Stain density is an important parameter for optimising the quality of ultrastructural data obtained from several types of 3D electron microscopy techniques, including serial block‐face electron microscopy (SBEM), and focused ion beam scanning electron microscopy (FIB‐SEM). Here, we show how some straightforward measurements in the TEM can be used to determine the stain density based on a simple expression that we derive. Numbers of stain atoms per unit volume are determined from the measured ratio of the bright‐field intensities from regions of the specimen that contain both pure embedding material and the embedded biological structures of interest. The determination only requires knowledge of the section thickness, which can either be estimated from the microtome setting, or from low‐dose electron tomography, and the elastic scattering cross section for the heavy atoms used to stain the specimen. The method is tested on specimens of embedded blood platelets, brain tissue and liver tissue.

中文翻译：

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估计常规制备的生物标本的电子显微镜染色密度的定量方法

染色密度是优化从多种 3D 电子显微镜技术获得的超微结构数据质量的重要参数，包括串行块面电子显微镜 (SBEM) 和聚焦离子束扫描电子显微镜 (FIB-SEM)。在这里，我们展示了如何使用 TEM 中的一些直接测量值来确定基于我们推导出的简单表达式的染色密度。每单位体积的染色原子数是根据从包含纯包埋材料和嵌入的感兴趣的生物结构的样本区域测量的明场强度比来确定的。确定只需要知道切片厚度，可以从切片机设置或低剂量电子断层扫描中估计，以及用于染色样品的重原子的弹性散射截面。该方法在嵌入的血小板、脑组织和肝组织的标本上进行了测试。