A DNA Mini-Barcoding System for Authentication of Processed Fish Products

Species substitution is a form of seafood fraud for the purpose of economic gain. DNA barcoding utilizes species-specific DNA sequence information for specimen identification. Previous work has established the usability of short DNA sequences—mini-barcodes—for identification of specimens harboring degraded DNA. This study aims at establishing a DNA mini-barcoding system for all fish species commonly used in processed fish products in North America. Six mini-barcode primer pairs targeting short (127–314 bp) fragments of the cytochrome c oxidase I (CO1) DNA barcode region were developed by examining over 8,000 DNA barcodes from species in the U.S. Food and Drug Administration (FDA) Seafood List. The mini-barcode primer pairs were then tested against 44 processed fish products representing a range of species and product types. Of the 44 products, 41 (93.2%) could be identified at the species or genus level. The greatest mini-barcoding success rate found with an individual primer pair was 88.6% compared to 20.5% success rate achieved by the full-length DNA barcode primers. Overall, this study presents a mini-barcoding system that can be used to identify a wide range of fish species in commercial products and may be utilized in high throughput DNA sequencing for authentication of heavily processed fish products.