The preparation of gel was achieved by take of (3) g from gel sephadex G-200 was suspended in 105 ml distilled water and put in water bath at 90 ºC for 5 hours then wash twice with sodium phosphate buffer (0.2M , pH= 6.2) in the case glucoamylase while with acetate buffer ( 0.1 M , pH = 5.0 ), after that ,the gel was suspended in amount of the same buffers, then the gel was degassed by using vacuum pump , the gel was packaged gently in glass column with dimensions (2×40 cm) the column was equilibrated using same buffers which used in gel