Detail of DNA exhibit. View of the wall in the centre of the 'Who Am I?' gallery in the Wellcome Wing at the Science Museum, London. 'Who Am I?' looks at what contemporary biomedical science, genetics and neuroscience can tell us about our identity as human beings and as individuals. This section of the wall features a repeated pattern using the letters A, T, C and G, to signify the four chemicals which link together to make DNA (deoxyribonucleic acid).