| Description | Enzymes extracted from mammalian testes (e.g., sheep testes) can hydrolyze mucopolysaccharides of the hyaluronic acid type. They may contain a suitable stabilizer. Potency: Minimum 3000 IU of hyaluronidase activity per milligram (of dry substance).ProductionAnimals used for producing hyaluronidase Enzymes extracted from mammalian testes (e.g., sheep testes) can hydrolyze mucopolysaccharides of the hyaluronic acid type. They may contain a suitable stabilizer. Potency: Minimum 3000 IU of hyaluronidase activity per milligram (of dry substance).ProductionAnimals used for producing hyaluronidase must meet the health requirements for animals intended for human consumption.Characteristics1.Appearance: White or yellowish-white, amorphous powder.2.Solubility: Soluble in water, almost insoluble in acetone and absolute ethanol.IdentificationA solution containing 100 IU of hyaluronidase in 1 mL of 9 g/L sodium chloride solution depolymerizes a 10 g/L sodium hyaluronate BRP solution at 20°C, resulting in a significant decrease in viscosity. Heating the hyaluronidase at 100°C for 30 minutes destroys this effect.Tests1.Appearance of Solution: The solution should be clear. Dissolve 0.10 g in water and dilute to 10 mL with the same solvent.2.pH: 4.5 to 7.5. Dissolve 30 mg in carbon dioxide-free water and dilute to 10 mL with the same solvent.3.Loss on Drying: Maximum 5.0%. Determine by drying 0.500 g at 60°C under a pressure not exceeding 670 Pa for 2 hours.4.Bacterial Endotoxins: ≤ 0.2 EU/IU.AssayThe activity of hyaluronidase is determined using a slope-ratio assay, by comparing the rate at which it hydrolyzes sodium hyaluronate BRP with the rate obtained using the International Standard or a reference preparation calibrated in International Units.Substrate SolutionIn a 25 mL conical flask, add 0.10 g of sodium hyaluronate BRP, then slowly add 20.0 mL of water at 4°C. The addition rate must be slow enough to allow the substrate particles to swell (approximately 5 minutes). Maintain at 4°C and stir for at least 12 hours. Store at 4°C and use within 4 days.For both the test solution and the reference solution, prepare the solutions and perform dilutions at 0°C to 4°C.1.Test Solution: Dissolve an appropriate amount of the substance in hyaluronidase diluent to obtain a solution containing 0.6 ± 0.3 IU of hyaluronidase per mL.2.Reference Solution: Dissolve an appropriate amount of hyaluronidase BRP in hyaluronidase diluent to obtain a solution containing 0.6 IU of hyaluronidase per mL.In a reaction vessel, mix 1.50 mL of phosphate buffer solution (pH 6.4) and 1.0 mL of the substrate solution, and equilibrate at 37 ± 0.1°C. At time t₀ = 0 (using the first timer), add 0.50 mL of the test solution containing E milligrams of the enzyme to be tested, mix well. Maintain the mixture at 37 ± 0.1°C using a suitable viscometer, record the flow time t using a second timer (with 0.1-second intervals), and perform multiple measurements over approximately 20 minutes (monitoring with the first timer). Use the following viscometer: microviscometer (DIN 51 562, Part 2), capillary type MII, with a viscometer constant of approximately 0.1 mm²/s².Repeat the above procedure using 0.50 mL of the reference solution containing hyaluronidase BRP. Calculate the viscosity ratio using the following expression:K = Viscometer constant (in mm²/s², indicated on the viscometer);t₂ = Flow time of the solution (in seconds);0.6915 = Kinematic viscosity of the buffer solution at 37°C (in mm²/s).Since the enzymatic reaction continues during the flow time measurement, the actual reaction time is equal to t₀ + t/2 (i.e., half of the flow time (t/2) is added to the initial measurement time t₀). Plot (ln η)⁻¹ as a function of the reaction time (t₀ + t/2) (in seconds); a linear relationship should be obtained. Calculate the slope (b) of the substance to be tested and the slope (bᵣ) of the reference preparation. Determine the specific activity in International Units per milligram using the following expression:A = Specific activity of hyaluronidase BRP (in International Units per milligram).Perform at least three complete sets of the procedure and calculate the average activity of the substance to be tested.StorageStore in a tightly closed container at a temperature of 2°C to 8°C. If the substance is sterile, the container should also be sterile and tamper-proof... 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 | Inquire | Carboxypeptidase B catalyzes hydrolysis of the basic amino acids lysine, arginine and histidine from theC-terminal end of polypeptides. The molecular weight is 34,500 daltons, the pH optimum is 8.0, and pI is 6.0.Carboxypeptidase B is competitively inhibited by arginine and lysine. The enzyme is Carboxypeptidase B catalyzes hydrolysis of the basic amino acids lysine, arginine and histidine from theC-terminal end of polypeptides. The molecular weight is 34,500 daltons, the pH optimum is 8.0, and pI is 6.0.Carboxypeptidase B is competitively inhibited by arginine and lysine. The enzyme is also inhibited by metal chelating agents, e.g., EDTA. Recombinant Carboxypeptidase B (EC 3.4.17.2) is expressed in E.Coli and purified by high pressure liquid chromatography. There is no trace of other enzyme (such as carboxypeptidase A and chymotrypsin) activity. No protease inhibitors such as PMSF are present in the preparation.Animal origin free:eliminate the risk of virus presence, or of any other potential adventitious agents found in animal-derived carboxypeptitase B.Stability:A sterile recombinant carboxypeptidase B lyophilized eliminates the risk of contamination and decreases the chances of activity loss in the process of transport and storage. High purity:1) Recombinant carboxypeptidase B provides increased specific activity and eliminates contaminating protease activities found in extracted enzymes with lower purity level. 2) No other contaminating proteases such as chymotrypsin and carboxypeptidase A. 3）Less than 10ppm of recombinant trypsin... Read More | BackgroundStreptavidin is a tetrameric bacterial protein isolated from Streptomyces avidinii providing 4 high-affinity biotin binding sites. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin. With a dissociation constant on the order of ≈10⁻¹⁴ mol/L,BackgroundStreptavidin is a tetrameric bacterial protein isolated from Streptomyces avidinii providing 4 high-affinity biotin binding sites. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin. With a dissociation constant on the order of ≈10⁻¹⁴ mol/L, the binding of biotin to streptavidin is one of the strongest non-covalent interactions known in nature. Unlike egg-white avidin, which has a net positive charge at neutral pH and contains about 7% carbohydrate, streptavidin has almost no net charge at neutral pH, does not contain carbohydrate, and exhibits lower non-specific background. Streptavidin conjugates are widely used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids and other molecules. This FITC-streptavidin conjugate was prepared by highly purified Streptavidin and free FITC was removed. Streptavidin (FITC) is a useful second-step reagent for the indirect immunofluorescent staining of cells in combination with biotinylated primary antibodies for flow cytometric analysis. Excitation at 488nm light leads to a fluorescence emission maximum of 520 nm.Recommended Usage：Every lot of Streptavidin-FITC is tested by flow cytometry using biotinylated primary antibodies. From this testing it is recommended that between 0.02 and 0.25 µg of streptavidin be used per 106 cells in a 100 µl staining volume... Read More |