(319c) Dynamic Binding in a Tethered-Particle Study of DNA Hybridization

The tethered-particle method is used to probe the complex process of DNA hybridization. This experiment analyzes tethers formed between PEGylated polystyrene microspheres and PEGylated glass surfaces, to which DNA strands have been grafted. This experiment is performed near the duplex melting temperature, resulting in dynamic binding and unbinding. Single molecular tethers are analyzed using high performance particle tracking with a high-speed CMOS camera. The results of our experimental study are compared with simple Monte Carlo simulations of the tether complex. We seek to understand the transient adhesion and rolling behavior of the DNA tethered microspheres. Lastly, we probe cooperativity using the motion of particles in multiply-tethered states.