Figure 1. SDS-PAGE analysis of rhGM-CSF followed by silver staining (lane 1) or Western blot (lanes 2 and 3). Lane 1: purified CHO-derived rhGM-CSF. Lane 2: CHO-derived rhGM-CSF from culture supernatant. Lane 3: E. coli-derived rhGM-CSF. Lane 4: Molecular weight standards (kDa).