Functionalized DocetaxelProbes for Refined Visualizationof Mitotic Spindles by Expansion Microscopy

Visualizing the ultrastructure of mitotic spindles, the macromolecular machines that segregate chromosomes during mitosis, by fluorescence imaging remains challenging. Here we introduce an azido- and amino-functionalized docetaxel probe, which upon labeling of microtubules can be fixed, click-labeled and linked into hydrogels. The new probe is particularly useful for super-resolution imaging of dense microtubule structures in mitotic spindles. Multicolor expansion microscopy of mitotic cells allowed us to visualize the different phases of mitosis with unprecedented spatial resolution.