| Description | Inquire | Inquire | 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 | This kit is used to extract miRNAs from various animal tissues, plant tissues and cells. The extracted miRNA molecule is complete and high purity, which is suitable for various molecular biology experiments such as Northern blot, real timepcr, miRNA microarray chip, in situ hybridization, This kit is used to extract miRNAs from various animal tissues, plant tissues and cells. The extracted miRNA molecule is complete and high purity, which is suitable for various molecular biology experiments such as Northern blot, real timepcr, miRNA microarray chip, in situ hybridization, RNase protection assay, etcComposition:Scope of application：Nucleic acid extraction and purificationInstruction：1.Experimental preparation：1.1.All reagents were prepared with DEPC-treated solvents. Please use RNase-free tip and centrifuge tube to avoid RNA degradation by RNase during extraction.1.2.70 % ethanol, -20C pre-cooling.2.Operational procedure：There is a slight difference in the operation of miRNA extraction from different samples. The specific steps are as follows :【 Extraction of miRNA from animal tissues】1.Take 20-40 mg tissue, transfer to a pre-cooled mortar, and add liquid nitrogen to grind into powder.Please click below to describe the amount of organization used :①RNA-rich tissue ( e.g. liver ) : no more than 30 mg②Tissues with low RNA content ( e.g., muscle ) : no more than 100 mg③When the amount of tissue used was less than 20 mg : the amount of R-I, R-II and isopropanol used was halved.④When the amount of tissue used was more than 40 mg : the use of R-I, R-II and isopropanol increased proportionally.2.Add 400 ul Buffer R-I, repeatedly aspirate 8-10 times with a syringe equipped with a 21-25 needle, and transfer to a 1.5 m : centrifuge tube ( provided in the kit ). 3.Add 150 µl BufferR-1l, swirl for 15-30 s, centrifuge at 12,000 X g for 5 min. [ Centrifugation at 4 °C is recommended ] 4.Take the supernatant to 1.5ml centrifuge tube, add 180 u anhydrous ethanol, mix evenly.5.The preparation tube was placed in a 2 m : centrifuge tube ( provided in the kit ), the mixture in step 4 was transferred to the preparation tube, and 12,000 X g was centrifuged for 1 min. [ 1 Centrifugation at 4 °C is recommended ; 2 miRNA in the filtrate, pay attention to preserve the filtrate. ]6.Abandon the preparation tube, add 500µl isopropanol to the filtrate, and mix evenly.7.12,000Xg centrifuged for 10 min, discard the supernatant.8.Add 700µl 70 % ethanol ( pre-cooled at -20 °C ), centrifuged at 12,000Xg for 5min.9.The supernatant was discarded and dried at room temperature for 5-10 min.10.70 ul Buffer TE ( nucdease-free ) or RNase-free water was added to the centrifuge tube to elute miRNA.【 Extraction of miRNA from plant tissue 】1.Take 30-150 mg tissue, transfer to a pre-cooled mortar, and add liquid nitrogen to grind into powder.Please click below to describe the amount of organization used :①Plant leaves : usually 10-80 mg② Plant fiber tissue : usually 100-150 mg③When the amount of plant leaf tissue was less than 30 mg : the amount of R-I, R-II and isopropyl alcohol used was halved.④When the amount of plant leaf tissue was more than 80 mg : the use of R-I, R-II and isopropanol increased proportionally.⑤When the amount of plant fiber tissue was more than 150 mg : the use of R-I, R-II and isopropanol increased proportionally.2.Add 400 ul BufferR-I, use a syringe with a 21-25 needle to repeatedly suck 8-10 times, and transfer to a 1.5mI centrifuge tube ( provided in the kit ). 3.Add 150 ul Buffer R-1I, vortex oscillation 15-30 s, 12.000 x g centrifugation 5 min. [ Centrifugation at 4 °C is recommended ]4.Take the supernatant to 1.5ml centrifuge tube, add 180 mountain anhydrous ethanol, mix evenly.The preparation tube was placed in a 2 mI centrifuge tube ( provided in the kit ), the mixture in step 4 was transferred to the preparation tube, and 12.000 xg was centrifuged for 1 min. It is recommended to centrifuge at 4 °C ; 2 miRNA in the filtrate, pay attention to preserve the filtrate. ]Abandon the preparation tube, add 500µl isopropanol to the filtrate, and mix evenly.7.12,000xg high heart for 10 min, discard the supernatant.8.Add 700 ul 70 % ethanol ( -20 °C precooling ), 12,000 xg centrifuge for 5 min.9.The supernatant was discarded and dried at room temperature for 5-10 min.10.70 ul Buffer TE ( nucdease-free ) or RNase-free water was added to the centrifuge tube to elute miRNA.