A simple one-step PCR method for the identification between European and American razor clams species

A specific multiplex polymerase chain reaction (PCR) was applied to differentiate samples of razor clams Ensisarcuatus, Ensissiliqua, Ensisdirectus, and Ensismacha. Universal primers were used for the amplification of internal transcribed spacer 1 (ITS-1) in each species. The alignment of the obtained sequences was the basis for the specific design of species-specific reverse primers (ITSArSil-R, ITSDir-R, and ITSMa-R) located in the ITS-1 region. A multiplex PCR using each specific primer together with a common forward primer allowed identification of razor clam species by means of the different sizes of the species-specific amplicons separated in an agarose gel electrophoresis. This work provides a simple, reliable and rapid protocol for the accurate identification of Ensis species. The present methodology can be very useful for traceability of the species and to reinforce labelling regulations.