Last modified on Wed 12 May 2021 23.19 EDT Andrew Thomson, who has died aged 80 after a stroke, played a crucial role early in his career in the discovery of a widely used anti-cancer drug, cisplatin, before going on to do pioneering work in the field of spectroscopy, enhancing our understanding of the functioning of substances vital to life, such as haemoglobin. As an Oxford research chemist with a background in platinum chemistry, in 1967 Andrew was invited to Michigan State University by a group of biophysicists who had found that passing an electric current, using platinum electrodes, through a culture of the bacterium E coli had an inhibiting effect on the cell replication. They needed a chemist to determine the active substance. Andrew solved their problem by suggesting and synthesising two potential inhibitors and identifying the active one – now known as cisplatin.