Figure 3.
Comparison of sss nuclease preparations for detection of G:C→A:T transitions. OXI1 heteroduplexes (A–H in Table 1) were digested and products displayed as in Figure 2, except that optimized enzyme–buffer cocktails and incubation conditions were used. Enzymes are present at 1 U/ml. From left to right: CEL I in CEL I buffer (10 mM KCl, 10 mM MgSO4, 10 mM HEPES pH 7.5, 0.002% Triton X100 and 0.0002 mg/ml BSA), 45°C, 15 min; Surveyor™ in CEL I buffer, 45°C, 15 min; CJE in CEL I buffer, 45°C, 15 min; MBE in Bis–Tris buffer (10 mM MgSO4, 0.2 mM ZnSO4, 20 mM Bis–Tris pH 6.5, 0.002% Triton X100 and 0.0002 mg/ml BSA), 60°C, 30 min; mung bean nuclease in Bis–Tris buffer, 60°C, 30 min; S1 nuclease in 2 mM ZnCl2, 10 mM potassium acetate pH 5.5, 10 mM MgSO4, 0.002% Triton X100 and 0.0002 mg/ml BSA, 45°C, 30 min. Top, IRD700; bottom, IRD800, where the image gain was increased overall for clarity.