IAMS Lecture Announcement
中研院原分所演講公告

Title: Learning cell biology with new tools: ultrahigh-speed non-fluorescence optical microscopy, nanoparticles, image processing, and biomimetic membranes
Speaker: Dr. Chia-Lung Hsieh (IAMS, Academia Sinica) 

               謝佳龍博士 (本所助研究員)

Time: 3:30 PM, July 11 (Thursday), 2019
Place: Dr. Poe Lecture Hall, IAMS (本所浦大邦講堂　臺大校園內)

Contact: Dr. Kuei-Hsien Chen 陳貴賢所長

Abstract

The biological cell is a complex system. Through biochemical and molecular biology approaches, key molecules and their pathways in many biological processes have been identified. Protein structures have been resolved at high resolution by nuclear magnetic resonance, X-ray crystallography and cryo-electron microscopy. To learn the spatial distribution and migration of these important molecules in the living systems, fluorescence microscopy has been commonly employed. Although a lot have been learned by using the aforementioned techniques, little is known about how biological events are accomplished at the molecular scale where the functional interactions take place. Biomolecules are small in size and they move constantly in the living systems driven by thermal fluctuation. The main challenge is to measure the motion and interaction of molecules at high spatial and temporal resolutions simultaneously (nanometer length scales and microsecond timescales). Fluorescence-based approaches fail to fulfill such extreme requirements due to the fundamental photophysics and photochemistry of the fluorophores (i.e., the effects of photobleaching and saturation).

Our group has taken a different strategy for studying cell biology at the nanoscale. We choose to detect linear scattering light of the sample through interference. Linear scattering is arguably the simplest form of light-matter interaction, and the scattering signal is stable and indefinite, potentially suitable for high-speed and high-precision measurements. In this talk, I will explain the concepts of interferometric detection of linear scattering signal and the resulting advantages in bioimaging. I will show the image processing algorithms we have developed for background removal. A few examples of nanoscopic cell dynamics that were discovered by our methods in a label-free manner will be presented, including the early-stage viral infection and intracellular active transportation of cell vesicles. I will then describe the use of nanoparticles as labels for studying single-molecule dynamics in live cells and biomimetic membranes. Combining this new set of tools, we are at a unique position to explore cell biology at the molecular scales with unprecedented clarity.