Rapid PCR-RFLP method for the identification of 5 billfish species

Abstract

A rapid and reliable polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was developed to identify billfish species Xiphias gladius (swordfish), Makaira nigricans (blue marlin), Makaira indica (black marlin), Istiophorus platypterus (sailfish), and Tetrapturus audax (striped marlin). After DNA extraction and amplifying, the 348-bp PCR products from gene encoding of cytochrome b were subjected to restriction enzyme analysis. No single enzyme tested was able to distinguish the 5 species at the same time, but the combination of results obtained from the digests of Bsa JI and Cac 81 could be used to differentiate the 5 billfish species. This sensitive, rapid, and valid method can be used to detect fraudulent substitutes.