A group-specific, quantitative real-time PCR assay for detection of crab, a crustacean shellfish allergen, in complex food matrices

•A real-time PCR assay was developed for detection of crab in foods.•The assay was linear over 6-8 orders of magnitude and the LOD was 0.1 ppm.•The assay was specific for crab compared to other types of crustaceans.•The assay successfully detected crab in real, commercial food products.

A real-time PCR assay was developed for detection of crab, a crustacean allergen, in food products. Group-specific primers and probes were developed to detect numerous species of crab. Method validation included tests of detection in complex food matrices, evaluation of commercial food products, and cross-reactivity testing on a wide variety of crustaceans. The method was able to detect several species of crab spiked into complex food matrices at levels ranging from 0.1 to 105 parts per million (weight/weight), worked equally well on different platforms, exhibited high specificity for crab over other types of crustaceans, and yielded much higher signals from commercial food products listing crab as an ingredient than from those containing other crustaceans.