Phosphate buffer, solution preparation

The chromatographic procedure may be carried out using (a) two stainless steel columns in series the first (25 cm x 4.6 mm) packed with particles of silica, the surface of which has been modified with chemically bonded hexysilyl groups (5 /im) (Spherisorb C6 is suitable) and the second (25 cm x 4.6 mm) packed with cation exchange resin (10 /an) (Partisil-10 SCX is suitable) (b) as the mobile phase at a flow rate of 1.0 ml/min, a mixture of 25 volumes of acetonitrile, 25 volumes of a phosphate buffer solution prepared by dissolving 58.5 g of sodium dihydrogen orthophosphate... 

An amount of enzyme preparation equivalent to 900 mg of wet cells was made up to 25 ml with the above potassium phosphate buffer solution. 150 mg (1.15 mmol) of 5-fluorouracil and 1.0 gram of thymidine (4.12 mmol) were dissolved in 15 ml of the above potassium phosphate buffer solution. The mixture was incubated at 37°C for 18 hours. After this time, enzyme action was stopped by the addition of four volumes of acetone and one volume of peroxide-free diethyl ether. The precipitated solids were removed by filtration, and the filtrate was evaporated under nitrogen at reduced pressure until substantially all volatile organic solvent had been removed. About 20 ml of aqueous solution, essentially free of organic solvent, remained. This solution was diluted to 100 ml with distilled water. 

C18-0120. You are doing undergraduate research for a biology professor. Your first assignment is to prepare a pH =7.50 phosphate buffer solution to be used in the isolation of DNA from a cell culture. The buffer must have a total concentration of 0.500 M. On the shelf you find the following chemicals solid NaOH concentrated HCl (12.0 M) concentrated H3 PO4 (14.7 M) KH2 PO4 and K2 HPO4. Write a quantitative detailed set of instmctions that describe how you would prepare 1.5 L of the buffer solution. 

Transfer the residue prepared as in Section 6.1.1 into a 300-nL separatory funnel with 25 mL of phosphate buffer solution (0.1 M, pH 7.4). Add 10 mL of saturated aqueous sodium chloride and 50 mL of 0.5 M sodium hydrogen carbonate to the funnel and shake the funnel vigorously for 1 min. Add 70 mL of ethyl acetate to wash the aqueous layer to the funnel, shake, separate, and discard the ethyl acetate layer. Repeat this extraction procedure three times. Add 2 mL of phosphoric acid and 20 mL of an acetate buffer solution (0.1 M, pH 4) to the aqueous layer and extract the mixmre with 50 mL of ethyl acetate three times. Combine the extracts and filter into a 500-mL round-bottom flask through 60 g of anhydrous sodium sulfate supported by a plug of cotton wool in a funnel. Concentrate the filtrate to dryness under reduced pressure. 

The native SGPA crystals have been prepared from a phosphate buffered solution at a pH of 4.3 (cf. Ref. 118)... 

To prepare an antibody protein array, a monolayer of protein A, which was compressed at a surface pressure of 11 mN m l was transferred to a compartment containing anti-ferritin antibody in 10 mM pH 7.0 phosphate buffer. The antibody molecules were self assembled onto the protein A layer. The protein A/antibody molecular membrane was transfered to a compartment containing ultrapure water for rinsing, and was then transfered onto the surface of an HOPG plate by the horizontal method. AFM measurements were made in a pH 7.0 of 10 mM phosphate buffer solution. 

Sorensen is usually considered to be the first to have realized the importance of hydrogen ion concentration in cells and in the solutions in which the properties of cell components were to be studied. He is also credited with the introduction of the pH scale. Electrochemistry started at the end of the nineteenth century. By 1909, Sorensen had introduced a series of dyes whose color changes were related to the pH of the solution, which was determined by the H+ electrode. The dyes were salts of weak acids or weak bases. He also devised simple methods for preparing phosphate buffer solutions covering the pH range 6-8. Eventually buffers and indicators were provided covering virtually the whole pH range. 

The immobilized lipase was prepared by adsorption of the hpase onto Amberlite XAD7. The lipase solution (50 mL) was prepared by dissolving 2.2 g of cmde lipase in 50 mL of phosphate buffer solution, pH 7. The lipase solution was gently stirred for a few minutes until dissolved. 

Stock solution 5. 1 m stock solution of potassium phosphate buffer was prepared by dissolving K2HP04-3H20 (11.423 g) and KH2PO4 (6.805 g) in deionized water to a final volume of 100 mL. The pH was adjusted to 7.0. This 1 m stock solution was diluted to the desired concentration of 50 mM with deionized water. Buffers were stored at 0-4 °C. 

