Abstract
We examine the effect of physiological cations Na(+), K(+), Mg(2+), and Ca(2+) on the mechanical properties of bundles of λ-phage DNA using silicon nanotweezers (SNTs). Integrating SNTs with a microfluidic device allows us to perform titration experiments while measuring the effect in real-time. The results show that only for Mg(2+) and in particular, at the intra-nuclear concentration (100 mM), the interaction occurs.