| Description | 3-Phosphoglycerate kinase (PGK) is a key enzyme in glycolysis, widely present in animals, plants, and microorganisms. It catalyzes the reaction of 3-phosphoglycerate and ATP to produce 1,3-bisphosphoglycerate. The latter, under the action of glyceraldehyde-3-phosphate dehydrogenase and NADH, 3-Phosphoglycerate kinase (PGK) is a key enzyme in glycolysis, widely present in animals, plants, and microorganisms. It catalyzes the reaction of 3-phosphoglycerate and ATP to produce 1,3-bisphosphoglycerate. The latter, under the action of glyceraldehyde-3-phosphate dehydrogenase and NADH, produces glyceraldehyde-3-phosphate and NAD+. The activity of 3-phosphoglycerate kinase (PGK) is determined by measuring the decrease in NADH.Component100TStorageExtraction Buffer100 mL2-8℃. Store in the dark.Reagent 11EA-20℃. Store in the dark.Reagent 23EA2-8℃Reagent 31EA-20℃Reagent 415 mL2-8℃Reagent 51EA-20℃Reagent Preparation:Reagent 1 (Powder, 1 vial):Before use, centrifuge at 8000 g, 4°C for 2 min to collect the powder at the bottom (tap manually if needed).Add 1.1 mL of distilled water to dissolve.The dissolved reagent can be aliquoted and stored at -20°C.Reagent 2 (Powder, 3 vials):Before use, centrifuge at 8000 g, 4°C for 2 min to collect the powder at the bottom (tap manually if needed).Add 0.4 mL of distilled water to dissolve.The dissolved reagent can be aliquoted and stored at -20°C (use within one month after dissolution).Reagent 3 (Liquid, 1 vial):Before use, centrifuge at 8000 g, 4°C for 2 min to collect the liquid at the bottom (tap manually if needed).Add 1.1 mL of distilled water to dissolve. The dissolved reagent can be aliquoted and stored at -20°C.Reagent 5 (Powder, 1 vial):Before use, centrifuge at 8000 g, 4°C for 2 min to collect the powder at the bottom (tap manually if needed).Add 1.1 mL of distilled water to dissolve.The storage period is the same as the kit's expiry date.User-Prepared Instruments & MaterialsMortar (homogenizer), ice bucket (ice maker), benchtop centrifuge, adjustable pipettes, water bath (oven, incubator, metal bath), 96-well plate, centrifuge tubes, microplate reader, distilled water (deionized water or ultrapure water is acceptable).Sample Extraction1. Tissue Samples: Weigh approximately 0.1 g of tissue, add 1 mL of Extraction Buffer, homogenize on ice, and then centrifuge at 12000 rpm, 4°C for 5 minutes. Collect the supernatant for assay.Note: If increasing the sample amount, use a ratio of 1:5 to 1:10 (tissue weight (g) : Extraction Buffer volume (mL)) for extraction.2. Bacterial/Cell Samples: Collect bacteria or cells into a centrifuge tube by centrifugation and discard the supernatant. Take approximately 5 million bacteria or cells, add 1 mL of Extraction Buffer, and disrupt using ultrasound on ice (power 200 W, ultrasonicate for 3 s, interval 10 s, repeat 30 times). Centrifuge at 12000 rpm, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.Note: If increasing the sample amount, use a ratio of 500-1000 (x10⁴ cells) : 1 (mL Extraction Buffer) for extraction.Assay Procedure1. Preheat the microplate reader for 30 minutes. Set the wavelength to 340 nm and the temperature to 25°C.2. Thaw all reagents to room temperature (25°C).3. In a well of the 96-well plate, add sequentially:Reagent (µL)Test TubeSample20Reagent 110Reagent 210Reagent 310Reagent 4140Mix well and incubate at room temperature (25°C) for 10 minutes.4. Add Reagent (µL)Test TubeReagent 5105. Mix gently. At room temperature (25°C), read the absorbance at 340 nm at 30 seconds (A1) and then again after 10 minutes (A2). Calculate ΔA = A1 - A2.Notes:1. If ΔA is close to zero, the reaction time can be appropriately extended to 20 minutes before reading A2. The modified reaction time (T) must be substituted into the calculation formula. Alternatively, increase the sample volume appropriately (e.g., to 40 µL, with a corresponding decrease in Reagent 4 volume). The modified sample volume (V1) must be substituted into the calculation formula.2. If the decreasing trend is unstable, read the absorbance every 20 seconds and select a linear decreasing period for calculation. The corresponding ΔA value should be substituted into the calculation formula.3. If the initial absorbance A1 is too high (e.g., >2, as in deeply pigmented plant leaves), appropriately reduce the sample volume. The modified sample volume (V1) must be substituted into the calculation formula. Alternatively, add a small amount of activated carbon to the sample, mix, let stand for 5 min, then centrifuge at 12000 