title: Species identification and quantification in meat and meat products using droplet digital PCR (ddPCR).
abstract: Species fraud and product mislabelling in processed food, albeit not being a direct health issue, often results in consumer distrust. Therefore methods for quantification of undeclared species are needed. Targeting mitochondrial DNA, e.g. CYTB gene, for species quantification is unsuitable, due to a fivefold inter-tissue variation in mtDNA content per cell resulting in either an under- (-70%) or overestimation (+160%) of species DNA contents. Here, we describe a reliable two-step droplet digital PCR (ddPCR) assay targeting the nuclear F2 gene for precise quantification of cattle, horse, and pig in processed meat products. The ddPCR assay is advantageous over qPCR showing a limit of quantification (LOQ) and detection (LOD) in different meat products of 0.01% and 0.001%, respectively. The specificity was verified in 14 different species. Hence, determining F2 in food by ddPCR can be recommended for quality assurance and control in production systems.
authors.affiliation: Institute of Veterinary Medicine, University of Göttingen, Burckhardtweg 2, 37077 Göttingen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Floren
authors.affiliation: Institute of Veterinary Medicine, University of Göttingen, Burckhardtweg 2, 37077 Göttingen, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Wiedemann
authors.affiliation: Institute of Veterinary Medicine, University of Göttingen, Burckhardtweg 2, 37077 Göttingen, Germany. Electronic address: bbrenig@gwdg.de.
authors.forename: B
authors.initials: B
authors.lastname: Brenig
authors.affiliation: Institute of Veterinary Medicine, University of Göttingen, Burckhardtweg 2, 37077 Göttingen, Germany; Chronix Biomedical GmbH, Goetheallee 8, 37073 Göttingen, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Schütz
authors.affiliation: Chronix Biomedical GmbH, Goetheallee 8, 37073 Göttingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Beck
mesh_terms: D000818:Animals; D002417:Cattle; D006736:Horses; D008460:Meat / Q000032:analysis*; D008461:Meat Products / Q000032:analysis*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D013045:Species Specificity; D013552:Swine
keywords: Droplet digital PCR; Meat products; Nuclear DNA; Quantification; Species determination