Comment on 'Modeling the conductance and DNA blockade of solid-state nanopores'.

Recently, Kowalczyk et al (2011 Nanotechnology 22 315101) introduced a model for calculating the conductance of an hourglass-shaped nanopore, and the conductance change when DNA is introduced into such a pore. Here, we comment on their model in the context of other literature addressing the same general problem. Existing work includes widespread use of an alternative model, contradicts the authors' claim that the conductance change should be expected not to vary with pore size, and has frequently utilised access resistance.