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Deguchi T, Ries J. Simple and robust 3D MINFLUX excitation with a variable phase plate. LIGHT, SCIENCE & APPLICATIONS 2024; 13:134. [PMID: 38849346 PMCID: PMC11161593 DOI: 10.1038/s41377-024-01487-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 05/06/2024] [Accepted: 05/16/2024] [Indexed: 06/09/2024]
Abstract
MINFLUX has achieved extraordinary resolution in superresolution imaging and single fluorophore tracking. It is based on localizing single fluorophores by rapid probing with a patterned beam that features a local intensity minimum. Current implementations, however, are complex and expensive and are limited in speed and robustness. Here, we show that a combination of an electro-optical modulator with a segmented birefringent element such as a spatial light modulator produces a variable phase plate for which the phase can be scanned on the MHz timescale. Bisected or top-hat phase patterns generate high-contrast compact excitation point-spread functions for MINFLUX localization in the x, y, and z-direction, respectively, which can be scanned across a fluorophore within a microsecond, switched within 60 microseconds and alternated among different excitation wavelengths. We discuss how to compensate for non-optimal performance of the components and present a robust 3D and multi-color MINFLUX excitation module, which we envision as an integral component of a high-performance and cost-effective open-source MINFLUX.
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Affiliation(s)
- Takahiro Deguchi
- European Molecular Biology Laboratory, Cell Biology and Biophysics, Heidelberg, Germany
| | - Jonas Ries
- European Molecular Biology Laboratory, Cell Biology and Biophysics, Heidelberg, Germany.
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria.
- University of Vienna, Center for Molecular Biology, Department of Structural and Computational Biology, Vienna, Austria.
- University of Vienna, Faculty of Physics, Vienna, Austria.
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He C, Zhan Z, Li C, Sun X, Liu Y, Kuang C, Liu X. Effects of optical aberrations on localization of MINFLUX super-resolution microscopy. OPTICS EXPRESS 2022; 30:46849-46860. [PMID: 36558626 DOI: 10.1364/oe.475425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
A novel super-resolution imaging technique based on the minimum photon flux (MINFLUX), can achieve nanometer-scale localization precision and sub-5-nm imaging. However, aberrations can affect the localization performance and degrade the quality of reconstructed images. In this study, we analyze the effects of different low-order aberrations on the MINFLUX system through both theoretical limits and Monte Carlo methods. We report that 1) defocus and spherical aberration have little effect on 2D localization performance, whereas astigmatism and coma have significant negative effects; 2) system aberrations that can be measured in advance cause changes primarily in the magnitude and angular uniformity of localization precision, whereas sample-induced aberrations that cannot be a priori introduce large biases and reduce localization accuracy.
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Barrantes FJ. Fluorescence microscopy imaging of a neurotransmitter receptor and its cell membrane lipid milieu. Front Mol Biosci 2022; 9:1014659. [PMID: 36518846 PMCID: PMC9743973 DOI: 10.3389/fmolb.2022.1014659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/01/2022] [Indexed: 05/02/2024] Open
Abstract
Hampered by the diffraction phenomenon, as expressed in 1873 by Abbe, applications of optical microscopy to image biological structures were for a long time limited to resolutions above the ∼200 nm barrier and restricted to the observation of stained specimens. The introduction of fluorescence was a game changer, and since its inception it became the gold standard technique in biological microscopy. The plasma membrane is a tenuous envelope of 4 nm-10 nm in thickness surrounding the cell. Because of its highly versatile spectroscopic properties and availability of suitable instrumentation, fluorescence techniques epitomize the current approach to study this delicate structure and its molecular constituents. The wide spectral range covered by fluorescence, intimately linked to the availability of appropriate intrinsic and extrinsic probes, provides the ability to dissect membrane constituents at the molecular scale in the spatial domain. In addition, the time resolution capabilities of fluorescence methods provide complementary high precision for studying the behavior of membrane molecules in the time domain. This review illustrates the value of various fluorescence techniques to extract information on the topography and motion of plasma membrane receptors. To this end I resort to a paradigmatic membrane-bound neurotransmitter receptor, the nicotinic acetylcholine receptor (nAChR). The structural and dynamic picture emerging from studies of this prototypic pentameric ligand-gated ion channel can be extrapolated not only to other members of this superfamily of ion channels but to other membrane-bound proteins. I also briefly discuss the various emerging techniques in the field of biomembrane labeling with new organic chemistry strategies oriented to applications in fluorescence nanoscopy, the form of fluorescence microscopy that is expanding the depth and scope of interrogation of membrane-associated phenomena.
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Affiliation(s)
- Francisco J. Barrantes
- Biomedical Research Institute (BIOMED), Catholic University of Argentina (UCA)–National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
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Xu X, Jia S, Xi P. Raster-scanning Donut simplifies MINFLUX and provides alternative implement on other scanning-based microscopes. LIGHT, SCIENCE & APPLICATIONS 2022; 11:293. [PMID: 36216797 PMCID: PMC9550861 DOI: 10.1038/s41377-022-00983-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A donut excitation moves around a single molecule with a zigzag configuration lattice by lattice. Such a method implemented in scanning fluorescence microscopy simplifies the conventional MINFLUX process. Consisting of hollow zero-intensity excitation, single-pixel detection, time-correlated single photon counting, and drift stabilization, the system achieves localization precision and resolution very close to conventional MINFLUX theoretically and experimentally. An averaged high-SNR reference, and pixel-registered intensity from a single molecule is essential to reconstruct localization in maximum likelihood estimation. With performance reaching nearly conventional MINFLUX's, the proposed raster-scanning MINFLUX can inspire researchers expertized in STED or confocal setup to quickly transform to MINFLUX and develop for further exploring on bio-specimens or optical applications.
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Affiliation(s)
- Xinzhu Xu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332, USA
- UTS-SUStech Joint Research Centre for Bio-medical Materials & Devices, Department of Biomedical Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Shu Jia
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332, USA
| | - Peng Xi
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China.
- UTS-SUStech Joint Research Centre for Bio-medical Materials & Devices, Department of Biomedical Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.
- National Biomedical Imaging Center, Peking University, Beijing, 100871, China.
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