Abstract
Dynamin-like protein 1 (Drp1) is the master regulator of mitochondrial fission. Drp1 translocates from the cytosol to the mitochondrial outer membrane to execute the scission process. Here we describe an immunofluorescence-based method to measure the mitochondrial translocation of Drp1 and quantify Drp1-related mitochondrial fission by labeling the mitochondrial import receptor subunit TOM20 in fixed cell culture.