ABSTRACT
The antigen binding properties of a particular monoclonal antibody may be ideal in terms of its specificity and affinity, but its usefulness as a reagent may be limited by its isotype, such that certain effector functions cannot be harnessed in vivo or, alternatively, Fc receptors on the antigen interfere with specific reactions. Considerable progress is being made in the isolation and manipulation of antibody genes. Bispecific antibodies are constructed from more than one source such that they retain the specificities of both original antibodies. For most antibody applications, such as diagnostic assays and antigen purification, the Fc region is unnecessary: its presence or absence has no effect on the binding of antibody to antigen. The failure of the hybridoma method to reliably produce human monoclonal antibodies suitable for therapy coincided with general technological advances in molecular biology such as DNA sequencing and the polymerase chain reaction. Human antibodies for therapeutic applications have been expressed in transgenic mice.
