content (µ g/104 cell)=[(Δ A ÷ (ε× d) × V2 × 106 × MR] ÷ (500 × V1 ÷ V) × D=1.7 × Δ A × D. 3. Calculated by liquid volume:1PG/G1P content (µ g/mL)=[(Δ A ÷ (ε× d) × V2 × 106 × Mr] ÷ V1=836 × Δ A ε---NADPH Molar extinction coefficient，6.22×103 L/mol/cm； d---96 Orifice plate optical diameter，0.5cm； V---Add volume of extraction solution，1 mL； V1---Add sample volume，0.02mL V2---Total reaction volume；0.2mL=2×10-4L； W---Sample quality，g； Mr---Glucose-1-phosphate（1PG/G1P）Molecular weight；260； 500---Number of cells, in millions； D---Dilution ratio，Undiluted is 1。 /... Read More | Products contentNote: The amount of individual primers used is 1 µl, each N7-end primer can perform 10 DNA library constructs, and each kit can perform 240 DNA library constructs.Products IntroductionThis kit is a companion kit to the transposase-based Rapid DNA Library Construction Kit for Products contentNote: The amount of individual primers used is 1 µl, each N7-end primer can perform 10 DNA library constructs, and each kit can perform 240 DNA library constructs.Products IntroductionThis kit is a companion kit to the transposase-based Rapid DNA Library Construction Kit for Illumina platform library construction. Each kit contains one N5 primer and 24 N7 primers, which can be used to prepare 24 different single-ended Index libraries. All reagents provided in the kits have been subjected to stringent quality control and functional validation to maximize the stability and reproducibility of library construction. The libraries can be used for sequencing on Illumina platforms such as HiSeq X-10/4000/2500/2000 and MiSeq. Provide your own instruments, reagents and consumables1. Magnetic frame: DynaMagTM-2 is recommended.2. DNA purification and recovery kit: It is recommended to use Kangwei DNA purification and recovery kit by magnetic bead method.3. DNA building kit: It is recommended to use the Kangwei Century transposase method second-generation sequencing rapid DNA building kit.4. Anhydrous ethanol.5. Reaction tubes: It is recommended to use low adsorption PCR tubes with 1.5 ml centrifuge tubes; Tip: It is recommended to use a high quality filter tip to prevent contamination of kits and library samples. Pre-experiment Preparation and Important NotesPlease centrifuge briefly before opening the cap so that the liquid collects at the bottom of the tube to avoid cross-contamination between different primers. procedureFor the use of the CombiVision Second Generation Sequencing Multisample Primer Kit, please follow the CombiVision Second Generation Sequencing Rapid DNA Library Kit protocol. Index N501 Primer for Illumina Index N901-N996 Primer for Illumina... Read More | Product contentComponentY665957-1mlY665957-5ml2×GoldStar Probe Mixture1 ml5×1 mlProbe Primer Mix300 µl5×300 µlHuman DNA Standard（100 ng/µl）100 µl5×100 µl50×High ROX40 µl200 µlProduct IntroductionThis product is a real-time Product contentComponentY665957-1mlY665957-5ml2×GoldStar Probe Mixture1 ml5×1 mlProbe Primer Mix300 µl5×300 µlHuman DNA Standard（100 ng/µl）100 µl5×100 µl50×High ROX40 µl200 µlProduct IntroductionThis product is a real-time fluorescence quantitative PCR kit for detecting the concentration of human male Y chromosome, including carefully optimized PCR reaction solution, primer mixture and standards, especially suitable for the quantitative detection of precious and micro DNA samples. The kit adopts a new efficient and fast hot-start amplification enzyme GoldStar Taq DNA Polymerase, which effectively avoids non-specific amplification caused by non-specific binding of primers and templates or primer dimerization at room temperature. This product realizes accurate quantification of Y chromosome and can be applied in various fields such as genetic mapping, species polymorphism research, disease gene localization, paternity testing and forensic analysis.ROX dye is used to correct the fluorescence signal error generated between wells of a quantitative PCR instrument, and is generally used in Real Time PCR amplifiers from ABI, Stratagene, and other companies. The excitation optics vary from instrument to instrument, so the concentration of ROX dye must be matched to the corresponding fluorescence quantitative PCR instrument.Instruments that do not require ROX calibration: Roche LightCycler 480, Roche LightCyler 96, Bio-rad iCyler iQ, iQ5, CFX96, etc.Instruments requiring Low ROX calibration: ABI Prism7500/7500 Fast, QuantStudio®3 System, QuantStudio®5 System, QuantStudio®6 Flex System, QuantStudio®7 Flex System, ViiA 7 System, Stratagene Mx3000/Mx3005P, Corbett Rotor Gene 3000, and others.Instruments requiring High ROX calibration: ABI Prism7000/7300/7700/7900, Eppendorf, ABI Step One/Step One Plus, etc.Note: High Rox and Low Rox are formulated as described in Method of Use 3.Scope of applicationThis product is suitable for quantitative testing of male Y chromosome DNA in scientific research, clinical, forensic medicine and paternity testing.Usage1. Amplification template preparationThe library samples to be detected were diluted with TE (10 mM Tris-Cl, pH 8.0, 1 mM EDTA), and the concentration after dilution was as close as possible to the range of 0.05-10 ng/µL. 4°C on ice was set aside.2. Standard dilution: according to the following table, firstly dilute Human DNA Standard (100ng/uL) with TE to make 5 standards of different concentrations according to the table below. 