Single molecule measurements of DNA transport through a nanopore.
We examined the voltage-driven movement of single-stranded DNA molecules in a membrane channel or "nanopore". Using single channel recording methods and a statistical analysis of many single molecule events, we determined how voltage influences capture and translocation in the nanopore. We verified that the mean time between capture events follows a simple exponential distribution, whereas the translocation times follow a unique distribution that is partly Gaussian and partly exponential. Measurements of polymer sequence effects demonstrated that translocation duration is heavily influenced by specific or nonspecific purine-channel interactions. The single molecule approach we used revealed molecular interactions that can influence both capture rates and translocation velocities in a manner that enriches naive barrier crossing models.
Meller
Amit
A
The Rowland Institute for Science at Harvard, 100 Edwin H. Land Boulkevard, Cambridge, MA 02142, USA. meller@rowland.org.
Branton
Daniel
D
D004277:DNA, Single-Stranded / Q000378:metabolism*; D004553:Electric Conductivity; D007700:Kinetics; D008567:Membranes, Artificial; D008956:Models, Chemical; D015233:Models, Statistical; D036103:Nanotechnology; D010539:Permeability; D016062:Porosity
D004277:DNA, Single-Stranded; D008567:Membranes, Artificial