Colloquium: Leilei Peng

    Thursday, March 30, 2017 - 3:30pm - 5:00pm
    Meinel 307

    3D superresolution imaging with full-field structured stimulated emission depletion


    Fluorescence microscopy has long been an essential tool for studying cell structure and function. Various superresolution microscopy methods, which offer resolution surpasses the diffraction limit of resolution, have become faster and safer for live imaging. Nonlinear Structured-Illumination Microscopy (NSIM) refers to a group of full-field superresolution imaging methods that operate under the principle of NSIM, which predicts any non-polynomial effect on either the fluorophore or fluorescence emission can be the vehicle to achieve unlimited resolution. We developed a new nonlinear structured illumination (NSIM) microscopy method that utilizes a weak full-field structured stimulated emission depletion (STED) effect to perform 3D superresolution imaging under epi-fluorescence excitation. Despite the weak nonlinear effect, STED NSIM demonstrated superior resolution, 3D imaging applicability, and robust performance (ranging from single molecules to dense structures). Experimentally, the STED NSIM microscope reached a lateral resolution of 53 nm at a far-red wavelength, which is further away from the diffraction limit that previous NSIM records, and demonstrated super z-section imaging of cytoskeletal structures under the epi-fluorescence excitation. Results further demonstrated STED NSIM can truthfully image single molecules at full resolution, and produce artifact-free images of a variety of structures ranging from single molecules to dense 3D cellular structures under identical experimental settings. Due to it compatibility with commonly used fluorophores and low light intensity, STED NSIM can be a powerful tool for multi-color 3D imaging of biological samples beyond the diffraction limit.

    Speaker Bio(s): 

    Dr. Peng's research interest is inventing and building new fluorescence imaging tools for biomedical research. Her current research interests include:

    1.Developing novel superresolution microscopy method for live wide-field imaging on membrane resident or near membrane structure, and

    2.Developing high-resolution multi-color fluorescence lifetime imaging method in deep tissue for live imaging of complex protein interactions at cellular level in whole organisms.

    Dr. Peng's group has the full research ability of conceiving new imaging techniques, building instruments, and applying new techniques to collaborative biological studies. They maintain close collaborations with multiple research groups in system biology, developmental biology and genetics. Through these collaborations, they are applying our unique advanced imaging techniques to fundamental questions remaining in the biomedical research field and cancer research.