Determination of quantitative distributions of heavy-metal stain in biological specimens by annular dark-field STEM
Determination of quantitative distributions of heavy-metal stain in biological specimens by annular dark-field STEM
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DOI：
10.1016/j.jsb.2008.01.007
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发表时间：
2008-04-01
影响因子：
3
通讯作者：
Leapman, R. D.
中科院分区：
文献类型：
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作者：
Sousa, A. A.;Hohmann-Marriott, M.;Leapman, R. D.
研究表明，在扫描透射电子显微镜（STEM）中以两种不同相机长度采集的暗场图像可得出染色生物样本中重原子和轻原子的定量分布。对成对的STEM图像进行定量分析需要了解弹性散射截面，这是根据美国国家标准与技术研究院（NIST）弹性散射截面数据库计算得出的。研究结果揭示了生物基质内固定剂和染色剂分布的定量信息，并为评估用于标记细胞内蛋白质的重金属簇的检测限提供了依据。在仅用四氧化锇染色的切片细胞中，我们发现平均每立方纳米有1.2±0.1个锇原子，对应锇原子与碳原子的原子比约为0.02，这表明在轻度染色的样本中可以检测到十一金和纳米金的小重原子簇。由爱思唯尔公司出版。
It is shown that dark-field images collected in the scanning transmission electron microscope (STEM) at two different camera lengths yield quantitative distributions of both the heavy and light atoms in a stained biological specimen. Quantitative analysis of the paired STEM images requires knowledge of the elastic scattering cross sections, which are calculated from the NIST elastic scattering cross section database. The results reveal quantitative information about the distribution of fixative and stain within the biological matrix, and provide a basis for assessing detection limits for heavy-metal clusters used to label intracellular proteins. In sectioned cells that have been stained only with osmium tetroxide, we find an average of 1.2 +/- 0.1 Os atom per nm(3), corresponding to an atomic ratio of Os:C atoms of approximately 0.02, which indicates that small heavy atom clusters of Undecagold and Nanogold can be detected in lightly stained specimens. Published by Elsevier Inc.