Nanofluidic Device for Manipulation and Modification of DNA by Proteins

Single-molecule techniques provide important details supplementing the framework obtained from traditional bulk experiments. Many cellular processes such as DNA replication, DNA repair, and telomere maintenance involve interaction among multiple proteins, their co-factors, and DNA. To investigate such interactions and to differentiate the function of each component necessitate a technique that allows the combinatorial exposure of DNA to multiple proteins and co-factors as well as manipulation of the DNA configuration. We present a nanofluidic device with the capability of active combinatorial exchange of up to three buffers in real-time and dynamic manipulation of DNA under physiologically relevant conditions. We demonstrate its utility in monitoring compaction of DNA by telomeric proteins, DNA modification by an endonuclease, and DNA loop extrusion by cohesin.