Purification of the refolded BF2*1501 complex (BF2*1501, chicken β2m and the epitope MDV-MEQRRR9) by FPLC Superdex 200 16/60 HiLoad gel-filtration and Resouce-Q anion-exchange chromatography (GE Healthcare). (a) Gel-filtration profile of the refolded products. Peak 1 corresponds to the aggregated BF2*1501 heavy chain, peak 2 corresponds to the correctly refolded complex (∼44 kDa) and peak 3 corresponds to excess chicken β2m. Inset, reduced SDS–PAGE gel (15%) for peaks 1, 2 and 3. Lane M contains molecular-mass markers (labelled in kDa). (b) Anion-exchange chromatography profile of the refolded products. Peak 1 corresponds to correctly refolded complex, which was eluted at an NaCl concentration of 16–20%. Inset, reduced SDS–PAGE gel (15%) for peak 1. Lane M contains molecular-mass markers (labelled in kDa).