This is the story behind the discovery of polynucleotide hybridization. In the early 1950s, the double helix structure of DNA had just been published, however, the structure of RNA was still unknown. Alexander Rich and his colleagues were investigating this question without much success until Rich combined polyadenylic acid and polyuridylic acid and, to his amazement, saw the diffraction pattern of a double helix. He realized that the base pairs had undergone hybridization to form a double stranded RNA structure. In the intervening 60 years, hybridization has become the foundation of much of modern biotechnology.
Alexander Rich was the Sedgwick Professor of Biophysics at the Massachusetts Institute of Technology where he was a faculty member since 1958. As well as discovering polynucleotide hybridization and the structure of double stranded RNA, Rich showed that protein synthesis occurs in a cluster of ribosomes (the polysome), he determined the structure of yeast tRNAPhe, and… Continue Reading