Sephadex g 50

Sephadex G-50 (MP Biomedicals Cat# ICN19558010; Solon, OH, USA) was hydrated in deionized water for 3 h at 100 °C prior to loading the column. A 45 cm × 2.5cm glass column was used. A 34 cm long column of Sephadex G-50 was equilibrated for 24 h with 0.5 M imidazole buffer (pH 7.0) containing 0.02% sodium azide. A portion (1 mL) of concentrated sample was loaded onto the bottom of the gel bed and eluted ascendingly (0.5 M imidazole buffer (pH 7.0) containing 0.02% sodium azide) at a rate of 2 mL/min (120 mL/h) in a 2–5 °C chromatography refrigerator. Fractions (6.6 mL) were collected using a Gilson FC 203B fraction collector (Middleton, WI, USA). All fractions which demonstrated DNase activity were pooled together. Activity was measured using the acid soluble assay at 55 °C with a digestion time of 20 min.

Sephadex G-50 (MP Biomedicals Cat# ICN19558010; Solon, OH, USA) was hydrated in deionized water for 3 h at 100 °C prior to loading the column. A 45 cm × 2.5 cm glass column was used. A 34 cm long column of Sephadex G-50 was equilibrated for 24 h with 0.5 M imidazole buffer (pH 7.0) containing 0.02% sodium azide. A portion (1.0 mL) of concentrated sample was loaded onto the bottom of the gel bed and eluted ascendingly with the 0.5 M imidazole buffer at a rate of 2 mL/min in a refrigerated chromatography cabinet (2–5 °C). Fractions (6.6 mL) were collected using a Gilson FC 203B fraction collector (Middleton, WI, USA). All fractions which demonstrated RNase activity were pooled together. Activity was measured using the acid soluble assay at 55 °C with an incubation time of 20 min.