7. Polyribonucleotides of defined repeating sequences of two to four bases helped to end the decoding work Khorana successfully developed a method to synthesize polyribonucleotides of defined repeating sequences using a combination of organic synthesis and enzymatic techniques Polypeptides synthesized using these polyribonucleotides had repeating one to a few amino acids Sequences for specific genetic codes can be determined by comparing the information obtained here and those obtained by using rNAs having random sequences made from two nucleotides of determined ratio7. Polyribonucleotides of defined repeating sequences of two to four bases helped to end the decoding work • Khorana successfully developed a method to synthesize polyribonucleotides of defined repeating sequences using a combination of organic synthesis and enzymatic techniques. • Polypeptides synthesized using these polyribonucleotides had repeating one to a few amino acids. • Sequences for specific genetic codes can be determined by comparing the information obtained here and those obtained by using RNAs having random sequences made from two nucleotides of determined ratio