3.4.19.3 guanidine-HCl approximately 70% of the original activity is retained after preincubation with 10 mM DTT, 50 mM Na-phosphate buffer (pH 7.0) containing less than either 0.01% SDS, 1 M urea, or 1 M guanidine-HCl at 37°C for 15 min 722561 3.4.19.3 SDS approximately 70% of the original activity is retained after preincubation with 10 mM DTT, 50 mM Na-phosphate buffer (pH 7.0) containing less than either 0.01% SDS, 1 M urea, or 1 M guanidine-HCl at 37°C for 15 min 722561 3.4.19.3 urea approximately 70% of the original activity is retained after preincubation with 10 mM DTT, 50 mM Na-phosphate buffer (pH 7.0) containing less than either 0.01% SDS, 1 M urea, or 1 M guanidine-HCl at 37°C for 15 min 722561 3.4.19.3 acetonitrile at 50% (v/v) concentrations more than 50% of the initial activity is retained -, 727453 3.4.19.3 Ethanol the enzyme retains stability at concentrations up to 90% (v/v) -, 727453 3.4.19.3 isopropanol at 50% (v/v) concentrations more than 50% of the initial activity is retained -, 727453 3.4.19.3 Methanol the enzyme retains stability at concentrations up to 75% (v/v) -, 727453