Effect of different diluents on stability of mixed enzyme-labeled antibody / 中国生物制品学杂志

ABSTRACT

@#Objective To investigate the effect of different diluents on the stability of the mixed enzyme-labeled antibody,and screen a suitable diluent for the mixed enzyme-labeled antibody,which can protect the stability of the cocktail mixture of horseradish peroxidase(HRP) conjugated secondary antibody and alkaline phosphatase(AP) conjugated secondary antibody.Methods Using Tris-HCl buffer as the base solution,four different diluent formulations(A,B,C,D) were prepared with different kinds of stabilizers contained in each formula,such as protein,metalion,surfactant and bacteriostatic agent.Mixed enzyme-labeled antibodies were prepared with different diluents and stored at 2～8 ℃ and 37 ℃,which were detected for the stability by ELISA,enzyme activity assay and immunohistochemistry(IHC) staining.Results D solution [Tris(50 mmol/L)+BSA(1.5%,g/100 mL)+Tween-20(0.3%)+Proclin-950(0.1%,g/100 mL)+sodium chloride(150 mmol/L)+L-Ascorbic Acid(1 mmol/L)+L-methionine(5 mmol/L)+L-histidine(5 mmol/L)+sodium caseinate(1%,g/100 mL)+zinc chloride(0.1 mmol/L)+trehalose(8%,g/100 mL)] was of the optimal protective effect.When stored at 37 ℃ for 10 weeks,the working solution of HRP conjugated secondary antibodies and AP conjugated secondary antibodies showed the highest titer,the activity residual ratios of HRP and AP were 93.46% and96.07%,respectively,and there was no significant difference in IHC results.Conclusion This formula diluent can be used for the preparation of mixed enzyme-labeled antibody working solution.