| 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 | M666110 Component 96 T Storage M666110A Buffer WSL 40 mL RT M666110B Buffer MSL 40 mL RT M666110C Buffer CW1 (concentrate) 90 mL RT M666110D Buffer GW1 (concentrate) 40 mL RT M666110E Buffer GW2 (concentrate) 50 mL RT M666110F Buffer EB 30 mL RT M666110G Proteinase K 4×1.25 mL RT M666110H M666110 Component 96 T Storage M666110A Buffer WSL 40 mL RT M666110B Buffer MSL 40 mL RT M666110C Buffer CW1 (concentrate) 90 mL RT M666110D Buffer GW1 (concentrate) 40 mL RT M666110E Buffer GW2 (concentrate) 50 mL RT M666110F Buffer EB 30 mL RT M666110G Proteinase K 4×1.25 mL RT M666110H Magbeads V3 2×1 mL RTProduct Introduction：The reagent kit provides a simple, fast, and efficient method for extracting genomic DNA from blood samples. In the presence of high salt, DNA binds to the surface of silica coated Magheads. After rinsing, high-purity DNA is eluted in Buffer EB or deionized water. The purified DNA has good purity (A260/280 ratio between 1.7-1.9) and high integrity (>15 kb), and can be used for downstream experiments such as second-generation sequencing, quantitative PCR, and chip detection.Self provided instruments and reagents1) Constant temperature mixer2) 2/15 ml magnetic frame3) 32 channel nucleic acid extractor4) 96 channel nucleic acid extractor5) 96 DW Plate6) 8 channel Comb7) Spin tips pack8) Anhydrous ethanolPreparation and important precautions before the experiment1.Before the first use, add anhydrous ethanol to Buffer CW1, Buffer GW1, and Buffer GW2 according to the label of the reagent bottle and mark them properly.2.Magheads are strictly prohibited from freezing or centrifugation. Freezing and centrifugation may cause irreversible damage to Magheads.Operation stepsI. Manual single tube operation1. Use punching forceps to take 1 blood spot with a diameter of 6 mm or 4 blood spots with a diameter of 3 mm (depending on the actual situation) from the blood spot and place them in a 2.0 mL centrifuge tube.2. Add 40 to the centrifuge tube µ L Protein K and 300 µ L Buffer WSL, then place the centrifuge tube on a constant temperature mixer at 75 ℃ and 1200 rpm, shake and crack for 45 minutes to form Lysate. Remove the centrifuge tube from the constant temperature mixer, centrifuge briefly, and take the supernatant.Attention: If there is no constant temperature mixer, vortex the centrifuge tube for 10 seconds and incubate it in a 75 ℃ water bath for 30 minutes. During this period, vortex every 10 minutes for 10 seconds.3. Suck the supernatant into a new 2.0 mL centrifuge tube and add 300 µ L Buffer MSL, 300 µ L isopropanol and 20 µ L Magheads V3. Afterwards, place the centrifuge tube on a constant temperature mixer at 25 ℃ and 1600 rpm, shake and crack for 15 minutes, or invert the centrifuge tube and mix continuously for 15 minutes.4. Place the centrifuge tube on a magnetic stand and let it stand for 1 minute. After Magheads are completely adsorbed on the side wall of the centrifuge tube, discard the solution thoroughly (keep the centrifuge tube fixed on the magnetic stand).5. Remove the centrifuge tube from the magnetic frame and add 900 µ L Buffer CW1 (please check if anhydrous ethanol has been added before use), vortex point shake for 1 minute or vortex shake for 5 seconds, and then place it on a constant temperature mixer at 25 ℃ and 1600 rpm to shake and mix for 2 minutes (ensure that Magheads are in a mixed state during the shaking process). Afterwards, place the centrifuge tube on a magnetic stand and let it stand for 1 minute. After Magheads are completely adsorbed on the side wall of the centrifuge tube, gently invert the magnetic stand and wash the impurities on the centrifuge tube cover to completely discard the solution (keep the centrifuge tube fixed on the magnetic stand).6. Remove the centrifuge tube from the magnetic frame and add 500 µ L Buffer GW1 (please check if anhydrous ethanol has been added before use), vortex point shake for 1 minute or vortex shake for 5 seconds, and then place it on a constant temperature mixer at 25 ℃ and 1600 rpm to shake and mix for 2 minutes (ensure that Magheads are in a mixed state during the shaking process). Afterwards, place the centrifuge tube on a magnetic stand and let it stand for 1 minute. After Magheads are completely adsorbed on the side wall of the centrifuge tube, gently invert the magnetic stand and wash the impurities on the centrifuge tube cover to completely discard the solution (keep the centrifuge tube fixed on the magnetic stand).7. Remove the centrifuge tube from the magnetic frame and add 900 µ L Buffer GW2 (please check if anhydrous