GFP – the proteins that allow jellyfish to glow their astonishing luminescent green – changed the way we understand biology. Transferred into plant, bacterial or animal cells, GFP allows them to glow when a blue light is shined on them. But what are the limitations – and where next for ‘reporter proteins’?

Professor John Christie, of the University of Glasgow, talks about how GFP transformed our understanding of cell biology, and its limitations. His lab is developing new reporter proteins to overcome these issues and allow viral and bacterial infections to be studied more effectively..