English: Microtubule destabilizing effect of IC261 and nocodazole in mitotic cells. CV-1 cells expressing EYFP-tubulin were cultured in a flow-through chamber and observed by time-resolved fluorescence microscopy. At time point “0 min” cells were treated with DMSO (0.125%), IC261 (1 µM, 3.2 µM) or 0.4 µM nocodazole. Here exemplary cells are shown for indicated time points. Treatment with low concentrations of IC261 induced a depolymerization of spindle microtubules within a few minutes in a concentration dependent manner and interestingly by nocodazole treatment a similar phenotype could be observed. Cells entering mitosis during IC261 treatment had spindle poles and microtubule nucleating centers, but could not form a spindle.