Modulating Dna Adsorption On Silica Beads Using An Electrical Switch

摘要

We demonstrate active tuning of DNA adsorption on silica beads using an electrical switch in a microfluidic device; we use electrolysis of water to alter pH in a packed bed of silica beads and switch the silica bead surface between being adsorptive and desorptive for DNA molecules.rnDNA adsorption/desorption on solid surfaces serves as the underlying mechanism for the vast majority of DNA preconcentration and separation techniques that are available for genetic analysis of biological samples. Silica surfaces are the most common ones that are applied for DNA extraction and concentration. DNA interaction with silica surface has been intensively studied to illustrate mechanistic details of these adsorption/desorption processes. In the majority of reported protocols, DNA extraction from biological samples was performed by inducing DNA binding onto a silica surface in a high ionic strength buffer in the presence of high concentration salts (e.g. 6 M guanidinium HC1) and later eluting DNA out in a low ionic strength buffer.