Enzyme-linked immunosorbent assay (ELISA) inhibition method to estimate the level of airborne bovine epidermal antigen in cowsheds.

A method based on inhibition of the enzyme-linked immunosorbent assay was developed for measuring airborne bovine epidermal antigen (BEA) in cowsheds. BEA extract served as the solid-phase reactant competing with the sample for binding of a rabbit immune serum. A sample of swine epithelial extract was used to ascertain the specificity of the reaction. Cowshed air samples were collected according to a standardized volumetric filter method. A specific inhibiting activity was detected in all samples tested corresponding to concentrations between 137 ng/m3 and 19.8 micrograms/m3. The interest coefficient of variation of cowshed samples was 9.5%.