Detection of the allergenic celery protein component (Api g 1.01) in foods by immunoassay

Abstract

Among food allergens, celery is a frequent cause for adverse food reactions in allergic patients. In this study, the celery allergen protein Api g 1.01 RNA was amplified by RT-PCR and cloned into the pET-32a expression vector. The recombinant plasmid was transformed into E.coli BL21(DE3) pLys for the expression of protein Api g 1.01. Monoclonal antibodies were prepared against the expressed purified Api g 1.01 protein. A sandwich enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of celery soluble proteins in processed foods was developed using the prepared monoclonal antibodies. The developed ELISA had a high specificity, although it showed slight cross-reactivity to carrot. The limit of quantification (LOQ) was 0.28 μg/mL (equivalent to 5.6 μg whole celery protein/g food sample). The recovery ranged from 83 to 115%, whereas coefficients of variation were 6.7–8.9%.