HUVECs were infected with Lentiviral particles expressing GFP-Tagged Cytochrome C oxidase VIII @ passage 1. Puromycin resistant Mitochondria-GFP-HUVECs were selected and shipped in frozen vials (cells are provided @ passage 3). Endothelial Growth Medium is recommended for cell culture and these cells have a minimum of 18 population doubling levels when cultured following the protocols described below).