Interaction of divalent antibody with cell surface antigens.

This paper presents a thermodynamic description of the interaction between divalent protein in solution and monovalent ligand attached to a cell membrane, but freely mobile therein. The intrinsic differences between this system and interaction which takes place in a uniform bulk solution are discussed. Specific problems which are addressed include the determination of the number of ligand sites on a specific cell system, comparison of several cell systems in terms of common antigenic components, comparison of different antibody preparations, and attempts to study solubilized cell-surface antigens using established serological methodology.