Sphingomyelin (SM)-rich membrane nano-domains, called lipid rafts, have attracted the interest of researchers due to their potential involvement in the formation of signaling platform. Although there are many studies on lipid rafts, the direct observation of lipid rafts is still challenging owing to two critical reasons. One is the lack of an appropriate fluorescent probe mimicking the native behavior of raft lipids; fluorescent labeling often alters the intrinsic disposition of raft lipids. The other is their spatio-temporal stability; the size of lipid rafts is much smaller than the optical resolution of usual microscopy and their lifetime is much shorter than image acquisition duration. These issues are hampering the visualization of lipid rafts. Our review highlights the recent advances in microscopic techniques to visualize the partition and dynamic behavior of SMs, disclosing the detailed structure of lipid rafts. Moreover, we will elucidate the importance of SM-SM interactions in the stabilization of signaling platforms as lipid rafts.

富含鞘磷脂（SM）的膜纳米域（称为脂质筏）由于其潜在参与信号平台的形成而吸引了研究人员的兴趣。尽管关于脂质筏的研究很多，但是由于两个关键原因，直接观察脂质筏仍然具有挑战性。一种是缺乏一种合适的荧光探针来模拟筏脂的天然行为。荧光标记通常会改变筏脂的固有分布。另一个是它们的时空稳定性。脂质筏的尺寸比常规显微镜的光学分辨率小得多，并且其寿命比图像采集时间短得多。这些问题阻碍了脂质筏的可视化。我们的综述突出了显微技术的最新进展，以可视化SM的分区和动态行为，揭示了脂质筏的详细结构。此外，我们将阐明SM-SM相互作用在稳定脂筏等信号平台中的重要性。