| Description | Blood potassium plays a crucial role in maintaining normal osmotic pressure, acid-base balance, sugar and protein metabolism, and ensuring normal neuromuscular function. Its concentration is closely related to various important physiological functions. Abnormally high or low levels can disrupt Blood potassium plays a crucial role in maintaining normal osmotic pressure, acid-base balance, sugar and protein metabolism, and ensuring normal neuromuscular function. Its concentration is closely related to various important physiological functions. Abnormally high or low levels can disrupt normal physiological activities. Hyperkalemia increases neuromuscular excitability but decreases myocardial excitability, leading to bradycardia. Hypokalemia can cause muscle weakness or even flaccid paralysis, increase myocardial excitability, and result in tachycardia, arrhythmias, or even cardiac arrest during systole.Detection Principle: Potassium ions (K⁺) in serum react with sodium tetraphenylboron to form water-insoluble potassium tetraphenylboron. The turbidity produced is directly proportional to the potassium ion concentration within a certain range. The serum potassium ion content is determined by measuring this turbidity.Applicable Sample: SerumG1501769Component96 TStorageG1501769AExtraction Buffer50 mL2-8℃G1501769BReagentⅠ2.4 mL2-8℃G1501769CReagentⅡ1EA2-8℃. Store in the dark.G1501769DReagentⅢ20 mL2-8℃G1501769EStandard1 mL2-8℃Note: Before formal testing, it is recommended to perform a preliminary test with 2-3 samples expected to have significant differences.User-Prepared Instruments and ReagentsMicroplate reader or visible spectrophotometer (capable of measuring absorbance at 520 nm)96-well plate or micro glass cuvettes, adjustable micropipettes and tipsCentrifugeDeionized water, Concentrated Sulfuric AcidExperimental Procedure1. Reagent PreparationReagent NameReagent PreparationNotesExtraction Buffer/Slightly irritating. Use appropriate personal protective equipment during handling.Working Extraction BufferPrepare before use: Mix Extraction Buffer (mL) and Concentrated Sulfuric Acid (µL) in a 5:12 ratio as needed. Prepare freshly for each use.If precipitate forms, prepare a new batch.Reagent Ⅱ Working SolutionPrepare before use: Add the entire contents of Reagent Ⅰ into the Reagent Ⅱ vial. Mix well. This is the Reagent Ⅱ Working Solution.Can be stored at 4°C protected from light for one week.ReagentⅢPreheat in a 25°C water bath for at least 30 minutes before use./StandardReady-to-use; Equilibrate to room temperature before use.Store at 4°C.2. Sample PreparationSerum Pretreatment: Take a microcentrifuge tube. Sequentially add 50 µL of serum and 450 µL of Working Extraction Buffer. Mix thoroughly. Centrifuge at 8,000 rpm for 10 minutes at room temperature (approximately 25°C). Collect the supernatant for assay.3. Assay Steps3.1 Preheat the microplate reader or visible spectrophotometer for at least 30 minutes. Set the wavelength to 520 nm. For spectrophotometers, zero the instrument with deionized water.3.2 Assay Procedure (perform in a 96-well plate or micro glass cuvette):ReagentBlank Well (µL)Standard Well (µL)Test Well (µL)Deionized Water4000Standard0400Supernatant0040Reagent Ⅱ Working Solution202020Mix well and let stand for 5 minutes.ReagentⅢ1401401403.3 Mix well after addition. Measure the absorbance at 520 nm. Record the absorbance of the Blank well as A blank, the Standard well as A standard, and the Test well as A test. Note:The Blank and Standard tubes only need to be set up 1-2 times.It is recommended to perform a preliminary test with 2-3 samples expected to have significant differences before the formal experiment. If A <sub> test </sub> is less than 0.02, consider increasing the sample volume appropriately. If A <sub> test </sub> is greater than 1.1, further dilute the sample with Working Extraction Buffer (multiply the result by the dilution factor) or reduce the sample volume used for extraction.4. Calculation of ResultsNote: We provide both the derived formula and a simplified formula. They are equivalent. It is recommended to use the simplified formula in bold for final calculation.Blood Potassium Concentration (mmol/L) = [C Standard × (A test - A blank ) ÷ (A standard - A blank )] × n = 5 × (A test - A blank ) ÷ (A standard - A blank )Parameter Definitions:C Standard : 0.5 mmol/Ln: Sample dilution factor (10)Precautions1. Before formal testing, it is recommended to perform a preliminary test with 2-3 samples expected to have significant differences.2. Biochemical reagents are generally irritating and potentially biologically toxic. For your safety and health, please use appropriate