Directly observing the motion of DNA molecules near solid-state nanopores.

ABSTRACT: We investigate the diffusion and the drift motion of λ DNA molecules near solid-state nanopores prior to their translocation through the nanopores using fluorescence microscopy. The radial dependence of the electric field near a nanopore generated by an applied voltage in ionic solution can be estimated quantitatively in 3D by analyzing the motion of negatively charged DNA molecules. We find that the electric field is approximately spherically symmetric around the nanopore under the conditions investigated. In addition, DNA clogging at the nanopore was directly observed. Surprisingly, the probability of the clogging event increases with increasing external bias voltage. We also find that DNA molecules clogging the nanopore reduce the electric field amplitude at the nanopore membrane surfac

SUBMITTER: Ando G 

PROVIDER: S-EPMC3508321 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature