Cornell University researchers have devised a new tool to study epigenetic changes in DNA that can cause cancer and other diseases: a nanoscale fluidic device that sorts and collects DNA one molecule at a time.
The new device was developed in the lab of Harold Craighead, the Charles W. Lake Jr. Professor of Engineering, The device works by pushing a mix of DNA molecules through a nanofluidic channel. Molecules tagged with a fluorescent tag trigger an electric field that diverts them to one side. A biochemical reaction attaches a fluorescent tag to methylated DNA molecules. The sample is then driven through a nanofluidic channel about 250 nanometers across -- small enough that DNA molecules go through one at a time. Lasers illuminate the stream and cause fluorescence. When a fluorescing molecule goes by, a detector triggers a pulsed electric field that pushes the molecule to one side just before the channel splits into a Y. Methylated molecules go down one branch, everything else down the other.
The device is detailed in the May 21 early online edition of the Proceedings of the National Academy of Sciences.