Abstract
This article reviews the characteristics of high affinity IgE receptors (FcεRI) and their role in the response to allergenic proteins. The requirements for successful cross‐linking of FcεRI on basophils and mast cells and subsequent degranulation by allergenic proteins will be explained in detail. Methods for in vitro analysis of allergen‐induced mast cell and basophil degranulation will be described and issues/problems in applying these methods will be discussed. Finally, implications for manipulation of protein allergens will be discussed.