(365c) DNA Electrophoresis In a Nanofence Array

We will present separation data obtained in a new post array geometry for long DNA electrophoresis that we call the “nanofence” array. Previous post array devices used relatively dense arrays of posts, with typical pore spaces of 0.5 to 5 microns. The nanofence device consists of periodic regions of closely spaced posts (600 nm diameter and 600 nm gap size, arranged in two offset rows), which are the fences. They are separated by a relatively long distance of 20 microns to allow relaxation of the DNA between fences. The idea is to force the DNA to collide with a nanopost in order to pass through the fence. The distance between the collisions then becomes deterministic, and the band broadening only arises due to variations in the holdup time at a fence. We fabricated the device using a combination of projection lithography and deep reactive ion etching. To demonstrate the principle of the separation, we used λ-DNA and its XhoI digest. These species were baseline resolved after a few minutes with a significant reduction in band broadening.