Gel-filtration chromatography of β112 Cys→Asp chains. Gel-filtration chromatography of purified (≈ 70 μmol/L in 200 μL) β^A chains (A), β112 Cys→Asp chains (B), and a mixture of the two chains (C) was performed at a flow rate of 0.5 mL/minute in 0.1 mol/L phosphate buffer, pH 7.0. Vo and Vt refer to void and total column volumes, respectively.