Histone octamer can be rapidly reconstituted by one-pot refolding. (a) Histones are insoluble after bacterial overexpression (lane 1; total cell lysate, lane 2; soluble fraction), but solubilized after one-pot refolding (lane 3; total fractions, lane 4; soluble fraction). M; size markers (kDa). (b) Metal-affinity purification of histones after one-pot refolding. In; input refolded histones, FL; flowthrough, W; wash. (c) Polyhistidine-tag was cleaved from H2A by TEV protease. (d) Final purification step on a Superdex 200 PG column. The fractions on the dashed line were analyzed by SDS-PAGE.