biosafety precautions throughout the experiment, including wearing lab coats, masks, gloves, and head covers. Perform experiments in a fume hood or biosafety cabinet.3. This product is for research use only. Not for use in clinical diagnosis... Read More | Inquire | Product content： Component G665666 200 preps Buffer P1 60ml Buffer P2 60ml Buffer E3 60ml Buffer PW (concentrate) 25ml Buffer EB 30ml RNase A (10 mg/ml) 600 µl Spin Columns DM 200 with Collection Tubes 200Product Introduction:This reagent kit is suitable for extracting 1-5 ml of Product content： Component G665666 200 preps Buffer P1 60ml Buffer P2 60ml Buffer E3 60ml Buffer PW (concentrate) 25ml Buffer EB 30ml RNase A (10 mg/ml) 600 µl Spin Columns DM 200 with Collection Tubes 200Product Introduction:This reagent kit is suitable for extracting 1-5 ml of bacterial solution. On the basis of alkaline lysis of cells, it efficiently and specifically binds plasmid DNA through a new silicon-based membrane. Each adsorption column can adsorb up to 40% µ The plasmid DNA of g is effectively removed with a special buffer system to effectively remove impurities such as proteins. The yield and purity of plasmids obtained from this kit are high, and the quality is stable. It is suitable for downstream experiments such as cell transfection, DNA sequencing, PCR, PCR based mutations, in vitro transcription, transformed bacteria, and endonuclease digestion.Self prepared reagents: anhydrous ethanol, isopropanol.Preparation and important precautions before the experiment:1. All components can be stably stored for 1 year in a dry, room temperature (15-30 ℃) environment. The adsorption column can be stored for a longer time at 2-8 ℃. 2.Buffer P1 with RNase A added can be stably stored for 6 months at 2-8 ℃. Before use, add RNase A to Buffer P1 (add all RNase A provided in the reagent kit), mix well, and store at 2-8 ℃. Before use, it is necessary to leave it at room temperature for a period of time, and then use it after returning to room temperature.3.Before the first use, anhydrous ethanol should be added to the Buffer PW according to the instructions on the reagent bottle label.4. Before use, please check if there is any crystallization or precipitation in Buffer P2 and Buffer E3. If there is any crystallization or precipitation, you can take a water bath at 37 ℃ for a few minutes to restore clarity.5. Note that Buffer P2 and Buffer E3 contain irritating substances. Please wear gloves when operating and immediately cover the lid after use.6.The amount and purity of plasmid extraction are related to factors such as bacterial culture concentration, strain type, plasmid size, and plasmid copy number.7. The maximum volume of Spin Columns DM is 750 µ l. If the sample volume is greater than 750 µ L can be added in batches.Operation steps：1. Take 1-5 ml of overnight cultured bacterial solution and add it to a centrifuge tube (provided). Centrifuge at 13000 rpm (~16200 × g) for 1 minute to collect bacteria, and try to discard all the supernatant as much as possible.2. Add 200 to the centrifuge tube containing bacterial sediment µ Buffer P1 (please check if RNase A has been added first), mix thoroughly with a pipette or vortex oscillator, and suspend bacterial precipitation.Attention: If the bacterial blocks are not thoroughly mixed, it will affect the cracking effect, resulting in low extraction amount and purity.3. Add 200 to the centrifuge tube µ Buffer P2, gently invert and mix 8-10 times to fully lyse the bacterial cells. At this point, the solution should become clear and viscous.Attention: Mix gently and do not shake vigorously to avoid interrupting genomic DNA and mixing genomic DNA fragments in the extracted plasmid. If the solution does not become clear, it indicates that the bacterial count may be too large and the lysis may not be complete. The bacterial count should be reduced or the dosage of P1, P2, E3, and isopropanol should be increased proportionally.4. Add 200 to the centrifuge tube µ Buffer E3, immediately invert and mix 8-10 times, at which point white flocculent precipitates appear. Centrifuge at 13000 rpm for 5 minutes.Attention: After adding Buffer E3, it should be mixed evenly immediately to avoid local precipitation.5. Add 260 to the spin columns DM that have been loaded into the collection tube µ After adding isopropanol, immediately add the supernatant collected in step 4 and mix it upside down.Attention: After adding isopropanol, immediately add the supernatant and mix well to avoid isopropanol dripping into the collection tube after being left for a long time. The maximum volume of the adsorption column is 750 µ l. If the sample volume is