| Description | Catalase (CAT, EC 1.11.1.6) is widely found in animals, plants, microorganisms, and cultured cells. It is the primary H₂O₂-scavenging enzyme and plays a crucial role in the reactive oxygen species (ROS) scavenging system. H₂O₂ has a characteristic absorption peak at 240 nm. Catalase (CAT, EC 1.11.1.6) is widely found in animals, plants, microorganisms, and cultured cells. It is the primary H₂O₂-scavenging enzyme and plays a crucial role in the reactive oxygen species (ROS) scavenging system. H₂O₂ has a characteristic absorption peak at 240 nm. CAT decomposes H₂O₂, causing the absorbance of the reaction solution at 240 nm to decrease over time. The CAT activity can be calculated based on the rate of change in absorbance.Component50TStorageExtraction Buffer60 mL2-8℃Working Solution60 mL2-8℃User-Prepared Instruments and ReagentsUV spectrophotometer, benchtop centrifuge, adjustable pipettes, 1 mL quartz cuvette, mortar, ice, and distilled water.Experimental Procedure1. Crude Enzyme Extract Preparation1.1 Bacterial/Cell SamplesCollect bacteria or cells into a centrifuge tube, centrifuge, and discard the supernatant. Use a bacteria/cell count (10⁴) to Extraction Buffer volume (mL) ratio between 500:1 and 1000:1 (recommended: 5 million bacteria/cells in 1 mL Extraction Buffer). Disrupt the bacteria or cells by sonication (ice bath, power 20% or 200W, pulse 3s on, 10s off, repeat 30 times). Centrifuge at 8,000 g, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.1.2 Tissue SamplesUse a tissue mass (g) to Extraction Buffer volume (mL) ratio between 1:5 and 1:10 (recommended: weigh approx. 0.1 g tissue, add 1 mL Extraction Buffer). Homogenize in an ice bath. Centrifuge at 8,000 g, 4°C for 10 minutes. Collect the supernatant and keep it on ice for assay.1.3 Serum (Plasma) SamplesAssay directly.2. Assay Steps2.1 Preheat the spectrophotometer for at least 30 minutes. Set the wavelength to 240 nm. Zero the instrument with distilled water.2.2 Before assay, incubate the CAT Working Solution in a water bath at 37°C (for mammals) or 25°C (for other species) for 10 minutes.2.3 Add 35 µL of sample and 1 mL of Working Solution into a 1 mL quartz cuvette. Mix well and immediately measure the initial absorbance at 240 nm (A₁). Measure the absorbance again after 1 minute (A₂). Calculate ΔA = A₁ - A₂.3. CAT Activity Calculation3.1 Calculation of CAT Activity in Serum (Plasma)Unit Definition: One unit of enzyme activity is defined as the amount that catalyzes the degradation of 1 nmol of H₂O₂ per minute per milliliter of serum (plasma).Derived Formula:CAT Activity (nmol/min/mL) = [ΔA × Vtotal reaction÷ (ε × d) × 10⁹] ÷ Vsample÷ TSimplified Formula:CAT Activity (nmol/min/mL) = 678 × ΔA3.2 Calculation of CAT Activity in Tissues, Bacteria, or Cells(1) Based on Sample Protein ConcentrationUnit Definition: One unit of enzyme activity is defined as the amount that catalyzes the degradation of 1 nmol of H₂O₂ per minute per milligram of tissue protein.Derived Formula:CAT Activity (nmol/min/mg prot) = [ΔA × Vtotal reaction÷ (ε × d) × 10⁹] ÷ (Vsample× Cpr) ÷ TSimplified Formula:CAT Activity (nmol/min/mg prot) = 678 × ΔA ÷ Cpr(2) Based on Sample Fresh WeightUnit Definition: One unit of enzyme activity is defined as the amount that catalyzes the degradation of 1 nmol of H₂O₂ per minute per gram of tissue.Derived Formula:CAT Activity (nmol/min/g fresh weight) = [ΔA × Vtotal reaction÷ (ε × d) × 10⁹] ÷ (W × Vsample÷ Vtotal sample) ÷ TSimplified Formula:CAT Activity (nmol/min/g fresh weight) = 678 × ΔA ÷ W(3) Based on Bacterial or Cell DensityUnit Definition: One unit of enzyme activity is defined as the amount that catalyzes the degradation of 1 nmol of H₂O₂ per minute per 10⁴ bacteria or cells.Derived Formula:CAT Activity (nmol/min/10⁴ cells) = [ΔA × Vtotal reaction÷ (ε × d) × 10⁹] ÷ (500 × Vsample÷ Vtotal sample) ÷ TSimplified Formula:CAT Activity (nmol/min/10⁴ cells) = 1.356 × ΔAParameter Definitions:1.ΔA: Change in absorbance (A₁ - A₂)2.Vtotal reaction: Total reaction volume (1.035 × 10⁻³ L)3.ε: Molar extinction coefficient of H₂O₂ (4.36 × 10⁴ L/mol/cm)4.d: Light path length of the cuvette (1 cm)5.10⁹: Unit conversion factor (1 mole = 10⁹ nmoles)6.Vsample: Volume of sample added to the reaction (0.035 mL)7.T: Reaction time (1 min)8.Cpr: Sample protein concentration (mg/mL)9.W: Sample weight (g)10.Vtotal sample: Total volume of extraction buffer added (1 mL)11.500: Total number of bacteria or cells (5 million)Precautions1.Before formal testing, it is essential to perform a preliminary test with 2-3 samples expected to have significant differences.2.This product is for research use only. Not for use in clinical diagnosis.Frequently Asked Questions (FAQ)Q: What should I do if I get a negative value?A: Check if bubbles formed during the reaction. Excessive bubbling indicates very high enzyme activity, and bubbles can interfere, causing negative values. Try diluting the sample 10-fold with Extraction Buffer and re-assaying. If no bubbles form (with diluted sample or original reaction) and a small negative value persists, it indicates that the enzyme activity in this sample is below the detection limit... 