Aminodextran as a Migration Moderator in Capillary Gel Electrophoresis of Charged Polysaccharides

Abstract

Aminodextran (AD) is shown here as an effective electrolyte additive for a size-dependent separation of hyaluronate (HA) oligomers in capillary gel electrophoresis. AD interacts mainly with the negatively charged HA through an ion-exchange mechanism, while its participation is dependent on the polymer chain size. The degree of complexation and, consequently, electrophoretic mobility can be adjusted through charge density in the analyte or additive molecules through a choice of pH or addition of competing ions to the separation buffer. This approach enables adequate separation, in a large molecular-size range, without the need for highly viscous polymer solutions, thus simplifying a buffer replacement between the runs. Through a proper choice of buffer components, resolution of the individual HA polymer chains up to molecular masses of about 70 000 Da was achieved in less than 45 min. The migration behavior is discussed and presented in combination with its descriptive models.