Phytinove is a new biotech company that specialises in engineering, production in bacteria and plants, and purification of recombinant pharmaceutical proteins. Collaborating with the Molecular Immunology Laboratory of Bordeaux 2 University, Phytinove targets its R & D more specifically on recombinant antibodies. A scFv type antibody having applications in lymphoma diagnostic and therapy has been engineered and expressed in bacteria cells ( Escherichia coli ). The antibody's presence in the bacterial extracts was demonstrated by western-blot and its capacity too bind to the antigen was shown by ELISA. The scFv was purified from these extracts by affinity chromatography. The gene coding for the antibody was then introduced into tobacco cells ( Nicotiana tabacum ) by transitory expression in isolated leaves or by stable transformation in entire plants. The sequence coding for the scFv was optimised for its expression in plant cells. Different genetic constructions were tested, with or without optimisation of the scFv gene , under the dependence of different promoters and fused with different targeting peptides. The presence of these antibodies in tobacco leaves was demonstrated by western-blot.