10ng/µL of DNA Standard 1 (Std.1) can be stored stably at -20℃ for 1 month; Std2-5 can only be used on the same day, and should be placed at 4℃ or on ice when not in use for the time being after preparation. When Std2-5 are not used temporarily after preparation, they should be stored at 4℃ or on ice.Standard sampleCorresponding concentration(ng/µl)Minimum Dilution Volume (Unit：µl）Std.11010 [100 ng/µl DNA Standard]+ 90 TEStd.22.520 [Std. 1] +60 TEStd.30.62520 [Std. 2] +60 TEStd.40.1562520 [Std. 3] +60 TEStd.50.039062520 [Std. 4] +60 TE3. qPCR reaction system preparationBefore preparation, the cryopreserved reagents to be used were completely melted and mixed by inverting several times, then centrifuged briefly and prepared. Standards and templates were diluted as described above and prepared.The base reaction system for 20 µL was as follows:Reagent20 µl Reaction system2×GoldStar Probe Mixture10 µlProbe Primer Mix3 µlTemplate4 µlddH₂O3 µlNote: High ROX model: add 1 µL of 50×High ROX per 50 µL of reaction system; Low ROX model: add 1 µL of 50×High ROX per 500 µL of reaction system.A sufficient amount of reaction system mixture was prepared according to the need, and after the reaction system was prepared and mixed thoroughly, it was added to the reaction wells in a volume of 16 µl per well. Then add the prepared standards and diluted samples into the corresponding reaction wells, the amount of addition is 4µL/well. TE was added to the blank control tube, and the same amount was added at 4 µL/well.It is recommended to use 20 µL for the reaction, if you need to perform a smaller system reaction, reduce the system components in equal proportion.4. qPCR reaction programThe PCR mix of this kit contains a FAM fluorescent probe for the target gene and a VIC fluorescent probe with internal reference to Internal PCR Control (IPC). qPCR program with dual fluorescence of hydrolyzed probes needs to be selected for the assay. Please follow the instructions of the instrument used to set up the qPCR program, and the PCR temperature conditions are as follows:1. Standard curve productionThe standard curve was plotted with reference to the Excel sheet for data processing. The correlation coefficient R2 of the standard curve should be not less than 0.98, and the slope should be located between -3.1 and -3.6 when the Ct value is used as the longitudinal coordinate. If the parameters of the standard curve are unreasonable, it is recommended to repeat the experiment.DNA Standard NameDNA Standard Concentration（ng/µL）DNA Standard 110DNA Standard 22.5DNA Standard 30.625DNA Standard 40.15625DNA Standard 50.03906252. Analysis of results and calculation of concentrationsThe Ct difference between experimental replicate wells for FAM signaling of the target gene should be no more than 0.3, otherwise invalid data need to be deleted or the experiment needs to be repeated, do not use Ct outside the valid Ct range of the standard curve to calculate the concentration of the sample.For specific calculations, please refer to the data processing Excel for this product.If the FAM signal is abnormal, the VIC signal of the internal reference Internal PCR Control (IPC) needs to be analyzed to confirm whether the PCR reaction process is abnormal. If the Ct value of the sample null VIC is significantly larger than that of the standard or blank control wells, it means that the sample inhibits the PCR reaction.matters needing attention1. Before testing, these instructions should be read in detail. It should be operated by personnel with professional experience or qualified by training.2. For use, please mix gently by turning up and down, avoid foaming as much as possible, and use it after centrifugation for a short period of time.3. Avoid repeated freezing and thawing of the product, repeated freezing and thawing may degrade the performance of the product.4. When preparing the reaction solution, please use new or non-contaminated tips and centrifuge tubes to prevent contamination as much as possible... Read More |