Analysis of monoclonal antibodies kinetic rate constants by surface plasmon resonance

Accurate measurement of physical-chemical parameters, such as rate constants and affinity are very important in order to understand the biological activity of antibody molecules. Surface Plasmon Resonance (SPR) is particularly usefull for the detection and quantification of antigen-antibody interactions which are followed in real time during association and dissociation phase thus allowing a rapid calculation of kinetic rate constants. The biosermor BIAcore(TM) uses the Surface Plasmon Resonance optical phenomenon for monitoring interactions of two or more macromolecules. We have used the BIAcore(TM) in order to select monoclonal antibodies directed to the Hepatitis B Surface Antigen (HBsAg) to be used in the affinity purification of the Hepatitis B Virus (HBV) particles. The HRsAg was covalently coupled to the carboxymethylated dextran matrix which covers the gold film of the instrument sensorchip. By using the BIA technology we have analysed the binding of anti-HBsAg monoclonal antibodies to their specific antigen and evaluated the association and dissociation kinetic rates and the affinity constant of the selected monoclonal antibodies.