Abstract: Objective To localize Der f 2 in the body of Dermatophagoides farinae. Methods Live mites were embedded. Serial mite paraffin sections were made and checked under light microscope. The sections were incubated with anti-recombinant Der f 2 monoclonal antibody as the first antibody. They were then reacted with the fluorescent isothiocyanate conjugated goat anti-mouse IgG as the secondary antibody. The sections were examined with fluorescent light microscopy. Results Der f 2 reacting with immunofluorescent antibodies was found localized in the tissue and contents of the mid-gut of the mite. Conclusion The major allergen Der f 2 distributes in the gut and fecal pellets of Dermatophagoides farinae.

Key words: Dermatophagoides farinae, Der f 2, Allergen localization