rpm, 4°C for 10 min, and use the supernatant for detection.4. If ΔA is greater than 0.5, reduce the reaction time (e.g., to 5 min) or reduce the sample volume (e.g., to 10 µL). The modified reaction time (T) and sample volume (V1) must be substituted into the calculation formula.PGK Activity Calculation1. Based on Sample Mass:Unit Definition: One unit of enzyme activity is defined as the consumption of 1 nmol NADH per minute per gram of tissue.Formula:PGK (nmol/min/g fresh weight) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (W × V1 ÷ V) ÷ T = 321.6 × ΔA ÷ W2. Based on Sample Protein Concentration:Unit Definition: One unit of enzyme activity is defined as the consumption of 1 nmol NADH per minute per mg of protein.Formula:PGK (nmol/min/mg prot) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (V1 × Cpr) ÷ T = 321.6 × ΔA ÷ Cpr3. Based on Bacterial/Cell Count:Unit Definition: One unit of enzyme activity is defined as the consumption of 1 nmol NADH per minute per 10⁴ cells.Formula:PGK (nmol/min/10⁴ cell) = [ΔA ÷ (ε × d) × V2 × 10⁹] ÷ (500 × V1 ÷ V) ÷ T = 0.64 × ΔAParameter Description:ε: NADH molar extinction coefficient, 6.22 × 10³ L/mol/cmd: Light path of the 96-well plate, 0.5 cmV: Volume of Extraction Buffer added, 1 mLV1: Volume of sample supernatant added, 0.02 mLV2: Total reaction volume, 0.2 mL = 2.0 × 10⁻⁴ LT: Reaction time, 10 minW: Sample mass, g500: Cell number, in units of 10⁴Cpr: Protein concentration of the supernatant, mg/mL; Aladdin BCA Protein Quantification Kit (B665595) or Ready-to-Use BCA Protein Quantification Kit (R1491648) are recommended.PrecautionsIt is recommended to first select 1-3 samples with significant differences (e.g., different types or groups) for preliminary experiments to familiarize yourself with the procedure. Determine or adjust the sample concentration based on the preliminary results to prevent unnecessary waste of samples or reagents... Read More | B669951 Component 50T Storage B669951A Buffer ATL 15 mL RT B669951B Buffer AL 15 mL RT B669951C Buffer AW1 (concentrate) 13 mL RT B669951D Buffer AW2 (concentrate) 15 mL RT B669951E Buffer EB 15 mL RT B669951F Proteinase K 1.25 mL RT B669951G Spin Columns DM with Collection Tubes 50 sets B669951 Component 50T Storage B669951A Buffer ATL 15 mL RT B669951B Buffer AL 15 mL RT B669951C Buffer AW1 (concentrate) 13 mL RT B669951D Buffer AW2 (concentrate) 15 mL RT B669951E Buffer EB 15 mL RT B669951F Proteinase K 1.25 mL RT B669951G Spin Columns DM with Collection Tubes 50 sets RTProductsThis kit is suitable for extracting high purity total DNA from Gram-negative and Gram-positive bacteria. 106-108 cells can be processed at a time, and up to 20 µg of total DNA can be obtained within one hour without the need for toxic solvents such as phenol or chloroform, and without the need for ethanol precipitation. The optimized buffer system enables the DNA in the lysate to be efficiently and specifically bound to the silica matrix centrifugal adsorption column, while other contaminants can flow through the membrane, and the inhibitors of PCR and other enzymatic reactions can be effectively removed through a two-step washing step, and finally washed off with low-salt buffer or water, so that high-purity DNA can be obtained.The purified DNA can be used for downstream experiments such as digestion, PCR, Real-Time PCR, library construction, Southern Blot and molecular labeling, molecular labeling and other downstream experiments. Self-contained reagents: anhydrous ethanol; Enzymatic Lysis Buffer is required for extraction of Gram-positive bacteria.Enzymatic Lysis Buffer was prepared by 20 mM Tris, pH 8.0; 2 mM Na2-EDTA, pH 8.0; and 1.2% Triton X-100. 121°C sterilization for 20 minutes, and the appropriate amount of Lysozyme was added at a final concentration of 20 mg/ml. Pre-experiment Preparation and Important Notes1. Add 1.25ml Proteinase K Storage Buffer to Proteinase K to dissolve it and store it at -20℃. Do not leave the prepared Proteinase K at room temperature for a long time, and avoid repeated freezing and thawing to avoid affecting its activity.2. Repeated freezing and thawing of the sample should be avoided, as this may result in smaller DNA fragments and a decrease in the amount of extracted DNA.3. If extracting genomes from bacterial cultures with high accumulation of secondary metabolites or thick cell walls, it is recommended that samples be collected early in the logarithmic phase.4. 