X-ray micro computed-tomography scanner

生物实验室通常配备成像工具，如共聚焦显微镜、逆显微镜、光片显微镜和超分辨率显微镜。虽然所有这些显微镜对于解决生物学问题至关重要，但它们并不能满足对小生物、器官、患者组织和活检样本进行高通量全身成像的需求。自1972年开发以来，x射线计算机断层扫描由于其坚固性和低成本而成为标准的医学成像设备。桌面实验室x射线CT扫描仪的性能从那时起在空间分辨率上有了显著提高，提供了500纳米的分辨率和样品吞吐量（每天几十个样品）。在过去的几年里，x射线计算机断层扫描成为生物和组织的三维结构成像和单细胞分辨率的首选方法。由于高穿透性，样品可以在（人工）物理环境中进行非破坏性观察，如土壤中的植物根或生物材料中的组织。相关方法将通过荧光显微镜观察到的感兴趣的特定蛋白质与x射线提供的结构信息联系起来。此外，最近的分层成像方法表明，x射线断层扫描对于定位电子显微镜和超分辨率显微镜进一步研究的特定区域非常有用，增加了所获得结果的保真度，减少了样品切片的需要以及相关的时间和成本。所要求的x射线微ct扫描仪是一种最先进的仪器，具有高空间分辨率（500纳米），吞吐量（16个探针自动采样），可容纳大型标本的大视场和现有x射线微ct扫描仪中的重建算法。如第3节所述，它一方面将解决比较结构分析的需要，另一方面将改善其他显微镜技术（如光学和电子显微镜）的上游工作流程。

Biological laboratories are routinely equipped with imaging tools such as confocal, inverse, light-sheet, and super-resolution microscopes. While all these microscopes are vital for addressing biological questions, they do not fulfill the need for high throughput whole-body imaging of small organisms, organs, patient’s tissue and biopsy samples. Since its development in 1972, x-ray computed tomography became the standard medical imaging device due to its robustness and low costs. The performance of table-top laboratory x-ray CT scanners has since then significantly improved in spatial resolution, providing 500 nm in resolution and sample throughput (tens of samples per day). Over the last years, x-ray computed tomography became the method of choice for 3-D structural imaging of organisms and tissues and at single cell resolution. Due to high penetration, the samples can be observed non-destructively - within an (artificial) physical environment, like plant roots in soil or tissues within biomaterials. Correlative approaches link specific proteins of interest observed via fluorescence microscopy with structural information provided by x-rays. Furthermore, recent approaches for hierarchical imaging show that x-ray tomography is extremely useful to locate a specific region of interest for further investigation by electron microscopy and super-resolution microscopy, increasing fidelity of the obtained results and reducing the need for sample sectioning and associated time and costs. The requested x-ray microCT scanner is a state-of-the-art instrument with the high spatial resolution (of 500 nm), throughput (automatic sampling of 16 probes), large field of view to accommodate large specimens and reconstruction algorithms among existing x-ray microCT scanners. As described in section 3, it will address the need of comparative structural analysis on one hand, and it will improve the workflow upstream of other microscope techniques such as light and electron microscopy on the other hand.