We have developed a simple, safe and versatile method, termed antifection, by which antibodies are used as delivery vehicles to introduce genes into cells expressing specific surface antigens. Antibodies directed against CD3, CD34 or surface immunoglobulins were covalently coupled to plasmids containing marker genes (neoR, beta-galactosidase). Such conjugates were used in vitro and/or in vivo to antifect (transfect using antifection) cells bearing the respective targeted epitope on either normal splenic B lymphocytes or lymphoid-related cell lines. In these conditions the expression of the protein encoded by the marker gene was readily detected. Antifection is a method of delivering genes through a physiological cellular pathway, receptor-mediated endocytosis, into specific cell types, and thus may be considered as an alternative for gene therapy strategy.