Characterization of the anti-CEA Fab-H-2K^b/ova conjugate. (A) Elution profile from a Superdex 200 FPLC column of the purified H-2K^b/ova peptide complex. (B) Elution on the same S200 column of the H-2K^b/ova complex after coupling to anti-CEA Fab' fragments. The conjugate is eluted after a peak of aggregates and is followed by a peak of uncoupled MHC I complexes and Fab' fragments. (C) Final S200 purification of the anti-CEA Fab-H-2K^b/ova conjugate eluted with an apparent Mr of 95 kDa. (D) SDS-PAGE showing the migration under non-reducing (lane 1-5) and reducing (lane 6-8) conditions of anti-CEA Fab-H-2K^b/ova conjugate (lane 5, 6) and its two main components: the H-2K^b/ova complex (lane 4, 7) and the anti-CEA Fab' fragment (lane 3, 8). The intact anti-CEA mAb (150 kDa, lane 1) and the anti-CEA F(ab')₂ fragment (100 kDa, lane 2) together with a high range molecular weight protein mixture were used as standards (central lane).