Specific IgG Antibody to the Mite Dermatophagoides Farinae

Radioimmunoassay using antigen-bound Polystyrene Tubes

Abstract

There are various methods of measuring allergen-specific IgG antibodies. However, each assay method has its merits and drawbacks, and there has been no established assay method.
We attempted to assay allergen-specific antibody by the sandwich method using polystyrene tubes and investigated the assay conditions.
The optimal concentration of the antigen used for coating the tube was found to be 2μg/ml, and the proper dilution of the test serum was 50-fold. The inhibition test demonstrated the specificity of this reaction system. Within- and between-assay variations were small. Thus, this assay method proved to be fit for use. A stability test was performed to examine how long the tube-coating antigen was stable. The antigen was found to be stable for up to 3 days.
This method showed that the serum of subjects sensitized with Dermatophagoides farinae for at least 6 months contained a significantly higher titer of D. farinae-specific IgG antibody than did the serum of non-sensitized subjects.