Valency of Antibody Binding to Enveloped Virus Particles as Determined by Surface Plasmon Resonance

A simple method is described for determining the valency of binding of immunoglobulin G to immobilized influenza A virus. Where there is a free Fab arm (monovalent binding), a second virus particle is captured. This is detected by surface plasmon resonance. The methodology should be applicable to all enveloped and nonenveloped viruses.