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.5. Before use, please check Buffer GTL and Buffer GL for crystallization or precipitation. If crystallization or precipitation occurs, please re-dissolve Buffer GL and Buffer GTL in a 56℃ water bath.6. If the downstream experiments are sensitive to RNA contamination, 4µl of DNase-Free RNase A (100mg/ml) can be added before adding Buffer GL. RNase A is not provided in this kit.If the extracted samples are Gram-positive bacteria, customers need to prepare their own Enzymatic Lysis Buffer to treat the bacteria, which requires the use of Lysozyme (lysozyme) at a concentration of 20 mg/ml, which is not provided in this kit.Procedurei Extraction of genomic DNA from Gram-negative bacteria1. Take 1-5 ml of bacterial culture (106-108 cells, maximum 2×109 cells) and put it into a centrifuge tube (provided), centrifuge it at 12,000 rpm (~13,400×g) for 1 minute, and aspirate the supernatant as much as possible.2. Add 180 µl Buffer GTL to the precipitate and shake to resuspend the bacteria.3. Add 20 µl of Proteinase K, vortex and mix well, incubate at 56°C until the solution becomes clear, and invert or shake the centrifuge tube at intervals during the incubation to disperse the sample.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, shake to mix, and leave for 5-10 minutes at room temperature.4. Add 200µl Buffer GL and mix well with vortexing and shaking. Add 200µl of anhydrous ethanol and mix well with vortexing and shaking.Centrifuge briefly so that the solution on the walls of the tube collects at the bottom.Note: 1) If multiple samples are manipulated together, Buffer GL and anhydrous ethanol can be mixed in equal proportions and then added together, shaking to mix.2) The addition of Buffer GL and anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.5. Add all of the solution obtained in step 4 (including the precipitate formed) to the Spin Columns DM in the collection tube, or if the solution cannot be added all at once, transfer it several times. centrifuge at 12,000 rpm for 1 minute, discard the waste solution, and return the column to 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 return the adsorption column to 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 adsorbent column at room temperature for several minutes to dry thoroughly. Note: The purpose of this step is to remove residual ethanol from the adsorbent column; ethanol residue can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).9. Place the adsorption column in a new centrifuge tube, add 50-200 µl Buffer GE to the middle part of the adsorption column overhanging the center of the adsorption column, leave it at room temperature for 2-5 minutes, centrifuge it at 12,000 rpm for 1 minute, collect the DNA solution, and store the DNA at -20 ℃. note: 1) If the downstream experiments are sensitive to the pH or EDTA, the elution can be done with sterilized water. The pH of the elution solution has a great influence on the elution efficiency. If water is used as the elution solution it should be ensured that its pH is 7.0-8.5 (the pH of water can be adjusted to this range with NaOH), and the elution efficiency is not high when the pH is lower than 7.0.2) Incubation at room temperature for 5 minutes prior to centrifugation increases yield.3) Re-elution with an additional 50-200 µl Buffer GE or sterilized water can increase the yield.4) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 9 can be re-spiked onto the adsorbent membrane and step 9 repeated; if the elution volume is less than 200 µl, the final concentration of DNA can be increased, but the total yield may be reduced. If the amount of DNA is less than 1 µg, elution with 50 µl Buffer GE or sterilized water is recommended.(5) DNA stored in water will be affected by acidic hydrolysis. For long-term storage, it is recommended to elute with Buffer GE and store at -20℃.i. Extraction of genomic DNA from Gram-positive bacteria1. Take 1-5 ml of bacterial culture (106-108 cells, maximum 2×109 cells) and put it into a centrifuge tube (provided), centrifuge it at 12,000 rpm (~13,400×g) for 1 minute, and aspirate the supernatant as much as possible.2. Add 180µl Enzymatic Lysis Buffer (self-provided) to resuspend the bacteria.Enzymatic Lysis Buffer is prepared as described in the Self-Prepared Reagents section in the front of the manual.3. Incubate at 37°C for 30 minutes.4. Add 20µl Proteinase K and mix well. Add 200µl of Buffer GL and mix well with vortexing and shaking.Note: Do not add Proteinase K directly to Buffer GL.Incubate at 5.56°C for 30 minutes.Note: 1) If desired, incubation at 95°C for 15 minutes will inactivate the pathogen, but 95°C incubation will cause some DNA degradation.