A simple procedure to elute proteins from polyacrylamide gels

To electroelute the protein, the stained band is sliced from the gel, cut to small pieces, washed in excess of distilled water for 10 min and finally equilibrated for 30 min in the electroelution buffer. The gel pieces are transferred to the electroelution tube, previously filled with buffer and electrophoresis is carried out for 3 to 4 hours at 25 mA. The dialyzing tube is removed together with the bottom buffer and electroeluted protein can be recovered by precipitation with 25% trichloroacetic acid or extensively dialyzed and lyophilized. Amino acid analysis was carried out according to the procedure of Spackman et al.