Tri- -methane

A variety of buffers is used in electrophoresis. The selected buffer must contain ions to carry the current. Other than current-carrying capacity, the most critical criterion for buffer selection is the stability of the sample to be analyzed. Many proteins are unstable in acidic pHs, so alkaline buffers are frequently employed. Tris-(hydroxymethyl)amino methane (TRIS or THAM), sodium acetate, and ethylenedi-aminetetraacetate (EDTA) are common solutes in buffers, with pHs between 7.9 and 8.9 typical. (Refer to Chapter 5 for a discussion of buffers.) These buffers also work well with nucleic acid fragments. In addition, phosphate buffers, e.g., 10 mMK3P04, are often used with nucleic acid fragments (1.0 mM = 0.0010 M). 

Prepare 100 mL (500 mL if the gel is to be run under the buffer) of an electrophoresis buffer that is 20 mM tris-(hydroxymethyl)amino methane (TRIS or THAM), 6 mM sodium acetate, and 1 mM disodium EDTA. Adjust the pH of this solution to 7.9 using concentrated HC1. Also prepare small volumes of solutions of hemoglobin and cytochrome C in the buffer (the concentration is not important) and also a mixture solution of these two solutes. Add a quantity of sucrose to each. 

Prepare 500 mL of a mobile phase that is 25 mM KC1, 5 mM MgCl2, and 50 mM tris-(hydroxym-ethyljamino methane (TRIS or THAM). Adjust the pH to 7.2 using concentrated HC1. Filter and degas this mobile phase using a vacuum filtration apparatus equipped with 0.45-/LL filters. 

Prepare a buffer solution that is 20 mM tris-(hydroxymethyl)amino methane (TRIS or THAM), 6 mM sodium acetate, and 1 mM disodium EDTA. Adjust to pH = 7.9. 

Tris-(hydroxymethylamino)methane (TRIS) [77-86-1] M 121.1, m 172 . Tris can ordinarily be obtained in highly pure form suitable for use as an acidimetric standard. If only impure material is available, it should be crystd from 20% EtOH. Dry in a vacuum desiccator over P2O5 or CaCl2. 

Tris(hydroxymethyl)amino-methane (tris or tham)... 

Selenium-enriched yeast, regarded as one of the most interesting materials for Se speciation, has also been studied through extraction procedures with water and buffered solutions as well, typically with 30 mmol l-1 tris(hydroxymethyl)amino-methane (Tris)-HCl at pH = 7.0. The investigations performed by several independent research groups almost always led to the same results both water extraction (at 50-90°C for l-2h) and Tris-buffered extraction (at 37°C for 1 h) achieved about 10 percent extraction of Se, the main Se species identified being Se-adenosyl-homocysteine, a small amount of free SeMet and some nonmetabolized, inorganic Se(IV) in the fermentation-media [21, 40, 41, 43, 44]. 

The highly reactive perfluoroalkenes 28 react under mild conditions with the bromotrifluoro-methane/tris(diethylamino)phosphane system, giving rise to monosubstitution products 29. in... 

Mono-chlor methane Di-chlor methane Tri-chlor methane Tetra-chlor methane... 

ANTI)]-, ammonium, 26 24 C H2,Cl2PSis, Phosphonous dichloride, tris(trimcthylsilyl)methyl]-, 27 239 C, iH2iiSi), Methane, tris(trimethylsilyl)-, 27 238... 

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