A COS-CELL-BASED SYSTEM FOR RAPID PRODUCTION AND QUANTIFICATION OF SCFV-IGC-KAPPA ANTIBODY FRAGMENTS

Single-chain Fv (scFv) antibody (Ab) fragments were transiently produc ed in COS-1 cells utilizing a mammalian expression vector featuring a murine immunoglobulin (Ig) light-chain leader sequence for efficient s ecretion and a murine Ig kappa constant domain (IgC kappa) for detecti on. Several hundred milliliters of supernatants from large-scale COS c ell transfections were sufficient to purify the scFv::IgC kappa fusion proteins by one-step affinity chromatography utilizing an immobilized rat anti-mouse IgC kappa monoclonal Ab. Furthermore, the murine IgC k appa domain allowed for accurate quantification of the scFv::IgC kappa fusion protein secreted into the COS cell supernatant by a sandwich e nzyme-linked immunosorbent assay (S-ELISA).