Flow immunoassay using a cation exchange column and fluorescence-labelled antibody for detection of allergen

An allergen detection was carried out based on a fluorescence immunoassay with a flow injection system. Allergen and fluorescein isothiocyanate (FITC) conjugated IgE antibody complex was separated from free FITC conjugated IgE antibody using a cation exchange column. The fluorescence intensity correlated linearly with a concentration of allergen in the range of 0.01–2.0 mg ml−1. Reuse of free FITC conjugated IgE was possible. This simple and rapid immunoassay method can be used for the continuous detection of allergen.