Flow Behavior Characterization of DNA Molecules in Passive Nanofluidic Devices

This work aims to develop a method for analyzing the dynamic flow of single DNA molecules through nanochannels in fluidic chip which work passively. For this purpose, a two-laser system was used, which is coupled into a fluorescence microscope and can detect labeled DNA molecules using a single photon counter for signal read-out in real time. The two laser spots are focused at different points of the nanochannel, and can be used to obtain the speed and molecular extension of the DNA. For example, a velocity of 1.82 µm/ms and a spatial extension of 0.9 µm were determined for pUC18/19 DNA (2686 bp) in a nanochannel with a width and depth of 200 nm x 100 nm and a length of 10 µm.