(2) If RNA removal is required, add 4µl of RNase A solution at a concentration of 100mg/ml after the above steps are completed, shake and mix well, and leave for 5-10 minutes at room temperature.6. Add 200µl of anhydrous ethanol and mix well with vortex shaking.Note: The addition of anhydrous ethanol may produce a white precipitate that will not affect subsequent experiments.7. Add all of the solution obtained in step 6 (including the precipitate formed) to the Spin Columns DM that have been loaded into 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 for 1 minute, pour off the waste liquid from the collection tube, and put the column back into the collection tube.8. 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.9. Add 500 µl Buffer GW2 to the adsorption column (check that anhydrous ethanol has been added before use), centrifuge the column at 12,000 rpm for 1 minute, pour off the waste liquid in the collection tube, and put the column back into the collection tube.Note: Step 9 can be repeated if further DNA purity is required.10. 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; ethanol residue can interfere with subsequent enzymatic reactions (digestion, PCR, etc.).11. Place the adsorption column in a new centrifuge tube (self-provided), add 50-200 µl of Buffer GE to the center of the adsorption column overhanging the center of the adsorption column, let it stand at room temperature for 2-5 minutes, centrifuge at 12,000 rpm for 1 minute, collect the DNA solution, and store the DNA at -20℃.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) Incubation at room temperature for 5 minutes prior to centrifugation increases yield.3) Re-elution with an additional 50-200 µl Buffer GE or sterilized water can increase the yield.4) If the final concentration of DNA is to be increased, the DNA eluate obtained in step 11 can be re-spiked onto the adsorbent membrane and step 11 repeated; if the elution volume is less than 200 µl, the final concentration of DNA can be increased, but the total yield may be reduced. If the amount of DNA is less than 1 µg, elution with 50 µl Buffer GE or sterilized water is recommended.(5) DNA stored in water will be affected by acidic hydrolysis. For long-term storage, it is recommended to elute with Buffer GE and store at -20℃... Read More | DescriptionThe Baran Late-Stage Toolkit is a convenient collection of 12 highly innovative reagents that are highly effective in the diversification of complex molecules. The contents in the box are 11 Baran Diversinates™and one vial of Palau′Chlor®in amounts of 100 mg each. For DescriptionThe Baran Late-Stage Toolkit is a convenient collection of 12 highly innovative reagents that are highly effective in the diversification of complex molecules. The contents in the box are 11 Baran Diversinates™and one vial of Palau′Chlor®in amounts of 100 mg each. For obtaining larger amounts of any desired kit component, see the kit component table at the bottom of the page.Useful Topics:Late Stage FunctionalizationBaran Group – Professor Product PortalPalau′ChlorDiversinates... Read More | Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 100u of high-purity plasmid DNA from 30-100 ml of Product introduction：This kit uses an improved SDS alkaline lysis method combined with DNA preparation membrane to selectively adsorb DNA to achieve the purpose of rapid purification of plasmid DNA. It is suitable for extracting up to 100u of high-purity plasmid DNA from 30-100 ml of bacterial culture for sequencing, in vitro transcription and translation, restriction enzyme digestion, bacterial transformation and other molecular biology experiments.Scope of application：Nucleic acid extraction and purification... Read More | S665948 Component 1 mL 5 mL Storage S665948A 2×SYBR qPCR Master Mix 1 mL 5×1 mL -20℃. Avoid freeze/ Thaw cycle. S665948B qPCR Primer Mix 100 µL 5×100 µL -20℃. Avoid freeze/ Thaw cycle. S665948C DNA Standard 1 100 µL 5×100 µL -20℃. Avoid S665948 Component 1 mL 5 mL Storage S665948A 2×SYBR qPCR Master Mix 1 mL 5×1 mL -20℃. Avoid freeze/ Thaw cycle. S665948B qPCR Primer Mix 100 µL 5×100 µL -20℃. Avoid freeze/ Thaw cycle. S665948C DNA Standard 1 100 µL 5×100 µL -20℃. Avoid freeze/ Thaw cycle. S665948D DNA Standard 2 100 µL 5×100 µL -20℃. Avoid freeze/ Thaw cycle. S665948E DNA Standard 3 100 µL 5×100 µL -20℃. Avoid freeze/ Thaw cycle. S665948F DNA Standard 4 100 µL 5×100 µL -20℃. Avoid freeze/ Thaw