AMINODEXTRAN AS A MIGRATION MODERATOR IN CAPILLARY GEL-ELECTROPHORESIS OF CHARGED POLYSACCHARIDES

Aminodextran (AD) is shown here as an effective electrolyte additive f or a size-dependent separation of hyaluronate (HA) oligomers in capill ary gel electrophoresis. AD interacts mainly with the negatively charg ed HA through an ion-exchange mechanism, while its participation is de pendent on the polymer chain size, The degree of complexation and, con sequently, electrophoretic mobility can be adjusted through charge den sity in the analyte or additive molecules through a choice of pH or ad dition of competing ions to the separation buffer. This approach enabl es adequate separation, in a large molecular-size range, without the n eed for highly viscous polymer solutions, thus simplifying a buffer re placement between the runs. Through a proper choice of buffer componen ts, resolution of the individual HA polymer chains up to molecular mas ses of about 70 000 Da was achieved in less than 45 min. The migration behavior is discussed and presented in combination with its descripti ve models.