ethanol has been added before use), vortex point shake for 1 minute or vortex shake for 5 seconds, then place it on a constant temperature mixer at 25 ℃ and 1600 rpm, shake and mix for 2 minutes (ensure that Magheads are in a mixed state during the shaking process). Afterwards, place the centrifuge tube on a magnetic stand and let it stand for 1 minute. After Magheads are completely adsorbed on the side wall of the centrifuge tube, gently invert the magnetic stand and wash the impurities on the centrifuge tube cover to completely discard the solution (keep the centrifuge tube fixed on the magnetic stand).8. Remove the centrifuge tube from the magnetic frame and add 300 µ After shaking with 75% ethanol for 1 minute or 5 seconds, place the mixture on a constant temperature mixer at 25 ℃ and 1600 rpm for 2 minutes (ensure that the Magheads are in a mixed state during the shaking process). Afterwards, place the centrifuge tube on a magnetic stand and let it stand for 1 minute. After Magheads are completely adsorbed on the side wall of the centrifuge tube, gently invert the magnetic stand and wash the impurities on the centrifuge tube cover to completely discard the solution (keep the centrifuge tube fixed on the magnetic stand).9. Keep the centrifuge tube fixed on the magnetic frame, use a pipette to further remove the solution from the bottom and cover of the centrifuge tube, and then leave it at room temperature for 5-10 minutes to allow the ethanol to evaporate completely.10. Remove the centrifuge tube from the magnetic frame and add 50-200 µ L Buffer EB. Vortex oscillation causes the magnetic beads to completely suspend in the eluent and then place them on a constant temperature mixer at 56 ℃ and 1600 rpm for 10 minutes of shaking and elution, or incubate the centrifuge tube in a 56 ℃ water bath for 10 minutes, with vortex oscillation every 3 minutes for 10 seconds.11. Place the centrifuge tube on a magnetic stand and let it stand for 2 minutes. After Magheads are completely adsorbed on the side wall of the centrifuge tube, transfer the eluent to a new centrifuge tube using a pipette and store at -20 ℃ for later use.II. Matching with CWE21001. Use punching forceps to take 1 blood spot with a diameter of 6 mm or 4 blood spots with a diameter of 3 mm (depending on the actual situation) from the blood spot and place them in a 2.0 mL centrifuge tube.2. Add 40 to the centrifuge tube µ L Protein K and 300 µ L Buffer WSL, then place the centrifuge tube on a constant temperature mixer at 75 ℃ and 1200 rpm, shake and crack for 45 minutes to form Lysate.3. Add the corresponding reagents to the 96DW deep well plate according to the table below. Position Reagent 1&7 Colume Lysate: All Buffer MSL: 300 µL isopropanol：300 µL Magbeads V3: 20 µL 2&8 Colume Buffer CW1: 900 µL 3&9 Colume Buffer GW1: 500 µL 4& 10 Colume Buffer GW2: 900 µL 5& 11 Colume 75%ethanol: 300 µL 6& 12 Colume Buffer EB: 70 µL4.Place the deep well plate and magnetic sleeve that have been added to the reagent at the corresponding positions of CWE2100/CWE3200, run the blood slide extraction program, and after about 40 minutes, the program ends. Remove the deep well plate and magnetic sleeve.5.Transfer the elution products from columns 6 and 12 of the deep well plate to a 1.5 mL centrifuge tube for low-temperature storage.III. Matching with CWE9601. Use punching forceps to take 1 blood spot with a diameter of 6 mm or 4 blood spots with a diameter of 3 mm (depending on the actual situation) from the blood spot and place them in a 2.0 mL centrifuge tube.2. Add 40 to the centrifuge tube µ L Protein K and 300 µ L Buffer WSL, then place the centrifuge tube on a constant temperature mixer at 75 ℃ and 1200 rpm, shake and crack for 45 minutes to form Lysate.3. Add the corresponding reagents to the 96DW deep well plate according to the table below Position Reagent Plate 1 Lysate: All Buffer MSL: 300 µL isopropanol ：300 µL Magbeads V3: 20 µL Plate 2 Buffer CW1: 900 µL Plate 3 Buffer GW1: 500 µL Plate 4 Buffer GW2: 900 µL Plate 5 75% ethanol : 300 µL Plate 6 Buffer EB: 70 µL4. Place the deep well plate and magnetic sleeve that have been added to the reagent at the corresponding positions on CWE960, run the blood slide extraction program, and after about 40 minutes, the program ends. Remove the deep well plate and magnetic sleeve.5. Transfer the elution products from Plate 6 to a 1.5 mL centrifuge tube for low-temperature storage... 