"We are developing a solid-state device for recording sequences
of single DNA molecules as they pass through a nanometre-
diameter pore in a silicon membrane," researcher Aleksei
Aksimentiev told nanotechweb.org. "The smaller the diameter of
the pore, the more control we have over the conformations of DNA
[inside the pore] and the better are our chances for reading the
sequence of DNA nucleotides - the genetic code - of the
molecules."  According to Aksimentiev, computer simulations
suggested that applying a strong electric field would enable the
researchers to push double-stranded DNA through a pore smaller
than the diameter of the DNA molecules in solution. The team
found that this was indeed the case - they forced double-
stranded DNA through pores with a diameter of less than 2.5 nm.
It appeared that the electric field was able to stretch out the
DNA molecules, making them thinner.  The scientists carried out
their tests in a membrane transport bicell with two
compartments, each containing potassium-chlorid