Buffer solutions with a specific

Now suppose we want to prepare a buffer solution with a specific pH. How do we go about it Equation (16.1) indicates that if the molar concentrations of the acid and its conjugate base are approximately equal, that is, if [acid] = [conjugate base], then... 

Calculating the mass of a salt required to give an acidic buffer solution with a specific pH... 

The synthesis of the title compound, 214, the active-site-directed photoaffinity radiolabel for androgen-binding proteins ( ABP ), has been accomplished180,181 by treatment of excess 17a-[( )-2-tributyltin(IV)ethenyl]androsta-4,6-dien-17 -ol-3-one, 215, with sodium iodide-125 of specific activity 27 Cimmol-1 in a sodium acetate-AcOH buffered solution and a solution of 30% H2O2 in glacial AcOH (equation 77). 

The typical test (illustrated in Figure 15.7) is performed using mice, normally female CBA mice 6-10 weeks of age. Female BALB/c and ICR mice have also been used. After animal receipt, they are typically acclimated to standard laboratory husbandry conditions for 7-10 days. The usual protocol will consist of at least two groups (vehicle control and test article treated) of five mice each. They are treated on the dorsal surface of both ears with 25 pi (on each ear) of test article solution for three consecutive days. Twenty-four to forty-eight hours after the last test article exposure, the animals are given a bolus (0.25 ml) dose of [3H]thymidine (20 pCi with a specific activity of 5.0-7.0 Ci/mmol) in phosphate buffered saline via a tail vein. Five hours after the injection, the animals are euthanized by C02 asphyxiation and the auricular lymph nodes removed. 

Fig. 10.6 Concept of multitarget affinity specificity screening (MASS). Macromolecular targets (typically structured RNA constructs or proteins) in nondenaturing buffers are mixed in solution with a collection of potential ligands derived from natural product fractions, combinatorial libraries, or other diverse compound collections. The...

Affinity capillary electrophoresis is an approach where the migration pattern of interacting molecules are used to identify and quantify specific binding and estimate binding constants. Therefore, the solutes are first separated conventionally by CE. In a second run, the run buffer is doped with a specific complex-forming substance, and the change in the retention time... 

A combination of chelators for divalent cations is suitable to buffer the free Ca " concentration from 0.1 -100 (iM under experimental conditions. Added Mg " and ATP as well as the pH of the medium must be considered, because they alter the equilibrium between Ca and the chelators present. The free Ca and Mg " concentrations are calculated by a computer program and controlled by Ca and Mg " specific electrodes (Fohr et al., 1993). Each Ca " buffer is prepared separately from stock solutions, with a final check of pH, pCa, or pMg. If no Ca electrode is available, the calculated total amount of Ca (as CaCy and Mg (as Mg(CH3COO)2) must be added before the pH adjustment. Buffers can be stored at -20 °C but should be thawed only once, mainly because of decomposition of ATP. 

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