was next evaluated for its potential use as a cellular stain using the immortalised cervical epithelial cell line, HeLa. These cells were first incubated with complex 8 and subsequently counterstained with DAPI, a very commonly used nucleus stain. Comparison between the luminescence signal from complex 8 and the fluorescent DAPI signal revealed that complex 8 demonstrates intracellular localisation (Figure ). Further staining of HeLa cells using the membrane potential-dependent mitochondrial stain, MitoSpy red, following incubation with complex 8 revealed co-distribution of the two signals suggesting that complex 8 may localise to the mitochondria (Figure ). Superimposition of images collected through both the channel used for complex 8 (488 nm) and the 561 nm channel was possible due to the lack of spectral overlap between the two emissive compounds.