Cockroach allergens appear to be a major cause of inner city asthma. Because of the suspected relationship between domestic cockroach species and allergy and asthma symptoms, the Food and Drug Administration (FDA) wants to standardize cockroach allergen vaccines for use in the U.S. Allergen standardization comprises two important components: the selection of a reference preparation of allergenic extract and the selection of procedures to compare manufactured products to the reference allergen extract.