greater than 750 µ l. Isopropanol and the supernatant can be collected in a centrifuge tube (provided by oneself), mixed well, and passed through the column in batches.6.13000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.7. Add 400 to the adsorption column µ L Buffer PW (please check if anhydrous ethanol has been added first), centrifuge at 13000 rpm for 1 minute, and discard the waste liquid in the collection tube.8. Place the adsorption column in a new collection tube and add 50-100 to the middle of the adsorption membrane µ Centrifuge at 13000 rpm for 1 minute using buffer EB and collect the plasmid solution into a centrifuge tube- Store the plasmid at 20 ℃.Note: 1) To increase the efficiency of plasmid recovery, the obtained solution can be added back to the adsorption column, left at room temperature for 2-5 minutes, centrifuged at 13000 rpm for 2 minutes, and collected into a centrifuge tube.2) When the plasmid copy number is low or>10 kb, preheating the buffer EB in a water bath at 65-70 ℃ can increase the extraction efficiency... Read More | Products contentN665993Component240 TStorageN665993AIndex N501 Primers for Illumina240 µL-20℃. Avoid freeze/ Thaw cycle.N665993BIndex N925-N948 Primers for Illumina24×10 µL-20℃. Avoid freeze/ Thaw cycle. Products Introduction This kit is a companion kit to the transposase-Products contentN665993Component240 TStorageN665993AIndex N501 Primers for Illumina240 µL-20℃. Avoid freeze/ Thaw cycle.N665993BIndex N925-N948 Primers for Illumina24×10 µL-20℃. Avoid freeze/ Thaw cycle. Products Introduction This 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 IlluminaIndex N901-N996 Primer for Illumina... Read More | Product introduction：PMA qPCR live bacteria detection kit provides an effective means to detect bacterial activity. This kit provides a mixture of PMA dye and SYBR green dye based qPCR. The optimal amount of dye and the number of samples that can be processed may vary depending on the type ofProduct introduction：PMA qPCR live bacteria detection kit provides an effective means to detect bacterial activity. This kit provides a mixture of PMA dye and SYBR green dye based qPCR. The optimal amount of dye and the number of samples that can be processed may vary depending on the type of sample. PMA is a DNA binding dye with high affinity, especially with double stranded DNA. The dye itself has weak fluorescence, but it can emit brighter fluorescence after binding with nucleic acids. PMA is impermeable to the cell membrane, so it can selectively modify the DNA of dead cells with damaged membrane. After bllight (~464 nm) photolysis of PMA modified DNA, the photoreactive azido group on PMA is converted into highly reactive azene radical, which reacts with any hydrocarbon moiety near the DNA binding site to form a stable covalent nitrogen carbon bond, resulting in permanent DNA modification. This modification process will make the DNA insoluble, and it will be lost together with cell debris in the later genomic DNA extraction process. The unbound PMA remaining in the solution reacts with water molecules under strong light irradiation and decomposes into hydroxylamine compounds without cross-linking activity, so that it can no longer covalently bind DNA. Based on this characteristic of PMA, our company combines PMA and qPCR technology to form a new detection method - PMA qPCR, which is used for the screening of live bacteria. At present, the method has been validated in a variety of bacterial strains as well as yeast, fungi, viruses and parasites. The treatment of complex samples, such as feces or soil, may require optimization of sample dilution, dye concentration, and light treatment time. Treatment of diluted samples, such as water testing, may require filtration or concentration prior to dye treatment. Component： 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 ( used for the photolysis step after PMA modified DNA ) ;② Bacterial genomic DNA extraction kit ; 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 procedureNote : 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. 3. 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 : Product parameters：Pma: ex = 464 nm; Ex/em = 510/610 nm (following photolysis and reaction with dna/rna)Scope of application：Live bacteria detection Matters needing attention：1.Please instantaneously centrifuge the product to the bottom of the tube before use, and then carry out subsequent experiments ; 2.the kit components contain fluorescent dyes, and attention should be paid to avoiding light during use and preservation ; 3.For your safety and health, please wear experimental clothes and disposable gloves... Read More |