When a DNA molecule travels through a nanopore in a salty water solution, its genetic sequence can be determined or the location of bound proteins can be mapped via the electrical ionic current signature. Understanding and ultimately controlling the motion of individual DNA molecules is key to the precision of these measurements. Knowing this, Lucas and members of the Tabard-Cossa Lab explored the fundamental aspects of how DNA molecules approach the nanopore and how their conformation changes as they thread through the nanopore. They used salt asymmetry—the practice of making the ionic concentrations unequal on either side of the membrane—to independently modulate the various forces that affect polymer capture and translocation. In doing so, they experimentally confirmed several predictions of tension propagation theory, and emphasized the importance of the electric field gradient outside the nanopore. A manuscript, in which Lucas is co-first author, is currently in preparation. In addition, Lucas presented this research at the Canadian Association of Physicists’ Best Student Presentation competition. His presentation on “Kinetics of Capture and Translocation in Salt Asymmetry” earned him second place in the division of Physics in Medicine and Biology.
Lucas is immensely grateful to PhD student Martin Charron, with whom he worked closely throughout his research project. Lucas says, “Martin is a kind mentor who thinks carefully about the physics at hand. It was a pleasure to interact with him on a daily basis.” He would also like to thank Dr. Kyle Briggs, a postdoctoral fellow in the Tabard-Cossa lab, for his guidance as an experienced researcher and for training him in the fabrication of nanopores. Finally, Lucas is very grateful for the opportunity Prof. Tabard-Cossa gave him to work in his lab on a such as fascinating topic, where fundamental discoveries can find rapid practical applications.
Lucas shares with other students, “ask yourself why you want to be a researcher, and understand what will motivate you to keep going when nothing is going your way. Find that fuel that keeps you relentlessly curious and nurture it, whatever it may be.”
