In-cell click labelling of small molecules to determine subcellular localisation.

UNLABELLED Small molecule fluorometric boron dipyrromethene probes were developed to bind hepatitis C virus-encoded NS5A protein and aid subcellular distribution studies. These molecules did not co-locate with NS5A, therefore alternative 'silent' azide reporters were used to obtain a more relevant picture of their distribution. Following pre-incubation with replicon cells, click chemistry was used to append a fluorophore to the azide that confirmed the co-localisation of the small molecule with the NS5A protein, thus providing greater insight into the antiviral mode of action of this chemotype. ELECTRONIC SUPPLEMENTARY MATERIAL The online version of this article (doi:10.1007/s12154-010-0047-1) contains supplementary material, which is available to authorized users.