Khorana, who was born at Raipur (now in Pakistan), gained his BSc (1943) and MSc (1945) from the University of Punjab. He then traveled to Liverpool University to work for his doctorate. On receiving his PhD in 1948, he did two years postdoctoral research in Switzerland before taking up a Nuffield Fellowship at Cambridge University. There he worked with Alexander Todd, who fired his interest in nucleic acid research – the field in which Khorana later made his name.

Shortly after Khorana joined Wisconsin University in 1960 he became interested in unraveling the genetic code. He synthesized each of the 64 nucleotide triplets that make up the code, and for this work received the Nobel Prize for physiology or medicine in 1968, sharing the award with Marshall Nirenberg and Robert Holley.

Khorana's next major achievement came in 1970, when he announced the synthesis of the first artificial gene. The same year he moved to the Massachusetts Institute of Technology, where, by 1976, his team had made a second gene, which (unlike the first) was capable of functioning in a living cell. Such work has far-reaching possibilities, bringing scientists a step nearer to understanding gene action. The future could see artificial genes being used to make valuable proteins (e.g., insulin) and perhaps to cure human hereditary diseases.