【miRNA extraction from cells】Steps 1-3 According to the different ways of cell culture, two experimental methods, a or b, can be selected.a. Suspension cultured animal cells or cell suspension obtained from petri dishes or culture flasks or freshly isolated animal tissue single cell suspension :1a.Collect 2X 10 * -1X 10 ' cells, centrifuge 2,000Xg for 5 min, discard the supernatant ;2a. Add 400 µl Buffer R-I, repeatedly draw 8-10 times with a syringe containing 21-25 needles, and transfer to a 1.5 mI centrifuge tube ( provided in the kit ) ;3a. Add 150µl Buffer R1I, vortex oscillation 15-30s, 12.000Xg centrifugal 5min. [ build at 4 °C centrifugal ].b. Cells cultured on 96-well L, 24-well, 12-well or 6-well plates :Cells were collected from 96-well, 24-well, 12-well or 6-well culture plates, and the medium was discarded as much as possible, and 400 u / well Buffer R-I was added to each well, and the pipette gun was used to blow up and down 8-10 times ;2b.Transfer the above cell suspension to a 1.5ml centrifuge tube ( provided in the kit ), and repeatedly draw 8-10 times with a syringe containing 21-25 needles ;3b. Add 150 µl Bufflr R-II, swirl for 15-30 s, centrifuge for 5 min at 12,000 × g. [ Recommended at 4 °C ]4.Take the supernatant to 1.5ml centrifuge tube, add 180 mountain anhydrous ethanol, mixing evenly.5.The preparation tube was placed in a 2 ml centrifuge tube ( provided in the kit ), the mixture in step 4 was transferred to the preparation tube, and centrifuged at 12.000 Xg for 1 min. [ 1 Centrifugation at 4 °C is recommended ; 2 miRNA in the filtrate, pay attention to preserve the filtrate. ]6.Abandon the preparation tube, add 500 u of isopropanol to the filtrate, and mix evenly.7.12,000Xg high heart for 10 min, discard the supernatant.8.Add 700µ70 % ethanol ( pre-cooled at − 20 °C ), centrifuged at 12,000 × g for 5 min.9.Abandon the supernatant, dry at room temperature for 5 - 10 min.10.70 ul Bufer TE ( nucdease-free ) or RNase-free water was added to the centrifuge tube to elute mRNA.3.Flow chartMatters needing attention：Buffer R-I contains irritating compounds, when operating to wear latex gloves and glasses, to avoid contamination of the skin, eyes and clothes, be careful not to inhale the nose and mouth. If the skin, eyes, to immediately rinse with a lot of water or saline, if necessary, seek medical advice... Read More | Product introduction： The MA qPCR live bacteria detection kit provides an effective means for detecting bacterial activity. The kit provides a mixture of PMA dye and qPCR based on SYBR Green dye. The optimal amount of dye and the number of samples that can be treated may vary depending on theProduct introduction： The MA qPCR live bacteria detection kit provides an effective means for detecting bacterial activity. The kit provides a mixture of PMA dye and qPCR based on SYBR Green dye. The optimal amount of dye and the number of samples that can be treated may vary depending on the type of sample. PMA is a high-affinity DNA-binding dye, especially with double-stranded DNA. The dye itself has weak fluorescence, but it can emit brighter fluorescence after binding to nucleic acids. PMA is impermeable to cell membranes, so it can selectively modify the DNA of dead cells with damaged membranes. After the PMA-modified DNA is photolyzed by blue light ( ~ 464 nm ), the photoreactive azide group on the PMA is converted into a highly reactive nitrene radical, which reacts with any hydrocarbon near the DNA binding site to form a stable covalent nitrogen-carbon bond, resulting in permanent DNA modification. This modification process will make DNA insoluble and lost with cell debris during the later genomic DNA extraction process. The unbound PMA remaining in the solution reacts with water molecules under strong light irradiation to decompose into hydroxylamine compounds without cross-linking activity, so that it can no longer covalently bind to DNA. Based on this feature of PMA, PMA was combined with qPCR technology to form a new detection method, PMA-qPCR, for the screening of live bacteria. At present, the method has been verified in a variety of bacterial strains, yeast, fungi, viruses and parasites. The treatment of complex samples, such as manure or soil, may require optimization of sample dilution, dye concentration, and light treatment time. The treatment of diluted samples, such as water testing, may require filtration or concentration prior to dye treatment. Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. the components of the kit contain fluorescent dyes. Avoid light during use and storage. 3. for your safety and health, please wear experimental clothes and disposable gloves.Product parameters:Spectral characteristics :PMA: Ex = 464 nm; Ex/Em = 510/610 nm (following photolysis and reaction with DNA/RNA)Component： PMA：Ex = 464 nm; Ex/Em = 510/610 nm (following photolysis and reaction with DNA/RNA) Instruction： Precautions before use： 1.This live bacteria detection kit distinguishes dead bacteria and live bacteria according to cell membrane permeability. Many methods of killing bacteria cause damage to the cell membrane and are therefore compatible with this kit. But some methods, such as ultraviolet irradiation, may not immediately cause cell membrane rupture. Therefore, before selecting this kit, it is necessary to carry out literature search and pre-experiment to determine whether the kit is suitable for the bacterial type and killing method you choose. 2.After PMA treatment, the bacteria need to be photolyzed to covalently bind the dye to dead cell DNA. Photolysis operations can use blue or white light sources. Generally speaking, the brighter the lamp, the higher the efficiency of the photolysis step. Non-LED lamps ( such as halogen lamps ) may heat your sample and have a negative impact on the analysis. Ice is required to cool the sample during irradiation. 3.Sample can be cryopreservation after photolysis. Frozen samples before PMA treatment photolysis may damage the cell membrane and produce false negative results. If the sample needs to be frozen before detection, it is recommended to perform a pre-experiment first. 4.Part of the mechanism of PMA is to remove PMA covalently modified DNA from the sample by precipitation ; therefore, when extracting genomic DNA, it is necessary to use the same volume of genomic DNA eluent for volume normalization. The positive control can use the genomic DNA of living cells. 5.In order to verify the effectiveness of PMA in the test sample, the Ct ( dCt ) changes between- / + PMA can be compared. Experimental materials ( self-provided )：①Light source ( for the photolysis step after PMA modification of DNA ) ; ② Bacterial genomic DNA extraction kit ; ③ effective qPCR primers corresponding to the sample type Experimental procedure： 1.Suck 10 µL of E.coli bacterial solution in liquid LB medium, and culture E.coli in the bacterial incubator overnight or longer to the logarithmic growth phase ( OD600 ≈ 1.0 ) ; Note : The culture time is adjusted according to the experiment. 2.Two portions of live E.coli, 400 µL each, were placed in a clean centrifuge tube ; 3. ( Recommended ) Preparation of dead E.coli. If the dead E.coli is needed as a control, the dead E.coli can be obtained by heating the living E.coli in a water bath at 95 °C for 5 min, or at 58 °C for 3 h. the subsequent operation of the dead E. coli is the same as that of the living E. coli ; 4.Two copies of live E.coli, one without PMA treatment, and one with 25 µM PMA treatment ( the optimal PMA concentration for treating different types or different sources of bacteria needs to be consulted in the relevant literature ) ; 5.The PMA-treated samples were placed on a shaker at room temperature and incubated in the dark for 10 min to fully mix the dye with the sample ; 6.Exposure of the sample, you can use blue or white light source, irradiation time to explore their own. For example, a 60 W blue light can be used for 15 min. Note : 1 If a halogen lamp is used, we recommend that the PMA-treated sample tube be placed on an ice block 20 cm away from the light source. Ice should be placed in a transparent tray. Adjust the light source to point directly to the sample, photolysis for 5-15 min ; if the bacteria obtained from the environment are directly used for experiments, due to the complexity or turbidity of the environmental samples, the photolysis time needs to be prolonged appropriately. 