A downstream purification procedure for recombinant human interferon-γ(rhIFN-γ) expressed in E. coli was described. An essentially two-step chromatographic purification procedure, i. e., size exclusion chromatography(SEC) and high-performance hydrophobic in-teraction chromatography (HPHIC), was used for purification of homogeneity of rhIFN-γ from the inclusion body. The specific activity of purified rhIFN-Y was 1.0×108 IU/mg pro-tein. The product of purification rhIFN-γ was analyzed by an analytical high-per formance SEC and a significant sigle symmetrical peak had been found. The purity of purified rhIFN-Y was greater than 95% from analysis, determination by analytical HPSEC and SDS-PAGE with Coomssie Blue. The molecular weight was ca. 15 000. It was shown that this procedure was an effective method for purifying rhIFN-γ.
