美国陈-扎克伯格生物中心Shalin B. Mehta小组的最新研究开发了渗透率张量成像（PTI）——高分辨率三维（3D）干质量和3D取向的模块化无标记成像技术。相关论文于2024年6月18日发表在《自然-方法学》杂志上。

研究人员开发了一种用于三维测量PT的无标记计算显微技术PT成像（PTI）。PTI利用斜照、偏振敏感检测和体积采样将不可见的PT编码成图像。利用矢量成像模型和多通道逆算法，在假设每个体素单轴对称的情况下，从数据中解码PT。研究展示了各向同性磁珠、各向异性玻璃磁珠、小鼠脑组织、感染细胞和组织学切片的高分辨率PT成像。

在分辨细胞器、细胞和组织的三维方向和对称性方面，PTI优于以往的无标记成像技术，如矢量断层扫描、平片成像和明场成像。研究人员提供开源软件和模块化硬件，促进该方法的推广和应用。

据了解，通过测量生物分子的介电常数张量（PT），可以在没有标签的情况下对生物分子的干质量和取向进行成像，介电常数张量揭示了生物分子如何影响光的相位和偏振。PT应用于三维成像一直具有挑战。

附：英文原文

Title: Permittivity tensor imaging: modular label-free imaging of 3D dry mass and 3D orientation at high resolution

Author: Yeh, Li-Hao, Ivanov, Ivan E., Chandler, Talon, Byrum, Janie R., Chhun, Bryant B., Guo, Syuan-Ming, Foltz, Cameron, Hashemi, Ezzat, Perez-Bermejo, Juan A., Wang, Huijun, Yu, Yanhao, Kazansky, Peter G., Conklin, Bruce R., Han, May H., Mehta, Shalin B.

Issue&Volume: 2024-06-18

Abstract: The dry mass and the orientation of biomolecules can be imaged without a label by measuring their permittivity tensor (PT), which describes how biomolecules affect the phase and polarization of light. Three-dimensional (3D) imaging of PT has been challenging. We present a label-free computational microscopy technique, PT imaging (PTI), for the 3D measurement of PT. PTI encodes the invisible PT into images using oblique illumination, polarization-sensitive detection and volumetric sampling. PT is decoded from the data with a vectorial imaging model and a multi-channel inverse algorithm, assuming uniaxial symmetry in each voxel. We demonstrate high-resolution imaging of PT of isotropic beads, anisotropic glass targets, mouse brain tissue, infected cells and histology slides. PTI outperforms previous label-free imaging techniques such as vector tomography, ptychography and light-field imaging in resolving the 3D orientation and symmetry of organelles, cells and tissue. We provide open-source software and modular hardware to enable the adoption of the method.

DOI: 10.1038/s41592-024-02291-w

Source: https://www.nature.com/articles/s41592-024-02291-w