Ratcheting charged polymers through symmetric nanopores using pulsed fields: Designing a low pass filter for concentrating DNA

Abstract

When nanopores are used to capture and translocate DNA molecules through a membrane, the resulting capture rate is essentially independent of molecular size, which makes the process incapable of changing relative concentrations in a mixture. Using Langevin Dynamics simulations, we show that it is possible to design pulsed fields to ratchet captured semiflexible molecules in such a way that only short chains successfully translocate, effectively transforming the nanopore process into a low pass molecular filter. The process itself can be run with many pores in parallel, thus increasing its potential usefulness.