Soft Matter Seminar: Seongjin Park

Prof. Seongjin Park, Department of Physics, Syracuse University

“Super-resolution imaging, Singe Particle Tracking and DNA Sequencing”

Research interests: Single Molecule Localization Microscopy (SMLM), Single Particle Tracking (SPT), Two-photon microscopy, microfluidics

Abstract: Until the past decade, the diffraction barrier limited the resolution to be ~200 nm in light microscopy. Super-resolution microscopy technique has emerged breaking the barrier, allowing access to nanometer scale information. With a statistical analysis, super-resolved images can provide countable observables such as RNA copy numbers in a single cell. Moreover, with the advancement of fast cameras, the technique can be applied to highly dynamic systems such as diffusing molecules in live cells, providing ~400 Hz of tracking in nanometer scale. Mean squared displacement (MSD) calculation of tracking data provides diffusion coefficients and extraction of different populations of the molecule of interest, leading to new discoveries in previously inaccessible systems. One example is Hfq, an RNA-binding protein in bacterial cells. How the limited number of Hfq proteins per cell can be efficiently recycled to provide post-transcriptional gene regulation was investigated by observing its interactions with RNAs and the ribosome. The technique has many potential applications in various systems not only in academia but beyond, such as in the DNA sequencing industry. How various optical techniques are used in DNA sequencing will also be discussed.