Standardization of allergen extracts.

Allergens are molecules with the capacity to elicit IgE responses in humans. When stimulated with allergens, most allergic patients respond with production of IgE specific for several proteins/allergens in the source material. The standardization of allergen extracts is essential in order to control variability and to achieve consistency and reproducibility in a clinical setting. Because the IgE binding capacity of an allergen extract is related to the content of one or a few major allergens, it is important that the standardization procedure ensures consistency, not only in the overall IgE binding potency, but also in the content and ratio of individual major allergens. Owing to the complexity of allergen extracts, a key element in standardization of allergen extracts is the use of standards. This chapter describes the principles for standardization of allergen extracts to be used by research laboratories. Other chapters in this volume describe methods in detail.