Open reading frames (ORFs) are sequences of nucleotides in a nucleic acid molecule (such as DNA or RNA) that are read consecutively in groups of three, starting from a start codon (usually AUG) and ending at a stop codon (UAA, UAG, or UGA). These sequences are potential protein-coding regions within the genome.


The term "open" in open reading frame signifies that the sequence is free from any stop codons within its reading frame, allowing for the uninterrupted translation of the genetic information into a protein. ORFs are important in molecular biology and genomics because they serve as the basis for identifying potential protein-coding genes within DNA or RNA sequences. By identifying and analyzing ORFs, researchers can gain insights into the genetic makeup of organisms and the functions of their genes.