From microfluidics to nanofluidics: DNA separation using nanofluidic entropic trap array device

Fluidic devices with sub-micrometer dimensions provide new opportunities in manipulation and analysis of various biomolecules, such as deoxyribonucleic acid (DNA). As an example of such devices, a microchannel with an array of `entropic traps' is introduced. The existence of sub-100 nm constriction causes long double-stranded DNA molecules to be entropically trapped, and the length-dependent escape of DNA from the trap enables a band separation of DNA. Entropic traps are also used to manipulate and collect many DNA molecules into a narrow, well-defined initial band for electrophoresis launching. In addition to its speed and compactness, another important advantage of this artificial separation device over conventional gel electrophoresis is the ability to modify and control the device precisely for the optimization of a separation process. The similar device could be used to analyze proteins or other biopolymers.