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arXiv · 2507.06718

Three-Dimensional Isotropic STED Nanoscopy using a Single Objective

Renlong Zhang·Xiaoyu Weng·Haoxian Zhou·Luwei Wang·Fangrui Lin·Wei Yan·Xiumin Gao·Bin Yu·Danying Lin·Liwei Liu·Chenshuang Zhang·Kayla K. Green·Ewoud R. E. Schmidt·Songlin Zhuang·Junle Qu
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Abstract

Accurate three-dimensional (3D) imaging requires an isotropic point spread function (PSF). However, the inherent missing aperture of a single objective lens results in an elongated, cigar-like PSF, which has rendered isotropic resolution in fluorescence microscopy seemingly insurmountable without a 4π configuration for decades. To address this long-standing challenge, we introduce ISO-STED (Isotropic Single-Objective STED) Nanoscopy, a novel approach that employs a single objective lens and a single depletion beam. By utilizing a hollow depletion focus, ISO-STED achieves an isotropic PSF without relying on a 4π configuration. This innovative design enables uniform fluorescence suppression in all directions, thereby yielding an isotropic 3D resolution of approximately 70 nm. Our work not only demonstrates the potential of ISO-STED Nanoscopy to provide a compact and versatile solution for isotropic 3D imaging in complex specimens but also paves the way for more accessible and practical applications in various research fields, including biomedical research and neuroscience.

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Renlong Zhang, Xiaoyu Weng, Haoxian Zhou, Luwei Wang, Fangrui Lin, Wei Yan, Xiumin Gao, Bin Yu, Danying Lin, Liwei Liu, Chenshuang Zhang, Kayla K. Green, Ewoud R. E. Schmidt, Songlin Zhuang, Junle Qu. 2025-07-09. Three-Dimensional Isotropic STED Nanoscopy using a Single Objective. https://arxiv.org/abs/2507.06718

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