"Universal" PCR primer design in the mtDNA ND3 region

    The diagram shows part of the DNA sequences of the ND3 subunit gene from the mitochondrial DNA (shown 5' 3', left to right) of four species of mammalian Carnivora. These are three Canoids: Harbour Seal (Phoca), Grey Seal (Halichoerus), and domestic dog (Canis), and a Feloid domestic cat (Felis). The nucleotide region shown in colour is a potential PCR primer site. The 25 bp region is identical between seal species sequences, and  >92% identity [23 of 25 bp] with the other Canoid and (or) Feloid sequences. This primer, paired with another a few hundred or few thousand bases away, will likely amplify the intervening gene region for most species of Carnivora.