N ational Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973,USA.
Department of Chemistry, Stony Brook University, Stony Brook, NY 11794,USA.
Metallomics. 2022 Dec 8;14(12). doi: 10.1093/mtomcs/mfac093.
X-ray fluorescence microscopy (XFM) has become a widely used technique for imaging the concentration and distribution of metal ions in cells and tissues. Recent advances in synchrotron sources, optics, and detectors have improved the spatial resolution of the technique to <10 nm with attogram detection sensitivity. However, to make XFM most beneficial for bioimaging-especially at the nanoscale-the metal ion distribution must be visualized within the subcellular context of the cell. Over the years, a number of approaches have been taken to develop X-ray-sensitive tags that permit the visualization of specific organelles or proteins using XFM. In this review, we examine the types of X-ray fluorophore used, including nanomaterials and metal ions, and the approaches used to incorporate the metal into their target binding site via antibodies, genetically encoded metal-binding peptides, affinity labeling, or cell-specific peptides. We evaluate their advantages and disadvantages, review the scientific findings, and discuss the needs for future development.
X 射线荧光显微镜（XFM）已成为一种广泛用于成像细胞和组织中金属离子浓度和分布的技术。近年来，同步加速器源、光学和探测器的进步将该技术的空间分辨率提高到了 <10nm，并具有 attogram 检测灵敏度。然而，为了使 XFM 最有益于生物成像——特别是在纳米尺度——必须在细胞的亚细胞环境中可视化金属离子分布。多年来，人们已经采取了多种方法来开发 X 射线敏感染料，这些染料可使用 XFM 对特定细胞器或蛋白质进行可视化。在这篇综述中，我们检查了所使用的 X 射线荧光团的类型，包括纳米材料和金属离子，以及通过抗体、基因编码的金属结合肽、亲和标记或细胞特异性肽将金属掺入其靶结合位点的方法。我们评估了它们的优缺点，回顾了科学发现，并讨论了未来发展的需求。
