Size exclusion chromatography profiles of affinity purified hu3S193 direct linked (scFv-0) proteins isolated from either the soluble protein fraction or the urea-solubilized fraction. (A) hu3S193 VH-0-VL soluble, (B) hu3S193 VH-0-VL urea solubilized, (C) VH-0-VL KR variant soluble, (D) VH-0-VL KR variant urea solubilized, (E) reverse VL-0-VH soluble, and (F) reverse VL-0-VH urea-solubilized fraction.