Detection of fish allergen by droplet digital PCR

Fish is one of fourteen allergens that must be highlighted on the label within the ingredients list. It should be noted that the European regulation, is very restrictive to allergens with zero tolerance. Therefore it is important to establish sensitive and specific methods for detecting fish allergen. Applicability to detect and quantify fish allergen by droplet digital polymerase chain reaction (ddPCR) has been evaluated in this work. Genomic DNA of three fish species belonging to the most common fish families were analyzed. PCR primers were designed to amplify a 166 bp region of the 18S rRNA gene. Comparative studies were performed to establish the optimal primer and probe concentrations.  Annealing temperature was determined by using thermal gradient. The results have shown good applicability of the optimized 18S rRNA gene-method to detect and quantify small amounts of the target in all samples analyzed. However, validation studies are needed in order to apply ddPCR technology for routine allergens analysis.