Optical Investigation of DNA Behaviour in Flow using Confocal Detection Incorporated with Fluorescence Correlation Spectroscopy (FCS)

Investigation of the behavior of biopolymers in flow such as Deoxyribonucleic acid (DNA), is a critical challenge in engineering, polymer, and life sciences. In this study, we studied the rheological properties of DNA and flow characteristics in real-time. The velocity measurement was carried out using confocal detection incorporated with Fluorescence Correlation Spectroscopy (FCS). Optical experiments provided an understanding of the diffusion- and flow-dominated regimes for molecules treated in microfluidic channels and lab-on-chip devices in general. We found that the flow-dominated regime starts at a flow rate of 0.3 µl/min and the transitional regime falls into 0.02-0.3 µl/min flow rates. There are a few examples for the detection of DNA and different fragments in flow as such. It is therefore believed to provide valuable insights into the subject of flow dynamics of DNA.