The selection of intracellular antibodies

The intracellular expression of antibodies in mammalian cells is a strategy to inhibit the in vivo function of selected molecules but is limited by th e unpredictable behaviour of antibodies when intracellularly expressed, Rec ent advances in the field of antibody expression in Escherichia coli show t hat the introduction of mutations can improve the properties of some antibo dy domains, but the general applicability of this approach to intracellular antibodies remains to be proved. As a complement to rational approaches, w e describe selection schemes in which antibodies are selected on the basis of their performance in vivo as intracellular antibodies.