2023-07-20 ワシントン大学セントルイス校
◆研究者は超明るいフルオロフォアと呼ばれる特殊なマーカーを使用し、サンプルを水と接触することで膨張するゲルに埋め込みます。これにより、ニューロンの細かい枝など、通常見えない特徴をトレースできます。従来の方法では光信号が弱まる問題を、プラズモニック-フルオロ（PF）と呼ばれる超明るいフルオロフォアで解決しました。
◆この技術はニューロンのネットワークをマッピングするのに役立ち、将来の研究で従来のフルオロフォアの代わりに使用できます。また、PFは任意のフルオロフォアを使用して作成できます。
＜関連情報＞
- https://engineering.wustl.edu/news/2023/Brighter-fluorescent-markers-allow-for-finer-imaging-of-nanoscopic-objects.html
- https://pubs.acs.org/doi/10.1021/acs.nanolett.3c01256
プラズモン増強拡大顕微鏡法 Plasmon-Enhanced Expansion Microscopy
Priya Rathi, Prashant Gupta, Avishek Debnath, Harsh Baldi, Yixuan Wang, Rohit Gupta, Baranidharan Raman, and Srikanth Singamaneni
Nano Letters Published:June 12, 2023
Abstract
Expansion microscopy (ExM) is a rapidly emerging super-resolution microscopy technique that involves isotropic expansion of biological samples to improve spatial resolution. However, fluorescence signal dilution due to volumetric expansion is a hindrance to the widespread application of ExM. Here, we introduce plasmon-enhanced expansion microscopy (p-ExM) by harnessing an ultrabright fluorescent nanoconstruct, called plasmonic-fluor (PF), as a nanolabel. The unique structure of PFs renders nearly 15000-fold brighter fluorescence signal intensity and higher fluorescence retention following the ExM protocol (nearly 76%) compared to their conventional counterparts (<16% for IR-650). Individual PFs can be easily imaged using conventional fluorescence microscopes, making them excellent “digital” labels for ExM. We demonstrate that p-ExM enables improved tracing and decrypting of neural networks labeled with PFs, as evidenced by improved quantification of morphological markers (nearly a 2.5-fold increase in number of neurite terminal points). Overall, p-ExM complements the existing ExM techniques for probing structure–function relationships of various biological systems.
