Monoclonal antibody-based method to quantify Gly m 1. Its application to assess environmental exposure to soybean dust

Background: The demonstration that some asthma epidemics have been caused b y allergens of soybean-hull dust prompted us to develop a two-site ELISA, s uitable for the quantification of the major allergen (Gly m 1), to be used for the prevention of new episodes. Methods: BALB/c mice were injected with Gly m 1 purified from soybean hulls . After fusion and screening, 10 monoclonal antibodies (mAbs) were obtained that were shown to be specific for Gly m 1. Two of them (6G1 as the captur e antibody; 1G10 as the tracer) were selected to develop a quantitative two -site ELISA for the indoor and outdoor determination of Gly m 1. Results: The two-site ELISA developed is very sensitive, with a detection l imit of less than 0.2 ng/ml and a practical working range of 0.4-10 ng/ml. The assay is also highly reproducible with an intra-assay coefficient of va riation of 3.5% and an interassay coefficient of variation of 12.5%. The me thod was applied to measure the concentration of Gly m 1 in air-sampler fil ters and in house-dust samples. Our results illustrate that there is a good correlation between the content of Gly m 1 in a number of samples and the allergenic activity as measured by ELISA inhibition. Conclusions: A specific and sensitive method is presented that can be used for the quantification of Gly m 1. The application of this method may allow the establishment of risk limits for soybean dust, and thus may contribute to the control of environmental contamination and to the prevention of new asthma epidemics.