Dioxetane phosphate visualization solution Prepare 0.1 mg/ml AMPPD or CSPD (Applied Biosystems) or 0.1 mg/ml Lumigen-PPD (Lumigen) substrate in dioxetane phosphate substrate buffer (see recipe). Prepare just before use. Lumi-Phos 530 (Boehringer Mannheim or Lumigen) is a ready-to-use solution and can be applied directly to the membrane. 

Multi-immunoaffinity chromatography columns were prepared by the coupling of monoclonal antibodies against AMP to activated sepharose. Both sensitivity and specificity were tested for the most commonly used penicillins (AMP, AMO, PenG, OXA, CLO, DICL). Recoveries ranging from 67% to 100% were obtained from phosphate buffer solutions, and it was assumed... 

The analytical utility of near-infrared spectroscopy can be illustrated by establishing and characterizing calibration models for the measurement of glucose in a set of aqueous solutions composed of glucose, lactate, urea, ascorbate, alanine, and triacetin. In this experiment, 80 different samples were prepared with randomized concentrations of each component ranging from 1 to 35 mM.6 Solute concentrations were randomized to minimize covariance between the different solute concentrations. All solutions were prepared in a pH 6.8 phosphate buffer solution. 

The new system was applied for standard ethanol solutions prepared in phosphate buffer solutions (pH 7.0). Extracted ethanol solutions were also used with 10% (w/v) NaCl by NBR 13992 1997 from gasohol blends (12) (Brazilian Association Technical Standard). Table 3 shows the concentrations of the extracted ethanol solutions measured by HPLC and respective gasoholblends. This new integrated system biosensor-FIA was used for the range of 0.05-1.5 g of ethanol/L, and good results were obtained compared with the ethanol content measured by the HPLC standard method. 

An amount of enzyme preparation equivalent to 900 mg of wet cells was made up to 25 ml with the above potassium phosphate buffer solution. 150 mg (1.15 mmol) of 5-fluorouracil and 1.0 gram of thymidine (4.12 mmol) were dissolved in 15 ml of the above potassium phosphate buffer solution. 

To localize the precursors of Acp, the low molecular weight compounds present in yeast cells were isolated by cell disruption, centrifugation and ultrafiltration (Schieberle, P., in preparation). Boiling and continous extraction of a phosphate buffer solution containing the compounds of a molecular weight lower than 1000 produced substantial amounts of Acp. Furthermore, the free proline content of the yeast used in these experiments was analysed and calculated to be more than 200 mg/kg yeast. 

Unless otherwise prescribed, use phosphate buffer solution pH 7.4 R containing 3.0% ntfV of bovine albumin K for the preparation of the solutions and dilutions used in the assay. 

Cyclic Voltammetric Behavior of the PPy-GOD Film. Figure 1 shows the cyclic voltammetric curves of a PPy-GOD film (4000 A) in phosphate buffer solution with pH 7.4 at different scan rates. Both anodic and cathodic peaks should correspond to the redox reactions of PPy chains. The peak potentials, which were recorded at the scan rate of 200 mV/s, were -380 mV and -200 mV for cathodic and anodic peaks, respectively. This is similar to the potential shifts of the PPy film doped with large anions (27) such as poly(p-styrenesulfonate). Enzyme protein molecules are composed of amino acid and have large molecular size, which can not move out freely from the PPy-GOD film by the application of the reduction potential. In order to balance the charge of the Pfy-GOD film, cations must move into the film, and redox potentials move toward a more negative potential. This behavior is different from the one observed for the PPy-GOD film, which was prepared in the solution of GOD... 

The polymeric drugs prepared from VBFU can also be expected to release 5-FU by amide hydrolysis as shown in Scheme 6. The hydrolysis of poly(VBFU) and poly(VBFU-co-MAn) was observed in a phosphate buffer solution (pH 7.0)... 

Prepare 0.25 M pH buffer solutions ranging from pH 0.5 to 9. (Note that phosphate buffer is only good for pH = 4.5-9 due to the dissociation constant.) Before coming to the lab, review how to make a pH buffer solution in a freshman chemistry textbook and calculate the relative amounts of KH2PO4 (monobasic phosphate) and K HPO O (dibasic phosphate) needed to make these phosphate buffer solutions. 

Prepare the starch substrate by diluting the 20 g l-1 starch solution prepared in step 1 with an equal volume of pH 7.0 phosphate buffer solution. This results in a working starch concentration of 10 g 1 1. Add 2 ml of the starch solution to each of the test tubes. 

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