A tunable refractive index matching medium for live imaging cells, tissues and model organisms

In light microscopy, refractive index mismatches between media and sample cause spherical aberrations that often limit penetration depth and resolution. Optical clearing techniques can alleviate these mismatches, but they are so far limited to fixed samples. We present Iodixanol as a non-toxic medium supplement that allows refractive index matching in live specimens and thus a substantial improvement of the live-imaging of primary cell cultures, planarians, zebrafish and human cerebral organoids.在光学显微成像中，介质与样品之间的折射率失配会引发球差，往往会限制成像的穿透深度与分辨率。光学透明化技术（Optical Clearing）可缓解这类失配问题，但目前这类技术仅适用于固定样本。本研究报道碘克沙醇（Iodixanol）作为一种无毒的培养基添加剂，能够实现活样本的折射率匹配，从而大幅提升原代细胞培养、涡虫、斑马鱼以及人类大脑类器官的活细胞成像效果。