Rapid Characterization of Monoclonal Antibodies using the Piezoelectric Immunosensor

Monoclonal antibodies with specificity against the Francisella tularensis outer lipopolysaccharide (LPS) membrane were prepared and characterized using the piezoelectric immunosensor with immobilized LPS antigen from F. tularensis. Signals obtained by the immunosensor were compared with ELISA and similar sensitivity was noticed. Signal of negative controls obtained using the biosensor was below 0.5% of the signal obtained for the selected specific antibody clone 4H3B9D3. Testing of cross reactivity based on the sensors with immobilized LPS from Escherichia coli and Bacillus subtilis confirmed selectivity of this antibody. Furthermore, the 4H3B9D3 antibody was successfully isotypized as IgM using the piezoelectric sensors with secondary antibodies. Kinetics parameters of antibody were evaluated in the flow-through arrangement. The kinetic rate constants for the antibody 4H3B9D3 were k(a) = (2.31 ± 0.20)·10(5) l mol(-1)s(-1) (association) and k(d) = (0.0010 ±0.00062) s(-1) (dissociation) indicating very good affinity to the LPS antigen.