A Photo-immobilized Allergen Microarray for Screening of Allergen-specific IgE

ABSTRACT We developed an in vitro system to diagnose allergy using an allergen microarray and photo-immobilization technique. Photo-immobilization is useful for preparing the allergen microarray because it does not require specific functional groups of the allergen and because any organic material can be immobilized by a radical reaction induced by photo-irradiation. To prepare the plates, allergen solutions were mixed with polymer and a bis- azidophenyl derivative, a photo-reactive cross-linker, the mixtures were micro-spotted on the plate, and the droplets were dried. The plate was irradiated with an ultraviolet lamp for immobilization. For the assay, human serum was added to the microarray plate. Allergen-specific immunoglobulin E (IgE) adsorbed on the micro- spotted allergen was detected by peroxidase-conjugated anti-IgE antibody. The chemiluminescence intensities of the substrate decomposed by the peroxidase were detected with a sensitive CCD camera. All allergens were immobilized by this method and used to screen allergen-specific IgE.