Technische Universität Berlin, Institut für Optik und Atomare Physik, Hardenbergstraße 36, Berlin10623, Germany.
Berlin Laboratory for Innovative X-ray technologies (BLiX), Hardenbergstraße 36, Berlin10623, Germany.
Microsc Microanal. 2020 Dec;26(6):1124-1132. doi: 10.1017/S1431927620024447.
Laboratory transmission soft X-ray microscopy (L-TXM) has emerged as a complementary tool to synchrotron-based TXM and high-resolution biomedical 3D imaging in general in recent years. However, two major operational challenges in L-TXM still need to be addressed: a small field of view and a potentially misaligned rotation stage. As it is not possible to alter the magnification during operation, the field of view in L-TXM is usually limited to a few tens of micrometers. This complicates locating areas and objects of interest in the sample. Additionally, if the rotation axis of the sample stage cannot be adjusted prior to the experiments, an efficient workflow for tomographic imaging cannot be established, as refocusing and sample repositioning will become necessary after each recorded projection. Both these limitations have been overcome with the integration of a visible-light microscope (VLM) into the L-TXM system. Here, we describe the calibration procedure of the goniometer sample stage and the integrated VLM and present the resulting 3D imaging of a test sample. In addition, utilizing this newly integrated VLM, the extracellular matrix of cryofixed THP-1 cells (human acute monocytic leukemia cells) was visualized by L-TXM for the first time in the context of an ongoing biomedical research project.
近年来，实验室传输软 X 射线显微镜（L-TXM）已成为与基于同步加速器的 TXM 和高分辨率生物医学 3D 成像互补的工具。然而，L-TXM 仍然存在两个主要的操作挑战：视场小和旋转台可能未对准。由于在操作过程中无法改变放大倍率，因此 L-TXM 的视场通常限于几十微米。这使得在样品中定位感兴趣的区域和物体变得复杂。此外，如果在实验前无法调整样品台的旋转轴，则无法建立用于层析成像的有效工作流程，因为每次记录投影后都需要重新聚焦和重新定位样品。通过将可见光显微镜（VLM）集成到 L-TXM 系统中，可以克服这两个限制。在这里，我们描述了测角台样品台的校准程序以及集成的 VLM，并展示了测试样品的最终 3D 成像结果。此外，利用这个新集成的 VLM，首次在一个正在进行的生物医学研究项目中，通过 L-TXM 可视化了冷冻固定的 THP-1 细胞（人急性单核细胞白血病细胞）的细胞外基质。
