Thompson Karen J, Harley Cynthia M, Barthel Grant M, Sanders Mark A, Mesce Karen A
Department of Biology, Neuroscience Program, Agnes Scott College, Decatur, United States.
Department of Entomology, Graduate Program in Neuroscience, University of Minnesota, Saint Paul, United States.
Elife. 2015 Dec 15;4:e09388. doi: 10.7554/eLife.09388.
The staining of neurons with silver began in the 1800s, but until now the great resolving power of the laser scanning confocal microscope has not been utilized to capture the in-focus and three-dimensional cytoarchitecture of metal-impregnated cells. Here, we demonstrate how spectral confocal microscopy, typically reserved for fluorescent imaging, can be used to visualize metal-labeled tissues. This imaging does not involve the reflectance of metal particles, but rather the excitation of silver (or gold) nanoparticles and their putative surface plasmon resonance. To induce such resonance, silver or gold particles were excited with visible-wavelength laser lines (561 or 640 nm), and the maximal emission signal was collected at a shorter wavelength (i.e., higher energy state). Because the surface plasmon resonances of noble metal nanoparticles offer a superior optical signal and do not photobleach, our novel protocol holds enormous promise of a rebirth and further development of silver- and gold-based cell labeling protocols.
用银对神经元进行染色始于19世纪，但直到现在，激光扫描共聚焦显微镜的高分辨率尚未被用于捕捉金属浸染细胞的聚焦和三维细胞结构。在这里，我们展示了通常用于荧光成像的光谱共聚焦显微镜如何用于可视化金属标记的组织。这种成像不涉及金属颗粒的反射，而是银（或金）纳米颗粒的激发及其假定的表面等离子体共振。为了诱导这种共振，用可见波长激光线（561或640nm）激发银或金颗粒，并在较短波长（即较高能量状态）收集最大发射信号。由于贵金属纳米颗粒的表面等离子体共振提供了优异的光学信号且不会发生光漂白，我们的新方案为基于银和金的细胞标记方案的复兴和进一步发展带来了巨大希望。
