Over the last decades, super-resolution techniques have revolutionized the field of fluorescence microscopy. Among them, interferometric or 4Pi microscopy methods exhibit supreme resolving power in the axial dimension. Combined with single-molecule detection/localization and adaptive optics, current 4Pi microscopy methods enabled 10-15 nm isotropic 3D resolution throughout whole cells. In the first part of this talk, I will give a brief review of major super-resolution techniques. In the second part of the talk, I will present the concept and unique features of the 4Pi single-molecule localization microscopy (4Pi-SMLM) and demonstrate its resolving power on nuclear pore complexes. Finally, I will explain the localization algorithms for 4Pi-SMLM data, due to the complexity of interferometric point spread functions (PSF), it is challenging to extract the position information from the PSF patterns. I will explain both state-of-the-art methods and the recent developments in PSF fitting.

Biography:

Sheng Liu is a Postdoctoral Researcher at European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.  She received her BS degree in Optical Information Science and Technology in 2009 from Beijing Jiaotong University, China. She then joined Professor Keith Lidke’s lab at the University of New Mexico in 2010 as a PhD student and started her journey in the field of super-resolution microscopy. She received her PhD degree in Optical Science and Engineering in 2014. Her PhD thesis work was focused on the development of a phase retrieval algorithm for 3D single-molecule localization microscopy (SMLM). She joined Dr. Fang Huang’s lab at Purdue University in 2015 as a Postdoctoral Researcher and worked on the instrument and algorithm development of a 4Pi-SMLM system. She then joined Dr. Jonas Ries’ Lab at EMBL Heidelberg in 2020 as a Postdoctoral Researcher and works on further development of the 4Pi-SMLM system and a commercial MINFLUX system. To date, Dr. Liu has authored in 13 publications.