cycle. S665948G DNA Standard 5 100 µL 5×100 µL -20℃. Avoid freeze/ Thaw cycle. S665948H 50×High ROX 40 µL 200 µL -20℃. Avoid freeze/ Thaw cycle.Product IntroductionThis product is used for real-time fluorescence quantitative PCR (qPCR) using the product after NGS library construction by dye method (SYBR Green I). The kit provides the reaction mixture, DNA primer mixture, and standards required for the qPCR process, and the reagent system is complete, easy and convenient to operate. The kit uses a new chemically modified high-efficiency hot-start polymerase, the activation of the enzyme needs to be incubated at 95 ℃ for 10 min. the product is highly specific, high amplification efficiency, and able to quickly and accurately quantify the concentration of the constructed library. It is suitable for fluorescent quantitative PCR instruments that do not require ROX as a calibration dye, such as Roche LightCycler 480, Roche LightCyler 96, Bio-radiCyleriQ, iQ5, CFX96.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 Use 2.Scope of applicationThis product is designed for absolute quantification of the concentration of Illumina platform second-generation sequencing libraries. The end of the library contains Illumin P5 and P7 chip binding sequences, the length of which does not exceed 1kb, and the concentration of which is not less than 0.002pM can be used to perform quantitative experiments with this product. The qPCR Primer Mix provided in the kit contains the following two primer sequences:Primer 1:5'-AAT GAT ACG GCG ACC ACC GA-3' Primer 2: 5'-CAA GCA GAA GAC GGC ATA CGA-3'The primer sequence can be used in advance to confirm whether the library can be amplified by that primer pair.UsageAmplification 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 0.01-20 pM. 4°C on ice was set aside.qPCR reaction system preparationThe desired cryopreservation reagent is pre-melted completely and mixed by inverting several times before preparation, then centrifuged briefly and set aside.The base reaction system for 20 µl was as follows:Reagent20 µl Reaction system2×SYBR qPCR Master Mix10 µlqPCR Primer Mix 10.8 µlTemplate4 µlddH₂O5.2 µlDescription: High Rox model: add 1 µl High Rox per 50 µl of reaction system;Low Rox model: 1 µl High Rox per 500 µl of reaction system.Prepare a sufficient amount of reaction system mixture according to the need, mix well and add to the reaction wells in a volume of 16 µl per well, add the same volume of TE to the blank control, and then add the prepared standards and diluted samples to the corresponding reaction wells in a volume of 4 µl/well. It is recommended to use 20 µl reaction system, if you need to carry out a smaller system reaction, the system components can be reduced in equal proportion.qPCR reaction programThe annealing temperature should be 60-64°C as a reference for the setting range, and the annealing temperature can be increased when a non-specific reaction occurs.If the average length of the library is greater than 700bp, the annealing/extension time should be increased appropriately.data analysisStandard curve productionThe standard curve was plotted using Ct values in the valid range. The standard curve correlation coefficient R2 should not be less than 0.99 and the slope should lie between -3.1 and -3.6. If the standard curve parameters are not reasonable, it is recommended to repeat the experiment.DNA Standard NameDNA Standard ConcentrationDNA Standard 120 pMDNA Standard 22 pMDNA Standard 30.2 pMDNA Standard 40.02 pMDNA Standard 50.002 pMLibrary Concentration CalculationsThe difference in Ct between the three replicate wells of the experiment should be no more than 0.2, otherwise the invalid data should be deleted or the experiment should be repeated. Do not use the Ct outside the valid Ct range of the standard curve to calculate the concentration of the diluted libraries. Please refer to the data processing Excel of this product for the specific library concentration calculation method.matters needing attentionThese instructions should be read in detail before testing. It should be carried out by personnel with specialized experience or qualified by training.Mix gently by turning up and down, avoid foaming as much as possible, and centrifuge for a short time before use.Avoid repeated freezing and thawing of this product; repeated freezing and thawing may degrade product performance.When preparing reaction solutions, use new or non-contaminated tips and centrifuge tubes to prevent contamination as much as possible... Read More |