A new method of allergen standardization. Passive cutaneous anaphylaxis inhibition in a mouse-to-rat system in comparison with other methods.

Various methods have been employed for standardization of potency of allergen extracts. We used passive cutaneous anaphylaxis (PCA) inhibition in a mouse-to-rat system as a new means of standardization. Several allergen extracts, including mite, short ragweed, house dust, Aspergillus, Candida, and Japanese cedar, were examined. Mouse IgE antibodies were produced after two or three injections of antigen and alum. The potency measured by PCA inhibition in the mouse-to-rat system was compared with that of protein nitrogen (PN) content, end point of prick test in humans, and 50% radioallergosorbent test (RAST) inhibition. Our studies suggest that the mouse-to-rat system could be used to determine allergenic potency and to standardize allergen extracts.