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 | Products Content:F666101Component500 U5000 UStorageF666101AFastStar Probe Buffer (for bisDNA)2×1.2 mL2×12 mL-20℃. Avoid freeze/thaw cycle. Protect from light.F666101BSuperFastStar DNA Polymerase (5U/µL)100 µL1 mL-20℃. Avoid freeze/thaw cycle. Protect from light.Products Content:F666101Component500 U5000 UStorageF666101AFastStar Probe Buffer (for bisDNA)2×1.2 mL2×12 mL-20℃. Avoid freeze/thaw cycle. Protect from light.F666101BSuperFastStar DNA Polymerase (5U/µL)100 µL1 mL-20℃. Avoid freeze/thaw cycle. Protect from light.Products IntroductionThis product is mainly used for PCR using bisulfite-treated DNA as template, in which SuperFastStar DNA Polymerase is a new high-efficiency hot-start enzyme modified by bis-monoclonal antibody, which is completely blocked at room temperature, thus effectively avoiding non-specific amplification caused by the non-specific binding of the primer to the template or the primer dimerization under the condition of room temperature. The optimized FastStar Probe Buffer (for bisDNA) contains PCR Buffer, dNTPs and Mg2+, etc., which is easy to use as customers only need to add templates, primers and probes.caveat1 Before use, please mix the product gently by turning it up and down after it has been completely melted and centrifuged briefly.2. Avoid repeated freezing and thawing of the product, which may degrade its performance. This product can be stored at -20℃ for a long period of time, protected from light. If frequent use is required within a short period of time, it can be stored at 2-8℃.Usage The following examples are conventional PCR reaction systems and conditions, which should be improved and optimized according to the template, primer structure and target fragment size.1.PCR reaction system Note: 1) Usually, better results can be obtained with a primer concentration of 0.2 µM, and 0.1-1.0 µM can be used as a reference for setting the range.2）The concentration of the probe used is related to the fluorescence quantitative PCR instrument used, the type of probe, and the type of fluorescent labeling substance, so please refer to the instrument manual or the specific requirements for the use of each fluorescent probe to adjust the concentration.3）Usually the amount of DNA template is 10-100 ng of genomic DNA or 1-10 ng of cDNA as a reference. Since the templates of different species contain different copy numbers of the target gene, the templates can be diluted in gradients to determine the optimal amount of template to use.2.PCR reaction conditionsNote: 1) The initial denaturation of this product at 95°C for 30s is sufficient for enzyme activation; complex templates can be extended to 3min denaturation.(2) It is recommended to use two-step PCR reaction program, if you can't get good experimental results due to the use of primers with lower Tm value, etc., you can try three-step PCR amplification, and the annealing temperature should be set in the range of 56℃-64℃ as a reference... 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 | N665917 Component 1 mL 5 mL Storage N665917A 2×SYBR qPCR MasterMix 1 mL 5×1 mL -20℃. Avoid freeze/ Thaw cycle. N665917B qPCR Primer Mix 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665917C DNA Standard A 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665917 Component 1 mL 5 mL Storage N665917A 2×SYBR qPCR MasterMix 1 mL 5×1 mL -20℃. Avoid freeze/ Thaw cycle. N665917B qPCR Primer Mix 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665917C DNA Standard A 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665917D DNA Standard B 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665917E DNA Standard C 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665917F DNA Standard D 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665917G DNA Standard E 100 µL 500 µL -20℃. Avoid freeze/ Thaw cycle. N665917H 50×High ROX 40 µL 200 µL -20℃. Avoid freeze/ Thaw cycle.Product IntroductionThis is a dye-based (SYBR Green I) qPCR NGS library quantification kit for cfDNA, which provides the reaction mixture, DNA primer mixture, standards, and sample dilutions required for the qPCR process, making it a complete reagent system that is easy and convenient to use. The fluorescent dye SYBR Green I contained in the reaction mixture binds to all double-stranded DNA. 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, the length of the standard in the kit (about 270bp) is comparable to the average length of the cfDNA NGS libraries (250-300bp), which is able to quickly and accurately quantitate the concentration of the constructed cfDNA libraries. quantification.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, ViiA7 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 Method of Use 2.Applicable scopeThis product is designed for the absolute quantification of the concentration of Illumina platform second generation sequencing libraries. The end of the library contains Illumina P5 and P7 microarray binding sequences, the length of which does not exceed 1kb, and the concentration is not less than 0.02pM can be used for quantitative experiments. 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 0.01-60 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 MasterMix10 µlqPCR Primer Mix0.8 µlTemplate4 µlddH₂O5.2 µlDescription: High Rox model: 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.3.qPCR reaction programIf the average length of the library is greater than 700bp, the annealing/extension time should be increased appropriately.Refer to the specific instrument setup program for dissolution curves.data analysisStandard curve productionThe standard curve was plotted according to the data processing Excel sheet. The correlation coefficient R2 of the standard curve should be not less than 0.99, and the slope should be located between -3.1 and -3.6 when the Ct value is the longitudinal coordinate. If the parameters of the standard curve are unreasonable, it is recommended to repeat the experiment.DNA Standard NameDNA Standard ConcentrationDNA Standard A60 pMDNA Standard B6 pMDNA Standard C0.6 pMDNA Standard D0.06 pMDNA Standard E0.006 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 |