Directional migration propensity of calf thymus DNA in a gradient of metal ions

Herein we report the migrational behaviour and spatial distribution of calf thymus DNA in a gradient of different physiologically relevant monovalent and divalent cations under two different conditions – (i) microfluidic and (ii) evaporating droplets. Amplified phoresis toward high concentrations of Mg²⁺ and Ca²⁺ compared to other ions and non-uniform DNA coating in a gradient of ions were observed. This process, which was governed by the effective charge and diffusion coefficient of the DNA–metal ion complex, can have potential applications in nucleic acid-based spatiotemporal surface patterning, biosensors, and dynamic biocolloidal assembly and transport.