Novel method for the discrimination of tuna (Thunnus thynnus) and bonito (Sarda sarda) DNA

A novel method for the discrimination of bluefin tuna (Thunnus thynnus) fro m Atlantic bonito (Sarda sarda) was developed, based on species-specific am plification of a region of the mitochondrial cytochrome b gene by Polymeras e Chain Reaction (PCR). The method, which uses a one-step amplification rea ction, is more rapid to perform than any of the currently described techniq ues for species determination in fish. The species of origin of the DNA is indicated by the distinctive size of the PCR product on electrophoresis, bu t the test could readily be adapted to other forms of electrophoresis or fl uorescence-based systems for quantification. Given the possibility of intra specific variability in mitochondrial DNA and the consequent desirability o f performing two independent tests, the new method constitutes a valuable a ddition to the range of tuna speciation methodologies currently available.