Imaging Dynamin-Related Protein 1 (Drp1)-Mediated Mitochondrial Fission in Living Cells.

Mitochondria form highly dynamic networks that continuously undergo fission and fusion. Dynamin-related protein 1 (Drp1), a key regulator of mitochondrial division, self-assembles into a helical polymer around pre-marked scission sites and generates the constriction force necessary to sever the organelle. Live-cell fluorescence imaging of Drp1 oligomerization dynamics and mitochondrial fission can provide unprecedented insights into the spatiotemporal relationship between these coupled processes. The high-resolution images provided by the laser scanning confocal microscope facilitate the observation of the finer details of mitochondrial structure as well as Drp1 polymer dynamics in real time. We provide a detailed description of the confocal imaging methods used to characterize mitochondrial dynamics in living cells with an emphasis on Drp1-mediated mitochondrial fission.