In this paper, we report a factor of 3 improvement in the resolution and a factor of 10 improvement in the speed of fractionation of ∼100-kb DNA molecules in Brownian ratchet arrays. In our device, the electrophoretic flow is tilted at a small angle relative to the array axis. Tilting accelerates the fractionation speed because a higher fraction of the diffusing molecules is "ratcheted" at each step in the array. Molecules of lengths 48.5 and 164 kb can be separated in ∼70 min with a resolution of ∼3.8, using a 12-mm-long array. The Brownian ratchet arrays are not limited to DNA separation, but can, in principle, be used for any particle in this size range.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry