Electron spectroscopic imaging of chromatin
Electron spectroscopic imaging of chromatin
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DOI：
10.1006/meth.1998.0729
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发表时间：
1999-02-01
期刊：
影响因子：
--
通讯作者：
Hendzel, MJ
中科院分区：
文献类型：
--
作者：
Bazett-Jones, DP;Hendzel, MJ
被称为电子光谱成像(ESI)的分析电子显微镜技术在DNA：蛋白质复合体的研究中有许多应用。该方法为可能太大或太多而无法用结晶学或磁共振光谱学研究的络合物的体外结构研究提供了中等水平的空间分辨率。ESI的一个优点是，可以通过绘制元素磷的图谱来确定核酸在核蛋白复合体中的分布，与蛋白质相比，磷在核酸中的含量较高。磷含量的测量与质量测定相结合，可以估计这些复合体中蛋白质和核酸的化学计量关系。ESI也适用于核结构的原位研究。结合氮和磷地图的质量敏感图像可以用来区分核酸成分和主要以蛋白质为基础的核结构。用这种技术可以研究染色质间颗粒簇(IGC)外围的染色质与连接IGC外部及其核心的蛋白质亚结构之间的相互作用。该方法还避免了重原子染色的使用，这是传统电子显微镜所需的试剂，无法根据生化成分区分结构。讨论了电火花成象的原理和方法的技术问题。(C)1999年学术出版社。
The analytical electron microscope technique called electron spectroscopic imaging (ESI) has a number of applications in the study of DNA:protein complexes. The method offers an intermediate level of spatial resolution for in vitro structural studies of complexes that may be too large or heterogeneous to study by crystallography or magnetic resonance spectroscopy. An advantage of ESI is that the distribution of nucleic acids can be resolved in a nucleoprotein complex by mapping the element phosphorus, present at high levels in nucleic acid compared to protein. Measurements of phosphorus content together with mass determination allows estimates to be made of stoichiometric relationships of protein and nucleic acids in these complexes. ESI is also suited to in situ studies of nuclear structure. Mass-sensitive images combined with nitrogen and phosphorus maps can be used to distinguish nucleic acid components from nuclear structures that are predominantly protein based. Interactions between chromatin on the periphery of interchromatin granule clusters (IGC) with the protein substructure that connects the exterior of the IGC to its core can be studied with this technique. The method also avoids the use of heavy atom stains, agents required in conventional electron microscopy, that preclude the distinguishing of structures on the basis of their biochemical composition. The principles of ESI and technical aspects of the method are discussed. (C) 1999 Academic Press.