Ultrahigh-speed scattering-based interference laser microscopy for nanoscale bioimaging
Chia-Lung Hsieh1*
1IAMS, Academia Sinica, Taipei, Taiwan
* Presenter:Chia-Lung Hsieh, email:clh@gate.sinica.edu.tw
Modern optical bioimaging techniques have primarily relied on fluorescence because of its excellent contrast and sensitivity. Unfortunately, in fluorescence-based microscopy, the spatial and temporal resolutions are strictly limited by the photophysics and photochemistry of fluorophores (e.g., photobleaching, blinking, and saturation). Without a suitable tool, many important biological events at the nanoscale remain unexplored. In this talk, I will introduce scattering-based interference laser microscopy and its application to bioimaging. The scattering signal is stable and indefinite, ideal for high-speed, high-precision, and long-term measurements. In addition, by detecting the intrinsic scattering of biological entities, scattering-based approaches can observe biological events in their most native forms without any label. I will explain the advantages of interferometric detection in detecting weakly scattering bio-nanoparticles. The strategy of removing nonspecific scattering background will also be discussed. Then I will showcase our recent results of label-free imaging and 3D tracking of biological nanoparticles, including virus particles and cell vesicles, in live cells with nanometer spatial localization precision at an ultrahigh speed of 100,000 frames per second. The interference microscopy also allows us to measure dynamics of very small metallic nanoparticles (as small as 10 nm) which can be used as probes for high-resolution single-molecule studies.

[1] Huang YF, Zhuo GY, Chou CY, Lin CH, Chang W, Hsieh CL, “Coherent brightfield microscopy provides the spatiotemporal resolution to study early stage viral infection in live cells,” ACS Nano, 11(3), pp. 2575-2585 (2017).
[2] Huang YF, Zhuo GY, Chou CY, Lin CH, Hsieh CL, “Label-free, ultrahigh-speed, 3D observation of bidirectional and correlated intracellular cargo transport by coherent brightfield microscopy,” Nanoscale, 9, pp. 6567-6574 (2017).
[3] Cheng CY, Hsieh CL, “Background estimation and correction for high-precision localization microscopy,” ACS Photonics, 4(7), pp. 1730-1739 (2017).
[4] Hsieh CL, “Label-free, ultrasensitive, ultrahigh-speed scattering-based interferometric imaging,” Optics Communications, 422, pp. 69-74 (2018).

Keywords: Bioimaging, Microscopy, Interference, Scattering, High-speed