Schematic representation (A) and sequences (B) of major components of mammalian cassette vector, pDR-OriP-Fc1 for transient expression of scFv-Fc. The vector is derived from pcDNA3.1 with some modifications which result in the same SfiI-SfiI cassette sequences as pDR-D1 for scFv cloning followed by hybrid signal sequences composed of mouse kappa leader (Lmκ) and pelB signal sequences. Human Fcγ1 (hFc) sequences and hinge region are followed by the cloning site to allow in-frame fusion of scFv and hFc. The scFv-Fc expression unit is under the control of the human cytomegalovirus promoter (phCMV). oriP sequences are also included to mediate episomal amplification and maintenance of the transfected episomal DNA in 293E cells.