Analysis of the protein by SDS/PAGE during enzyme purification and testing of the homogeneity of the purified CESP. 2(I): Proteins from different stages of the purification were analyzed by 12% SDS-PAGE. Different lanes were loaded with pooled proteins from different steps. Lane 1, crude homogenate (8 μg); Lane 2, gel filtration (4 μg); Lane 3, Phenyl-Sepharose (2.5 μg); Lane 4, DEAE-cellulose 2 μg; Lane 5, Arginine Sepharose (2 μg). 2(II): Analysis of the purified protease from Biogel P60 was carried out both by (A) SDS/PAGE on 12% polyacrylamide gel (1.8 μg) and (B) nondenaturing PAGE on 7% polyacrylamide gel (2 μg).