Electroelution

The gel sliced in microtube sterile was transferred into the dialysis membrane with the cutoff range of the protein molecular weight is >12.000 kda. Before used, the pretreatment of the membrane (10 cm) must be performed to activate the membrane. The activation was done by treating the membrane with 1 mM EDTA pH 8 and 2% sodium bicarbonate, then heated at 60°C for 10 min. The membrane was then rinsed using sterile distilled water, followed by heating in 100 mL 1 mM Ethylenediaminetetraacetic acid (EDTA) at 60°C for 10 min. The membrane was then re-washed with sterile distilled water, then the membrane was ready to be used for the electroelution process. The membrane dialysis tube was filled with 100 μl sterile PBS solution and the sliced gel was placed in the dialysis tube with the tied cap on both sides using sewing thread. The tubing was placed in electroelution apparatus containing elution buffer. The electroelution was performed at room temperature, 50 V, for 3 h. After the electroelution was completed, the sewing thread was removed and the solution contained eluted protein was stored in a sterile microtube.