Cloning and Bacterial Expression of an Esterolytic sFv

In 1988 the first report on the expression of a fully functional recombinant Fab in E. coli (1 ) was one of the initiating events in the development of the field of antibody engineering. Shortly after came the report of the cloning and expression of antibody-variable domains as single-chain F_v or sF_v (2 ). This provided a method for rapid cloning of stable antibody domains from hybridoma cells into E. coli in a fully functional form. More recent developments in the field, such as expression and selection of libraries of sF_v or Fab on phage particles, have allowed the de novo generation of antibodies with binding properties equivalent to or, in some cases, better than those derived by traditional hybridoma methods (3 ).