Fig. 1.

Characterization of scFv preparations. a, b Size exclusion chromatography of scFv(1aa) multibodies purified by different methods. IMAC with subsequent HiTrap Q HP purification (a) yielded trimers, whereas IMAC followed by affinity chromatography selected tetramers (b), which were a small part of the original scFv(1aa) preparation. Numbers on top of the graph indicate the M _r of marker proteins; some of them were drawn as vertical lines. c SDS-PAGE of scFv(1aa) during various purification steps. Note that multimers disintegrate into monomers under these conditions. Lanes 1 and 2 IMAC-purified scFv(0aa) and scFv(1aa), respectively; 3 affinity-purified scFv(0aa); 4 HiTrap Q HP-purified scFv(1aa); 5 molecular markers; 6 and 7 DTPA-conjugated scFv(0aa) and scFv(1aa), respectively