Spiess M, Bächi T
Institute of Immunology and Virology, University of Zürich, Switzerland.
Histochemistry. 1992 Aug;98(1):13-7. doi: 10.1007/BF00716933.
Video-enhanced microscopy allows the detection and tracking of individual colloidal gold particles. The analysis of immunogold reactions can also be conducted as a function of time and thus allows the study of dynamic events in living cells. The direct visualization in real time is reported of the reaction of immunogold particles with a surface antigen. This time-resolved immunocytochemistry was achieved by continuous observation of living cells infected with a virus (respiratory syncytial virus) following their incubation with colloidal gold (30 nm) coated with antiviral antibodies. The progress of the immunoreaction was visualized as a sequential deposition of individual gold granules on the viral particles until saturation was reached after 60 min. Binding of colloidal gold was an irreversible event as no elution or dislocation of surface-bound granules took place. Comparative imaging of colloidal gold particles by electron microscopy and by video microscopy demonstrated that the video-imaged immunoreactions represented events involving single gold particles; their signal was sometimes clearly enhanced by secondary depositions taking place in close proximity, i.e. at a distance below the lateral resolution of the light microscope. Our experiments demonstrate that video-enhanced microscopy provides a powerful tool for studying antibody-antigen reactions with a high spatial and temporal resolution.
视频增强显微镜可用于检测和追踪单个胶体金颗粒。免疫金反应分析还可作为时间的函数进行，从而有助于研究活细胞中的动态事件。本文报道了免疫金颗粒与表面抗原反应的实时直接可视化。通过在感染病毒（呼吸道合胞病毒）的活细胞与包被抗病毒抗体的胶体金（30纳米）孵育后持续观察，实现了这种时间分辨免疫细胞化学。免疫反应的进程表现为单个金颗粒在病毒颗粒上的顺序沉积，直至60分钟后达到饱和。胶体金的结合是不可逆的事件，因为表面结合的颗粒没有发生洗脱或移位。通过电子显微镜和视频显微镜对胶体金颗粒进行的对比成像表明，视频成像的免疫反应代表了涉及单个金颗粒的事件；它们的信号有时会因附近发生的二次沉积而明显增强，即距离低于光学显微镜的横向分辨率。我们的实验表明，视频增强显微镜为以高空间和时间分辨率研究抗体-抗原反应提供了一个强大的工具。
