Nirenberg's genetic codon table. This chart from late 1965 lists the initial research on correspondence between genetic units called codons (down left) and amino acids (across top). This research was carried out by US biochemist Marshall Warren Nirenberg (1927-2010) and others at the US National Institutes of Health. By 1966, Nirenberg announced that he had deciphered the 64 RNA codons for all 20 amino acids. The red boxes show potential matches. For the final results of the research, see image C025/9215. Nirenberg shared the 1968 Nobel Prize in Physiology or Medicine for this fundamental work on genetics and amino acids.