BACKGROUND Immunogold labeling in combination with transmission electron microscopy analysis is a technique frequently used to correlate high-resolution morphology studies with detailed information regarding localization of specific antigens. Although powerful, the methodology has limitations and it is frequently difficult to acquire a stringent system where unspecific low-affinity interactions are removed prior to analysis. RESULTS We here describe a combinatorial strategy where surface plasmon resonance and immunogold labeling are used followed by a direct analysis of the sensor-chip surface by scanning electron microscopy. Using this approach, we have probed the interaction between amyloid-β fibrils, associated to Alzheimer's disease, and apolipoprotein E, a well-known ligand frequently found co-deposited to the fibrillar form of Aβ in vivo. The results display a lateral binding of ApoE along the amyloid fibrils and illustrates how the gold-beads represent a good reporter of the binding. CONCLUSIONS This approach exposes a technique with generic features which enables both a quantitative and a morphological evaluation of a ligand-receptor based system. The methodology mediates an advantage compared to traditional immunogold labeling since all washing steps can be monitored and where a high stringency can be maintained throughout the experiment.

中文翻译：

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结合表面等离子共振，免疫金标记和扫描电子显微镜对载脂蛋白E与Aβ淀粉样蛋白结合的形态进行分析。

背景技术免疫金标记与透射电子显微镜分析相结合是一种经常用于将高分辨率形态学研究与有关特定抗原定位的详细信息相关联的技术。尽管该方法功能强大，但仍存在局限性，通常很难获得严格的系统，在分析之前先去除非特异性的低亲和力相互作用。结果我们在此描述了一种组合策略，其中使用了表面等离振子共振和免疫金标记，然后通过扫描电子显微镜直接分析传感器芯片的表面。使用这种方法，我们探究了与阿尔茨海默氏病相关的淀粉样β纤维与载脂蛋白E之间的相互作用，常见的一种常见配体是在体内共沉积到Aβ的原纤维形式中。结果显示，ApoE沿淀粉样蛋白原纤维横向结合，并说明金珠如何代表该结合的良好报道分子。结论该方法揭示了一种具有通用特征的技术，该技术能够对基于配体-受体的系统进行定量和形态学评估。与传统的免疫金标记相比，该方法具有优势，因为可以监控所有洗涤步骤，并且在整个实验过程中可以保持高度严格性。结论该方法揭示了一种具有通用特征的技术，该技术能够对基于配体-受体的系统进行定量和形态学评估。与传统的免疫金标记相比，该方法具有优势，因为可以监控所有洗涤步骤，并且在整个实验过程中可以保持高度严格性。结论该方法揭示了一种具有通用特征的技术，该技术能够对基于配体-受体的系统进行定量和形态学评估。与传统的免疫金标记相比，该方法具有优势，因为可以监控所有洗涤步骤，并且在整个实验过程中可以保持高度严格性。