Nonspecific protein adsorption remains an important issue in the development of biosensors and biomedical devices. Grafted dextran has been shown to reduce protein adsorption on a variety of surfaces. When dextran is physically adsorbed on a silicon substrate with a native oxide coating, bovine serum albumin (BSA) adsorption is essentially unchanged compared to that on the uncoated surface. Covalently attached dextran is much more effective at reducing bioadhesion. In this study, dextran is oxidized using standard periodate methods to form a desired dialdehyde, allowing for side-on covalent attachment to surface amine groups. Oxidized dextran maintains an equilibrium between the dialdehyde and a hemiacetyl structure. To optimize the binding of oxidized dextran to surfaces of interest, the kinetics of dextran oxidation and the equilibrium constant between the dialdehyde and hemiacetyl structure were investigated. The conversion of dextran was measured by formic acid titration at varying reaction times, pH levels and initial periodate concentrations. The dextran oxidation reached equilibrium conversion after 48 hours. In the range of pH 3 to 11, the dialehyde was dominant over the hemiacetyl structure, showing little variation with changes in pH.