Fig. 4. Association of BSCR 2 with mitochondria is not membrane potential dependent. 3D maximum projection images showing fluorescence obtained with HeLa cells incubated with 100 nM MitoTracker green FM (488 nm excitation, first column) and either 1 μM Tetramethylrhodamine ethyl ester control (TMRE, Ctrl) or caged TFNB sulfonate diester 2 (561 nm excitation second column), composite merge of the two fluorescent channels (third column) and an enlargement of regions to show colocalisation. Both BSCR 2 and TMRE show similar patterns of colocalisation with MitoTracker green FM (top two rows). The addition of FCCP (10 μM) eliminates the mitochondrial membrane potential and TMRE staining, but does not have an observable effect on MitoTracker green FM or the caged TFNB sulfonate diester 2, with its colocalisation staying intact (row three and four, respectively). All scale bars = 10 μm.