Antibodies have been used extensively for diagnostic applications for decades. Antibodies also can be used to target specific cells or specific molecules to produce agonist, antagonist, or neutralizing activity. Antibody therapies have been applied successfully in the treatment of several human diseases (1 ). The advantages of antibodies over other molecules are that they have high affinity for their targets and they bind to targets with high specificity. Antibodies, with six highly diversified complementaritydetermining regions (CDRs) supported by stable β-sheet framework regions, are capable of binding virtually any molecule including proteins, carbohydrates, nucleic acids, and haptens. The intrinsic features of specificity and affinity when combined offer a great advantage in the discovery of a wide-range of lead drug candidates.
