Microtubules (MT) are the most rigid component of the cytoskeleton. Nevertheless, they often appear highly curved in the cellular context and the mechanisms governing their overall shape are poorly understood. Currently, in vitro microtubule analysis relies primarily on electron microscopy for its high resolution and Total Internal Reflection Fluorescence (TIRF) microscopy for its ability to image live fluorescently-labelled microtubules and associated proteins. For three-dimensional analyses of microtubules with micrometer curvatures, we have developed an assay in which MTs are polymerized in vitro from MT seeds adhered to a glass slide in a manner similar to conventional TIRF microscopy protocols. Free fluorescent molecules are removed and the MTs are fixed by perfusion. The MTs can

An endogenous circadian clock system enables organisms to adapt to time-of-day dependent environmental changes. In consequence, most physiological processes exhibit daily rhythms of, e.g., energy metabolism, immune function, sleep, or hormone production. Hypothalamic circadian clocks have been identified to play a particular role in coordinating many of these processes. Primary neuronal cultures are widely used as a physiologically relevant model to study molecular events within neurons. However, as circadian rhythms include dynamic molecular changes over longer timescales that vary between individual cells, longitudinal measurement methods are essential to investigate the regulation of circadian clocks of hypothalamic neurons. Here we provide a protocol for generating primary