AbstractIn a previous publication we have described a simple quantitative model describing the agglutination process due to antigenantibody interactions in IgGlatex immuno-assays. To achieve colloidal stability, however, some additives had to be used. In this paper we study the immunoreactivity of F(ab)2 antibody physical and chemically adsorbed onto sulphonate polystyrene and chloromethylstyrene particles, respectively. This kind of latex immuno-assay does not show stability problems under physiological condi-tions. The influence on the agglutination kinetics of the protein coating level has been now studied for the whole coverage range. Also the influence of coupling procedure, storage time and ionic strength of the reaction medium have been investigated.