Figure 2: Analysis of the purified endonuclease by polyacrylamide gel electrophoresis and gel filtration chromatography. (a) M: standard protein markers; lane 1: cell-free extract; lane 2: 0–60% ammonium sulfate fraction; lane 3: protein purified by DEAE-cellulose chromatography; lane 4: protein purified by hydrophobic interaction chromatography. (b) Molecular weight determination by gel filtration chromatography on a Sephacryl S-200HR column.