| Description | DescriptionCobalt is a transition metal that serves as a trace dietary mineral for all multicellular organisms. Cobalt is an important cofactor for the Vitamin B12class of compounds where it occupies the center of the vitamin B12corrin ring. Cobalt can also be coordinated in the active site of the DescriptionCobalt is a transition metal that serves as a trace dietary mineral for all multicellular organisms. Cobalt is an important cofactor for the Vitamin B12class of compounds where it occupies the center of the vitamin B12corrin ring. Cobalt can also be coordinated in the active site of the non-corrin containing metalloenzyme methionine aminopeptidase.Suitability: Suitable for quantitating cobalt concentrations in a variety of samplesPrinciple: The Cobalt Assay kit provides a simple and direct procedure for measuring cobalt in a variety of samples. In this assay, cobalt reacts with 2-mercaptoethanol under basic conditions to form a complex with a strong absorbance at 475 nm. Interference from the metal ions Fe2+, Cu2+, Ni2+, Zn2+, and Mn2+is <10% at this wavelength. This assay gives a linear range of 10-50 nmoles of cobalt.}Preparation instructionsSuitable for quantitating cobalt concentrations in a variety of samplesPrincipleThe Cobalt Assay kit provides a simple and direct procedure for measuring cobalt in a variety of samples. In this assay, cobalt reacts with 2-mercaptoethanol under basic conditions to form a complex with a strong absorbance at 475 nm. Interference... Read More | Inquire | The perfect KitAlysis Labware starter kit that combines the KitAlysis Inertion Box (Z742064) with the KitAlysis 24-Well Reaction Block and Screwdriver Set (Z742107).Provides an inert environment to run oxygen sensitive cross-coupling reactions in a laboratory fume hood.Designed to be used with The perfect KitAlysis Labware starter kit that combines the KitAlysis Inertion Box (Z742064) with the KitAlysis 24-Well Reaction Block and Screwdriver Set (Z742107).Provides an inert environment to run oxygen sensitive cross-coupling reactions in a laboratory fume hood.Designed to be used with KitAlysis High-Throughput Screening Kits.Components:Ιnertion Box24-Well Reaction BlockTorque Screwdriver set with bitReaction Block Replacement Screws (10ea)... Read More | Product content: M665559Component50 TStorageM665559ABuffer GTT15 mLRTM665559BBuffer GL15 mLRTM665559CBuffer GW1（concentrate）13 mLRTM665559DBuffer GW2（concentrate）15 mLRTM665559EBuffer GE15 mLRTM665559FProteinase K1.25 mLRTM665559GSpin CoLumns DM with CoLLection Tubes50 Product content: M665559Component50 TStorageM665559ABuffer GTT15 mLRTM665559BBuffer GL15 mLRTM665559CBuffer GW1（concentrate）13 mLRTM665559DBuffer GW2（concentrate）15 mLRTM665559EBuffer GE15 mLRTM665559FProteinase K1.25 mLRTM665559GSpin CoLumns DM with CoLLection Tubes50 EART Product Introduction:This reagent kit is suitable for extracting high-purity total DNA from fresh or frozen mouse or rat tails. The method provided by this reagent kit is simple and feasible, and the purification process does not require phenol or chloroform extraction. It can obtain DNA fragments up to 50 kb, and can also effectively recover fragments of 100 bp. This reagent kit uses a unique lysis solution to effectively lyse mouse tail samples. The optimized buffer system efficiently binds the DNA generated after the lysis of mouse tail to the silica matrix adsorption column, while other pollutants can flow through the membrane; Inhibitors of PCR and other enzymatic reactions can be effectively removed through a two-step washing process, followed by washing with low salt buffer or water to obtain high-purity DNA. The purified DNA can be directly used for downstream experiments such as enzyme digestion, PCR, ReaL Time PCR, library construction, Southern BLot, and molecular labeling.Self prepared reagent: anhydrous ethanol.Preparation and important precautions before the experiment:1. Samples should avoid repeated freeze-thaw cycles, otherwise it may result in smaller extracted DNA fragments and a decrease in extraction volume.2.Before the first use, anhydrous ethanol should be added to BufferGW1 and BufferGW2 according to the instructions on the reagent bottle label.3. Before