[en] A solid-phase radioimmunoassay employing ¹²⁵I-labeled enterotoxins and polystyrene tubes coated with specific antibody has been developed for assaying the relative concentrations of antibodies to staphylococcal enterotoxins A and B. Competitive binding occurs between tube-bound antibody and free antibody for binding sites on ¹²⁵I-labeled enterotoxin. The sensitivity of the system is affected by the amount of antibody on the walls of the tubes, the concentration of ¹²⁵I-labeled enterotoxin added to the system, and probably by the relative binding affinities of the bound and unbound antibodies. Antibody, 0.01 to 0.07 μg/ml, inhibited the uptake of ¹²⁵I-labeled enterotoxin by 20 percent. Both the antibody and antigen solid-phase radioimmunoassay inhibition systems can be appropriately represented by either of the following two models: Log/sub e/ (Y/1 -- Y) = α₀ + α₁ Log/sub e/X and Log/sub e/Y = β₀ + β₁ Log/sub e/X, where Y is bound activity, X is antigen or antibody concentration for inhibition , and α₀, α₁, β₀, and β₁ are regression coefficients. Estimates from the first model were slightly more precise for the antibody system, whereas the reverse was true for the antigen system. (U.S.)