ble 5-5 A Purification Table for a Hypothetical Enzyme* Fraction Total Procedure volume protein Specific activity or step (m) (mg) (units) (units/mg) 1. Crude cellular extract 1,40010,000100,000 10 2. Precipitation with ammonium sulfate 280 3,000 96,000 32 3. lon-exchange chromatography 0 400 80.000 200 4. Size-exclusion chromatography 100 60.000 600 5. Affinity chromatog raphy 6 45,000 15000 " All data represent the status of the sample after the designated procedure has been carried out. Activity and specific activity are defined on page 137