7.Treated and untreated live E.coli 5000 × g, centrifuged for 10 min, remove the supernatant ; 8.Select the appropriate genomic DNA extraction kit according to the sample type, and use the same elution volume for each group of samples when elution DNA. Note : DNA extraction steps refer to the instructions of the kit used. Part of the mechanism of action of PMA is to remove PMA-bound DNA from the sample by precipitation ; therefore, when extracting genomic DNA, each group should use the same volume of genomic DNA eluent for volume normalization ( the amount of genomic DNA extracted from dead bacteria and live bacteria is inconsistent, so the concentration of the two is significantly different ). 9.Preparation of reaction mixture according to the following system : Note : 1 For the DNA extracted by commercial DNA extraction kit, the qPCR template was optimized with 2 µL as the initial volume ; 2 The template volume should not exceed 10 % of the final reaction volume ; 3 Template concentration : gDNA as template, usually 1-10 ng ; the final concentration of PCR primers is usually 0.4µM, which can get better results. When the reaction performance is poor, the primer concentration can be adjusted in the range of 0.2-1µM. 10.Slightly vortex the reaction mixture, transfer the fixed volume to the PCR tube. 11. Test procedure Note : 1 The extension time is adjusted according to the instrument ; the Taq enzyme in mix can be activated within 2 min, but the genomic DNA may require longer denaturation time, which can be increased at this time, and the specific denaturation time can be adjusted according to the sample type.12. ( Optional ) Data analysis Using live bacteria and dead bacteria as controls, the number of live cells in the sample was analyzed and calculated. It is recommended to verify the suitability of primers and PCR procedures before starting PMA qPCR detection of live bacteria. Calculation of dead and living bacteria control dCt ( 1 ) After the end of qPCR, the Ct value of each sample was calculated by instrument software ; ( 2 ) By calculating the dCt of each control bacteria, it was judged whether PMA successfully inhibited the amplification of dead bacterial DNA. The calculation is as follows : dCt live = Ct ( live, PMA treated ) -Ct ( live, PMA untreated ) dCt die = Ct ( die, PMA treated ) -Ct ( die, PMA untreated ) ( 3 ) The dCt expectation of living bacteria is close to 0 ± 1, which indicates that PMA does not affect the amplification of living cell DNA ;( 4 ) The expected value of dCt of dead bacteria is greater than 4 ( dCt is 4 means that it is reduced by about 16 times, that is, 94 % of dead bacterial DNA is removed ; a dCt of 8 indicated a decrease of about 250 times, that is, 99.6 % of the dead bacterial DNA was removed ).( 5 ) The dCt of dead bacteria depends on many factors, including : strain / cell type ; the way bacteria are killed ; the concentration of PMA used ; amplified sequence length. 13. Calculation of the proportion of viable ( optional ) bacteria If the control results of dead and live bacteria are normal, the proportion of live bacteria in the sample can be calculated.( 1 ) Calculate the dCt value of the sample : dCt sample = Ct ( sample, PMA treated ) -Ct ( sample, PMA untreated ) ( 2 ) Conversion of dCt value to live bacteria ratio : PMA inhibition multiple = 2 ( sample dCt ) Viable bacteria % = 100 / PMA inhibition multiple 14. ( Optional ) Calculate the absolute number of live bacteria If you want to calculate the absolute number of viable bacteria in the sample, you need to use a known number of target bacteria genomic DNA to make a standard curve. It is recommended that the diluted concentrations of several groups of genomes are within the range of the qPCR analysis system.( 1 ) qPCR was performed with the appropriate genome, and the Ct value was used as the ordinate, and the number of cells was used as the abscissa. The R2 value is calculated to determine the linearity, and the slope and y-axis intercept are displayed. ( 2 ) Calculate the copy number of the experimental samples : Ct = slope * cell number + y axis intercept ( y = mx + b ) Bacterial count sample = ( Ct-y axis intercept ) / slope Note : The live bacterial DNA was not lost during the purification process. Examples : Scope of application：Live bacteria detection... Read More |