Electrophoresis visualizing solution

Gel electrophoresis provides a simple method for separating complex protein mixtures. Because proteins are visualized using stains that may not be linearly incorporated in the gel, the intensity of the stained bands may be poorly correlated with the amount of protein. For this reason, gel electrophoresis is at best a semiquantitative technique capable of generating relative purity results. In CE, separations are commonly performed in free solution, i.e., in the absence of any support such as gel matrices. This allows the replacement of the capillary s content in between analyses and therefore the automation of the process. The use of UV-transparent fused-silica capillaries enables direct on-line optical detection of focused protein zones, eliminating the requirement for sample staining. The detection systems available to CE provide true quantitative capabilities. 

Visual examination of crystals using a light microscope does not indicate whether the crystals consist of only the protein or the protein-DNA complex. Therefore, the crystals are washed free of any uncrystallized DNA and protein several times with a solution containing the precipitant and any additives, etc. at the concentration and pH used for growing crystals (mother liquor). Finally, the crystals are separated from the mother liquor by microcentrifugation, dissolved in a suitable buffer, and analysed biochemically. The protein content is determined by SDS polyacrylamide gel electrophoresis, the protein concentration by BIO-RAD assay, and amino acid composition by mass-spectroscopy. The DNA can be detected by staining the gel with ethidium bromide or methylene blue (Jordan et al., 1985), whereas... 

Nucleic acids can be visualized on the slab gel after separation by soaking in a solution of ethidium bromide, a dye that displays enhanced fluorescence when intercalated between stacked nucleic acid bases. Ethidium bromide may be added directly to the agarose solution before gel formation. This method allows monitoring of nucleic acids during electrophoresis. Irradiation of ethidium bromide-treated gels by UV light results in orange-red bands where nucleic acids are present. 

In capillary electrophoresis a sample, usually containing charged species, is introduced into the end of a capillary that has been filled with a solution of buffer (or electrolyte). Under the influence of an electric field, the analytes migrate away from the injection end of the capillary toward the detector end, where they are visualized. Three distinct separation mechanisms have been developed for the separation of analytes by CE. 

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