Opt Lett. 2020 May 1;45(9):2628-2631. doi: 10.1364/OL.386172.
Interferometric scattering (iSCAT) microscopy enables us to track nm-sized objects with high spatial and temporal resolutions and permits label-free imaging of biomolecules. Its superb sensitivity, however, comes at a cost by several downsides, such as slow three-dimensional imaging and limited vertical tracking. Here, we propose a new method, Remote Focusing-iSCAT (RF-iSCAT) microscopy, to visualize a volume specimen by imaging sections at different depths without translation of either the objective lens or sample stage. We demonstrate the principle of RF-iSCAT by determining the -position of submicrometer beads by translating the reference mirror instead. RF-iSCAT features an unprecedentedly long range of vertical tracking and permits fast but vibration-free vertical scanning. We anticipate that RF-iSCAT would enhance the utility of iSCAT for dynamics study.
干涉散射（iSCAT）显微镜使我们能够以高时空分辨率跟踪纳米级物体，并实现生物分子的无标记成像。然而，其超高的灵敏度也带来了一些缺点，例如三维成像速度慢和垂直跟踪范围有限。在这里，我们提出了一种新的方法，即远程聚焦干涉散射（RF-iSCAT）显微镜，通过在不同深度的切片成像来可视化体积样本，而无需移动物镜或样品台。我们通过平移参考镜来确定亚微米珠的位置，从而证明了 RF-iSCAT 的原理。RF-iSCAT 具有前所未有的长垂直跟踪范围，并允许快速但无振动的垂直扫描。我们预计 RF-iSCAT 将增强 iSCAT 在动力学研究中的实用性。
