Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg, Austria.
Institute for Neuro- and Sensory Physiology, Göttingen, Germany; Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.
Methods Cell Biol. 2021;161:33-56. doi: 10.1016/bs.mcb.2020.04.016. Epub 2020 May 27.
Expansion microscopy is a recently developed super-resolution imaging technique, which provides an alternative to optics-based methods such as deterministic approaches (e.g. STED) or stochastic approaches (e.g. PALM/STORM). The idea behind expansion microscopy is to embed the biological sample in a swellable gel, and then to expand it isotropically, thereby increasing the distance between the fluorophores. This approach breaks the diffraction barrier by simply separating the emission point-spread-functions of the fluorophores. The resolution attainable in expansion microscopy is thus directly dependent on the separation that can be achieved, i.e. on the expansion factor. The original implementation of the technique achieved an expansion factor of fourfold, for a resolution of 70-80nm. The subsequently developed X10 method achieves an expansion factor of 10-fold, for a resolution of 25-30nm. This technique can be implemented with minimal technical requirements on any standard fluorescence microscope, and is more easily applied for multi-color imaging than either deterministic or stochastic super-resolution approaches. This renders X10 expansion microscopy a highly promising tool for new biological discoveries, as discussed here, and as demonstrated by several recent applications.
扩展显微镜是一种最近开发的超分辨率成像技术，为基于光学的方法（例如，STED）或随机方法（例如，PALM/STORM）提供了替代方案。扩展显微镜的想法是将生物样品嵌入可溶胀的凝胶中，然后各向同性地扩展它，从而增加荧光团之间的距离。这种方法通过简单地分离荧光团的发射点扩散函数来打破衍射障碍。因此，扩展显微镜可以达到的分辨率直接取决于可以实现的分离程度，即扩展因子。该技术的原始实现实现了四倍的扩展因子，分辨率为 70-80nm。随后开发的 X10 方法实现了 10 倍的扩展因子，分辨率为 25-30nm。与确定性或随机超分辨率方法相比，该技术可以在任何标准荧光显微镜上以最小的技术要求实现，并且更易于进行多色成像。如这里所讨论的，以及最近的一些应用所证明的，X10 扩展显微镜是用于新生物学发现的一种很有前途的工具。
