硫代硫酸钠在四甲基联苯胺贮液保存中的应用

Application of sodium thiosulfate pentahydrate in the storage of 3,3′,5,5′-tetramethylbenzidine stock solution

为解决试剂四甲基联苯胺（TMB）贮液在储藏时容易变色的问题，本研究改良了TMB贮液的配方，即在原有每毫升TMB贮液中加入3μL 2mg／mL的抗氧化剂五水硫代硫酸钠（Na2S2O3·5H2O）溶液。试验结果表明，新配方TMB贮液至少能在4℃下贮存3个月不变色且不影响显色效果。同时，对照原有配方中已经变色的TMB贮液，发现根据变色深浅，每毫升中加入2～6μL 2mg／mL Na2S2O3·5H2O溶液，3～6h后会变回无色，颜色消失的TMB贮液可重新利用而不影响显色效果。

3, 3＇, 5, 5＇ - tetramethylbenzidine （TMB） stock solutions easily change from brownish to dark color and affect the stability of the detection system. To solve this problem, we have developed an optimized reagent, ThreeμL 2mg/ mL sodium thiosulfate pentahydrate was added to t mL conventional TMB stock solution which can prevent the usual discoloration for at least 3 months at 46℃ without compromising the performance of the substrate in immunoassay applications. For the discolored TMB stock solutions, 2 - 6μL sodium thiosulfate pentahydrate was added to the discol- ored TMB solution, After 3 - 6 hours, the discoloration of TMB stock solution could be eliminated and the treated TMB stock solution utilized again.