Rapid Characterization of Monoclonal Antibodies using the Piezoelectric Immunosensor

Abstract: Monoclonal antibodies with specificity against the Francisella tularensis outerlipopolysaccharide (LPS) membrane were prepared and characterized using the piezoelectricimmunosensor with immobilized LPS antigen from F. tularensis. Signals obtained by theimmunosensor were compared with ELISA and similar sensitivity was noticed. Signal ofnegative controls obtained using the biosensor was below 0.5% of the signal obtained for theselected specific antibody clone 4H3B9D3. Testing of cross reactivity based on the sensorswith immobilized LPS from Escherichia coli and Bacillus subtilis confirmed selectivity ofthis antibody. Furthermore, the 4H3B9D3 antibody was successfully isotypized as IgM usingthe piezoelectric sensors with secondary antibodies. Kinetics parameters of antibody wereevaluated in the flow-through arrangement. The kinetic rate constants for the antibody4H3B9D3 were k_a = (2.31 ± 0.20)·10⁵ l mol^-1s^-1 (association) and k_d = (0.0010 ±0.00062) s^-1(dissociation) indicating very good affinity to the LPS antigen.