Dynamic SIMS ion microscopy imaging of individual bacterial cells for studies of isotopically labeled molecules
Dynamic SIMS ion microscopy imaging of individual bacterial cells for studies of isotopically labeled molecules
复制标题
DOI：
10.1016/j.apsusc.2008.05.129
复制
发表时间：
2008-12-15
影响因子：
6.7
通讯作者：
Madsen, Eugene L.
中科院分区：
文献类型：
--
作者：
Chandra, Subhash;Pumphrey, Graham;Madsen, Eugene L.
使用具有 500 nm 空间分辨率的 CAMECA IMS-3f SIMS 离子显微镜仪器对在所需处理中用 C-13 标记的苯酚处理的土壤中的单个细菌细胞进行成像。甲醛固定后，将含有细菌细胞的土壤样品涂抹在硅基底上。 O-2(+)一次离子束用于检测负二次离子。 CCD 相机以质量 24、25、26 和 27 信号记录单个细菌细胞的图像。相应的质量图像代表来自感兴趣的分子离子的贡献，例如 (24)(C-12(2)) 、 (25)((CC)-C-13-C-12) 、 (26)((CN)-C-12-N-14) 、 (27)((CN)-C-13-N-14) 以及与特定质量相关的干扰质量种类。然而，在用C-13标记的苯酚处理的细胞中，与仅用未标记的苯酚处理的样品直接比较，质量25和27图像中的信号分别由于(25)((CC)-C-13-C-12)和(27)((CN)-C-13-N-14)的信号增加而增强，明确表明细菌细胞中存在C-13标记的苯酚。单个细胞的质量 25/24 和 27/26 的比率图像揭示了 C-13-苯酚标记的细胞间异质性。这项研究表明离子显微镜可以有效地应用于微生物学和生物地球化学中标记分子的研究。 (c) 2008 Elsevier B.V. 保留所有权利。
A CAMECA IMS-3f SIMS ion microscope instrument capable of 500 nm spatial resolution was used for imaging single bacterial cells in the soil treated with C-13-labeled phenol in desired treatments. After formaldehyde fixation, the soil samples containing bacterial cells were smeared on the silicon substrate. The O-2(+) primary ion beam was used for the detection of negative secondary ions. Images of individual bacterial cells were recorded on a CCD camera in masses 24, 25, 26, and 27 signals. The respective mass images represented contributions from the molecular ions of interest, for example (24)(C-12(2)) , (25)((CC)-C-13-C-12) , (26)((CN)-C-12-N-14) , (27)((CN)-C-13-N-14) , as well as interfering mass species associated with a particular mass. However, in cells treated with C-13-labeled phenol the enhancement of signals in masses 25 and 27 images due to increased signals of (25)((CC)-C-13-C-12) and (27)((CN)-C-13-N-14) , respectively, unequivocally indicated the presence of C-13-labeled phenol in bacterial cells in direct comparison to the samples treated only with unlabeled phenol. The ratio images of masses 25/24 and 27/26 from individual cells revealed a cell-to-cell heterogeneity in the labeling with C-13-phenol. This study indicates that the ion microscope can be applied effectively for studies of labeled molecules in microbiology and biogeochemistry. (c) 2008 Elsevier B.V. All rights reserved.