Brilliant Minds Who Cracked Impossible Mysteries

Marshall Nirenberg was an American biochemist who worked at the National Institutes of Health in the early 1960s. In 1961, he used a cell-free system to study how RNA directs protein production. His team discovered that a sequence of identical bases, UUU, produced the amino acid phenylalanine. This was the first step in decoding the genetic code. His findings helped explain how DNA instructions translate into the proteins that build living organisms.