[Molecular characterization of allergens].

Allergenic source material consists of a great number of single components of which only a small number is IgE-reactive. Since allergenic source material is the basis of diagnostics and immunotherapy, there is a strong interest in identification, characterization and quantification of allergens. A further reason of interest is to explain the pathomechanism of the type I allergy. The structure of allergens is of central importance, because only a small number of antigens are allergens and the structure of these components is essential in giving rise to symptoms. The process and further prospects of molecular characterization of allergens are described and grass pollen allergens are used as paradigm. Allergies are an excellent model to study the meaning of specificity in immunologic disorders.