Mitochondria are dynamic organelles that continuously undergo fission and fusion processes. The main regulator of mitochondrial fission is the largely cytosolic GTPase, Dynamin Related Protein 1 (Drp1). Upon activation, Drp1 is recruited to the mitochondrial outer membrane where it interacts with receptors including Mff, MiD51 and/or MiD49 to facilitate fission. In an effort to gain additional insight into the mechanism of action of MiD51 in cells, mutations within the protein have been made to identify regions/residues that are important for its function. To analyze the effect of these mutations, a variety of methods were employed including analysis of Drp1 recruitment and effect on mitochondrial morphology through immunofluorescence studies, and time lapse imaging of the formation of scission sites through confocal microscopy. In addition, the MiD51 mutants generated are currently being purified for in vitro protein analysis to understand the potential structural effects caused by the mutation. Studies to identify binding partners for MiD51 and MiD49 are also being conducted.