In 4L beaker, add 2L of 5% bicarbonate, 1mM EDTA solution (2L solution: 100g of NaHCO3, 0.75 g Na4EDTA).Cut the dialysis tubing into appropriate length and put into the bicarbonate solution.Heat to nearly boiling (boil gently) for half hourRinse with distilled water three times.Gently boil in 2L 0.1% SDS (2g SDS in 2L water or 10mL 20% SDS).Rinse with distilled water six times.Gently boil in 2L of 5% bicarbonate, 1mM EDTA solution for 30 min.Gently boil dd H2O. Rinse with distilled water three times.