Mitochondria play an important role in various cellular processes.  More than 1000 genes encoding mitochondrial proteins have been identified through proteomic approaches. While many of these proteins have well characterized functions, a large number still have no known function within the mitochondria.  Genome editing is an emerging tool for the study of the role of uncharacterized proteins. Transcription activator like effector nucleases (TALENs) can be used to create cell lines where the expression of a targeted gene is permanently disrupted in a heritable fashion. A pair of specific targeted TALENs is required for nuclease mediated gene disruption. To increase the efficiency of TALEN mediated gene disruption, we have generated new TALEN expression vectors that co-express fluorescent proteins, allowing specific selection for cells expressing both TALENs. Studying the activity of mitochondria in these knockout cell lines will give new insights into the role of these uncharacterized mitochondrial proteins.