The species identity of a fish that has been skinned, cleaned, filleted, cooked, frozen, dried, and / or salted can be difficult to determine. Questions may arise as to the origin of a commercial product, for example, whether the catch in a boat's hold has been properly reported, or whether the label on a package is accurate. In some, a product may be physically altered to pass as another, for example by bleaching of fillets. Although physical identification may be impossible once skin and scales are gone, DNA survives processing in sufficient quantitites to provide a reliable test.
In the test shown
the identity of four salt-cured fish fillets was questioned. DNA
was amplified, sequenced, and compared to a DNA
data base of
cod, pollock, and hake species. The analysis produces a "family
which shows that each fish belongs to a different commercial species:
Alaska pollock, Atlantic
Pacific cod, and pollock
Commerical forensic testing of questioned
animal products is available from "The Helix & Primer"
DNA Sequencing Service at Memorial University