Identification of commercial canned tuna species by restriction site analysis of mitochondrial DNA products obtained by nested primer PCR

In this work, the authentication of five different tuna species from commercial canned tuna by Nested Primer PCR–RFLP has been developed. Species identification of commercial canned tuna by techniques based on PCR is rather difficult due to the presence of additives as well as to the fact that the DNA is usually severely degraded. The utilization of Nested Primer PCR, a technique which increases considerably the specificity and sensitive of the reactions, has allowed us to obtain an amplicon of 276 bp (TUN276) from commercial canned tuna in spite of the presence of additives. Consequently, a very useful tool to authenticate canned tuna in brine, oil, pickled, sauced and spiced is presented here. To our knowledge, this 276 bp amplicon is the longest fragment obtained so far from canned tuna. In this study, five diagnosis sites are described to discriminate the most common tuna species processed in the canning industry.