Abstract
The quantity and quality of antigen-specific IgE against purified major allergens from cow hair and dander was measured by a double-antibody radioimmunoassay. In serum from patients with allergic asthma to cow the affinity constant varied from 1-150 .times. 109 l/mol and the number of antibody combining sites from 0.01-0.4 .times. 10-9 mol/l serum for each antigen.