What was marshall nirenberg and heinrich matthaeis contribution to our current understanding of the genetic code?

Marshall Nirenberg and Heinrich Mattaeis contributed to out current understanding of the genetic code by discovering genetic codons. Their experiment deciphered the first of the 64 triplet codons in the genetic code by using nucleic acid homopolymer to translate specific amino acids. Their experiment cracked the first codon of the genetic code and showed that RNA controlled the production of certain types of proteins.