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 | 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 | Product contentS665868Component50 TStorageS665868ABuffer GL25 mLRTS665868BBuffer GW1 (concentrate)13 mLRTS665868CBuffer GW2 (concentrate)15 mLRTS665868DBuffer GE15 mLRTS665868EProteinase K2×1.25 mLRTS665868FSpin Columns DM with Collection Tubes50 setsRTProduct IntroductionThis kit is suitable Product contentS665868Component50 TStorageS665868ABuffer GL25 mLRTS665868BBuffer GW1 (concentrate)13 mLRTS665868CBuffer GW2 (concentrate)15 mLRTS665868DBuffer GE15 mLRTS665868EProteinase K2×1.25 mLRTS665868FSpin Columns DM with Collection Tubes50 setsRTProduct IntroductionThis kit is suitable for the extraction of genomic DNA from fresh saliva or saliva/preservation solution mixture.The purification process of this product does not require the use of toxic solvents such as phenol or chloroform, and ethanol precipitation is not necessary. The optimized buffer system enables DNA to bind heterogeneously to the silica matrix centrifugal adsorption column, and the inhibitors of PCR and other enzymatic reactions can be effectively removed by a two-step washing step, and finally eluted with a low-salt buffer or water to obtain high-purity DNA.The purified obtained can be directly used for enzyme digestion, PCR, Real-Time PCR, library construction, Southern Blot, molecular labeling and other downstream 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 GW1 and Buffer GW2 according to the instructions on the label of the reagent bottle before first use.3. Before use, please check whether Buffer GL appears to be crystallized or precipitated.Redissolve in a 56°C water bath.4. If the downstream experiments are sensitive to RNA contamination, 4 µL DNase-Free RNase A can be added in step 3(100 mg/mL).5. For prolonged storage of salivary DNA at room temperature, our Salivary DNA Preservation Tubes are recommended.Operation steps1. Add 400 µL of saliva sample or saliva/preservation solution mixture.Note: 1) Saliva mixtures added to the preservation solution require a 50°C water bath for 1 hour or an empty 50°C temperature chamber for 2 hours prior to extraction.2) If an increase in sample volume is required, multiply the volumes of Proteinase K, Buffer GL, and anhydrous ethanol in Steps 2-4, and the liquid can be transferred in multiple times in Step 5.2. Add 40 µL of Proteinase K.3. Add 400µL Buffer GL, vortex and shake to mix thoroughly, and water bath at 56℃ for 15-30 minutes.Note: If RNA removal is required, add 4 µL of RNase A solution at a concentration of 100 mg/mL after the above steps are completed, vortex for 15 seconds, and leave at room temperature for 2 minutes.4. Centrifuge briefly to remove water droplets from the inside of the tube cap. Add 400 µL of anhydrous ethanol and mix well by vortexing and shaking. Centrifuge briefly.Note: 1) Vortex and shake to mix immediately after adding Buffer GL and anhydrous ethanol.The addition of Buffer GL and anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.2) A sol-gel product may be formed after GL and anhydrous ethanol, in which case vigorous shaking or vortexing is recommended.3) The solution obtained in the previous step is added to the adsorption column in the Collection Tube.5. (Spin Column DM) in the collection tube, and if the solution cannot be added all at once, it can be transferred in several times. centrifuge at 12,000 rpm (∼13,400 × g) for 1 min, pour off the waste solution in the collection tube, and put the adsorption column back into the collection tube.6. Add 500 µL of Buffer GW1 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.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: Step 7 can be repeated if further DNA purity is required.8. 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.).9. Place the adsorption column in a new centrifuge tube (supplied), add 50-200 µL of Buffer GE or sterilized water to the middle of the adsorption column overhanging the column, let it stand at room temperature for 2-5 minutes, and centrifuge at 12,000 rpm for 1 minute to collect the DNA solution.-20°C to preserve DNA.Note: 1) If the downstream experiment is sensitive to pH or EDTA, you can use sterilized water for elution. The pH of the eluent has a great influence on the elution efficiency, if water is used as the eluent should ensure that its pH is 7.0-8.5 (you can use NaOH to adjust the pH of the water to this range), and the elution efficiency is not high when the pH is lower than 7.0.2) Buffer GE preheated in a 65-70°C water bath and incubated at room temperature for 5 min before centrifugation can increase the yield.3) Because DNA preserved in water is subject to acidic hydrolysis, for long-term storage, elution with Buffer GE and storage at -20°C is recommended... Read More |