目的  建立检测百日咳毒素（pertussis toxin，PT）活性的中国仓鼠卵巢（Chinese hamster ovary，CHO）细胞簇集法，并将建立的方法应用于无细胞百日咳疫苗生产的质量控制。方法  将PT标准品系列稀释后与培养的CHO细胞混合，观察PT引起CHO细胞簇集的敏感度，并研究反应时间、反应溶液的pH值、缓冲液浓度、加样顺序等因素对PT引起CHO细胞簇集的影响。应用建立的方法检测百日咳疫苗生产过程中脱毒前后的PT活性及丝状血凝素和百日咳黏着素组分中残留的PT活性。    结果  PT使CHO细胞发生最佳簇集的理想反应时间是24 h，最适pH值是7~8，适宜氯化钠缓冲液浓度为0.15 mol/L，最优加样顺序是先加CHO细胞再加PT。建立的CHO细胞簇集法的检测敏感度为10 pg/ml PT，且重复性良好。结论  CHO细胞簇集法可用于PT活性检测。

Objective   To establish Chinese hamster ovary (CHO) cell clustering method for determination of activity of Pertussis toxin (PT) and apply the established method to quality control in production process of acellular pertussis vaccine (APV). Methods PT standards diluted serially were mixed with CHO cells. Sensitivity of CHO cell clustering by induced PT was observed, and different influence factors on CHO cell clustering, including reaction time, pH value of reaction solution, buffer concentration and order of adding sample were studied. The established method was applied to PT activity detecting before and after detoxification and residual PT activity in filamentous hemagglutinin  and pertactin components in production process of APV. Results  The optimal reaction time, pH value of reaction solution, buffer concentration and order of adding sample for the best CHO cell clustering by induced PT were 24 h, pH7-8, 0.15 mol/L, first adding CHO cells and then PT, respectively. Sensitivity of the established CHO cell clustering method was 10 pg/ml PT. This method had good repeatability. Conclusion  The established CHO cell clustering method can be applied to detecting PT activity detecting.