Fig. 2. GFP-hFis1 is targeted to the mitochondria. (A) COS-7 cells transfected with pOTC-GFP, a mitochondrially located protein, or GFP-hFis1 were counterstained with MitoTracker Red and analysed by fluorescence microscopy 24 hours after transfection. The far right panel depicts overlay images of the GFP and MitoTracker Red fluorescence. (B) High resolution confocal microscopy of mitochondrial tubules as seen in (A).