use, please check if there is any crystallization or precipitation in the Buffer GL. If there is any crystallization or precipitation, please dissolve the Buffer GL again in a 56 ℃ water bath.Operation steps:1. Take a tail of a rat or two mice with a length of 0.4-0.6 cm, grind it into fine powder in liquid nitrogen or cut it into pieces and place it in a centrifuge tube (provided by oneself). Join 180 µ L Buffer GTT, shake and mix well. Note: Ensure that the starting quantity of the organization does not exceed the recommended range.2. Add 20 µ L Protein K, vortex oscillation, thoroughly mix.3. Place in a 56 ℃ water bath until the tissue solution is completely clear. Generally, digestion is required for 6-8 hours. During the incubation process, vortex oscillation is required to evenly disperse the sample. Note: 1) If there is still gel like substance after incubation and vortex oscillation, digest overnight or add 20 more if necessary µ L Protein K digestion will not affect subsequent operations. 2) To remove RNA, add 4 after completing the above steps µ L 100 mg/mL RNase A solution, shake well and let stand at room temperature for 5-10 minutes.4.12000 rpm (~13400 × g) for 1 minute to remove undigested tissues similar to mouse hair. Transfer the supernatant to a new centrifuge tube (provided by oneself).5. Add 200 µ L Buffer GL, vortex oscillation, thoroughly mixed. Join 200 µ L anhydrous ethanol, vortex and shake, thoroughly mix. Short centrifugation allows the solution on the tube wall to be collected to the bottom of the tube.Attention: 1) After adding Buffer GL and anhydrous ethanol, immediately vortex and shake to mix well.2) If multiple samples are operated together, Buffer GL and anhydrous ethanol can be mixed in equal proportions and added to the samples together.3) The addition of Buffer GL and anhydrous ethanol may produce white precipitates, which will not affect subsequent experiments.6. Add all the solutions obtained in step 5 to the adsorption column (Spin CoLumins DM) that has been loaded into the collection tube. If the solution cannot be added at once, it can be transferred multiple times. Centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.7. Add 500 to the adsorption column µ L Buffer GW1 (check if anhydrous ethanol has been added before use), centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.8. Add 500 to the adsorption column µ L Buffer GW2 (check if anhydrous ethanol has been added before use), centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.Note: To further improve DNA purity, repeat step 8.9.12000 rpm for 2 minutes and discard the waste liquid from the collection tube. Place the adsorption column at room temperature for a few minutes to thoroughly air dry. Note: The purpose of this step is to remove residual ethanol from the adsorption column, which will affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).10. Place the adsorption column in a new centrifuge tube (provided by oneself) and add 50-200 to the middle of the adsorption column in the air µ L Buffer GE or sterilized water, leave at room temperature for 2-5 minutes, centrifuge at 12000 rpm for 1 minute, collect DNA solution, and store DNA at -20 ℃.Note: 1) If downstream experiments are sensitive to pH or EDTA, they can be washed off with sterilized water. The pH value of the eluent has a significant impact on the elution efficiency. If water is used as the eluent, its pH value should be ensured to be between 7.0-8.5 (NaOH can be used to adjust the pH value of the water to this range). When the pH value is below 7.0, the elution efficiency is not high.2) Incubating at room temperature for 5 minutes before centrifugation can increase yield.3) Use an additional 50-200 µ Re washing with L Buffer GE or sterilized water can increase yield.4) If you want to increase the final concentration of DNA, you can add the DNA eluent obtained in step 10 back onto the adsorption membrane and repeat step 10; If the elution volume is less than 200 µ L. It is possible to increase the final concentration of DNA, but it may reduce the total yield. If the amount of DNA is less than 1 µ g. Recommended 50 µ L Buffer GE or off... 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 |