[Solid phase radioimmunoassay for the quantitative determination of antigen-specific IgG-antibodies in the serum of patients with farmer's lung].

In this study we have investigated a number of technical aspects of a sensitive solid-phase radioimmunoassay (microtitre-plate RIA) for the quantitative determination of antigen-specific IgG antibodies in the sera of patients suffering from farmer's lung. Microtitre-plates were coated with antigens of Aspergillus fumigatus, Micropolyspora faeni, Aureobasidium pullulans, Alternaria tenuis, Thermoactinomyces vulgaris and hay. Optimal antigen concentration and serum dilution were determined, the temperature-dependence of the assay and the kinetics of the binding of antibodies and protein A were studied. A comparison between glutaraldehyde-activated and non-activated microtitre-plates showed that the RIA with activated microtitre-plates produces values approximately 10-times higher than those with non-activated plates. However, the use of activated plates did not significantly increase the ratio between patient and control values.