Fig. 1

CEPO identification using SDS-PAGE electrophoresis. Lane 1: markers; Lane 2: rhEPO, a broad band of 34 kDa (black arrow); Lane 3: rhEPO + endoproteinase Lys-C, 31 kDa (asterisk) and 16 kDa (filled triangle); Lane 4: CEPO, band around 34 kDa (white arrow); Lane 5: CEPO + endoproteinase Lys-C, a broad band around 34 kDa (white triangle) and a thinner band near 31KDA (asterisk). The 31 kDa band present in all lanes may be due to the Lys-C protein