Polymerase chain reaction (PCR) for the detection of celery (Apium graveolens) in food

A method based upon polymerase chain reaction (PCR) for the detection of celery (Apium graveolens) in food was developed. The method involves DNA isolation by chaotropic or non-chaotropic solid-phase extraction and PCR with primers oriented to the sequence of the nuclear gene encoding mannitol dehydrogenase. The PCR method was shown to be specific for celery, producing a 279 bp fragment with four celery varieties and negative results with other species commonly present together with celery in food products (16 samples). The detection limit of PCR was 490-1530 pg DNA, which corresponds to 10(2) genome copies. When evaluated with model samples of celery in meat pates, a detection limit of 0.1% (w/w) was determined. When used to analyse food products from the market (dried vegetable seasonings, dehydrated bouillons), all four products declared to contain celery were correctly identified as positive and all three products in which celery was not declared were identified as negative.