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【答案】应助回帖
我这里用传统的方法测定。我前段时间测的。
Superoxide dismutase (SOD) activity was analyzed using the nitroblue-tetrazolium (NBT) photoreduction method at 560 nm. One unit of SOD activity was defined as the amount of the enzyme that inhibited NBT reduction by 50% and was expressed as units g−1 fresh weight.
For the catalase (CAT) activity assay, the reaction mixture contained 2 ml of 50 mM potassium phosphate buffer (pH 7.0), 1 ml of 15 mM H2O2 and 150 µl of the enzyme extract. The reaction was initiated with the addition of hydrogen peroxide, and the decrease in absorbance was measured at 240 nm for 2 min. CAT activity was expressed as the change in absorbance per min per fresh weight (ΔOD240 min-1 g-1 FW).
For the determination of peroxidase (POD) activity, 50 μl of crude extract was added to 3 ml of substrate mixture containing 0.1 M potassium phosphate buffer (pH 6), 15 mM guaiacol and 7.5 mM of 30% H2O2. The formation of the oxidized tetraguaiacol polymer was monitored at 470 nm for 3 min. |
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