硫酸铵对DNS试剂测定几丁质酶活力的影响

Effects of Ammonium Sulfate on the DNS Assay of Chitinase Activity

分析了硫酸铵盐析引起的几丁质酶酶活力损失的原因,然后通过考察硫酸铵、硫酸钠、其他铵盐及氨水等对DNS试剂测定葡萄糖的影响,得出结论,硫酸铵等铵盐的存在,破坏了DNS试剂与还原糖发生显色反应所需要的强碱性环境,使显色反应不能正常进行,通过补加氢氧化钠恢复反应体系的强碱环境,这种干扰可被屏蔽;最后通过几丁质酶硫酸铵盐析实验进一步验证了实验结论。

Based on the inactivation mechanism of ammonium sulfate precipitation on chitinase, the effects of ammonium sulfate, sodium sulfate, ammonium salt and aqueous ammonia on the dinitrosalicylic acid （DNS） assay of glucose standards were investigated. The results showed that the alkaline conditions was favored the color reaction of the reducing sugars with DNS reagent, furthermore, the alkaline conditions changed when ammonium sulfate and other ammonium salt added to this reaction system which prevented the color reaction from advancing. Given the alkaline conditions of the reaction system recovered, the color reaction would develop again.