Quantitative detection assay development for enterovirus 71 antigen

Objective To develop a quantitative detection assay of enterovirus 71 (EV71) antigen for monitoring virus antigen content during vaccine production. Methods Anti-EV71 polyclonal antibody was prepared by immunizing New Zealand rabbits with EV71 antigen.Purified antibody was labeled with horseradish peroxidase to develop a double-antibody sandwich ELISA. A dose-response curve was plotted using EV71 antigen national reference as quantitative standard. The linear range and quantitative detection limit of the ELISA method were determined.The specificity, precision, stability, and feasibility of the method were evaluated. Results The linear range was 5-80 U/ml and coefficient of determination was ﹥0.990 0. The quantitative detection limit was 5 U/ml. The recovery rate of internal reference was 85%-110% and the coefficient of variation(CV) in reference detection was ﹤15%.The CV for same sample detection between coated plates placed in 2-8 ℃ and 37 ℃ for 3, 6 days was ﹤15%. No cross reaction with non-EV71 samples was observed. Conclusion A quantitative detection assay for EV71 antigen is developed, which may provide a simple monitoring method for quality control during vaccine production. Key words: Enterovirus A, human; Quantitative analysis; Enzyme-linked immunosorbent assay