Buffers interaction with

Scientific (Northbrook, IL) contain a silica support with a -y-glycidoxypropylsi-lane-bonded phase to minimize interaction with anionic and neutral polymers. The columns come in five different pore sizes ranging from 100 to 4000 A. The packing material has a diameter from 5 to 10 /cm and yields in excess of 10,000 plate counts. With a rigid silica packing material, the columns can withstand high pressure (maximum of 3000 psi) and can be used under a variety of salt and/or buffered conditions. A mobile phase above pH 8, however, will dissolve the silica support of the column (21). A summary of the experimental conditions used for Synchropak columns is described in Table 20.8. 

Why does EDTA cause only 90% inhibition, leaving 10% of the activity intact Buffer solutions usually contain 0.1 1 pM of contaminating Ca2+ when special precaution is not taken, and this concentration is much greater than the molar concentration of luciferase used in the experiments. Thus, one of the possibilities would be that Ca2+ interacts with the molecule of luciferase and can increase the activity of luciferase about 10 times, in spite of the fact that the molecule of luciferase lacks the Ca2+ binding site of EF-hand type (Thompson et al., 1989). Another possibility would be that EDTA interacts directly with the molecules of luciferase, to cause the inhibition. The question remains unresolved. 

The wavelength of maximum absorption and the molar absorptivity are very dependent on pH, buffer, temperature, solvent, and the presence of other materials that may interact with anthocyanins. In addition, anthocyanin absorption follows a linear relationship with concentration only when present at low levels therefore considerable dilution is usually necessary. Absorbance normally should vary from 0.2 to 1.0 unit in order to obey Lambert-Beer s law. However, absorbance values as high as 1.5 to 2.0 absorbance units may be valid for sophisticated new instruments. 

Chemical No interaction with the sample Good solubility High buffer capacity over wide pH range Low pH variation as a function of temperature Availability in different salt forms Low counterion mobility Mobility matching Good salting-in characteristics... 

The significant enhancement in emission quantum yields and lifetimes suggests that 3 can be used as a noncovalent probe in immunochemical assay and biophysical studies. This dye is quite soluble in aqueous buffer and interacts with... 

Prepare a 5 percent cell suspension in an appropriate buffer. Avoid amine-containing buffers, as these will interact with aldehydes. 

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