Perera, D.R.C.Gunathilaka, P.A.D.H.N.Rodrigo, W.W.P.Athapaththu, A.M.M.H.Bulumulla, P.B.A.I.K.2021-12-142021-12-1420169789550481095http://www.erepo.lib.uwu.ac.lk/bitstream/handle/123456789/7987/7-2016-DNA%20Fingerprinting%20of%20Thunnus%20obesus%20am.pdf?sequence=1&isAllowed=yDetection of species substitution has become an important topic within the food industry and there is a growing need for rapid, reliable, and reproducible tests to verify species in commercial fish and seafood products. The effects of species substitution are far-reaching and include economic fraud, health hazards, and illegal trade of protected species. In Sri Lanka tuna fish industry is a rapid developing field. However, the species identification prior to the processing is achieved through morphological characteristics, which is not a reliable method. Therefore, the aim of this study was to develop a diagnostic method by combining Polymerase Chain Reaction with Restriction digestion to differentiate Thunnus obesus (bigeye tuna) and Thunnus albacores (yellowfin tuna) species in order to facilitate the fish processing industries and fish exporters by developing the test for species confirmation. Deoxy ribonucleic acid (DNA) extracted from muscle tissues of T obesus and T albacores were analyzed. DNA was amplified using primers flanking a region of cytochrome b gene of 558 by and digested using two restriction endonucleases, EcoNI and Scat A product having band sizes of 187 by and 371 by was observed from T albacores after digesting with EcoNI. The digestive product by Scal resulted 215 by and 343 by band sizes for both T albacores and T obesus. The polymorphism of DNA profiles obtained by restriction digestion was used to differentiate the T albacores and T obesus species. Therefore, the current study carries a reliable approach to identify and distinguish T obesus and T albacores from the other tuna species. Keywords: Tuna species, DNA extraction, Polymerase chain reaction, Restriction Enzyme digestionenFishAnimal SciencesAquaculture and FisheriesBiotechnologyDNAOther