目的  建立定量检测白喉-破伤风-无细胞百日咳疫苗生产过程中破伤风类毒素（tetanus toxoid，TT）的方法。方法  TT免疫家兔以制备高效价血清抗TT抗体。辛酸-硫酸铵沉淀法纯化抗TT多克隆抗体并进行辣根过氧化物酶标记，建立双抗体夹心ELISA法。结果  建立的ELISA法与丝状血凝素、百日咳毒素及白喉类毒素无交叉反应，特异性较好。该ELISA法在0.5~16.00 Lf/L TT测量区间有最佳线性，决定系数＞0.99。实验内和实验间检测14.0、12.0、6.0、3.0和1.5 Lf/L TT，变异系数为4.7%~9.8%，回收率为92.7%~109.0%，精密度和准确度均符合常规质控要求。该法的定量下限为1.5 Lf/L TT。结论  建立的ELISA法可有效检测破伤风疫苗纯化过程中的TT含量，为破伤风疫苗质量控制奠定了基础。

Objective  To establish an ELISA method for quantitative determination of tetanus toxoid (TT) for DTaP.  Methods  Rabbits were immunized with purified TT to prepare high-titer serum antibodies against TT. Polyclonal anti-TT antibodies were purified by octanoic acid-ammonium sulfate precipitation method and labeled with horseradish peroxidase to establish a double antibody sandwich ELISA method.  Results  The ELISA method had good specificity for TT and no cross reactivities with filamentous hemagglutinin, pertussis toxin and diphtheria toxoid. The best linearity of the ELISA method was within the range of 0.75-16.00 Lf/L TT (R²＞0.99). The coefficient of variation and recover rates of intra- and inter-assay were 4.7%-9.8% and 92.7%-109.0%, respectively, when 14.0, 12.0, 6.0, 3.0 and 1.5 Lf/L TT standards were detected, and the precision and accuracy both met requirements of quality control. The detection limit of the ELISA method was 1.5 Lf/L TT.  Conclusion  The established ELISA method can be applied to detecting TT during purification of tetanus vaccine and lays foundation for quality control of TT.