Influence of pH on the migration properties of oligonucleotides in capillary gel electrophoresis.
The effect of pH on the electrophoretic migration properties of single-stranded oligodeoxyribonucleotides in capillary gel electrophoresis was investigated. Different homooligodeoxyribonucleotides of equal chain length showed significant differences in relative migration when the pH of the gel buffer was varied from pH 6 to 8, parallel with the running buffer. A similar variation in migration order was observed during the electrophoretic equilibration of a pH 8 gel-filled capillary column with a pH 6 running buffer. In the latter instance, the current reached the new level after 20 min of electrophoretic equilibration with the pH 6 running buffer. However, it was observed that the migration order characteristic of the pH 6 gel was achieved only after 4 h of electrophoretic equilibration. To avoid this time-consuming equilibration process, these results suggest that gel-filled capillary columns should be prepared with the same buffer (composition and pH) that will be used as the running buffer during the separations.
Guttman
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Central Isotope Laboratory, Semmelweis University of Medicine, Budapest, Hungary.
Arai
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Magyar
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K
D002021:Buffers; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D009841:Oligonucleotides / Q000032:analysis*
D002021:Buffers; D009841:Oligonucleotides