苯乙醇胺A单克隆抗体的研制及ELISA检测方法的建立

为制备苯乙醇胺A(phenylethanolamine A,PA)单克隆抗体,建立一种针对苯乙醇胺A的快速、简便、灵敏度高的检测方法,本试验采用重氮化法将制备的苯乙醇胺A衍生物分别与牛血清白蛋白(BSA)和卵清白蛋白(OVA)进行偶联作为免疫原和包被原。利用弗氏佐剂充分乳化免疫原(PA-BSA),按常规免疫程序免疫6～8周龄的雌性BALB/c小鼠,选择血清抗体效价较高的小鼠,取其脾细胞与SP2/0骨髓瘤细胞以PEG法进行细胞融合。结果显示,经3次细胞亚克隆筛选后,最终筛选出一株可稳定分泌抗苯乙醇胺A单克隆抗体的杂交瘤细胞株,命名为D6H8,利用此细胞以小鼠体内诱生法制备抗体。经鉴定,D6H8腹水抗体亚型为IgG1,轻链为κ链;纯化后的抗体与沙丁胺醇、盐酸克伦特罗、盐酸异丙肾上腺素和盐酸去氧肾上腺素均无明显的交叉反应(CR<0.18%),表明该抗体特异性良好。利用此抗体建立针对苯乙醇胺A药物残留检测的间接竞争ELISA方法,结果表明,腹水抗体效价为1∶12 800,猪肉中苯乙醇胺A添加浓度在5～1 000 ng/mL时线性关系良好,标准工作曲线为y=0.3861x-0.1845 (R^2=0.990),其IC₅₀为58.88 ng/mL,LOD为3.83 ng/mL,回收率在85.96%～104.32%之间。综上所述,本试验成功建立了检测苯乙醇胺A药物残留的间接竞争ELISA方法,该方法灵敏度高、稳定性较好。

Preparation of Monoclonal Antibodies Against Phenylethanolamine A and Establishment of ELISA Method

To prepare monoclonal antibodies against phenylethanolamine A (PA) and establish a fast,simple and sensitive method for the detection of PA,a derivative of PA was coupled with bovine serum albumin (BSA) and ovalbumin (OVA) as immunogen and coating antigen by diazotization.The immunogen that emulsified by Freund’s adjuvant was used for immunization of 6 to 8 weeks’ BALB/c mice in accordance with conventional procedures.The immune spleen cells of mice with high serum antibody titer were fused with SP2/0 myeloma cells by PEG method.After three subclonal screening,a hybridoma cell strain D6H8 of secreting anti-PA monoclonal antibody was screened out and the inducing ascites in vivo method was employed to produce monoclonal antibodies.The McAb was identified to be IgG1 subtype and kappa light chain.The purified antibody showed no cross-reactions with salbutamol amine,clenbuterol hydrochloride,isoprenaline hydrochloride and deoxyepinephrine hydrochloride (CR<0.18%),indicating that the antibody had good specificity.An indirect competitive ELISA method for PA drug residues was established using this antibody.The results showed that the titer of ascites antibody was 1∶12 800 and the linear relationship was good when the concentration of PA in pork was 5 to 1 000 ng/mL.The linear equation was y=0.3861x-0.1845 (R²=0.990).The concentration of IC₅₀and LOD were 58.88 and 3.83 ng/mL,respectively.The recovery rates were between 85.96% and 104.32%,indicating that the ELISA method was reproducible and stable.In summary,an indirect competitive ELISA method for the determination of PA residues had been successfully established with high sensitivity and good stability.