Combing of Molecules in Microchannels (COMMIC): A Method for Micropatterning and Orienting Stretched Molecules of DNA on a Surface

This paper presents a new method for creating microscopic patterns of stretched and oriented molecules of DNA on a surface. Combing of molecules in microchannels (COMMIC), a process by which molecules are deposited and stretched onto a surface by the passage of an air−water interface, creates these patterns. This approach demonstrates that the direction of stretching of the molecules is always perpendicular to the air−water interface; the shape and motion of this interface serve as an effective local field directing the chains dynamically as they are stretched onto the surface. The geometry of the microchannel directs the placement of the DNA molecules, while the geometry of the air−water interface directs the local orientation and curvature of the molecules. This ability to control both the placement and orientation of chains has implication for the use of COMMIC in genetic analysis and in the bottom-up approach to nanofabrication.