SDS-PAGE and size-exclusion chromatography of anti-VLY scFv. (A) Detection of expression of anti-VLY scFv 9B4 in E. coli by SDS-PAGE. Lane 1 - soluble fraction of the cell lysate, lane 2 - insoluble fraction of the cell lysate, lane 3 - total cell lysate. (B) SDS-PAGE of purified anti-VLY scFvs derived from hybridoma clones 9B4 (lane 1) and 23A2 (lane 2) by metal-chelate affinity chromatography. Lane M - pre-stained protein molecular weight marker (Thermo Scientific Fermentas). (C) Size-exclusion chromatography of purified anti-VLY scFv 9B4 (variant VL-VH) on a TSK-gel G2000 SWXL column. The column was calibrated with Gel Filtration LMW Calibration Kit (GE Healthcare, Uppsala, Sweden).