Àbùdá koodu jẹ a ṣeto ti mẹta-nucleotide ṣeto ti a npe ni codons ati kọọkan mẹta-nucleotide apapo designates ohun amino acid, fun apẹẹrẹ AUG (adenine-uracil-guanine) ni koodu fun methionine. Nitori DNA ni o ni mẹrin nucleotides, awọn lapapọ nọmba ti ṣee ṣe codons jẹ 64; hence, nibẹ ni diẹ ninu awọn redundancy ninu awọn genetic koodu, pẹlu diẹ ninu awọn amino acids ti a ti ṣalaye nipa diẹ ẹ sii ju ọkan codon. Genes ti koodu ninu DNA ti wa ni akọkọ transcribed sinu bi-messenger RNA (mRNA) nipasẹ awọn ohun elo bi RNA.
adenine-uracil-guanine (ìyẹn èròjà tí wọ́n ń pè ní adenine-uracil-guanine)